Microstructural and thermal characterization of neolithic ceramics

The aim of this research was to characterize some Neolithic ceramic finds collected during an excavation carried out at Lugo di Grezzana (Verona, Italy). Pottery shards with different paste and tempers were analyzed to better understand the manufacturing and firing technologies used for their production. Another task of the study was to determine whether highly refined artefacts, found in the site and resembling figulina-type ceramics, were of local production or imported from other places in the north of Italy, where the production of this sort of product has already been unambiguously assessed. Several results emerged from this investigation, providing indications on the finds from this Neolithic settlement and, therefore, on the technological expertise achieved by the primitive community. Moreover, a comparative study carried out on refined ceramic products found in Lugo and genuine figulina items from other northern Italian sites suggests that no trading exchange and commercial routes existed among those primitive communities.     

Efficient catalyst-free tricomponent synthesis of new spiro[cyclohexane-1,4′-pyrazolo[3,4-e][1, 4]thiazepin]-7′(6′H)-ones

A series of spirocyclohexane-1,4′-pyrazolothiazepinones were synthesized by one-pot multicomponent cyclocondensation reactions between 5-amino-1-arylpyrazoles, cyclohexanone and mercaptoacetic acid with good yields and easy purification protocols. Some control experiments involving isolation of reaction intermediates were performed leading to the proposal of three alternative mechanistic pathways conducting to the named spiroheterocycles. All target molecules were fully characterized by IR, NMR, melting point and HRMS.     

Unravelling the enhanced reactivity of bulk CeO2 doped with gallium: A periodic DFT study

Doping CeO₂ with gallium leads to promising materials with application in hydrogen purification processes for fuel cells. The bulk ceria–gallia is investigated by ab initio calculations. The outstanding reactivity is explained by important relaxations induced by gallium in the ceria host, having a strong impact in the electronic structure. As a result, the mixed oxide is found to be more reducible than the pure oxides in agreement with experimental data. It is thus possible to correlate structure and reactivity of the doped system on the molecular level, representing a step forward to the rational design of materials with selected properties.     

Dibenzophenazine-Based TADF Emitters as Dual Electrochromic and Electroluminescence Materials

Previous work has reported the synthesis of donor–acceptor–donor molecules based on dibenzophenazine acceptor group, presenting thermally activated delayed fluorescent (TADF) properties and their application in the assembly of highly efficient electroluminescent devices. Herein, we focus on the characterisation of charge carrier species through UV-Vis-NIR spectroelectrochemical and potentiostatic EPR techniques, in addition to the investigation of electropolymerisation properties of some compounds depicted in this study. The promising electrochromic features of both small molecules and conjugated polymers led to the assembly and investigation of electrochromic devices, evidencing the materials’ versatility, applied in such different approaches as electrochromic windows and electroluminescent devices. Furthermore, the assembled OLEDs provided high efficiencies, with small roll-off, EQEs up to 20.5 % and luminance values up to 85 000 cd/m².     

Trends in researching the socioeconomic influences on mathematical achievement

We introduce the topic of socioeconomic influences on mathematical achievement through an overview of existing research reports and articles. International trends in the way the topic has emerged and become increasingly important in the international field of mathematics education research are outlined. From this review, there is a discussion about what appears to be neglected in previous work in this area and how the papers in this issue of ZDM provide information about some of these neglected areas. The main argument in this article is that socioeconomic influences on mathematical achievement should not be considered as a taken-for-granted fact that is accepted uncritically. Instead, it is suggested that the relationship between multiple socioeconomic influences and various understandings of mathematical achievement are historically contingent ways of understanding exclusions and inclusions in mathematics education practices. Research is not simply “evidencing” the facts of these relationships; research is also implicated in constructing the ways in which we think about these. Thus, mathematics education researchers could devise more nuanced approaches for understanding the social, political and historical constitution of these relationships.     

Microfluidic Setup for Simultaneous Separation and Electrochemical Determination of Hg2+ and Ag+ Ions in Water

Here is presented a setup made of a combination of an injection valve, a hand-made chromatographic microcolumn and an electrochemical detector for the simultaneous separation of Hg²⁺ and Ag⁺ ions in water. The microcolumns were packed with exchanger resin and used for the separation of Hg²⁺ and Ag⁺ ions, whereas a screen-printed carbon electrode (SPCE) was the amperometric detector. The performances of the SPCE towards ions were firstly studied in a FIA setup. The efficiency of ion separation was then evaluated. The reproducibility, stability, and the regeneration of the obtained microcolumns were also studied and discussed.