An increase in the number of PhD candidates in the last decades has changed the landscape of employment and the nature of what it means to be a PhD holder. Embarking on a career in academia is a challenging endeavour for early‐career researchers while they are confronted with a limited number of job opportunities in academia. Taking into account that knowledge based societies need highly skilled professionals beyond the academic environment, it is important to understand what is the role and value of a PhD for the labour market; and what the current labour market perspectives are for PhD holders. To answer these questions, the authors analysed the available data on PhD holders' employment and conducted semi‐structured interviews with European experts on doctoral education and career development. The data and expert interviews point to different contexts across European countries. The numbers of researchers and PhDs employed in sectors outside higher education varies to a great extent—in business enterprises, government, and private non‐profit sectors. The article maps out different factors which need to be considered when assessing the labour market perspectives of PhD holders, such as the geographic area or country and its economic development, the sector of employment, type of work and the field of research.
3D printing technology enables the production of functional components in small quantities which can be used as end-use parts. The mechanical properties of the final product define its quality and determine its success or failure in a given application. One at the various additive manufacturing technologies - Fused Deposition Modelling is very often used due to its relatively low cost and the availability of 3D printers and thermoplastic materials. During the process, there are many factors that can affect the mechanical properties of the final product. The temperature of the extrusion nozzle and the layer thickness are two of the basic process parameters. The objective of this work is to investigate the effect of these two processing parameters on the final mechanical properties of the 3D printed samples from acrylonitrile butadiene styrene. Mechanical testing includes the tensile and flexural strength, as well as tensile and flexural modulus.
The presented study deals with the effects of different processing parameters during injection moulding on the morphological structure through the thickness of the injection-moulded samples and, consequently, on their mechanical properties. In this work, tensile bars of an isotactic polypropylene were injected under different conditions such as the flow rate, the melt temperature and the mould temperature. The morphological structure of the samples was investigated with polarized light microscopy using thin cross-sections cut perpendicularly to the flow direction. The fountain flow in the mould cavity influenced the crystallization kinetics and the presence of three distinct crystalline zones was observed; namely, the highly oriented non-spherulitic skin, the shear-nucleated spherulitic intermediate layer and the inner core composed of spherulites with a low orientation. The results showed that the flow rate has the highest influence on the thickness of the oriented skin layer. The mechanical properties of the tensile samples demonstrated that the larger thickness of the two outer skins provides the higher tensile strength. The same effect was also confirmed with a microhardness test where the skin layer was harder than the inner spherulitic core. Keywords: skin-core structure, polypropylene, morphology, tensile strength, microhardness Predstavljena {tudija obravnava vpliv razli~nih procesnih parametrov pri vbrizgavanju na morfologijo strukture, zaradi debeline vbrizganih vzorcev, in posledi~no na njihove mehanske lastnosti. V tem delu so bile natezne palice izotakti~nega propilena vbrizgane pri razli~nih pogojih, kot so: hitrost te~enja, temperatura snovi in temperatura kokile. Morfolo{ka struktura vzorcev je bila preiskovana z mikroskopijo s polarizirano svetlobo, z uporabo tankih rezin, odrezanih pravokotno na smer toka. Lijakasto litje v votlini orodja je vplivalo na kinetiko kristalizacije in opa`ena je bila prisotnost treh razli~nih kristalnih podro~ij, in sicer: mo~no orientirana ne-sferulitna skorja, s stri`enjem nukleirana sferulitna vmesna plast in notranje jedro, sestavljeno iz sferulitov, brez orientacije. Rezultati so pokazali, da ima hitrost toka najve~ji vpliv na debelino skorje. Mehanske lastnosti nateznih preizku{ancev so pokazale, da ve~ja debelina dveh zunanjih skorij zagotavlja vi{jo natezno trdnost. Enak u~inek je bil potrjen tudi s preizkusom mikrotrdote, kjer je bila plast skorje bolj trda kot pri notranjem sferulitnem jedru.
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