bluuebunny/crossref_metadata_2025 huggingface dataset:
A validation of the body compassion scale in females
Authors: Van Niekerk Leesa M , Muscella Gemma , Quinn Michael
Published: March 2023

Body compassion bridges together the constructs of body image and self-compassion and refers to the relationship people have with their bodies, encompassing defusion, common humanity and acceptance. The purpose of the current study was to validate the 23-item Body Compassion Scale (BCS), in a female sample, and to determine the distinctiveness of body compassion from the similar construct of self-compassion. A total of 513 females completed an online cross-sectional survey examining body compassion, self-compassion, body image, and psychological health. Results supported the validation of the three-factor structure of the BCS, with the subscales of defusion and acceptance being more strongly associated with measures of body image than self-compassion. The BCS subscale of common humanity revealed lower associations with body image compared to self-compassion. The findings suggest that body compassion is a body-specific construct relating to body image concerns and while related, is distinct, from the construct of self-compassion.
Debate pedagogy as a conducive environment for L2 argumentative essay writing
Authors: Majidi Abid el , Graaff Rick de , Janssen Daniel
Published: March 2023

Debate pedagogy may hold great potential for improving second language (L2) writing skills. This study investigates this potential by examining the effects of a debate intervention on the quality of argumentative essays of Dutch secondary school students. The intervention consisted of a number of speaking and writing activities, including case-writing and note-taking. The study, which employed a pretest–posttest–delayed-posttest design with a control group, involved 135 students from eight classes at three secondary schools in the Netherlands. To measure the effects of the intervention, we analysed argumentative essays composed by the students on three occasions (pretest, posttest, and delayed posttest). The students’ essays were analysed using a range of measures for fluency, syntactic and lexical complexity, accuracy, and cohesion, as well as for communicative adequacy. Multilevel analyses revealed that the intervention group made a significant improvement in a substantial number of measures in comparison to the control group. We discuss the findings in relation to key pedagogical features of the debate environment. We conclude with implications for L2 argumentative essay pedagogy.
Experimental investigation on composite girders with CSW-CFST truss chords subjected to combined flexure and torsion
Authors: Huang Hanhui , Chen Kangming , Wu Qingxiong , Nakamura Shozo
Published: March 2023

As a new type of composite girders, composite girders with corrugated steel webs and concrete-filled steel tubular (CSW-CFST) truss chords are extensively utilized in bridge engineering. To examine the structural behavior of composite girders with CSW-CFST truss chords subjected to combined flexure and torsion, model tests and finite element analysis (FEA) are employed. Using these efficient tools, the strain distribution, deformation law, failure mode, and bearing capacity of these composite girders subjected to pure torsion and combined flexure and torsion are methodically obtained. The primary objectives are to probe the applicability of existing flexure-torsion relation curves and introduce the calculation method for the bearing capacity of composite girders with CSW-CFST truss chords subjected to combined flexure and torsion. The obtained results reveal that their failure mode is influenced by the initial torsional moment. Further, their bearing capacities due to the applied initial torsional and bending moments can be maximally enhanced by about 21.6% and 6.6%, respectively. The deviation between the predicted bearing capacity by the FEA and that obtained from the tests is less than 8.6%, demonstrating the high accuracy of the FEA model. The contribution of the torsional moment to the flexural bearing capacity is either ignored or underestimated by the existing flexure-torsion relation curves, with a minimum deviation of about 22.3%. By comparing the results acquired by the extended FEA and the calculation method proposed in this paper, it is proved that the proposed calculation method for the bearing capacity of composite girders with CSW-CFST truss chords subjected to combined flexure and torsion may reduce the deviation from 22.3% to 8.3%.
Swedish exchange students’ alcohol use, drug use, risky sexual behaviour, mental health, and self-rated health: A follow-up study
Authors: Danehorn Emil , Oscarsson Marie , Smirthwaite Goldina , Peterson Ulla , Swahnberg Katarina
Published: March 2023

Aims: To follow up on exchange students’ alcohol use, drug use, mental health, self-rated health, and risky sexual behaviour after a semester abroad and to compare them with students who remained on campus. Methods: The study design was a follow-up study based on a previous baseline survey of 114 prospective exchange students and 451 campus students. Of the original 565 students, 48 (42.1%) prospective exchange students and 209 (43.3%) campus students responded to the follow-up. Both the baseline survey and the follow-up survey included the General Health Questionnaire 12, one single item from Self-Rated Health, and nine items from Knowledge, Attitudes and Sexual Behaviour in Young People in Sweden. Results: We found a statistically significant increase in the weekly consumption of alcohol among exchange students after their semester abroad. A larger proportion of exchange students had sex with a new partner and sex with more than three partners during their semester abroad compared to follow-up campus students. Conclusions: Our findings indicate that exchange students consume alcohol more frequently during their semester abroad and indulge in sexually risky behaviour. Exchange students’ use of alcohol and sexually risky behaviour could be associated with even greater risks due to them being in an unknown environment, unfamiliar culture, and with limited support from family and friends. This highlights the need for further research on exchange students’ experiences, especially concerning alcohol use and sex while abroad.
A systematic mapping of public health primary prevention interventions with relevance for policing
Authors: Sondhi Arun , Williams Emma
Published: March 2023

This study aimed to utilise systematic mapping techniques to assess existing empirical reviews of the evidence-base for primary prevention public health initiatives relevant to policing. In total, 9410 records were extracted of which 9373 were screened by two researchers; 356 studies were assessed for eligibility of which 134 titles were included. The majority of titles were academic publications (81%) across 16 subject domains. The main domains reviewed were violence (53%), substance misuse (37%) and mental health (27%). Forty-two per cent of the titles were across multiple points of contact and 38% were within school settings. Few primary prevention studies were delivered for domestic abuse, female genital mutilation, hate crime, road traffic accidents, terrorism and white-collar crimes. Positive outcomes were ascribed to parenting, family-based, school and pre-school primary prevention interventions. Definitional problems identifying primary prevention initiatives from the literature were identified as a major concern. Thematic analysis identified issues linking causal mechanisms with behaviour change and how to ensure high-quality methods are deployed to measure outcomes. Further work is required to develop preventative approaches in areas with limited knowledge. It is recommended that research focuses on expanding understanding causal mechanisms underpinning primary prevention initiatives.
Marxist sociology in East Berlin (1949–1989): A field-spatial analysis
Authors: Grüning Barbara
Published: March 2023

The main objective of the paper is to identify the logic of the sociological field in the GDR, looking at how it was spatialized in the city of East Berlin. In this regard, I am less interested in providing an overview of the different research streams of the main sociologists operating in the scientific and academic institutes located in Berlin than in reconstructing some crucial dynamics at work there and highlighting their effects at the social and symbolic levels. The underlying idea is that, especially in East Berlin, the sociological knowledge produced was less homogeneous than it has been represented in the existing literature. Without negating the existence of shared aspects characterizing Marxist-Leninist sociology, also superimposed on the political elite, a field analysis enables us to see how the different positions and trajectories of GDR-sociologists had an impact on their approaches to theoretical, epistemological, and methodological questions, and on their understanding and uses of concepts deriving from both Marxist-Leninist and “bourgeois” sociology. In the analysis, I will first compare the social trajectories of two of my interview-partners as paradigmatic of two different sociological habitus depending on their different academic/political socialization, networks, and positions in the field. As a second step, I will present a sketch of the sociological field drawn from 63 curricula of sociologists active in East Berlin in an attempt to pinpoint, on a larger scale, the homologies between the social and symbolic spaces of the field. Thus, the underlying idea is to examine the intersection of the “quasi-structural properties” of the field with its “phenomenological aspects” concerning the “feel for the game.” While the two understandings of field are interdependent, it is in the second one that the physical space as a localized social space played a crucial role in defining the material, social, and cultural constraints and opportunities actors faced which, in turn, influenced their practices and choices.
A disenchanted world: Max Weber on magic and modernity
Authors: Marotta Mario
Published: March 2023

Despite its great popularity in both the scientific and non-scientific fields, Max Weber’s concept of “disenchantment” remains mostly obscure and in recent years it has become the center of an interdisciplinary debate on modernity involving both Weberian specialists and non-specialists. The aim of the article is to return to Weber’s text and analyze Weber’s use of the term and the meaning of what he calls the “disenchantment of the world.” To do so I follow Taylor’s and Schluchter’s insight and investigate how Weber would picture an initial condition of enchantment. However, while these interpreters did not explore the Weberian perspective on magic, I instead show that not only Weber had a precise and original conception of magic as the primitive attitude toward the world, but also that this conception may clarify the meaning and dynamics of the process of disenchantment in both the spheres of religion and of science.
Biocompatibility and Biofunctionality of a Gelatin Impregnated Polyester Arterial Prosthesis
Authors: Chakfé Nabil , Marois Yves , Guidoin Robert , Deng Xiaoyan , Marois Michel , Roy Raynald , King Martin , Douville Yvan
Published: March 2023

The gelatin-impregnated vascular graft Gelseal® and its parent Triaxial® graft were evaluated in terms of biocompatibility in rats and in vivo biofunctionality as a thoraco-abdominal bypass in dogs. The biocompatibility study was performed by implantation of small segments of graft in the peritoneal cavity of rats for scheduled periods of upto 4 weeks. Peripheral total T cells (CD3), T helper cells (CD4) and T suppressor cells (CD8) and activated T cells expressing IL-2 receptors were quantified by cytofluorometry. Enzymatic and histopathological analyses of the tissue at the implant site were also performed. In the rat, the Gelseal® graft induced a significant reduction of CD4 cells at 3 days, 1 and 4 weeks post-implantation when compared to the control group (wounded rats without prosthesis). On the other hand, the Triaxial® graft showed similar results to the control group except for a significant reduction of CD4 cells after 1 week. The percentage of CD3, CD8 and activated T cells expressing IL-2 receptors were similar to the control group. There was no statistical difference in acid phosphatase activity in the tissue surrounding the Gelseal® and the Triaxial® grafts. Histological studies of the impregnated graft have revealed an inflammatory reaction with polymorphonuclear cells which lasted slightly longer than the 2 weeks observed for the non-impregnated polyester control. Thereafter, the inflammatory response of both grafts became chronic and moderate.

The investigation of in vivo biofunctionality was carried out by implanting the grafts as a thoraco-abdominal bypass in dogs for prescheduled periods of up to 6 months. The grafts were investigated for patency, morphology, healing sequerice, fibrin and platelet uptake and prostaglandin secretion. The healing characteristics of the Gelseal® graft were similar to the preclotted control. All grafts remained patent, and the small differences in platelet and fibrin uptake on the luminal surface between the impregnated and non-impregnated grafts were not statistically significant. The two healing sequences were also similar with the development of a collagenous internal capsule at 2 weeks post-implantation followed by the laying-down of endothelial-like cells at 1 month. The gelatin coating had completely eroded within the first month, at which time the PGI 2/ TXA 2 ratios determined on whole segments of grafts was higher than one.

The Gelseal® graft has shown good biocompatibility and excellent healing characteristics as a thoraco-abdominal bypass in dogs and compares favourably with its parent graft the Triaxial® polyester prosthesis.
Characterisation of Silver Filled Adhesives for Attachment of Microelectronic Chips to Substrates
Authors: Bjorneklett Are
Published: March 2023

Polymer based adhesives filled with silver particles are widely used in microelectronics for bonding semiconductor chips to substrates. This paper presents results from thermal conductivity and thermal resistance measurements in such adhesives as function of the volume fraction of silver and the thickness of the bond layer. This is an increasingly important issue because the power dissipation in typical semiconductor chips is increasing rapidly due to technological developments. The thermomechanical stress caused by different thermal expansions in the chip and the substrate was also measured. Thermomechanical stress may cause cracking of the chips and subsequent failure of the microelectronic device. Crack growth in the bond layer during temperature cycling was investigated by measuring the thermal resistance in the layer. The cracks are created because of the differences in thermal expansion which causes a cyclic mechanical boding of the adhesive during temperature cycling.
Interferometric Studies on Polymer Fibres. I. Application of Multiple-Beam Fizeau Method for the Characterisation of Homogeneous Polymer Fibres
Authors: Hamza A.A. , Fouda I.M. , Sokkar T.Z.N. , Shahain M.M. , Seisa E.A.
Published: March 2023

Multiple-beam Fizeau fringes with a modified method are described for the measurement of refractive indices and birefringence of fibres. This method is used to overcome difficulties in measuring refractive indices of immersion liquids as well as the correcting for dispersion and temperature. Two fibres are used for each measurement. The first fibre is of known mean refractive index and dispersion properties. The other fibre is of unknown values of refractive indices. A mathematical formula is derived for the modified method in case of the shape of multiple-beam interference Fizeau fringes crossing a homogeneous cylindrical fibre, as well as an equation to determine the refractive indices and birefringence for fibre having irregular cross-section. This method with microstrain device is applied to determine the optical properties of “Terylene” polyester fibre dynamically with different draw ratios. Also stretched polyethylene fibre is studied using the modified method. The calculated refractive indices using this method are compared with those obtained using the normal method. Microinterferograms are given for illustration.
Epoxy Resin Compositions Cured with Dianhydrides of Tetracarboxylic Acids
Authors: Rokicki Gabriel , Adamczyk Leszek
Published: March 2023

Curing of epoxy resin compositions with tetracarboxylic dianhydrides in the presence of BF 3 aromatic amines as initiators is presented. The presence of boron trifluoride amine complexes enables to crosslink the epoxy resin at room temperature. It was shown that the reactivity of the complex may be controlled by the nature of the amine. The influence of the initiator concentration and curing conditions on the mechanical and thermal properties of the epoxy resin is also presented. The epoxy resins cured at room temperature exhibit good mechanical properties and high thermal resistance. The deflection temperature of the composition was higher than 180°C and after postcuring heating the deflection temperature exceeded 220°C.
Blends and Composites Based on Polypropylene and a Thermotropic Liquid Crystalline Polymer
Authors: Heino Markku T. , Vainio Tommi P. , Seppälä Jukka V.
Published: March 2023

Blends of polypropylene (PP) and liquid crystalline polymer (LCP) processed without melting the LCP were compared with conventional melt processed blends. In a first stage, PP was blended with 20 wt.% of LCP in a twin-screw extruder with the take-up speed varied to achieve blends with different LCP fibre dimensions. In the second stage these blends were processed both below and above the T m of the LCP by extrusion and injection moulding.

At lower temperatures (180–200°C), where the material was processed without melting the LCP, a real composite structure was formed with solid LCP fibres in the PP matrix. When processed above the T m of the LCP (280°C) all the material was molten during processing and a composite-like blend morphology was created in-situ during cooling of the oriented melt phase. These blends exhibited a skin/core morphology, whereas the composites contained fibres throughout the sample. Due to this difference the impact strength of the composites was significantly higher than that of the blends. The blends exhibited higher modulus than the composites. Moreover, additional drawing can greatly improve the strength and stiffness of the blends. In composites the solid LCP fibres slightly increased the viscosity of PP, while in blends the molten LCP reduced the matrix viscosity and acted as a processing aid.
FRP Corrosion Resistance: The Role of the Glass Fibre Type
Authors: Santrach Drago , Matzeg Rick
Published: March 2023

The corrosion resistance studies of glass fibre reinforced plastics (RP) have primarily compared the resins and the surfacing veil materials using the ASTM C581 standard test method. As the corrosion barrier has been shown to delay and not stop the acid attack on the structural layers of the laminate, the more recent papers, by several authors, highlight the importance of the reinforcing fibres. In particular, the use of ECRGLAS® fibres is recommended in RP laminates subjected to the simultaneous stresses of mechanical loading and exposure to dilute material acids. A brief overview of the most pertinent literature related to the present work is given.

The experimental data on the resistance of RP laminates to corrosion attack in aqueous solutions of both sodium hydroxide and sulphuric acid is discussed. This work comprises a two level fraction factorial experiment design to study five factors: the glass fibre type (E vs. E-CR), the resin type (isophthalic vs. bisphenol A), the laminate construction (mat/mat/mat vs. mat/woven roving/mat), the exposure media type (sodium hydroxide vs. sulphuric acid) and the acid/base ion concentration (IN vs. 2N).

The laminates are compared using mechanical properties, and their retention, after exposure to the corrosive environments for up to 4 years.

Analysis of this study shows that E-CR glass offers improved performance compared to E glass in both environments. E-CR glass is significantly more resistant to sulphuric acid attack over long term exposure. In sodium hydroxide, E-CR glass performs better than E glass in the short term of up to 10 months. Neither glass type is able to resist sodium hydroxide attack in the long term. The resin type also plays a significant role in the corrosion resistance but mainly in the long run and primarily insodium hydroxide medium. The ion concentration and the laminate type are much less significant. The two glass types are also compared using C581 methodology. Again, E-CR outperforms E glass in the acidic environment and this effect increases with the increase in the exposure time.

ECRGLAS® is a registered trademark of Owens-Corning Fiberglas Corporation. Fiberglas Canada Inc. is a registered user.
Styrene Crosslinked Vinylesters II: Water Sorption, Water Diffusion and Cohesive Properties
Authors: Bellenger V. , Verdu J. , Ganem M. , Mortaigne B.
Published: March 2023

The sorption characteristics (water equilibrium concentration W m and coefficient of diffusion D) were determined gravimetrically for six styrene crosslinked vinylester networks at 30, 40 and 50°C, 95 % RH.

The equilibrium water concentration (0.5 -1.8% by weight) is independent of the temperature and appears to be closely related to the concentration of polar groups (especially hydroxyls) in the polymer. It is an increasing function of the solubility parameter. The water diffusivity is of the same order of magnitude as that of unsaturated polyesters but considerably higher than that of hydrophilic amine crosslinked epoxies. There is no apparent correlation between D and volumetric properties such as the packing density, crosslink density or local mobility determined from viscoelastic spectra. In contrast, the fact that D is a decreasing function of the hydrophilicity for all the systems under consideration (including unsaturated polyesters and epoxies) seems to indicate that water diffusion is kinetically controlled by the strength of polymer-water interactions.
A Review of 129Xe NMR as a Probe of Polymer Morphology
Authors: Walton Jeffrey H.
Published: March 2023

129 Xe NMR is a new tool for probing the morphology of polymers and polymer blends. Recent developments of the NMR of 129 Xe gas dissolved in polymers are reviewed. This technique yields information on polymer morphology via the NMR lineshape and the isotropic chemical shift and their temperature dependencies. Polymer glass transition temperatures are plainly evident. The miscibility of polymer blends is easily determined and thus phase diagrams may be mapped out. Of particular use is the potential ability to measure domain sizes in immiscible polymer blends by 2-D NMR techniques. Domain sizes from 0.1 micrometers to 25 micrometers should easily be measurable.
A Design Procedure for Elastomer-coated Rolls in Two-Roll Systems
Authors: Idelberger H. , Flade D. , Michael D. , Görke U.-J.
Published: March 2023

The preliminary calculation of the mechanical behaviour of two-roll systems and the influences on their performance derived from this are important for the efficient development and design of these kind of systems. This article describes the stages in a procedure which may be used to design the roll system taking into account the geometrical and physical non-linearities which occur and to determine the parameters which are important for the performance of this system, e.g. the nip width or the pressure distribution in the contact surface. The design procedure is explained using the example of a specific roll pairing. The numerical and analytical results are verified by experiments.
Experimental Verification on Simulating Shrinkage and Warpage of Thin Compression Moulded SMC Parts
Authors: Osswald Tim A. , Sun Esther M. , Tseng Shi-Chang
Published: March 2023

One of the important issues in designing plastic parts, especially those that are fibre reinforced, is to predict shrinkage and warpage of the moulded parts. Shrinkage and warpage result from material inhomogeneities caused by flow induced fibre orientation, curing, poor thermal mould lay-out, and processing conditions. Shrinkage and warpage are directly related to residual stresses which result from locally varying strain fields that occur during the curing or solidification stage of a manufacturing process. This paper presents research conducted in numerical simulation and experimental investigation of the shrinkage and warpage of compression moulded fibre reinforced composite parts. A coupled temperature and stress simulation program with a three-noded shell element formulation was developed to calculate the residual stress build-up during curing and solidification stages of a compression moulding process. The numerical model also included the spring forward effect present in curved parts. Correlation between experimentally measured and simulated shrinkage and warpage of the moulded composites is presented for various geometries and processing conditions.

The simulated results have shown excellent agreement with the experimental data. The results indicated that fibre orientation distributions which vary with different charge locations have a significant effect on the final warpage. Shrinkage and warpage can be substantially reduced by using lower shrinkage polyester matrix or by increasing the fibre content within the charge. Unsymmetric curing caused by uneven mould temperatures leads to a thermal moment which could increase or possibly even reduce warpage of a finished part. Preheating or increasing the fibre content of the charge could also help reduce the final warpage. The spring forward effect was found to be significant in large-curved parts.
Studies on the Synthesis of Polyarylates with Allylic Side Groups. Part 1. Polyarylates from 2,2-bis (3-allyl-4-hydroxyphenyl)propane and Isophthaloyl Chloride
Authors: Brzozowski Z.K. , Zadrozna I. , Lato E.
Published: March 2023

Conditions of synthesis of diallyl derivatives of bisphenol-A via a Claisen rearrangement reaction and the preparation of polyarylates from these derivatives via interfacial polycondensation with isophthaloyl chloride were established. The structure of polymers was confirmed by the methods of 1H-NMR, IR, and UV/Vis spectroscopy and elementary analysis. The results of intrinsic viscosity determinations and thermal analysis revealed the high molecular weight and considerable thermal resistance of these polyarylates.
The Long Term Mechanical Behaviour of Filled and Unfilled Injection Moulded Thermotropic Liquid Crystalline Polymers
Authors: Plummer Christopher J.G. , Kausch Hans-Henning , Wu Yujun , Gola Muzio
Published: March 2023

Injection mouldings of thermotropic liquid crystalline polymers (TLCPs) have complex, highly anisotropic layered structures, and correspondingly large spatial variations in orientation and mechanical properties. The room temperature axial mechanical properties of standard tensile test specimens moulded from TLCPs are remarkable (ten-fold and two-fold increases in modulus and strength respectively, compared with conventional resins). Nevertheless, in practice glassfibre or mineral fillers are recommended to overcome problems associated with the anisotropy of unfilled TLCP mouldings, such as warping. The resulting reduction of anisotropy and more uniform local properties are not found to compromise seriously the axial mechanical properties, and indeed may improve both the short and the long-term behaviour, depending on the moulding conditions. Short glass-fibre addition appears particularly beneficial for the creep and fatigue resistance.
Studies on Self-Crosslinking Blend System Based on Polychloroprene and Polyacrylamide: Cure Characteristics, Physical Properties and Degradation
Authors: Kole S. , Tripathy D.K. , De P.P.
Published: March 2023

Polychloroprene and polyacrylamide form a self-crosslinking blend during mixing and moulding in the temperature range 140 to 190°C and mis inter-crosslinking is revealed by a torque rise in the rheometric studies. The nature of the stress-strain curves of the blend indicates the generation of a bonded structure where one soft matrix is bonded with a rigid phase and the bonding fails after a critical loading. The results of hysteresis measurements are in agreement with a bonded structure. The SEM study shows that the majority of the polyacrylamide particles are covered with a layer of rubber matrix. It also shows the distribution of particles and the extent of breakdown of the particles in various blends. The SEM observations are also in line with interfacial bonding and help in understanding the physical properties of various blends based on the extent of inter-crosslinking reaction.

Thermogravimetric analysis of aqueous solutions, cast film, and dry powdered of polyacrylamide confirms the role of moisture in polyacrylamide degradation. It also confirms that although polychloroprene imparts some water resistance to the polyacrylamide component, it still remains degradable by water.
Preparation of New Polymeric Active Coatings for Vascular Applications, Based on Biocompatible Acrylic Systems with Anti-Inflammatory Components
Authors: Gallardo Alberto , Roman Julio San
Published: March 2023

Data on the preparation of hydrophilic polymeric systems based on copolymers of 2- hydroxyethyl methacrylate H, with new acrylic derivatives of 4-methoxyphenylacetic acid or Ibuprofen (drugs widely used as analgesic and non-steroidic anti-inflammatory agents) are presented. The copolymer systems prepared with 5–20% of the pharmacologically active acrylic derivative form hydrophilic films when a solution of the prescribed concentration is applied as a coating of biomaterials used for the preparation of vascular implants like knitted or woven meshes of Dacron or small-diameter vascular grafts of Goretex. After evaporation, thin films with good adhesion to the porous surface are obtrined, and the polymeric coating remains in standard flow conditions. The absorption of water after immersion of films in a buffered solution at pH = 7.2 was followed gravimetrically and the swelling behaviour at the equilibrium was analysed considering the average composition of the acrylic copolymer systems used in the present work.
Delamination Failure in Unidirectional Carbon Fibre/Epoxy under Mixed Mode Loading
Authors: Singh S. , Partridge I.K.
Published: March 2023

Delamination resistance of Fiberite's IM7/977-1 carbon fibre/epoxy composite was evaluated under Mode I, mixed Mode I/Mode II in the ratio of 4/3, and Mode II loadings. The need for Mode I pre-cracking of the UD composite beam prior to the actual fracture test was demonstrated. The fracture toughness data were found to fit a simple power law failure criterion and a physical meaning for the fitting parameter was suggested. Fractographic studies were carried out by SEM examination near the crack initiation areas of the fracture samples and illustrated the gradual change in the micromechanisms of failure as the loading mode changed from crack opening to forward shear.
Thermal, Structural, and Mechanical Properties of Strands of Blends of Liquid-Crystalline Copolyester and Copolyesteramide with Poly(ethylene terephthalate)
Authors: Kyotani Mutsumasa , Kaito Akira , Nakayama Kazuo
Published: March 2023

Rheological, thermal, structural, and mechanical properties of strands of two kinds of blends containing a liquid-crystalline copolyester (LCP-A) and a liquid-crystalline copolyesteramide (LCP-B) with poly(ethylene terephthalate) (PET), respectively, were investigated using differential scanning calorimetry, x-ray diffraction measurements, scanning electron microscopy, and tensile testing. The apparent melt viscosity of LCP-A/PET blends was slightly smaller than that of LCP-B/PET blends. Thermal behaviour of the two LCP/PET blends showed that both LCP-A and LCP-B are incompatible with PET. The cold crystallization temperature and the phase transition heat of the PET component became a little lower with increasing a draw ratio of the strands only for LCP-A/PET blends. The LCP-A component formed oriented fibrils more easily in the strands of blends below 50% LCP-A content even at low draw ratios, while the LCP-B one tended to form many spherical or elliptical structures. As a result, the strands of LCP-A/PET blends had better tensile properties than those of LCP-B/PET ones in this work.
Thermohydrolytic Ageing of the Polynadimide IP960
Authors: Hilaire B. , Verdu J.
Published: March 2023

This study deals with the thermal ageing of a polynadimide network of the IP960 type, with a secondary alcohol in the dianhydride bridge. An attempt has been made to provide a suitable representation of the network structure on the basis of the literature. Ageing in air at 300–360°C was then studied using FTIR, gravimetry, density measurements and flexural testing. The role of initially sorbed water was also investigated.
Effects of Structure and Microcracks on the Properties in Tension and Compression of Three-Dimensional Composites
Authors: Chou Shen , Chen Hong-En
Published: March 2023

Three dimensional carbon fibre/epoxy resin composites were prepared with either three-axis or five-axis three-dimensional carbon fibre fabrics (3D-3A & 3D-5A) in four woven gauges, and embedded with teflon® film in the fabric structures to simulate various types of microcrack. The mechanical properties of these 3-D composites were measured. The tensile properties of 3D-5A were 20% lower than those of 3D-3A, and the compressive properties of 3D-5A were 10% lower than those of 3D-3A. In addition, the 3-D composites had better resistance to fracture than 2-D composites. Micrographs of failed samples reveal that under compression, the fracture plane of a 3-D composite grows, not along the microcrack direction, but perpendicular to the loading direction and extends toward the free end. Whereas for 2-D composites, the fracture plane grows along the microcrack direction and extends obliquely toward the free end.
Shrinkage Control in Fibre Reinforced Polymers II: Epoxy Resins with Expanding Monomers
Authors: Piggott M.R. , Zhang X-D (David)
Published: March 2023

Experiments have been carried out with dinorbornene spiro ortho carbonate (DNSOC) to determine the extent to which this expanding monomer can be used to reduce the shrinkage stress in a moderately high Tg epoxy resin. Although the copolymers had good mechanical properties and past experience has shown that they can be used to make excellent fibre composites, the effect of the expanding monomer on shrinkage stress was small. Only about 7% of the monomer could normally be dissolved in the epoxy at 100°C, and this contributed only a very small shrinkage stress reduction. At the same time the Tg was reduced. The lack of useful effect is because high Tg polymers can normally only be produced by curing at high temperatures. During cure, most of the beneficial effect of the expansion disappears due to stress relaxation at the curing temperature. Hence, expanding monomers are not recommended for high performance composites for aerospace use.
Speciality Polymer Blends of Carboxylated Nitrile Rubber and Polyurethane Elastomers
Authors: Roy S.K. Singha , Das C.K.
Published: March 2023

Blends of polyurethane elastomers and carboxylated nitrile rubber, prepared by three different techniques in different blend ratios, have been studied. The properties of the blends were improved by blending with polyurethanes in a sulphur cured blend system. In the peroxide cure system the improvements occurred when the preblends were heated before incorporating curatives into it. Blend properties largely depend on the blend ratio and on the blending technique. IR spectra reveal that interchain crosslinking occurred between polyurethane and carboxylated nitrile rubber on heating, in the absence of curatives. The preheating of the blends before adding curatives improved the properties of the blends; the degradation process and weight loss were retarded. The extraction of the carboxylated nitrile rubber (XNBR) phase in the solvents was also restricted on preheating, due to interchain crosslinking.
Sorption/Desorption and Diffusion Anomalies in Santoprene-Alkane Systems
Authors: Aminabhavi Tejraj M. , Phayde Hemant T.S. , Ortego J. Dale
Published: March 2023

Kinetic curves for sorption/desorption cycles have been obtained by a gravimetric method for series of n-alkanes (C6 to C16), 2,2,4-trimethylpentane (TMP), cyclohexane and 1,2,3,4-tetra-hydronaphthalene (tetralin) into the miscible polymeric blend of ethylene-propylene random copolymer (60%) and isotactic polypropylene (40%) over the temperature interval of 25–70°C. Liquid diffusion coefficients have been calculated from mathematical relations derived from Fick's equation. A numerical method was used to describe the sorption and desorption processes. The kinetic curves obtained for these processes correlate well with the experimental results. The profiles of liquid concentration have been simulated for the Santoprene-alkane systems by solving Fick's diffusion equations and by Using numerical schemes. Activation parameters for diffusion and sorption were evaluated and these results are discussed in terms of molecular sizes and geometries of alkanes. Sorption and diffusion parameters exhibit dependence on size and shape of alkane molecules as well as temperature. The average values of diffusion coefficients have been analysed for concentration dependence. The diffusivity values ranged from a maximum of 2.93 x 10-6 cm2/s for heptane at 25° C to a minimum of 0.27 x 10-6 cm2/s for hexadecane. These values increase with increasing temperature. Activation energies for diffusion range from 6.4 to 18.8 kJ/mol, a value that is generally expected of rubbery polymer-organic solvent systems.
Opto-Thermal Properties of Fibres: 1. Effect of Annealing and Quenching Processes on the Optical Parameters of Courtelle Fibres
Authors: Fouda I.M. , Seisa E.A.
Published: March 2023

The effect of annealing and quenching temperatures, in the range (80–180°C), on various optical parameters has been studied for Courtelle (Courtaulds acrylic fibre) using a Pluta polarizing interference microscope. Relationships between the optical parameters at different temperatures are given for these fibres. The results obtained were utilized for calculations of the isotropic refractive indices and polarizabilities per unit volume, and relationships between these new parameters at different temperatures are given. Also, determinations of Cauchy's constants, dispersive power and the dielectric constant at infinity were carried out. The change in the refractive index profile of the annealed and quenched Courtelle fibres with temperature is given. Illustrations are given using graphs and microinterferograms.
Radiation Vulcanisation of Short-Carbon Fibre-Reinforced Styrene-Butadiene Rubber Composites
Authors: Abdel-Aziz M.M. , Youssef H.A. , Miligy A.A. El , Yoshii F. , Makuuchi K.
Published: March 2023

The effects of short-carbon fibres on the anisotropy swelling, mechanical and electrical properties of radiation vulcanized styrene-butadiene rubber (SBR) composites have been studied. The effect of radiation on the crosslinking density as well as the fracture mode of the composites have also been studied. It has been found that carbon fibre improves the reinforcement of SBR due to good adhesion between the fibre and the rubber matrix. However, increasing fibre loading leads to decrease the strength in spite of increasing the crosslinking density. Moreover, tensile fracture surfaces of the composites have been studied using scanning electron microscopy (SEM) in order to assess the failure criteria. SEM studies indicate that the fracture mode depends mainly on the adhesion between the fibre and the matrix.
Environmental Durability of F/A-18 Graphite/Epoxy Composite
Authors: Chester R.J. , Baker A.A.
Published: March 2023

An environmental durability trial is being conducted on F/A-18 graphite epoxy composites at five tropical test sites in Australia and Malaysia. Two types of specimen have been exposed in the external tropical environment for periods of up to 9 years and measurements have been made of moisture absorption levels, fatigue durability and residual strength. The maximum level of moisture absorption recorded has been 1.0 wt%. Sandwich beam specimens representative of an aircraft structure, containing different types of damage or simulated repairs, have withstood over 106 fatigue cycles at close to nominal design limit load in the tropical environment. This result indicates that F/A-18 composite structure should be very durable under long term tropical conditions.
A Review of Liquid Injection Techniques for the Manufacture of Aerospace Composite Structures
Authors: Abraham D. , McIlhagger R.
Published: March 2023

This paper reviews the current state of liquid injection moulding technology for the manufacture of aerospace composite components. The requirements of the process are based on the material specifications, which stipulate low void contents below 1%, high volume fractions of fibre and an optimised cure cycle. The liquid injection process must also be economically competitive with current aerospace composite production techniques. Most liquid injection techniques have been developed with consideration for automobile requirements which mainly use glass fibre preforms at relatively low fibre volume fractions when compared with aerospace requirements. High production rates for automobile components are also necessary, which in most cases leads to high void contents. Polyester resins are also commonly used whereas aerospace demands the physical properties of epoxy resins. This review discusses reported investigations and possible process variations which have the potential to deliver economically competitive, high performance and high quality composite material when compared with current aerospace processing.
The Effect of Annealing on the Degree of Orientation of Nylon 6 Fibres
Authors: Fouda I.M. , Seisa E.A.
Published: March 2023

The polarizing interference microscope was used to study the variation of the principal optical parameters of annealed nylon 6 Fibres at 160 ± 1°C. The resulting data were used to calculate optical orientation function, the angle of orientation and the specific refractivity of the isotropic dielectric over all the annealing time range. The change of refractive-index profile of the annealed nylon 6 fibres with time at a constant temperature of 160 ± 1°C are given. Also an empirical formula is given to inter-relate the structural parameters for the annealed nylon 6 fibres.
Cure of an Unsaturated Polyester Coating. Effect of Various Parameters
Authors: Salhi A. , Vergnaud J.M.
Published: March 2023

The cure of an unsaturated polyester coating was studied by using experiments and a model of the process. Experiments involved spraying the catalyst-resin mixture on a surface and following the hardness of the coating. The numerical model takes into account the heat transferred by convection at the surface of the coating and by conduction through the coating and the surface, as well as the heat generated by the cure reaction. The kinetics of heat evolved from the cure reaction was determined by calorimetry. The effect of various parameters, such as the temperature of the surrounding and the thickness of the coating was studied by considering the state of cure and the hardness.
Lignocellulosic Materials in Building Elements. Part II. Cement Light-Weight Building Bricks
Authors: Basta Altaf H. , Fadl Nairn A. , Gabra Usama I.
Published: March 2023

Wood processing and agricultural wastes (spruce wood, bagasse and cotton stalk) were used for the production of cemented lignocellulosic bricks. Pretreatment with 50% linseed oil, followed by hardening at 120°C was carried out to improve water repellency.

Several variables were investigated during the formation of the bricks, such as the mesh size of the lignocellulosic waste, the cement to wood ratio and the use of some additives, e.g. urea formaldehyde, aluminium oxide powder, emulsion acrylic (Nitobond AR), hemihydrate gypsum and polyvinyl alcohol. The results obtained indicate that bricks prepared by adding Nitobond AR to cement-wood mixtures have higher strength than those obtained using other additives. Also, bricks produced by blending treated wood waste with cement have better properties than those produced from blends of treated agricultural wastes (bagasse and barked cotton stalk) with cement. The field of application of the product was considered. A plant for the production of cemented lignocellulosic bricks was also designed.
Three’s (Not Necessarily) A Crowd: State-of-the-Art Review of the Strategic Triangle
Authors: Sobol Mor , Chang Yen-Jung
Published: March 2023

In the last four decades, the Strategic Triangle concept has established itself as an eclectic theoretical framework in the research domain of triangular analysis. As international politics has evolved, the literature on Strategic Triangle has followed suit. Specifically, it appears that scholars have succeeded in transcending beyond the ‘traditional’ regional setting and conceptualisation by testing existing theoretical assumptions, developing new models and offering new insights into the dynamics of triangular relationships. Against this background, this contribution primarily aims to provide a state-of-the-art, comprehensive overview of the scholarly literature on Strategic Triangles. This article also seeks to illustrate the existing room for further engagement and analysis of triangular relationships by offering concrete recommendations on how researchers could further develop the Strategic Triangle concept.
The Prevalence of Andropause and Its Relationship With Sexual Quality of Life Among Older Iranian Men
Authors: Mohammadi Mojtaba , Allahverdipour Hamid , Ghanbari Moghaddam Akram , Matlabi Hossein
Published: March 2023

Available evidence indicates insufficient knowledge about the status of andropause and sexual quality of life among Iranian older men. The study aimed to investigate the prevalence of andropause and its relationship with sexual quality among older adults. This descriptive-analytical study was conducted among 576 older people referred to urban health centers in Mashhad, Iran. The eligible samples were selected through the cluster sampling method. To collect data, the male andropause symptoms’ self-assessment questionnaire and the sexual quality of life-male were used. Forty-seven of the respondents ( n = 271) were diagnosed with a “moderate” level of andropause. A strong negative correlation was identified between the sexual quality of life and the severity of andropause ( r = −.366, p < .001). Sexual quality of life and andropause was also affected by age, marital status, health status, and exercise. Thirty-six percent of the changes in the quality of sexual life of older men were influenced by the independent variables (adjusted R2 = .36; R2 = .40; R = .63). The findings indicated that andropause has highly prevailed among the participants. There was a meaningful association between andropause and sexual quality of life among older men. Further studies are recommended to investigate sexual orientation qualitatively and to discover other factors influencing andropause among adult men.