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In this article, the Jeong et al.'s constitutive relation and the impulse-momentum theorem were coupled to characterize the compressive impact loading of EPP (Expanded polypropylene [EPP]) foams under varying strain rate conditions for each step. Simultaneous nonlinear NewtonRaphson method was applied to find the proper values for parameters in the constitutive relation along with quasistatic test data. Also, parameters which have physical meanings were expressed as functions of relative density. Moreover, coupling of the constitutive relation and the impulse-momentum theorem provided transient velocities of the striker successfully. Dynamic stress-strain curves from the analysis showed good agreement with data from instrumented impact tests and the potential to be applied to different material type polymeric foams. POLYM. ENG. SCI., 59:49-57, 2019., INTRODUCTION Crashworthiness and lightweight characteristics of automotive vehicle structures are crucial targets in coachwork nowadays because of rigorously renewed vehicle regulations and continuous demanding of energy savings as well as [...]

Fetal aqueductal stenosis (AS) is one of the most common causes of congenital hydrocephalus, which increases intracranial pressure due to partial or complete obstruction of cerebrospinal fluid (CSF) flow within the ventricular system. Approximately 2–4 infants per 10,000 births develop AS, which leads to progressive hydrocephalus, which enlarges the head often necessitating delivery by cesarean section. Most babies born with AS are severely neurologically impaired and experience a lifetime of disability. Therefore, a new device technology for venticuloamniotic shunting is urgently needed and has been studied to ameliorate or prevent fetal hydrocephalus development, which can provide a significant impact on patients and their family's quality of life and on the decrease of the healthcare dollars spent for the treatment. This study has successfully validated the design of shunt devices and demonstrated the mechanical performance and valve functions. A functional prototype shunt has been fabricated and subsequently used in multiple in vitro tests to demonstrate the performance of this newly developed ventriculoamniotic shunt. The shunt contains a main silicone-nitinol composite tube, a superelastic 90° angled dual dumbbell anchor, and an ePTFE valve encased by a stainless-steel cage. The anchor will change its diameter from 1.15 mm (collapsed state) to 2.75 mm (deployed state) showing up to 1.4-fold diameter change in human body temperature. Flow rates in shunts were quantified to demonstrate the valve function in low flow rates mimicking the fetal hydrocephalus condition showing "no backflow" for the valved shunt while there is up to 15 mL/h flow through the shunt with pressure difference of 20 Pa. In vivo ovine study results show the initial successful device delivery and flow drainage with sheep model. [ABSTRACT FROM AUTHOR]

Thin film nitinol produced by sputter deposition was used in the design of microstents intended to treat small vessel aneurysms. Thin film microstents were fabricated by 'hot-target' dc sputter deposition. Both stress-strain curves and differential scanning calorimetry curves were generated for the film used to fabricate stents. The films used for stents had an [A.sub.f] temperature of approximately 36[degrees]C allowing for body activated response from a microcatheter. The 10 [micro]m film was only slightly radio-opaque; thus, a Td marker was attached to the stents to guide fluoroscopic delivery. Thin film microstents were tested in a flow loop with and without nitinol support skeletons to give additional radial support. Stents could be compressed into and easily delivered with Keywords: stent, nitinol, thin film, aneurysm, transcatheter

This paper reviews the broad range of literature related to sustainable manufacturing published in theInternational Journal of Production Research(IJPR) over the past 50 years. It establishes research frontiers and contributions in the topic of sustainable manufacturing and the related impact to environmental sustainability. With the growing concern of the environmental impact of factors such as pollution and waste, the research areas of sustainable manufacturing and efficient resource utilisation have become significantly more important over the last decade. Whereas early papers focused on safety, workplace, design, and process improvements, research today focuses on ergonomics, intelligence, global manufacturing, environmental challenges, design for sustainability, product life cycle management, and green supply chain management. The paper also briefly surveys existing approaches and identifies commonly used analytical tools and methodologies. [ABSTRACT FROM PUBLISHER]