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Polylactide (PLA) is one of the most commonly used biomaterials nowadays, with many recognized benefits, particularly in the packaging and single-use products industries. However, little research has been conducted on its stretching behavior. This work investigates the optimal conditions of biaxial stretching of injection-molded PLA samples produced under different processing conditions (pressure, drying, and pre-processing by extrusion, to simulate a recycling step). The injection-molded samples were characterized to determine their mechanical, thermal and thermo-mechanical behavior, water absorption, thermal behavior, and crystallization kinetics. The extruded samples showed reduced thermal stability, lower viscosity, decreased mechanical properties, and higher crystallization rates due to thermal degradation. However, the stretched samples provided similar properties regardless of the materials pre-processing. Regarding the assessment of the biaxial stretching process, processing at lower temperatures provides the films with a higher yield and breaking strength, while the time and strain rates have little influence on such properties. It was then determined that 82 °C is the optimal temperature for stretching the PLA samples. An increase in the stretch ratio provided a higher elastic modulus and higher values of opacity due to an increased crystallinity induced by stress during the process. Films as thin as 50 μm can be obtained by biaxially stretching injection-molded preforms, producing a deformation over 150% and acquiring good mechanical properties: about 90 MPa for the yield and a breaking strength and elastic modulus of 4000 MPa.

The measurement of the fracture toughness of fiber reinforced composites at high rates of loading is still, despite years of research, not well established. This can be related to challenges in applying appropriate high rate loading on the specimen, accurately measuring the load, and in-situ determination of the crack length. In this work these challenges are addressed by using a direct wedge-on-specimen type loading of a double cantilever beam (DCB) specimen, high resolution optical deformation tracking, and a beam theory based analysis of the specimen deflection and crack length. This approach results in symmetric mode I opening of the crack and a robust analytical determination of the fracture toughness without the need to measure the external forces acting on the specimen nor to visually estimate the crack length. Tests carried out on carbon fiber reinforced epoxy composite at quasi-static and high rates (relative velocity up to 15 m/s) show the validity of the approach.

Plastics are used in various applications because of affordability and versatility, had a global annual production of 350 million tonnes (Mt) in 2015. However, the development of circular economy approaches has not accelerated resulting in the disposal of 4900 Mt (60%) of plastic waste from 1950-2015. This shows that there is a need for creative approaches to improve public awareness and increase the recycling of plastics. One such approach is production of showcase objects (e.g. outdoor furniture, storage boxes) from low-value, difficult-to-recycle waste plastic. The development of new products should be assessed for environmental impacts using life cycle analysis (LCA), consequently, this study aims to conduct a LCA of the showcase objects, identify hotspots in energy consumption during the production process, and make recommendations for improving the environmental feasibility of the process. The functional unit was defined as 1 quantity of showcase object. The system boundary includes raw material preparation with recycled and virgin plastics mix, production of showcase objects using rotational moulding and the associated energy requirements. The business-as-usual scenario includes raw material preparation containing 100% virgin plastics and similar production stages. The results will provide evidence of the environmental advantages of using recycled plastics for producing showcase objects which could include: (1) saving fossil resources by using recycled plastics instead of 100% virgin plastics, and (2) providing end markets for difficult-to-recycle plastics, thus extending the life of used plastics and preventing pressure on landfills. This research is part of PRIF project-ACCEPT Transitions (Queen's University Belfast).

Supplemental material, sj-docx-1-jtr-10.1177_00472875211037748 for The Rich Kids of Instagram: Luxury Travel, Transport Modes, and Desire by Scott Cohen, Hongbo Liu, Paul Hanna, Debbie Hopkins, James Higham and Stefan Gössling in Journal of Travel Research

This poster shares the progress related to an evaluation of computer science degree professional body accreditation, framed through an ongoing national review in the United Kingdom (UK). While this review substantially focuses on the UK, other countries, including South Africa and Ireland, have adopted a similar accreditation regime; furthermore, this work is evaluated in the context of the Washington Accord review, taking into account the memorandum's impetus for increased consistency in the UK. In parallel with this international review, the UK's Engineering Council is seeking to enhance and modernise the processes and procedures for degree accreditation (which includes the award of the protected professional title "Chartered Engineer") and the introduction of the new set of accreditation expectations on approved institutions. The review includes consideration of the value of accreditation to universities, students and employers. It was initiated in 2016 following two major national reviews looking at computer science and wider STEM degree accreditation. The intent is to better understand the value of professional body accreditation in computer science, as well as how to co-create improved outcomes for all accreditation stakeholders.

The present study deals with uncertainties in the material response of long fiber reinfoced thermoplastics (LFT). In an experimental study, the mechanical response of the material is investigated in direction longitudinal and perpendicular to the fiber preference orientation. Using an optical grey-scale correlation system, local strain measurements on the surface of regular tensile specimens are performed. From the results, local stress-strain curves and material parameters are derived. The results reveal a distinct local variability of the mechanical response of the material due to the variability in the local fiber orientation and fiber density. Based on the experimental observations, a probabilistic elasticity model for LFT materials is proposed. This model allows a numerically efficient virtual prediction of the effect of microstructural disorder of LFT materials on the macroscopic response of structures and structural components.

Transverse compression tests on a unidirectional composite were performed under quasi-static and high-rate loading conditions using servo-hydraulic machines as well as a direct impact Hopkinson bar. Aside the expected increase of compressive strength with increasing loading rate, a change of fracture plane orientation was observed. For quasi-static loading conditions, the fracture angle was 54.5°, for high rate-loading conditions this increased to 65°. Assuming a Mohr-Coulomb type of fracture for unidirectional composites under transverse compression loading, the change of fracture plane orientation indicates a rate dependency of the internal friction angle ϕ , which has not previously been reported for composite materials.

A perineal fluid-filled structure was discovered in a 6-year-old intact female Irish water spaniel suffering from intermittent constipation. Diagnostic tests revealed the structure was immediately caudal to the vagina and compatible with a cyst. Surgical excision was required for resolution of clinical signs. Histology confirmed the structure was a cyst. The exact origin is unknown; however, the variety of lining epithelia, including sections with mucin production, and a well-differentiated smooth muscle layer, were most consistent with development from the lower hindgut or urogenital sinus during embryonic growth. The histologic and anatomical similarities with human retrorectal cystic hamartomas were key in establishing the diagnosis of a perineal cystic hamartoma. Following removal, constipation resolved, and the cyst did not recur.

This paper presents a simplified design for a Split-Hopkinson Tension Bar (SHTB) which allows for pulse durations exceeding one millisecond. This testing apparatus is intended for material characterization requiring large amounts of elongation, necessitated either by large specimen dimensions, or large strains to failure. The design proposed here can be assembled from off the shelve components without the need for specialized machining tools. The simple mechanical design is accompanied by a comparatively low-cost, yet high-speed, means of independently measuring specimen strain using a fast line scan camera. The performance of this SHTB implementation is demonstrated by obtaining intermediate strain rate results for tensile yield strength of Polycarbonate in an unprecedented quality.

The joint of long fiber reinforced thermoplastic polymer–metal-hybrid structures is evaluated. For this the deformation and damage behavior of joints combining mechanical interlocking, force fit and direct adhesion is determined experimentally. Results show that each joining mechanism results in a specific deformation and damage behavior. Experimental results also show that the behavior of the combination is dependent on the interaction of the single joining mechanisms. With finite element simulations the deformation and damage behavior of joints with combined mechanism has been evaluated beyond the tested configurations. It is demonstrated how the developed simulation tool can be used to support the selection of the best joint configurations.

Gastrointestinal stromal tumors are uncommon when compared to all gastrointestinal neoplasms but are the most common mesenchymal tumors of the gastrointestinal tract. The largest gastrointestinal stromal tumor ever recorded in literature weighed approximately 6.1 kg and measured 39 cm × 27 cm × 14 cm. About two-thirds of GISTs are malignant. The tumor size, mitotic rate, cellularity, and nuclear pleomorphism are the most important parameters when considering prognosis and recurrence. The definitive treatment for these tumors is resection. In the year 2000, the first patient was treated with the tyrosine kinase inhibitor imatinib and since then, gastrointestinal stromal tumors with high-risk features have been treated successfully with tyrosine kinase inhibitors. We present the largest gastrointestinal stromal tumor recorded in medical literature measuring 42.0 cm × 31.0 cm × 23.0 cm in maximum dimensions and weighing in at approximately 18.5 kg in a 65-year-old African-American male who presented with increased abdominal distention. The mass was successfully excised, and the patient was treated with imatinib without local or distant recurrence 1.5 years postoperatively.

Testing procedures for two classes of adhesives with different characteristics for high rate testing using a Split Hopkinson Tension Bar are presented. The adhesive joints differ in their mechanical behavior, in the joint geometry, and in the interest of investigation. For thin layer adhesive joints, the adhesive thickness is usually below one millimeter. The strength is high and the strain to failure is comparatively small. In contrast, thick layer adhesive joints are characterized by adhesive thicknesses of several millimeters. The strength is comparatively small, however the strain to failure is quite large. For both classes of adhesives thick-walled butt joint specimens with different geometries were used for testing. The results show that for thin and thick layer adhesive joints Split Hopkinson Tension Bar experiments in the strain rate regime of 1000 s-1 can be performed successfully and results with high quality can be generated.

The current trend of increasing demand for air travel runs contrary to climate-related sustainability goals. The absence of behavioural and near-term technological solutions to aviation’s environmental impacts underscores the importance of policy levers as a means of curbing carbon emissions. Where past work has used qualitative methods to sketch public opinion of environmental aviation policies, this work uses data drawn from a survey of 2066 British adults to make a quantitative assessment of the acceptability of a broad range of aviation climate policy options. The findings indicate that there is significant support across demographic groups for a large number of policies, particularly those that place financial or regulatory burdens on industry rather than on individuals directly. Support for aviation policies strengthens with pro-environmental attitudes and is weaker among people who are aeromobile. Though self-interested considerations appeared to dominate policy option preferences, concern for fairness may also shape policy acceptability. Overall, this paper provides to policymakers a quantitative evidence base of what types of policies for addressing aviation climate emissions are most publically palatable.

The present study was conducted to determine the effect of shrimp protein concentrate on insulin resistance in a diet-induced obese mouse model. Male C57BL/6J mice fed a commercial high-fat diet (60 kcal% from fat) for 12 weeks were divided into three groups and then switched to a high-fat diet prepared in the lab. One group was used as the high-fat diet control and the other two were fed the high-fat diet with 35% or 70% of casein replaced by the same amount of protein from shrimp protein concentrate for 9 weeks. A group of age and sex matched C57BL/6J mice fed a low-fat diet (10% kcal from fat) all the time were used as the normal or low-fat diet control. Weekly body weight, daily food intake, weekly 4-hr fasting blood glucose, oral glucose tolerance and overnight fasting blood glucose, insulin and lipids were measured. It was observed that replacing dietary casein with shrimp protein significantly improved oral glucose tolerance and 4-hr fasting blood glucose levels while having no effect on the fasting blood glucose and insulin levels. There was a trend of increasing body weight and food intake, particularly at 35% replacement, which also increased blood total cholesterol levels while having no effect on triacylglycerol levels. There were mixed results of shrimp protein concentrate on metabolic phenotypes while a dramatic improvement in oral glucose tolerance was seen. Additional studies are required to verify the observed benefits and further look into the underlying mechanisms.

This report describes a case of severe rhabdomyolysis in a pregnant mare associated with histopathologic and biochemical features of both selenium deficiency and acquired multiple acyl-CoA dehydrogenase deficiency (MADD) due to seasonal pasture myopathy (SPM). This case highlights the importance of assessing plasma selenium levels in horses with clinical signs of pasture myopathy as this deficiency may be a contributing or exacerbating factor.

Bonded joints are nowadays seen as one of the preferred joining methods in aerospace applications. However, the difficulty in certifying bond strength and the relatively low energy absorption capability of the joint are barriers to widespread adoption. The use of a hybrid joint, that is, the combination of a mechanical and a bonded joint, allows for a fail-safe design and offers improved performance of the joint. The quasi-static properties of hybrid joints have been investigated by a number of researchers. In contrast, the high rate loading regime has been only sparsely investigated. In this work, hybrid joints are tested in quasi-static and high rate loading in order to analyze their loading rate dependence. The hybrid joint studied is a composite-aluminum double lap shear joint with Sikaforce 7752 adhesive and Hi-Lite-315 countersunk titanium bolts. In order to quantitatively analyze the high rate behavior of the hybrid joints and their respective sub-components, additional tests are carried out on simply bonded and simply bolted specimens. The high rate characterization was performed with a Split Hopkinson Tension Bar. The main challenges for these tests are the relatively large specimen size and complex specimen geometry needed to properly characterize the joint behavior, which both are in contradiction with the assumptions of the classical Split Hopkinson Bar-analysis. In this paper we describe an approach to solve these challenges based on an elastic wave analysis of the system.

The present study is concerned with a numerical scheme for the prediction of the uncertainty of the effective elastic properties of long fiber reinforced composites with thermoplastic matrix (LFT) produced by standard injection or press molding technologies based on the uncertainty of the microstructural geometry and topology. The scheme is based on a simple analysis of the single-fiber problem using the rules of mixture. The transition to the multi-fiber problem with different fiber orientations is made by the formulation of an ensemble average with defined probability distributions for the fiber angles. In the result, the standard deviations of the local fiber angles together with the local fiber content are treated as stochastic variables. The corresponding probability distributions for the effective elastic constants are determined in a numerically efficient manner by a discretization of the space of the random variables and the analysis of predefined cases within this space.

Split Hopkinson Tension Bar (SHTB) experiments can be used to test the material behavior with high strain rates in tension loading. The influence of the specimen mounting and the specimen design on the test results was investigated. Three mounting methods were tested. The best signal is achieve using a mounting based on form fit. The three tested specimen designs all lead to a valid fracture behavior, but result in a different local strain rate.

The aneurysmal bone cyst is a very infrequent, benign bone lesion in children which rarely can be found at the craniofacial skeleton. Here, we describe a case presenting in the mandible as an acute swelling of the cheek, which was initially misdiagnosed as osteomyelitis resulting in a delay to definitive surgical treatment. The cause of misleading diagnosis is often owing to the rapid growth of the lesion, sometimes associated with painful soft tissue swelling indicating an infectious origin or a malignant tumor. Magnetic resonance imaging revealed the classic characteristics of aneurysmal bone cyst with severe destruction of the mandible. Therefore, curative tumor embolization and complete surgical excision was successfully performed. The aneurysmal bone cyst is a curable condition by radical excision, although relapse may occur when only incomplete excision is obtained. Therefore, aneurysmal bone cyst should be considered early when children present with unusual, rapid-growing neoformations of the extremities or the facial region.

We evaluated the effects of immunostimulation in the development of postweaning multisystemic wasting syndrome (PMWS) in 930 pigs 53 to 54 d old in a grower/finisher barn with a history of PMWS. The pigs were allocated to 5 treatment groups: 4 groups received a single intramuscular injection of RespiSure-ONE (a commercial Mycoplasma hyopneumoniae vaccine; n = 197), Emulsigen (an oil-based adjuvant; n = 172), Alhydrogel (an aluminum-hydroxide-based adjuvant; n = 172), or physiologic saline (n = 218); 1 group received no treatment (n = 171). Pigs affected by PMWS were found in all the groups. Antigen to Porcine circovirus type 2 (PCV-2) was detected by immunohistochemical testing within lesions of mesenteric lymph node, spleen, Peyer's patch, and lung of affected pigs. There was no significant difference in the incidence of PMWS among the groups. The findings indicate that immunostimulation did not influence the expression of PMWS in this study. Thus, routine vaccination against swine diseases may not significantly contribute to the occurrence of PMWS under field conditions.

The pulmonary administration of drugs plays a crucial role in the management of various respiratory and systemic diseases. While the cellular properties of airway epithelial cells offer a great potential to deliver drugs into the lungs or the circulation, only little is known about the exact transport pathways. Recently, the high-affinity proton-coupled drug and peptide transporter PEPT2 was identified in the human respiratory tract. The expression of transporter mRNA and protein was localized to the airway epithelium and alveolar type II pneumocytes. In addition, transport studies revealed transporter-mediated uptake of substrates into epithelial cells indicating that the transporter is the molecular basis for the transport of peptides and peptidomimetic drugs in pulmonary epithelial cells. Since genotype analysis revealed no significant differences amongst different transporter genotypes concerning expression and function, the transporter displays an interesting novel target for pulmonary delivery of drugs.

The sensitivity of enzyme linked immunosorbent assay (ELISA) techniques for detection of cattle infected with Mycobacterium avium subspecies paratuberculosis (MAP) has been reported to be between 15 and 75%. Nearly all sensitivity evaluations of these ELISAs have utilized fecal-culture positive animals as the gold standard. This approach may result in inflated estimates of sensitivity, because animals in early stages of infection may not shed the bacteria consistently in their feces. The purpose of our study was to establish an estimate of the sensitivity of three ELISA tests for MAP, using sera from dairy cattle that were tissue-culture positive., American Association of Bovine Practitioners Proceedings of the Annual Conference, 2003