78 research outputs found
Investigation of the physical parameters of duplex stainless steel (DSS) surface integrity after turning
The article presents the influence of machining parameters on the microhardness of surface integrity (SI) after turning by means of a coated sintered carbide wedge with a coating with ceramic intermediate layer. The investigation comprised the influence of cutting speed on the SI microhardness in dry machining. The material under investigation was duplex stainless steel with two-phase ferritic-austenitic structure. The results obtained allow for conclusions concerning the exploitation features of processed machine parts
Evaluation of creep properties of steel P92 and its welded joint
This work is focused on testing and evaluation of creep properties of P92 base material (BM) and welded joints (WJ) as well. Up to date results of creep rupture test of P92 base metal and welds are presented in this article. Creep rupture strength (CRS) of WJ initially reaches values close to the BM, with longer times to fracture and especially at higher temperatures, creep strength of WJ decreases and the data is closer to the lower 40 % tolerance band
Influence of process parameters on castability at full mold casting
This paper examines the effect of the temperature of pouring the melt, the density of the model of foamed polystyrene and the casting with or without a vent on castability. The testing was carried out in accordance with the experiment plan 23 i.e. during testing the value of the parameters of influence was changed at two levels: the melt pouring temperature of 640 °C and 600 °C, casting with or without a vent, and the density of foamed polystyrene model of 15 kg/m3 and 30 kg/m3
Repairing reforms and transforming professional practices
Although much has been written on changing professionalism, only limited attention has been given to the way in which professionals themselves give shape to new requirements in everyday professional practice. This article investigates the understudied reform of postgraduate medical education. The reform takes in a shift from apprenticeship-based training based on “learning-by-doing” and socialization to time-restricted, streamlined, competency-based training programs based on competency-based training and standardized performance assessment.
We deploy a mixed-methods study design of surgical training reform in the Netherlands (2011-2012) to examine how surgeons and surgical residents give shape to changes in education as well as in the wider hospital context, and how this impact on surgical training from a micro perspective. Informed by sociological literatures on medical education and changing professionalism, this article reveals how the reform is repaired in everyday training practice. This repair work, as a form of institutional work, goes beyond restoring disrupted institutional arrangements in order to restore the status quo as is often argued. Instead, it involves acting with the reform; seeking feasible solutions that preserve old values and related practices while adopting new requirements that reconfigure institutionalized arrangements in professional training practices
Investigation of selected surface integrity features of duplex stainless steel (DSS) after turning
The article presents surface roughness profiles and Abbott - Firestone curves with vertical and amplitude parameters of surface roughness after turning by means of a coated sintered carbide wedge with a coating with ceramic intermediate layer. The investigation comprised the influence of cutting speed on the selected features of surface integrity in dry machining. The material under investigation was duplex stainless steel with two-phase ferritic-austenitic structure. The tests have been performed under production conditions during machining of parts for electric motors and deep-well pumps. The obtained results allow to draw conclusions about the characteristics of surface properties of the machined parts
Different Vancomycin Immunoassays Contribute to the Variability in Vancomycin Trough Measurements in Neonates
Substantial interassay variability (up to 20%) has been described for vancomycin immunoassays in adults, but the impact of neonatal matrix is difficult to quantify because of blood volume constraints in neonates. However, we provide circumstantial evidence for a similar extent of variability. Using the same vancomycin dosing regimens and confirming similarity in clinical characteristics, vancomycin trough concentrations measured by PETINIA (2011-2012, n = 400) were 20% lower and the mean difference was 1.93 mg/L compared to COBAS (2012-2014, n = 352) measurements. The impact of vancomycin immunoassays in neonatal matrix was hereby suggested, supporting a switch to more advanced techniques (LC-MS/MS)
Influence of argon pollution on the weld surface morphology
In this paper the surfaces of butt welded joints in steel tubes were analyzed using an optical
3D measurement system to determine the morphology and topographic parameters. It
was established that pollution of the argon shield gas with oxygen did not influence the
width of the heat-affected zone. However, the composition of the shield gas significantly
influenced the surface asymmetry, Ssk, and its inclination Sku. The measurement of these
parameters enabled the selection of a higher quality surface, which was visually proven
by the reduction in discoloration of the surface of the weld joint. High quality surfaces
eliminate a potential habitat for bacteria and a future source of corrosion as well as providing
less resistance to fluid flow
Developmental and Tumor Angiogenesis Requires the Mitochondria-Shaping Protein Opa1
While endothelial cell (EC) function is influenced by mitochondrial metabolism, the role of mitochondrial dynamics in angiogenesis, the formation of new blood vessels from existing vasculature, is unknown. Here we show that the inner mitochondrial membrane mitochondrial fusion protein optic atrophy 1 (OPA1) is required for angiogenesis. In response to angiogenic stimuli, OPA1 levels rapidly increase to limit nuclear factor kappa-light-chain-enhancer of activated B cell (NFκB) signaling, ultimately allowing angiogenic genes expression and angiogenesis. Endothelial Opa1 is indeed required in an NFκB-dependent pathway essential for developmental and tumor angiogenesis, impacting tumor growth and metastatization. A first-in-class small molecule-specific OPA1 inhibitor confirms that EC Opa1 can be pharmacologically targeted to curtail tumor growth. Our data identify Opa1 as a crucial component of physiological and tumor angiogenesis
Neonatal Screening in Europe Revisited: An ISNS Perspective on the Current State and Developments Since 2010
Neonatal screening (NBS) was initiated in Europe during the 1960s with the screening for phenylketonuria. The panel of screened disorders (“conditions”) then gradually expanded, with a boost in the late 1990s with the introduction of tandem mass spectrometry (MS/MS), making it possible to screen for 40–50 conditions using a single blood spot. The most recent additions to screening programmes (screening for cystic fibrosis, severe combined immunodeficiency and spinal muscular atrophy) were assisted by or realised through the introduction of molecular technologies. For this survey, we collected data from 51 European countries. We report the developments between 2010 and 2020 and highlight the achievements reached with the progress made in this period. We also identify areas where further progress can be made, mainly by exchanging knowledge and learning from experiences in neighbouring countries. Between 2010 and 2020, most NBS programmes in geographical Europe matured considerably, both in terms of methodology (modernised) and with regard to the panel of conditions screened (expanded). These developments indicate that more collaboration in Europe through European organisations is gaining momentum. We can only accomplish the timely detection of newborn infants potentially suffering from one of the many rare diseases and take appropriate action by working together
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