Influence of waxes remelting used in investment casting on their thermal properties and linear shrinkage

This paper presents the results of thermal properties and linear shrinkage of jewelry waxes utilized in investment casting. Three types of jewelry waxes were cyclically processed (by heating, holding in a molten state and cooling)in the temperature range between 25 and 90 °C for about 7 hours. The samples were tested after 5th, 10th and 15thcycle. The remelting was designed to simulate the process of waxes reusability for production of patterns. Changes in thermal properties of waxes were determined using differential scanning calorimetry (DSC) and linear shrinkage values were specified. The conducted examinations allowed to establish the way of multiple utilization of waxes in producing precise models

Manufacturing and characterization of sustainable and recyclable wood-polypropylene biocomposites:Multiprocessing-properties-structure relationships

In this study, sustainable polymeric materials with a polypropylene matrix reinforced with wood waste were developed for structural applications. The new polymer biocomposites (WPCs) were evaluated for their mechanical and structural properties regarding their susceptibility to multiple processing. As thermo-mechanical degradation processes are associated with the repeated processing of plastics, which causes changes in the properties and structure of these materials. Therefore, to determine the extent to which the composites can be used under operating conditions, the composites were examined by DMA. As a result of the study observed some effects caused by the repeated effects of shear stress and temperature on the rheological and mechanical properties of polymer composites. The first of these is related to a decrease in viscosity of WPC composites subjected to the six times processing and changes in flow conditions during extrusion and injection moulding due to the degradation of the polypropylene matrix. As the viscosity of the composites decreased, a reduction in tensile strength and other mechanical properties of the polypropylene matrix was noted. On the other hand, the second effect observed leads to the conclusion that, as the composites' processing cycles increase, the WPC composite's mechanical properties increase due to an increase in the degree of homogenization of the individual components of the WPC composition. This study aims to describe the relationship between these two primary processes and to determine the relationship between the properties and the structure of the new WPCs.</p

The observation of vibrating pear-shapes in radon nuclei (vol 10, 2473, 2019)

An amendment to this paper has been published and can be accessed via a link at the top of the paper

Coulomb excitation of 222Rn

The nature of quadrupole and octupole collectivity in 222Rn was investigated by determining the electricquadrupole (E2) and octupole (E3) matrix elements using subbarrier, multistep Coulomb excitation. The radioactive 222Rn beam, accelerated to 4.23 MeV/u, was provided by the HIE-ISOLDE facility at CERN. Data were collected in the Miniball gamma -ray spectrometer following the bombardment of two targets, 120Sn and 60Ni. Transition E2 matrix elements within the ground-state and octupole bands were measured up to 10 h over bar and the results were consistent with a constant intrinsic electric-quadrupole moment, 518(11) e fm2. The values of the intrinsic electric-octupole moment for the 0+ -> 3- and 2+ -> 5- transitions were found to be respectively -210 e fm3 and 2300+300-500 e fm3 while a smaller value, 1200+500-900 e fm3, was found for the 2+ -> 1- transition. In addition, four excited non-yrast states were identified in this work via gamma -gamma coincidences.Peer reviewe

Collective narcissism: Political consequences of investment of self-worth into an ingroup’s image.

This article proposes a new theoretical framework for the reviewed state-of-the-art research on collective narcissism–the belief that the ingroup’s exceptionality is not sufficiently appreciated by others. Collective narcissism is interpreted as the investment of an undermined sense of self-esteem into the belief in the ingroup’s entitlement to privilege. Collective narcissism lies in the hard of populist rhetoric. The belief in ingroup’s exceptionality compensates for a lack of self-worth, leaving collective narcissists hyper-vigilant to signs of threat to the ingroup’s position. People endorsing the collective narcissistic belief are prone to biased perceptions of intergroup situations and to conspiratorial thinking. They retaliate to imagined provocations against the ingroup but sometimes overlook real threats. They are prejudiced and hostile. Deficits in emotional regulation, hostile attribution bias and vindictiveness lie behind the robust link between collective narcissism and intergroup hostility. Interventions that support the regulation of negative emotions, such as experiencing self-transcendent emotions, decrease the link between collective narcissism and intergroup hostility and offer further insights into the nature of collective narcissism

Quadrupole collectivity in Ca 42 from low-energy Coulomb excitation with AGATA

A Coulomb-excitation experiment to study electromagnetic properties of Ca42 was performed using a 170-MeV calcium beam from the TANDEM XPU facility at INFN Laboratori Nazionali di Legnaro. γ rays from excited states in Ca42 were measured with the AGATA spectrometer. The magnitudes and relative signs of ten E2 matrix elements coupling six low-lying states in Ca42, including the diagonal E2 matrix elements of 21+ and 22+ states, were determined using the least-squares code gosia. The obtained set of reduced E2 matrix elements was analyzed using the quadrupole sum rule method and yielded overall quadrupole deformation for 01,2+ and 21,2+ states, as well as triaxiality for 01,2+ states, establishing the coexistence of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca42. The experimental results were compared with the state-of-the-art large-scale shell-model and beyond-mean-field calculations, which reproduce well the general picture of shape coexistence in Ca42