bluuebunny/crossref_metadata_2025 huggingface dataset:
Manufacturability of Fine-Celled Cellular Structures in Rotational Foam Molding
Authors: Pop-Iliev Remon , Xu Donglai , Park Chul B.
Published: April 2004

Any closed-cell polyolefin foam production tends to achieve the highest possible cell size distribution uniformity, cell size reduction, and cell density augmentation. However, the control of the cell size of rotationally foam-molded cellular structures formed on the base of a chemical blowing agent (CBA) might be often aggravated by some inherent limitations that are unique to the rotational molding process, which results in coarser-celled final cellular structures. Although a fine-celled morphology (cell size<100 [mm] and cell density > 106 [cells/cm3]) in rotationally molded foams has been closely approached, it has not been actually achieved yet, nor has it been ever clarified whether it is actually achievable in rotational foam molding or not. This study attempts to provide an answer to this fundamental question by focusing on the understanding of the mechanisms governing the formation, growth, shrinkage, and collapse of CBA-blown bubbles in nonpressurized polymer melts originating from extrusion melt compounded foamable resins in a pellet form.
A Study of Strain-Induced Nucleation in Thermoplastic Foam Extrusion
Authors: Tatibouët Jacques , Gendron Richard
Published: April 2004

The conditions that induce the phase separation and the bubble nucleation for the thermoplastic foam extrusion process in which physical foaming agents (PFA) are involved are obviously linked to the solubility parameters: temperature, PFA content, and pressure. However, it has been reported that flow or shear can significantly modify these degassing conditions. An in-line detection method based on ultrasonic sensors was used to investigate the influence of the flow on the foaming conditions of polystyrene/HFC134a mixtures, for PS resins of various melt flow rates. An increase of the apparent degassing pressure at low melt temperature was observed for high viscosity resins. Deviations from solubility data have been attributed to the combined effects of elongational and shear stresses.
Effect of Physical Foaming Agents on the Viscosity of Various Polyolefin Resins
Authors: Gendron Richard , Champagne Michel F.
Published: April 2004

The effect of temperature and type of physical foaming agent (HCFC-142b, n-pentane, and carbon dioxide) on the shear viscosity have been investigated for various types of polyolefin resins (PP, LLDPE, and HDPE). The viscosity changes have been monitored using a commercial on-line process control rheometer mounted on a twin-screw extruder.

A plasticization index, based on the respective molecular weights of the foaming agent and the repeat unit of the polymer, is proposed. Comparison with an amorphous polymer, namely polystyrene, is also made for mixtures using the same physical foaming agents.
Quasi-Static and Dynamic Compressive Behaviors of a S-2 Glass/SC15 Composite
Authors: Song Bo , Chen Weinong , Weerasooriya Tusit
Published: April 2004

A pulse-shaped split Hopkinson pressure bar (SHPB) was employed to determine the dynamic compressive mechanical responses and failure behaviors of a S-2 glass/SC15 composite along two perpendicular directions under valid dynamic testing conditions. The loading pulses in SHPB experiments were precisely controlled to ensure that the composite specimen deforms at a nearly constant strain rate under dynamically equilibrated stress during dynamic compression. Quasi-static experiments were conducted with an MTS and an Instron to study material rate sensitivity over a wider range. The compressive stress-strain behaviors along both directions were found to be strain-rate sensitive, but with different strain-rate sensitivities. A compressive constitutive model with strain-rate and damage effects was modified to accurately describe both quasi-static and dynamic compressive stress-strain behaviors of the composite material along the two perpendicular directions.
Similitude and Physical Modeling for Buckling and Vibration of Symmetric Cross-Ply Laminated Circular Cylindrical Shells
Authors: Ungbhakorn Variddhi , Singhatanadgid Pairod
Published: April 2004

The similitude invariant and the scaling laws of the symmetric cross-ply laminated circular cylindrical shells for buckling and free vibration problems are derived by applying the similitude transformation to the governing differential equations directly. The scaling laws obtained by this approach are unique because they are forced by the governing differential equations. In the absence of the experimental data, the validity of the scaling laws is verified by numerical experiments. This is done by calculating theoretically the buckling loads and fundamental frequencies for free vibration of the model and substituting into the scaling laws. The predicted values of the prototype from the scaling laws are then compared with those values from the closed-form solution. Examples for the complete similitude cases with various stacking sequences, number of plies, and radius ratios show exact agreement. The presented relationships between the model and prototype will greatly facilitate and reduce the costly experiment. In reality, it may not be feasible to construct the model to fulfill the similarity requirements completely. Several cases of partial similitude are investigated and verified numerically. Modeling with distortion in stacking sequences is recommended, but model with distortion in material properties yields moderately high percent of discrepancy.
On the Interlaminar Shear Stress Response for E-Glass/Epoxy Composite
Authors: Elawadly Khalil M.
Published: April 2004

An analytical and experimental investigation was performed to study the interlaminar shear response of laminated composite material. The main objective of this study is to determine the effect of the stacking sequences and the thickness of the layers on the interlaminar shear strength of E-glass/epoxy laminated composite tubular struts which will be used in superconducting magnetic energy storage. The experimental results showed that the first ply failures always happens at the middle section of the sample and the maximum interlaminar shear stress has its maximum along the neutral axis. The absence of plies perpendicular to the 10 direction are favorable for a good stress distribution. On the other hand these plies are very important to prevent the brooming under compression loads. The results also showed that the stress distribution, due to less thick and more 10 layers were better and gave a higher interlaminar shear strength. The interfaces between the 84 layer and 10 layer are the most probable locations to start interlaminar shear failure, that is because of the large mismatch in engineering properties between these layers. The experimental results and the corresponding analytical calculations are in good agreement.
Fracture Toughness of Carbon Foam
Authors: Choi S. , Sankar B. V.
Published: April 2004

Mode I fracture toughness of open cell carbon foam was measured using single edge notched four-point bend specimens. A micromechanical model was developed assuming a rectangular prism as the unit-cell. A small region surrounding the crack tip was modeled using finite elements. Displacement boundary conditions were applied to the boundary of the region based on linear elastic fracture mechanics for orthotropic materials. From the finite element results the Mode I stress intensity factor that will cause failure of a crack tip element was determined and it was taken as the predicted fracture toughness of the foam. A simpler model in which the foam consisted of struts of square cross section was also considered. The micromechanical simulations were used to study the variation of fracture toughness as a function of solidity of the foam. The good agreement between the finite element and experimental results for fracture toughness indicates that micromechanics can be an effective tool to study crack propagation in cellular solids.
Onsager’s Reciprocal Relation and Effective Coefficients of Transverse Coupled Hygrothermal Diffusion in Fiber Reinforced Composites
Authors: Hannila Raimo , Pramila Antti
Published: April 2004

A method for the determination of the effective constant coefficients of the transverse coupled hygrothermal diffusion is presented. Onsager’s reciprocal relation [2] is utilized to reduce the number of the diffusivity coefficients of constitutive materials from four to two. The so called cross coupling diffusivities are expressed in terms of the thermal conductivity and the coefficient of diffusion. The representative volume element of the composite is analyzed by applying a twodimensional finite element model. It is assumed that the composite is undamaged, and there is no resistance in diffusion and heat conduction at the interface of the fiber and the matrix. The method is tested numerically with a set of different cases. The coupling affects most clearly to the heat flux in the tests. The average coupled heat flux is significantly greater than the uncoupled heat flux.
Effect of Stitching on the Static and Fatigue Performance of Co-Cured Composite Single-Lap Joints
Authors: Aymerich Francesco
Published: April 2004

The paper investigates the effect of Kevlar stitching on the tensile static and fatigue properties of co-cured single-lap joints with cross-ply graphite- epoxy adherends. The variables considered in this study were the overlap length, the stitch spacing, and the off-edge distance. Experimental results indicate that while stitching does not improve the static strength, stitched joints exhibit much better fatigue performance than unstitched joints. Ultrasonic analyses and continuous monitoring of stiffness change during fatigue life allowed us to follow delamination progression and to clearly identify the nucleation and the propagation stages, in particular, stitching was observed to increase the durations of both the crack initiation and crack propagation phases, with stitches remaining intact until complete failure. Moreover, in the range of values examined, the fatigue behavior of stitched joints is improved by reducing the stitch spacing, while it appears to be insensitive to the variation of the off-edge distance of stitches.
Deformation Behavior of NiTi/Polymer Shape Memory Alloy Composites – Experimental Verifications
Authors: Murasawa Go , Tohgo Keiichiro , Ishii Hitoshi
Published: April 2004

Composites containing NiTi shape memory alloy (SMA) long-fiber, short-fibers or Ti long-fiber in a Polycarbonate (PC) matrix have been fabricated by the injection molding technique. Also, prestrained SMA long-fiber/Epoxy matrix composites have been fabricated. The fracture behavior and thermo-mechanical deformation behavior are examined; (1) Fracture behavior – uniaxial tensile tests up to fracture for SMA long-fiber and short-fiber composite (SMAC). (2) Thermomechanical deformation behavior – tensile loading–unloading tests for Pseudoelastic (PE) long-fiber/PC matrix composites. Several thermo-mechanical loading tests for Shape Memory Effect (SME) long-fiber/PC matrix and SME long-fiber/Epoxy matrix composites were used.

The obtained results are as follows: (1) The stress–strain relation up to the final fracture of the Shape Memory Alloy Composites (SMACs) showed the repeated up-and-down of the stress which corresponds to the necking of the specimen, fiber fracture, and matrix fracture. The strain for the initiation of necking and the strain for the fiber or matrix fracture in the SMACs were higher than those in the Ti composite. This is attributed to the unique stress–strain relations accompanied by the stress-induced martensitic transformation of the SMA fibers. (2) The SMAC containing PE fiber and PC exhibited the pseudoelastic-like deformation under tensile loading–unloading. (3) The SMAC containing SME fiber and PC exhibited the large contraction by heating after tensile loading–unloading, but the compressive residual stress in the matrix expected in this process was not remarkable. However, compressive residual stress in the matrix may become greater by embedding prestrained fiber in the matrix.
Measurement Research of Parameter on Three-Dimensional Braided Composite Material Preform Surface
Authors: Wan Zhenkai , Li Jialu
Published: April 2004

This paper describes a new measuring algorithm for three-dimensional (3-D) braided composite materials preform exterior average braided angle based on image texture. In this project, an advanced nonlinear filtered algorithm for image of 3-D braided composite materials preform was developed. The digital signal processor, TMS320C/F240, has been used as a device for the preform exterior image filtering. The nonlinear filter consisted of minimum, median, and maximum filters. The DUAL PORT RAM, TC514256, has been used as image buffer. The proposed implementations achieve more powerful and stable noise reduction than commercial algorithms.

In this research we also propose a more effective and rapid system design method and describe the procedure and how to implement our proposed algorithms by using the surface image testing system. A real time preform surface image collecting and filtering system was developed without PC controlling (the FPGA technology and digital signal process were used).

To show the effectiveness of the proposed designing scheme, angular power spectrum algorithms were designed and it generated an optimized and portable code using assemble and VC language; then it was downloaded to a PC. It built programs that helped speed up the system so as to produce high quality results in less time.

Experimental results show that the proposed method is feasible. The research was appraised by Science & Technology Committee of Tianjin. The appraisal report shows the research is advanced in the world. So far, the research is a new development for 3-D braided composite material preform measuring. It will provide the perfect data for improving artifact technology for 3-D braided composite material preform.
Coupled Bending-Torsional Dynamic Response of Axially Loaded Slender Composite Thin-Walled Beam with Closed Cross-Section
Authors: Jun Li , Xianding Jin
Published: April 2004

An analytical method towards investigating the dynamic coupled vibrations of axially loaded slender composite beams with a solid or closed thin-walled cross-section is presented. The classical composite beam theory is employed and the important effect of axial force is included in the present formulations. The exact natural frequencies and mode shapes of slender composite beams are computed by directly solving the governing differential equations of motion in free vibration and the orthogonality of the normal modes is derived. The theoretical expressions for the displacement response of axially loaded composite beams subjected to concentrated or distributed loads are obtained by using the normal mode method. The method is illustrated by its application to two test examples to demonstrate the effects of bending-torsion coupling and axial force on the dynamic behavior of composite beams. The numerical results for the dynamic bending displacements and torsional displacements are discussed in detail and the accuracy of the solutions is verified.
Static and Dynamic Characterization of Polymer Foams Under Shear Loads
Authors: Kanny Krishnan , Mahfuz Hassan , Thomas Tonnia , Jeelani Shaik
Published: April 2004

When a sandwich structure is subjected to transverse loads, the face sheets carry bending moments as tensile and compressive stresses and the core carries transverse forces as shear stresses. The core is typically the weakest component of the structure and is the first one to fail in shear. In this study the shear fatigue behavior of two closed-cell cellular PVC foams, Divinycell HD130 (linear) and H130 (cross-linked), with the same nominal density of 130 kg/m3, were investigated. Static shear tests reveal that HD130 foams are more ductile, have almost twice the energy absorption capability, and an extraordinary crack propagation resistance when compared to the H130 foams. Shear fatigue tests were conducted at room temperature, at a frequency of 3 Hz and at a stress ratio, R=0.1 on the HD130 and H130 foams. S–N curves were generated and shear fatigue characteristics were determined. The number of cycles to failure for the linear foams was substantially higher than that of the cross-linked PVC foams. HD foams have smaller cells with thicker faces and edges. This microstructure supports absorption of larger amounts of liquid resin forming a resin rich subinterface zone in the core. The high-intrinsic toughness of the subinterface delays the initiation of fatigue cracks and thereby increases the fatigue life. For both foams, shear deformation occurs without volume change and the materials fail by shearing in the vicinity of the centerline along the longitudinal axis. In both cases numerous 45° shear cracks form along the length and across the width of the specimen immediately prior to the final failure event. Details of the experimental investigation and the evaluation of the fatigue performance are presented.
In Situ Fracture Toughness Testing of Core Materials in Sandwich Panels
Authors: Shivakumar K. N. , Smith S. A.
Published: April 2004

The in situ fracture toughness of six core materials was measured using a new test method. The materials tested were seven composite sandwich panels fabricated using vacuum-assisted resin transfer molding (VARTM). The core materials were PVC or balsa of different densities. All of the core materials were tested with E-glass–vinylester face-sheets, while one was tested with carbon–epoxy face-sheets. The fracture tests were conducted using a modified Cracked Sandwich Beam (CSB) test configuration. The cracks in the foam-core panels grew in the subinterface region and paralleled the interface. The distance from the interface to the location of the sub-interface crack was related to the mismatch in the material properties between the face-sheet and core. The fracture toughness of the PVC core materials ranged from 367 to 1350 J/m2. The results for the sandwich specimens with PVC cores were compared to the Mode I fracture toughness of the neat PVC foam-core materials and values obtained from in situ testing of foam-cored sandwich panels using the Tilted Sandwich Debond (TSD) specimen with no tilt angle. The in situ fracture toughness of the core materials in a sandwich panel was found to be significantly higher than the Mode I fracture toughness of core material even though the cracks grew completely within the core. The crack growth in the balsa-cored panels was significantly different than that of the cracks in the foam panels. The cracks in the balsa panels grew in one of the three distinct fashions: as an interface crack when bonding between face-sheet and core was weak, or when the bonding was strong, as a through-the-thickness crack, or a sub-interface crack. The fracture toughness of the sandwich specimens with balsa-core materials ranged from 693 to 1008 J/m2. The results from the balsa-cored panels were compared to results obtained from similar balsa-cored sandwich materials using the Single Cantilever Beam (SCB) specimen.
Mechanics of Failure of Composite Laminates with an Embedded Fiber Optic Sensor
Authors: Shivakumar Kunigal , Emmanwori Legunchim
Published: April 2004

Embedding fiber optic sensor (FOS) in fiber reinforced composites caused resin pockets and geometric disturbance of the reinforcing fibers around the optical fiber. The disturbance angle varied from 6.2 to 8.2 and the resin pocket area varied from 7 to 10 times the cross-sectional area of the sensor. These two act like defects and cause premature failure initiation. Failure initiation was hypothesized as due to transverse stress concentration. A static experimental study was conducted to evaluate the effect of an embedded optical fiber in unidirectional composite laminates. Inclination of FOS with respect to reinforcing fiber (loading direction) varied from 0 to 90 and the laminate thickness varied from 8 to 20 plies. The embedment had practically no loss of tensile modulus and about 10% loss of tensile strength while compression strength reduction was as large as 40%.
Characterization of Constitutive Behavior of Satin-Weave Fabric Composite
Authors: Jacobsen A. J. , Luo J. J. , Daniel I. M.
Published: April 2004

As the use of woven fabric composites increases, understandingtheir elastic behavior is essential. For this study, an experimental approach wasundertaken to determine the elastic properties of a woven fabric composite, witha focus on determining stiffness coupling terms that are often neglected in analyticaland FEA models. Specimens were fabricated with a 5-harness satin-weave carbon–epoxy composite and were subjected to three loading conditions: tension, bending,and torsion. The approach taken to calculate the stiffness (or compliance) matrixterms is presented, along with symmetry properties that provide some relationshipsbetween these terms. The results indicate that the minor coupling terms are difficultto quantify due to the small strains that need to be measured. The results indicatethat the minor coupling terms are very sensitive to fiber misalignment. Carefulfiber alignment along the longitudinal (warp) direction of test coupons givescoupling terms corresponding to that direction which are much less sensitive to thefiber misalignment. The major in-plane and out-of-plane compliance terms were alsomeasured by the tests conducted.
Fatigue Analysis of Sandwich Beams Using a Wear-Out Model
Authors: Dai Jin , Hahn H. Thomas
Published: April 2004

In this paper, a wear-out model, which is based on the concept ofdeterministic strength degradation and equal ranking between static and residualstrengths, is used to assess the fatigue behaviors of several different sandwich beams.The model requires only two parameters to describe the strength degradation infatigue. One parameter represents the rate of strength degradation and the othera relative fatigue life. A new approach is used to determine these parameters fromexperimental data. The model is shown to be able to describe rather well both thestatic strength distributions and the fatigue stress-life relations of the sandwichbeams. The residual strength distribution after 5000 cycles was predicted for theEglass–vinylester–D100 balsa wood sandwich at 60% maximum stress level with thef and s obtained through the fitting method developed in this paper. There is a goodagreement between prediction and experiment.
Dynamic Stability of Long Cylindrical Sandwich Shells and Panels Subject to Periodic-in-Time Lateral Pressure
Authors: Birman Victor , Simitses George J.
Published: April 2004

The paper presents an analysis of dynamic stability of long cylindricalsandwich shells and shallow panels subject to a uniform periodic lateral pressure.The solution is obtained using the Sanders shell theory by assumption that the shellor panel remains in the state of plane strain during both steady-state and perturbedmotion. The steady-state motion of a shell is axisymmetric, while perturbedvibrations superimposed on the steady response are asymmetric. The analysis ofperturbed motion is reduced to specifying the conditions of stability of the Mathieuequation. Subsequently, the criteria of dynamic stability and the boundaries of theregions of unstable motion in the pressure amplitude–pressure frequency planeare immediately available. A shallow panel subjected to hydrodynamic pressureexperiences forced vibrations. However, these vibrations can become unstable.Dynamic stability of such vibrations is investigated through the solution of thelinearized equations for perturbed motion. It is shown that these equations can bereduced to a system of Mathieu equations.
Analysis and Optimization of a Pressurized Mid-plane Asymmetric Noncircular Sandwich Fuselage
Authors: Chen Zhaohui , Vinson Jack R.
Published: April 2004

For efficient cargo space in a global range transport aircraft, a noncircular cross-section fuselage is investigated. The cross-section investigated is a rectangle with rounded corners. In order to minimize the resulting bending stresses, sandwich construction is investigated, and in particular a mid-plane asymmetric construction is studied to utilize bending stretching coupling to minimize these bending stresses still further in the sandwich construction.

Traditionally, in almost all cases of sandwich constructions to date, the construction is mid-plane symmetric, i.e. the faces are of the same material and thickness. There are many needs for sandwich constructions using different faces. For example, for a racing boat, one face is subjected to corrosion, the other face is primarily subjected to an internal environment. On the other hand, considering that many advanced composite materials have different strengths and elastic moduli in tension and compression, even if the two faces are made of the same material, different face thickness can provide a superior structure.

The governing equations are obtained by applying the Theorem of Minimum Potential Energy and displacements are assumed. Solutions are derived for a non-circular shell, involving a mid-plane asymmetric sandwich construction that are subjected to a constant internal pressure for the structure with flat sides and rounded corners. The shell is simply supported at both ends. Solutions are obtained through piece-wise matching of plate and shell sections.
Colored Petri Net Modules of Complex Selecting Criteria
Authors: Arjona Enrique , Bueno Graciela
Published: April 2004

Colored Petri nets (CPNs) have been widely used as a mathematical modeling tool of dynamical systems, both for control and simulation. CPNs are very appealing and appear uncomplicated because of their simple graphical representation. However, as the CPN definition is very concise, specific processes have to be modeled with appropriate modules that sometimes are not easy to conceive. To broaden the use of CPNs in discrete event simulation, the authors present two CPN modules that model complex selecting criteria. The first module selects a constant number of entities from a set of places. The second module selects a variable number of entities from a set of places. The modules simulate the execution of the criteria, avoiding the use of superfluous components. These CPN modules were developed for automatic top-down refinement of CPN models but can also be used as templates for manual refinement of CPNs.
Quantization-Based Simulation of Differential Algebraic Equation Systems
Authors: Kofman Ernesto
Published: April 2004

The author studies the use of first-and second-order quantized state systems methods (QSS and QSS2) in the simulation of differential algebraic equation (DAE) systems. A general methodology to obtain the QSS and the QSS2 approximations of a generic DAE of index 1 is provided, and their corresponding discrete event system (DEVS) implementations are developed. Furthermore, an alternative method is given based on the block-by-block translation from block diagrams containing algebraic loops into coupled DEVS representations of the corresponding QSS and QSS2 approximations. The author shows that the main advantages provided by the quantization-based methods in the simulation of ordinary differential equations—stability properties, reduction of computational costs, sparsity exploitation, and so on—are still verified in DAEs. These advantages are illustrated and discussed in the simulation of two examples that show the main features of the methodology.
Object-Oriented Description of Hybrid Dynamic Systems of Variable Structure
Authors: Urquia Alfonso , Dormido Sebastian
Published: April 2004

Existing object-oriented modeling environments only support the simulation of a limited type of hybrid dynamic models of variable structure: those with exactly the same state variables and the same algebraic variables in all modes. The most general hybrid dynamic model of variable structure is one in which the number of state variables and algebraic variables is not necessarily equal in all modes. A new algorithm, which transforms such a general variable-structure model into a model suitable for simulation by means of existing object-oriented modeling languages of hybrid systems, is proposed.
Poisson Simulation as an Extension of Continuous System Simulation for the Modeling of Queuing Systems
Authors: Gustafsson Leif
Published: April 2004

Poisson simulation is an extension of continuous system simulation whereby randomness is modeled as opposed to just adding noise. This article treats how Poisson simulation can be used for modeling queuing systems. The focus is on the implementation of queues in Poisson simulation and the connections to queuing theory. This approach also has theoretical and practical implications. Dynamic and stochastic systems, especially when queues are involved, are often treated by discrete event simulation using a microscopic view in which individual entities are modeled. Poisson simulation makes it possible to handle many such systems on a macroscopic level using aggregated states. It is therefore interesting to compare these approaches. Parallel approaches can then be sketched with discrete event simulation in one branch and Poisson simulation in the other. A fundamental difference between the approaches is whether one prefers to base a model on individual, distinguishable entities or on lumped entities.
Pleasure, Freedom and Drugs
Authors: O’Malley Pat , Valverde Mariana
Published: April 2004

The article explores the ways in which discourses of pleasure are deployed strategically in official commentaries on drug and alcohol consumption. Pleasure as a warrantable motive for, or descriptor of, drug and alcohol consumption appears to be silenced the more that consumption appears problematic for liberal government. Tracing examples of this from the 18th century to the present, it is argued that discourses of ‘pleasure’ are linked to discourses of reason and freedom, so that problematic drug consumption appears both without reason (for example ‘bestial’) and unfree (for example ‘compulsive’), and thus not as ‘pleasant’. In turn, changes in this articulation of pleasure, drugs and freedom can be linked with shifts in the major forms taken by liberal governance in the past two centuries, as these constitute freedom differently.
Whose Data are They Anyway?
Authors: Parry Odette , Mauthner Natasha S.
Published: April 2004

Social scientists are increasingly encouraged to locate, access and analyse data from data archives worldwide. Although the vast majority of data archives which service the research community deal exclusively with the storage and provision of quantitative data, facilities also exist for the deposit and reuse of qualitative data.While archiving is generally understood as relatively unproblematic by the quantitative research community, there has been a mixed reaction to data archiving among qualitative social science researchers. Much of this concern stems from the assumption that qualitative data are similar to, and may therefore be treated in the same way as, quantitative data. However, the joint construction of qualitative data between researcher and respondent has important implications for the ownership and control of research material. The article suggests that the archiving of qualitative data raises a distinct set of issues surrounding confidentiality, respondent and researcher anonymity and respondent consent. It examines some of the practical, legal and ethical issues which may affect the archiving of qualitative research data, and in doing so it reflects on the viability of using qualitative data for theoretical and substantive secondary analysis. It also highlights the importance of drawing on the experience of other disciplines, such as oral history, with a longer tradition of archiving in order to develop appropriate disciplinary guidance for social scientists engaged in qualitative research.
Quoting and Counting
Authors: Letherby Gayle
Published: April 2004

In 1998 Ann Oakley published an article in Sociology entitled ‘Gender, Methodology and People’s Ways of Knowing: Some Problems with Feminism and the Paradigm Debate in Social Science’. Within this piece she suggests that the main methodological concern of feminist sociologists is whether qualitative or quantitative methods are the best way to find out about people’s lives. My reading of the feminist literature leads me to disagree and to suggest that the relationship between the process and product, between doing and knowing, i.e. how what we do affects what we get, while using both qualitative and quantitative methods, is the main concern of contemporary feminists. In this piece I present my own review of the feminist literature in order to demonstrate the centrality of the process and product/doing and knowing debate. I draw on a range of work, including other work of Oakley, and I also refer to my own experiences of research and show how issues of process and product/doing and knowing are relevant for me.
Matter over Mind?
Authors: Warren Samantha , Brewis Joanna
Published: April 2004

Data collected from interviews with mothers and one mother-to-be characterized pregnancy as a time during which a woman has little jurisdiction over her body.Some respondents found this loss of control discomfiting and unpleasant, but others told of how much they had enjoyed their pregnancies for the same reason. On this basis, we suggest that pregnancy may represent a specific ‘body episode’ which belies the modern Western conviction that we have and possess our bodies and are able to mould them accordingly. Second, we propose that its physical transitions provided for some informants a disturbing testament to the fact that our influence over our bodies is in fact incomplete – that they are in many ways obdurate and ‘wayward’. Third, we suggest that the more positive descriptions of pregnancy could be attributed to the demands of the ‘body project’, the efforts that women especially invest in sculpting their bodies in culturally acceptable ways. Pregnancy therefore may represent for some women an opportunity to luxuriate in their materiality, because during this period they are unable to govern their bodies in the ways to which they are accustomed in more mundane physical circumstances.
Is Northern Ireland Abnormal?
Authors: Mitchell Claire
Published: April 2004

This article places Northern Ireland within the unfolding sociological debate on religion in modern Britain. It measures secularization along Casanova’s three dimensions (1994): religious differentiation, decline and privatization. It finds that Northern Ireland has, in common with Britain, high levels of religious differentiation, grey areas of religious belief and little convinced secularism. However, Northern Ireland differs in that it has higher levels of religious affiliation and practice, and religion plays more roles in civil society than it does in other parts of Britain. The article explores the role of conflict in forming these religious trends, asking if they represent a persistence of the sacred, or simply mask deeper ethnic divisions. It concludes that the social dimensions of religion are just as important as the supernatural, and that they often inform each other. Finally, it suggests that the dynamics of religious change are comparable across regions and, as such, Northern Ireland might be a useful case study for British policy makers, particularly as it becomes increasingly multicultural and religiously plural.
The Social Differentiation of the Educational System
Authors: Vanderstraeten Raf
Published: April 2004

In line with a long sociological tradition, Niklas Luhmann has analysed the basic characteristics of modern society in terms of social differentiation. Luhmann has focused on the forms of differentiation, and argued that modern society is differentiated according to subsystems that concentrate on one function (e.g. the economy, law, science, politics, education). In the first part of the article, I explore the backgrounds of this systems-theoretical framework. In the second part, this framework is used to analyse the structural characteristics of the educational system. This system has its basis in the school’s complexes of interaction and organization. But education is also confronted with the consequences of its own autonomy, its own mode of operating. It is suggested that these secondary effects have more impact on the evolution of this system than its societal environment.
Occupational Identity on the Edge
Authors: Collinson Jacquelyn Allen
Published: April 2004

Throughout the higher education sector in the UK, recent decades have witnessed the increasing use of fixed-term and part-time labour, to the extent that around 50 percent of academic staff are currently employed on fixed-term contracts and in excess of 90 percent of researchers are employed on fixed-term contracts. Despite the importance of their contribution to the sector as a whole, relatively little research has been undertaken on the lived experience of undertaking contract research. The objective of this article is therefore to explore the reality and complexities of contract researchers’ working lives and the occupational identities and self-images that contract researchers construct and maintain.
(Inter)Dependence, Needs and Care
Authors: Watson Nick , McKie Linda , Hughes Bill , Hopkins Debra , Gregory Sue
Published: April 2004

In this article we examine the tensions between feminist and disability studies perspectives on care.We argue that an emancipatory model of care is one that must address these tensions. In developing this model we consider the notions of (inter)dependence and need across the lifecourse. Drawing on the work of Fraser (1989), we propose that the notion of ‘needscape’ can be used to construct a ‘discourse bridge’ that will mediate between the disability studies and feminist perspectives on care. Notions of care and caring have been subject to criticism by feminist and disability theorists.There is a presumption by some that care is an activity to which women are naturally suited and this forms a starting point for the claim associated with the feminist view that care is a source of women’s exploitation. For disability activists notions of care are dis-empowering.The person in receipt of care is often assumed to be passive and dependent. This is exemplified in the limited access of disabled people to choices over the nature and form of the social support that they may need.
Reading Bourdieu with Adorno
Authors: Karakayali Nedim
Published: April 2004

Scholarly activity presupposes a certain distance from the concerns of everyday life, which has both liberating and crippling effects. Bourdieu’s reflexive sociology hopes to undo these crippling effects by making the scholar aware of the limits of his/her ‘liberation’. Through his emphasis on the practical content of social life, Bourdieu provides a powerful alternative to theoretical critiques of contemporary society advanced by sociologists such as Adorno. At the same time, read against the background of Adorno’s ‘critical theory’, this reflexive move itself appears as a limitation. Due to its emphasis on the conditions of sociological knowledge, reflexive sociology tends to subordinate ‘theory’ to ‘epistemology’ and, therefore, hinders the sociologist from imagining a different society. Read together, Bourdieu’s and Adorno’s works provide important insights about two potential dangers that remain on the path of the sociologist. Adorno’s critique of ‘scientism’ implies that adhering to an epistemological principle may not be enough to escape the ‘ fallacious’ representations of social reality, while Bourdieu’s critique of ‘theoreticism’ implies that one cannot grasp social reality without ‘touching’ it.
Tragedy, Progress and the International Order: A Response to Frost
Authors: Mayall James
Published: April 2004

This response describes the circumstances that led Professor Mervyn Frost to write his article on tragedy in international relations. In examining his argument, it identifies several points of agreement but two points of disagreement. The first is over the evidence for the evolution of a global human rights culture; the second over the weight to be attached to the impediments to progress represented by the external world. These points are illustrated by reference to international developments since September 2001. The conclusion is that the modern world, despite its public commitment to the progressive idiom of democratic politics, and enlightened attempts to promote a democratic world order, cannot easily escape tragic outcomes.
Whose ‘Middle East’? Geopolitical Inventions and Practices of Security
Authors: Bilgin Pinar
Published: April 2004

Contesting those approaches that present the ‘Middle East’ as a region that ‘best fits the realist view of international politics’, this article submits that critical approaches are relevant to this part of the world as well. It is argued that instead of taking the relatively little evidence of enthusiasm for addressing the problem of regional insecurity in the Middle East for granted, a critical place for such approaches to begin is a recognition of the presence of a multitude of contending perspectives on regional security each one of which derives from different conceptions of security that have their roots in alternative worldviews. When rethinking regional security from a Critical Security Studies perspective, both the concepts ‘region’ and ‘security’ need to be opened up to reveal the mutually constitutive relationship between (inventing) regions and (conceptions and practices of) security.
Use of Polymeric Plasticizers in Polyvinyl Chloride to Reduce Conventional Plasticizer Migration for Critical Applications
Authors: Sunny M. C. , Ramesh P. , George K. E.
Published: April 2004

Di-(2-ethyl hexyl) phthalate (DEHP), a conventional plasticizer in polyvinyl chloride (PVC), was partially replaced by polymeric plasticizers. Three different elastomers such as nitrile rubber (NBR), carboxylated nitrile rubber (XNBR) and epoxidized natural rubber (ENR) were used as polymeric plasticizers. Mechanical properties and leaching of DEHP of the modified PVC in comparison to the compound containing DEHP alone were investigated. The study shows that the migration of the DEHP can be reduced significantly without affecting the useful mechanical properties.
FTIR Mapping: Polymer Swelling and Solvent Segregation in Benzene/Cyclohexane-Polyisoprene Rubber System
Authors: Li Gui-Yang , Koenig J. L.
Published: April 2004

The diffusion of binary solvents of benzene and cyclohexane in polyisoprene rubber networks was observed by Fourier Transform Infrared (FTIR) mapping spectroscopy. The spatial correlation of solvent diffusion and rubber swelling was established with a temporal resolution of 5 min and spatial resolution of 15 mm. The results suggest that the binary solvents combining the penetrability of benzene and the compatibility of cyclohexane, resulted in the rubber swelling more in the mixture of these two solvents than in either solvent alone. The segregation of solvents was monitored using different volume ratios of benzene and cyclohexane and it was found that the largest segregation appears with an equal volume mixture of benzene and cyclohexane, which also corresponds to the largest rubber swelling.
Blends of PS with SBR Devulcanized by Ultrasound: Rheology and Morphology
Authors: Scuracchio C. H. , Bretas R. E. S. , Isayev A. I.
Published: April 2004

The rheological properties and the morphology of blends of styrene-butadiene rubber (SBR), devulcanizated by ultrasound (dSBR), with polystyrene (PS) were studied. A compatibilizer, a styrene-butadiene block copolymer (SBS) was also added to dSBR/PS blends. The shear viscosity at low and high shear rates, the complex dynamic viscosity and the creep behavior were measured. It was observed that the addition of the dSBR to the PS caused little change in the shear viscosity at high shear rates, decreased the die swell and increased the elastic recovery. The analysis of the dSBR particles in blends after capillary rheometry showed that their shapes were extremely irregular with their sizes decreased and distribution narrowed with increase in the amount of dSBR and the shear rate. The addition of SBS to the blends was found to be more efficient on decreasing the dSBR particle size at the lowest concentration of dSBR. Depending on the dSBR concentration, the dSBR particle sizes in the blends varied between 18 and 6 mm. Thus in order to achieve a toughening of PS by an addition of dSBR, their particle size should be further reduced by changing the devulcanization process conditions.
The Global HIV/AIDS Epidemic and Related Mental Health Issues: The Crisis for Africans and Black Americans
Authors: Fitzpatrick Lisa , McCray Eugene , Smith Dawn K.
Published: April 2004

HIV/AIDS is one of the most devastating diseases that humanity has ever faced. Since the first clinical evidence of HIV/AIDS was reported in 1981, more than 60 million people have been infected with the virus and more than 20 million have died of AIDS. This article provides an overview of the global HIV/AIDS epidemic with a focus on its impact on sub-Saharan Africa and people of African descent in the United States.
Parenting Style and Black Adolescents’ Academic Achievement
Authors: Attaway Nicole M. , Bry Brenna Hafer
Published: April 2004

The relationships between maternal beliefs in control and responsiveness and adolescent academic achievement were examined by interviewing 59 Black mothers and female guardians of adolescents, ages 11 to 19, living in a northeastern small city or adjacent suburb and correlating their answers to year-end report cards of their adolescents. Demographic variables such as maternal education level and adolescent sex were also examined to determine whether they helped explain variation in adolescent grade point averages. The analyses revealed that higher maternal beliefs in control were significantly associated with lower grade point averages. No other statistically significant relationship was found in this sample between the other parenting and demographic variables and adolescent academic achievement. The results of this study are discussed in terms of factors that may mediate the relationship found.
Religiosity, Optimism, and Pessimism Among African Americans
Authors: Mattis Jacqueline S. , Fontenot Dwight L. , Hatcher-Kay Carrie A. , Grayman Nyasha A. , Beale Ruby L.
Published: April 2004

It generally is accepted that religiosity is associated with increased optimism and decreased pessimism. However, the empirical link between religiosity and optimistic and pessimistic expectancy outcomes remains underexamined. This study explored the association between early and current organizational religiosity, subjective religiosity and spirituality, positive and negative perceived relationship with God, and dispositional optimism and pessimism among a sample of African Americans (N = 307). Hierarchical regression analyses revealed that age, subjective spirituality, and a positive relationship with God were positive, independent predictors of optimism. Education, combined household income, and subjective spirituality negatively predicted pessimism. Negative relationship with God was a positive predictor of pessimism. Subjective religiosity and early and current organizational religious involvement did not predict optimism or pessimism. The significance of these findings is discussed.