Study of corrosion of aluminium alloys of nuclear purity in ordinary water, пart one

Effects of corrosion of aluminum alloys of nuclear purity in ordinary water of the spent fuel storage pool of the RA research reactor at VINČA Institute of Nuclear Sciences has been examined in the frame work of the International Atomic Energy Agency Coordinated Research Project "Corrosion of Research Reactor Aluminum-Clad Spent Fuel in Water" since 2002. The study presented in this paper comprises activities on determination and monitoring of chemical parameters and radio activity of water and sludge in the RA spent fuel storage pool and results of the initial study of corrosion effects obtained by visual examinations of surfaces of various coupons made of aluminum alloys of nuclear purity of the test racks exposed to the pool water for a period from six months to six years

Pulse-Shape discrimination with the Counting Test Facility

Pulse shape discrimination (PSD) is one of the most distinctive features of liquid scintillators. Since the introduction of the scintillation techniques in the field of particle detection, many studies have been carried out to characterize intrinsic properties of the most common liquid scintillator mixtures in this respect. Several application methods and algorithms able to achieve optimum discrimination performances have been developed. However, the vast majority of these studies have been performed on samples of small dimensions. The Counting Test Facility, prototype of the solar neutrino experiment Borexino, as a 4 ton spherical scintillation detector immersed in 1000 tons of shielding water, represents a unique opportunity to extend the small-sample PSD studies to a large-volume setup. Specifically, in this work we consider two different liquid scintillation mixtures employed in CTF, illustrating for both the PSD characterization results obtained either with the processing of the scintillation waveform through the optimum Gatti's method, or via a more conventional approach based on the charge content of the scintillation tail. The outcomes of this study, while interesting per se, are also of paramount importance in view of the expected Borexino detector performances, where PSD will be an essential tool in the framework of the background rejection strategy needed to achieve the required sensitivity to the solar neutrino signals.Comment: 39 pages, 17 figures, submitted to Nucl. Instr. Meth.

Medio-Frontal and Anterior Temporal abnormalities in children with attention deficit hyperactivity disorder (ADHD) during an acoustic antisaccade task as revealed by electro-cortical source reconstruction

<p>Abstract</p> <p>Background</p> <p>Attention Deficit Hyperactivity Disorder (ADHD) is one of the most prevalent disorders in children and adolescence. Impulsivity is one of three core symptoms and likely associated with inhibition difficulties. To date the neural correlate of the antisaccade task, a test of response inhibition, has not been studied in children with (or without) ADHD.</p> <p>Methods</p> <p>Antisaccade responses to visual and acoustic cues were examined in nine unmedicated boys with ADHD (mean age 122.44 ± 20.81 months) and 14 healthy control children (mean age 115.64 ± 22.87 months, three girls) while an electroencephalogram (EEG) was recorded. Brain activity before saccade onset was reconstructed using a 23-source-montage.</p> <p>Results</p> <p>When cues were acoustic, children with ADHD had a higher source activity than control children in Medio-Frontal Cortex (MFC) between -230 and -120 ms and in the left-hemispheric Temporal Anterior Cortex (TAC) between -112 and 0 ms before saccade onset, despite both groups performing similarly behaviourally (antisaccades errors and saccade latency). When visual cues were used EEG-activity preceding antisaccades did not differ between groups.</p> <p>Conclusion</p> <p>Children with ADHD exhibit altered functioning of the TAC and MFC during an antisaccade task elicited by acoustic cues. Children with ADHD need more source activation to reach the same behavioural level as control children.</p

V392 Persei: a γ-ray bright nova eruption from a known dwarf nova

V392 Persei is a known dwarf nova (DN) that underwent a classical nova eruption in 2018. Here we report ground-based optical, Swift UV and X-ray, and Fermi-LAT γ-ray observations following the eruption for almost three years. V392 Per is one of the fastest evolving novae yet observed, with a t2 decline time of 2 days. Early spectra present evidence for multiple and interacting mass ejections, with the associated shocks driving both the γ-ray and early optical luminosity. V392 Per entered Sun-constraint within days of eruption. Upon exit, the nova had evolved to the nebular phase, and we saw the tail of the super-soft X-ray phase. Subsequent optical emission captured the fading ejecta alongside a persistent narrow line emission spectrum from the accretion disk. Ongoing hard X-ray emission is characteristic of a standing accretion shock in an intermediate polar. Analysis of the optical data reveals an orbital period of 3.230 ± 0.003 days, but we see no evidence for a white dwarf (WD) spin period. The optical and X-ray data suggest a high mass WD, the pre-nova spectral energy distribution (SED) indicates an evolved donor, and the post-nova SED points to a high mass accretion rate. Following eruption, the system has remained in a nova-like high mass transfer state, rather than returning to the pre-nova DN low mass transfer configuration. We suggest that this high state is driven by irradiation of the donor by the nova eruption. In many ways, V392 Per shows similarity to the well-studied nova and DN GK Persei

Multiple Social Identities in Relation to Self-Esteem of Adolescents in Post-communist Albania, Bulgaria, the Czech Republic, Kosovo, and Romania

We test a model linking ethnic, familial, and religious identity to self-esteem among youth in Albania, Bulgaria, the Czech Republic, Kosovo, and Romania. All countries are post-communist nations in Europe, offering novel and underexplored settings to study identity. Participants were 880 adolescents (mean age, 15.93 years; SD, 1.40) with Albanian (n = 209), Bulgarian (n = 146), Czech (n = 306), Kosovan (n = 116), and Romanian (n = 103) background who filled in an Ethnic Identity Scale (Dimitrova et al., 2016), familial and religious identity scales adapted from the Utrecht Management of Identity Commitment Scales [U-MICS; Crocetti et al. Child and Youth Care Forum, 40, 7–23 (2011); Crocetti et al. Assessment, 1, 2–16 (2015)], and the Rosenberg’s Self-Esteem Scale [Rosenberg, Conceiving the self. Basic Books, New York (1979)]. A multigroup path model showed that ethnic, familial, and religious identities were significantly positively related to a single underlying construct of social identities. In all countries, youth with a stronger multiple identities reported higher self-esteem. These results are particularly valuable in addressing the scope of the proposed book by providing new knowledge on multiple social identities among under investigated samples from post-communist countries in Europe faced with dynamic societal changes. They also mirror increasing attention on multiple, inclusive, and intersectional identities as psychological assets for young generations

Understanding factors affecting well-being of marginalized populations in different cultural contexts: Ethnic and national identity of Roma minority youth in Europe

This chapter focuses on the intersection of the third, fourth and tenth Sustainable Development Goals (SDGs), referring together to key pillars for improving social inclusion of vulnerable disadvantaged youth. Based on both Positive Youth Development approach and mutual intercultural relations perspective, it sets out to investigate developmental assets (such as ethnic and national identities), optimal outcomes (self-esteem), and their relations among Roma youth in six European countries (Albania, Bulgaria, the Czech Republic, Italy, Kosovo, and Romania). Among these countries, the Czech Republic was initially recognized as the more favorable context facilitating potential alignment of Roma young people’s ecology with their identity resources, and therefore, promoting well-being. Results supported that in the Czech Republic youth experienced more stable integration of both Roma ethnic and national identities in terms of similar mean levels as well as positive associations of both identities with self-esteem. Results for the other countries were quite fragmented depending on the specific contextual conditions. The findings are discussed in light of the SDGs, the theoretical frameworks, research contexts and limitations, and implications

National collective identity in transitional societies: Salience and relations to life satisfaction for youth in South Africa, Albania, Bulgaria, the Czech Republic, Kosovo and Romania

In this study we investigated the salience of the construct of national collective identity and its associations with life satisfaction among adolescents living in transitional societies characterised by relevant change in the last decades . Participants were 1 066 adolescents (M = 15 .35 years, SD = 1 .35) from South Africa (n = 186) and five Central Eastern European countries, including Albania (n = 209), Bulgaria (n = 146), Czech Republic (n = 306), Kosovo (n = 116), and Romania (n = 103) . They completed a questionnaire including national identity and life satisfaction scales . Data were analysed using confirmatory factor analysis and multi-group structural equation modeling . Results showed that national identity of adolescents in transitional societies is multidimensional and pertains to different salient dimensions (i .e ., self-categorisation, evaluation, importance, attachment, and behavioural involvement) . Importantly, the findings provided evidence to suggest that higher levels of national collective identity are associated with increased levels of life satisfaction

Study of corrosion of aluminum alloys of nuclear purity in ordinary water: Part two

Since 2002, the effects of corrosion on aluminum alloys of nuclear purity in ordinary water of the spent fuel storage pool of the RA re search reactor at VINČA Institute of Nuclear Sciences have been examined in the frame work of the International Atomic Energy Agency Coordinated Research Project "Corrosion of Research Reactor Aluminum Clad Spent Fuel in Water". Coupons were ex posed to the pool water for a period of six months to six years. The second part of this study comprises extensive results obtained by detailed visual and microscopic examinations of the surfaces of the coupons and represents an integral part of the first report on the topic, previously presented in this journal