bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two Levels of Intervention in Low-Income Women With Depressive Symptoms: Compliance and Programme Assessment
Authors: Lara M. A. , Navarro C. , Rubí N. A. , Mondragón L. 
Published: April 2003

Aims: This study reports on the evaluation of a brief group intervention for women of limited means with depressive symptoms. Method: A comparison design was used with pre-, post-and four-month follow-up assessments for 93 women in the group intervention condition who were given six two-hour sessions of psycho-educational intervention, and 42 women in a minimum individual condition who received a 20-minute explanation in addition to the educational material, which yielded the following results. Results: Both conditions were effective in motivating participants to engage in self-help activities (making time for themselves every week, using writing as a means of sorting out problems, talking to someone about their problems and carrying out the reflection and cognitive behavioural exercises) and to seek further professional help when necessary. The intervention condition was more positively evaluated since participants regarded it as having a greater influence on their life and problems. Influence was related to better understanding and coping with problems, mood improvement, changes in the way they thought about things, knowing themselves better and being more accepting of themselves. Conclusions: The results suggest that both interventions tackle important issues related to depression in women but further data are needed for a better understanding of this relationship.
Attitudes of Hospital Staff Toward Mentally Ill Patients in a Teaching Hospital, Turkey
Authors: Aydin Nazan , Yigit Arzu , Inandi Tacettin , Kirpinar Ismet 
Published: April 2003

The aim of this study was to examine the attitudes of hospital staff toward major mental diseases: schizophrenia and depression. Negative attitudes were common among all of the hospital staff, and were more common among academicians, resident physicians and nurses. Causes of attitude variations were discussed. Background: Attitudes of hospital staff are important for admission, early diagnosis and treatment, and the rehabilitation process of mentally ill patients. Aims: The main objective of this study was to investigate and compare hospital workers' attitudes toward and knowledge of schizophrenia and depression. Methods: In 2001, a total of 160 hospital staff (40 academicians, 40 resident physicians, 40 nurses and 40 hospital employees) in a teaching hospital were interviewed with a questionnaire. The questionnaire included items about background information, a one-paragraph vignette, questions on social distance and expected burden, recognition of mental illness, hospitalization, prognostic outcome, and to whom and where the patient should be admitted. Results: Although academicians, resident physicians, and nurses have sufficient knowledge about schizophrenia and depression, the frequency of their negative attitudes towards mentally ill subjects was more than that for uneducated hospital employees. Conclusions: It was commented that this difference might be as a result of negative effects of the medical education system.
Effects of Moisture and Temperature on High Strain Rate Behavior of S2-Glass–Vinyl Ester Woven Composites
Authors: Haque A. , Hossain M. K. 
Published: April 2003

The effects of moisture and temperature on high strain rate responses of S2-glass–vinyl ester woven composites have been studied in this work. Compressive properties and micro-structural damage progression under high strain rate loading have been investigated using the Split Hopkinson Pressure Bar technique. The compressive stress pulse is applied through the thickness direction (TD) as well as through the filler direction. The stress strain responses at strain rates ranging 490–1470s−1 under various environmental conditions have been investigated and the relevant failure modes have also been identified by optical and scanning electron microscopic examinations. The results indicate that moisture and temperature degrade the compressive failure strength under high strain rate loading. The level of such degradation is seen to vary with strain rates and loading direction. In general, the failure strength and failure strain of both dry and wet samples are seen to be increased under high strain rate loading. The strain rate sensitivity of the woven composites is more significant if the failure is dominated by the resin materials. High temperature tests were conducted at temperatures ranging 23–204°C. The maximum rate effect is observed below the glass transition temperature, Tg (121°C) specifically for TD specimens. Microbuckling of the fiber, kinking and fiber splitting are the major failure modes for the specimens loaded in filler direction. The specimens loaded in the thickness direction mostly failed under matrix cracking.
Biaxial Failure Envelope and Creep Testing of Fibre Reinforced Plastic Pipes in High Temperature Aqueous Environments
Authors: Hale J. M. , Gibson A. G. , Speake S. D. 
Published: April 2003

Results are presented for a series of tests on filament wound glass fibre reinforced pipes which have been subject to prolonged exposure to high temperature water. Two materials systems in common use in offshore piping applications are tested: continuous fibre e-glass in a phenolic and an epoxy resin matrix, respectively. This is the first work on this type on water saturated GRP at very high temperatures up to 160 C. The results of water absorption tests on the two material systems at 95 C are presented. It is shown that saturated conditions can be achieved within seven days at this temperature. Creep modulus test results for the two material systems as a function of temperature up to 160 C are presented. The reduction in TG for the epoxy material in the saturated state is quantified and it is shown that the phenolic material is largely unaffected by water absorption. The results of biaxial tensile loading tests for the two material systems are presented in the form of failure envelopes at temperatures from 20to 160 C. The considerable weakening of the epoxy system, particularly under the matrix dominated loading conditions, is quantified and it is shown that the failure envelope for the phenolic system is largely unaffected by temperature. Finally, a comparison is made between the two materials as a function of loading condition and temperature as a design guide.
Effect of Thermal Cycling on Microcracking and Strength Degradation of High-Temperature Polymer Composite Materials for Use in Next-Generation SST Structures
Authors: Shimokawa Toshiyuki , Katoh Hisaya , Hamaguchi Yasumasa , Sanbongi Shigeo , Mizuno Hiroshi , Nakamura Hiroyuki , Asagumo Ryoji , Tamura Hirobumi 
Published: April 2003

The objective of this study was to investigate the effect of thermal cycles encountered by an SST in service on the cumulative frequency of microcracks and degradation of open-hole-compressive (OHC) strength in high-temperature polymer-matrix composite materials. One cycle of thermal cycling was designated as the sequence from room temperature (RT) to 54C, up to +177C, and back to RT. Thermal-cycling tests were conducted up to 10,000 cycles on two kinds of carbonfiber/thermoplastic polyimide composite material: IM7/PIXA, IM7/K3B, and up to 1000 cycles on G40-800/5260 carbon fiber/bismaleimide composite material. At scheduled thermal cycles, transverse microcracks initiated on the sectional surface of the laminates were observed and counted using an optical microscope. Static mechanical tests at RT provided OHC strength before and after thermal cycles. In addition, a simple and approximate finite element model (FEM) analysis using basic lamina data of the T800H/PMR-15 carbon fiber/polyimide composite was conducted to estimate the thermal stresses generated in the laminate. Major results obtained by the tests and FEM analysis are as follows: A fairly large number of microcracks were initiated, though the number as a function of thermal cycles varied according to the material; OHC strength before and after thermal cycles did not change during the course of this study; thermal cycles and transverse microcracks did not affect OHC strength; the calculated thermal-stress level in layers generated by one thermal-cycle of 231C temperature difference was under the limit for crack initiation of the T800H/PMR-15.
Fracture Behavior of Woven Composites Containing Various Cracks Geometry
Authors: Khashaba U. A. 
Published: April 2003

Recently, polymeric composite materials are widely used in automotive applications for reducing structural weight, saving fuel, and improving performance. Accidentalimpact damage is an important issue in the use of these composite materials as body components. The damages or cracks in the present work were represented by notched specimens. The test specimens were fabricated from polyester resin reinforced by woven E-glass fiber. A series of tests were conducted to measure the notched strength of composite laminates with various types of through-the-thickness cracks such as central normal notch (CNN), center inclined notch (CIN), single edge notch (SEN) and double edge notch (DEN). A Modified Point Stress Criterion (MPSC) was proposed for predicting the tensile strength of composite laminates with various aspect ratio (a/w), that is, notch length to specimen width ratio. The results show that the load–elongation diagrams of notched and unnotched glass fiber reinforced polyester (GFRP) specimens have a nonlinear behavior, with clear “Knee”, associated with audible noises. For the same notch length, the notched strength of GFRP specimens with symmetric cracks (CNN, CIN and DEN) is quite consistent. The lowest notched strength is for SEN specimens. An excellent agreement is found between the experimentalresults of centralnotched specimens (CNN and CIN) and the predicted values using the MPSC than the reviewed published theories. The critical stress intensity factor ( KIC) was determined from the centralnotched specimens and used to predict the notched strength of edge notched specimens (SEN and DEN). The type of the central notch (inclined or normal) insignificantly affects the values of the stress intensity factor, KIC.
Lamb Wave Interaction with Impact-induced Damage in Aircraft Composite: Use of the A0 Mode Excited by Air-coupled Transducer
Authors: Kaczmarek H. 
Published: April 2003

A novel technique has been experimented involving the use of an air-coupled transducer to excite Lamb mode in composite material, a pinducer to pick-up local response and a turn-table set-up to reveal impact damage-induced anisotropy. So, a fundamental antisymmetric A0 Lamb mode has been excited under unusual conditions. Its efficiency for detecting impact-induced damage in a multilayered thin quasi-isotropic carbon–epoxy composite laminate has been demonstrated and the knowledge on the A0 Lamb mode interaction with the damage has been improved using an original mapping. Some material characteristics have been obtained. Intrinsic material attenuation of this guided mode at a frequency of 370 kHz and a frequency-thickness product of 740 kHz mm has been assessed and in-plane energy distribution of the A0 mode has been mapped, revealing a relatively directive acoustic field. However, the composite material exhibits slightly anisotropic acoustic behaviour due to a lack of fibres in certain directions. Interactions between the A0 mode and multidelamination of the critical area were also investigated. In-plane mappings of the ultrasonic field have revealed two main phenomena: attenuation and scattering due to damage. Splitting of the ultrasonic wave was observed, creating a region of geometric shadow where attenuation occurs. It is shown on the mappings that the energy lost in this direction of propagation appears in other directions. An increase in the received energy was detected in certain directions, showing that the damage can be considered as a soft scattering centre.
A Model of Damage Initiation in Singly Oriented Ply Fiber Metal Laminate under Concentrated Loads
Authors: Nam H. W. , Jung S. W. , Jung C. K. , Han K. S. 
Published: April 2003

Damage initiation is modeled in singlyoriented ply(SOP) Fiber Metal Laminate (FML) under concentrated loading conditions. The finite element method (FEM) is used based on the first order shear deformation theoryfor modeling damage initiation in SOP FML. The failure indices of the fiber prepreg and the metal laminate were calculated using the Tasi–Hill failure criterion and the Miser yield criterion respectively. To verify the model, failure analysis was conducted under uniaxial loading and cylindrical bending, then under concentrated loading. Results show that the model is good. An indentation test was then conducted to compare the damage initiation load with the calculated failure index. The test was conducted under two side clamped conditions in order to studythe fiber orientation effect. The indentation curve was fitted using the Hertz equation, and the damage initiation load was defined as the point of divergence of the fitted curve from the real indentation curve. The damage initiation loads were obtained for various fiber orientations and were compared with the calculated failure index. The experiment results closelymatched the calculated failure index. It follows that the present method accuratelycaptures damage initiation of SOP FML.
Damage Mechanism of Hybrid Composites with Nonwoven Carbon Tissue Subjected to Quasi-static Indentation Loads
Authors: Lee Seung-Hwan , Aono Yuuta , Noguchi Hiroshi , Cheong Seong-Kyun 
Published: April 2003

Damage mechanisms of hybrid composites with nonwoven carbon tissue (NWCT) are investigated under a quasi-static indentation loading condition with a steel ball as an indentor. The damage level corresponds to an initial stage of damage due to an indentation loading, which leads to a strength degradation of the composite. The hybrid composites consist of the CFRP prepreg and the NWCT prepreg, which are made byinterleaving the NWCT prepreg into the CFRP layer interfaces. Four kinds of cross-plylaminates are studied; i.e., CFRP laminates ([05/905/05] and [03/903/03/903/03]) and hybrid laminates ([05//905//05] and [03//903//03//903//03]). Here, the symbol “//” means that the NWCT prepreg is located at an interface between CFRP layers. The hybrid effect is examined by investigating the delamination area and the absorption energyof two cross-plylaminates. As it has been recognized that the quasi-static indentation damage agrees well with the low velocity impact test results, the present static test results can then be used to understand the damage mechanism of low-energyimpact. The damaged parts of the specimens were observed bythe deplytechnique and the cut method which used a microscope. The NWCT interleaving’s effect was clarified based on the observation of the damage for the hybrid specimen’s cross-sections after indentation testing. The delamination area of the hybrid composites was reduced to about a half of the CFRP’s byindentation loading. It was clarified that the Mode II interlaminar fracture is predominant in the delamination bythe impact.
Bond Parameters to Improve Tensile Load Bearing Capacities of Co-Cured Single and Double Lap Joints with Steel and Carbon Fiber-epoxy Composite Adherends
Authors: Shin Kum Cheol , Lee Jung Ju 
Published: April 2003

A co-cured joining method has several advantages over an adhesivelybonded joining method for its simple manufacturing process. It requires neither an adhesive nor surface treatment of the composite adherend and uses excess resin to bond both adherends, including composite adherend. In this paper, the effects of bond parameters, including surface roughness on the steel adherend, stacking sequence of the composite adherend, and manufacturing pressure in the autoclave during the bonding process, on tensile load bearing capacities of plate-type co-cured single and double lap joints were investigated experimentally. Bond parameterswere related to interfacial parameterssuch asa contact area and adhesive thickness, which affected the joint strength. Experimental results were explained with respect to all of interfacial parameters and bond parameters through investigating failure surfaces of the steel adherend and a lot of data of tensile load bearing capacities. In order to predict tensile load bearing capacities of co-cured single and double lap joints, we considered two different failure models using stress distributions in both co-cured lap joints obtained from finite element analysis. Finally, optimal conditions to improve the joint strength of co-cured single and double lap joints have been presented.
The Behavior of Compressively Loaded Stiffener Runout Specimens – Part I: Experiments
Authors: Falzon Brian G. , Davies G. A. O. 
Published: April 2003

The development of the next generation of civil and military transport aircraft will inevitably see an increased use of advanced carbon fibre composite material in the primary structure if performance targets are to be met. One concern in this development is the vulnerability of co-cured and co-bonded stiffened structures to through-thickness stresses at the skin–stiffener interfaces, particularly in stiffener runout regions. These regions are a consequence of the requirement to terminate stiffeners at cutouts, rib intersections, or other structural features which interrupt the stiffener load path. This work presents the results of an experimental programme investigating the failure of thick-sectioned stiffener runout specimens loaded in uniaxial compression. For all tests, failure initiated at the edge of the runout and propagated across the skin–stiffener interface. It was found that the failure load of each specimen was greatly influenced by intentional changes in the geometric features of these specimens. High frictional forces at the edge of the runout were also deduced from a fractographic analysis, indicating a predominantly Mode II initial failure mode.
The Behavior of Compressively Loaded Stiffener Runout Specimens – Part II: Finite Element Analysis
Authors: Falzon Brian G. , Hitchings D. 
Published: April 2003

The termination of stiffeners in composite aircraft structures give rise to regions of high interlaminar shear and peel stresses as the load in the stiffener is diffused into the skin. This is of particular concern in co-cured composite stiffened structures where there is a relatively low resistance to through-thickness stress components at the skin–stiffener interface. In Part I, experimental results of tested specimens highlighted the influence of local design parameters on their structural response. Indeed some of the observed behavior was unexpected. There is a need to be able to analyse a range of changes in geometry rapidly to allow the analysis to form an integral part of the structural design process. This work presents the development of a finite element methodology for modelling the failure process of these critical regions. An efficient thick shell element formulation is presented and this element is used in conjuction with the Virtual Crack Closure Technique (VCCT) to predict the crack growth characteristics of the modelled specimens. Three specimens were modelled and the qualitative aspects of crack growth were captured successfully. The shortcomings in the quantitative correlation between the predicted and observed failure loads are discussed. There was evidence to suggest that high through-thickness compressive stresses enhanced the fracture toughness in these critical regions.
Carbon Dioxide Fire Suppressant Concentration Needs for International Space Station Environments
Authors: Hirsch D. , Hshieh F. -Y. , Beeson H. , Pedley M. 
Published: April 2003

Fire suppression onboard spacecraft is a critical issue. Currently, requirements for the International Space Station (ISS) include achieving a 50% concentration of carbon dioxide (CO2) fire suppressant when extinguishing fires. This requirement is in accordance with NFPA 12, the governing standard for CO2 extinguishing systems, which requires concentrations of 50% for smoldering fires and 34% for flaming combustion. NFPA 12 was developed for fire suppression at ground conditions. This paper discusses combustion of materials in microgravity and evaluates CO2 fire suppressant concentration needed in microgravity and specifically for ISS environments. In a normal 20.9% oxygen environment on the ISS, the NFPA requirement should be more than adequate to extinguish flaming combustion in on-orbit microgravity conditions. For environments with initial oxygen concentrations higher than 25%, if a CO2 concentration less than 34% is desired, materials control should be exercised.
Effects of Enzymatic Treatments on the Biomechanical Properties of Screws Made of Bone
Authors: Actis A. B. , Obwegeser J. A. , Bertolotto P. 
Published: April 2003

Nowadays, bone tissue employed to manufacture screws used as osteosynthesis material is obtained from organ donors. But in different medical fields there is an increasing need to use xenogenic grafts and implants, which still imply risks of transmission of some diseases and antigenicity. Two different autoclaving programs (A1, A2) and an alternative to reduce the antigenicity of screws made of xenogenic bone based on enzymatic treatment are analyzed from a biomechanical point of view. 128 screws made of bovine femur bone were employed. Some of them were partially demineralized with 0.6 N HCl, enzymatically digested with collagenase (specific) and pepsin (nonspecific) and then autoclaved. The specimens were subjected to tension, shear and screw torque tests and histologically evaluated. Compared to A1, A2 sterilization method (134°C but higher vacuum and longer time) considerably reduced the mechanical strength of specimens. The enzymatic digestion, expected to reduce antigenicity, did not affect the screw superficial structure and would not modify the bone biomechanical properties per se, but maybe because of the association with autoclaving and partial demineralization.
The Ordinary Superstition of Subjectivity
Authors: Papadopoulos Dimitris 
Published: April 2003

This paper attempts to provide evidence for the thesis that the concept of subjectivity is linked to contemporary liberal geoculture, especially new regulation practices and new forms of violence that started to become visible during the 1980s and 1990s. Two conceptualizations of subjectivity will be examined: traditional Marxist accounts, which focus on the notion of interest, and post-structuralist accounts, which emphasize the self-referential character of subjectivity. I will argue that, despite the critical impetus of both traditions, their historical genesis can be traced to the hegemony of North Atlantic liberal ideology. Furthermore, their broad application in the social sciences and in psychology corresponds to the present-day neo-liberal reorganization of societal conditions and the trans-formation of liberalism to geoculture. So that in the first place, I put for a general inclination of all mankind, a perpetual and restless desire of power after power, that ceaseth only in death. And the cause of this is not always that a man hopes for a more intensive delight than he has already attained to, or that he cannot be content with a moderate power, but because he cannot assure the power and means to live well, which he hath present, without the acquisition of more. (Hobbes, 1994, p. 58)