Unconventional Stoichiometries of Na–O Compounds at High Pressures

It has been realized that the stoichiometries of compounds may change under high pressure, which is crucial in the discovery of novel materials. This work uses systematic structure exploration and first-principles calculations to consider the stability of different stoichiometries of Na–O compounds with respect to pressure and, thus, construct a high-pressure stability field and convex hull diagram. Four previously unknown stoichiometries (NaO5, NaO4, Na4O, and Na3O) are predicted to be thermodynamically stable. Four new phases (P2/m and Cmc21 NaO2 and Immm and C2/m NaO3) of known stoichiometries are also found. The O-rich stoichiometries show the remarkable features of all the O atoms existing as quasimolecular O2 units and being metallic. Calculations of the O–O bond lengths and Bader charges are used to explore the electronic properties and chemical bonding of the O-rich compounds. The Na-rich compounds stabilized at extreme pressures (P > 200 GPa) are electrides with strong interstitial electron localization. The C2/c phase of Na3O is found to be a zero-dimensional electride with an insulating character. The Cmca phase of Na4O is a one-dimensional metallic electride. These findings of new compounds with unusual chemistry might stimulate future experimental and theoretical investigations.

Watercourses of the Carpathian Biosphere Reserve as a habitat, reproduction and conservation of fish gene resources

Natural watercourses, their forage base, and ichthyofauna of the Carpathian Biosphere Reserve of the Transcarpathian region have been studied. Information on the species composition is given, the names and genus of some of the specimens are specified. The systematic structure is reflected, the functional role of roundworms and fish in the studied ecosystem, dominant and endangered species are determined. Their geographical distribution in different zones of watercourses, structural-comparative analysis with the species registered in the Transcarpathian region are carried out. It is established: a characteristic feature of the ichthyocenosis is the presence of a significant number of salmon and aboriginal species. The urgency of research – global warming, human activities change the hydroecosystem of the reserve, have a negative impact on aboriginal fish species, which are indicators of changes in hydrological regime and microclimate, lead to the settlement of their areas indigenous. In total, we recorded 42 species belonging to 7 series, 11 families, 33 genera in the studied water areas. Additionally, 12 undescribed were identified. The growth of the total number of species by 66.67 % was due to allochtons. Emphasis was placed on the need for further genetic research, which could be a source of additional information on fish biodiversity in the Carpathian Biosphere Reserve and in the Tisza River, a tributary of the Danube.

Affective Responses to Image Color Combinations

Responses to colored patterns were collected for a group of 60 naive participants. We explicitly aimed at affective responses, rather than aesthetic judgments, so this is not ‘color harmony’ proper. Patterns were mainly spatially highly structured compositions, the color palettes reminiscent of what is found in generic ‘colorist’ art. Color combinations systematically cover mono-, di-, and trichromatic chromatic chords, whereas there was always an additional achromatic component. This sets the research apart from the bulk of the mainstream literature on ‘color harmony.’ Various ways of analysis are compared. Clustering methods reveal that the responses are highly structured through the teal–orange (cool–warm) dimension. Clustering reveals a large group of mutually concordant participants and various small, idiosyncratic groups. When the data is coarse-grained, retaining only a limited red–blue–yellow palette, the group as a whole appears quite concordant. It is evident that responses are systematic, thus the notion of a universal affective response to color combinations gains some credibility. The precise affective responses are specific because constrained by the seven categories used in the experiment. Thus, the systematic structure is perhaps to be understood as the generic result. We discuss tangencies with various traits found with ‘colorist’ art styles.

The composition of phytoplankton as an indicator of the ecological state of the middle course of the Ural River and its tributaries

The article presents the results of the analysis of the systematic structure of the algae flora of the studied reservoirs of the Orenburg region. The revealed richness of flora includes 104 species and varieties belonging to 7 divisions, 12 classes, 23 orders, 32 families, 58 genera. The dominant divisions are Chlorophyta, Bacillariophyta and Cyanophyta. The total number of microalgae at the study points was dependent on the anthropogenic load on the reservoir. Certain indices of saprobity of reservoirs indicate the presence of dissolved organic matter in the bulk of the studied reservoirs and pollution of natural waters. Keywords: NATURAL RESERVOIRS, WATER QUALITY, ALGOFLORA, URAL RIVER, SAPROBITY

Additive manufacturing of ceramics: Present status and future perspectives

At present, fabrication of ceramics using AM-based techniques mainly suffers from two primary limitations, viz: (i) low density and (ii) poor mechanical properties of the finished components. It is worth mentioning that the present state of research in the avenue of AM-based ceramics is focussed mainly on fabricating ceramic and cermet components with enhanced densities and improved mechanical properties. However, to the best of the authors’ knowledge, not much is known about the microstructure evolution and its correlation with the mechanical properties of the finished parts. Addressing the aforementioned avenue is highly essential for understanding the utilisation of these components for structural applications. To this end, the present review article is aimed to address the future perspectives in this avenue has been provided with a special emphasis on the need to establish a systematic structure-property correlation in these materials.

Additive manufacturing of ceramics and cermets: present status and future perspectives

The present decade has witnessed a huge volume of research revolving around a number of Additive Manufacturing (AM) techniques, especially for the fabrication of different metallic materials. However, fabrication of ceramics and cermets using AM-based techniques mainly suffers from two primary limitations which are: (i) low density and (ii) poor mechanical properties of the final components. Although there has been a considerable volume of work on AM based techniques for manufacturing ceramic and cermet parts with enhanced densities and improved mechanical properties, however, there is limited understanding on the correlation of microstructure of AM-based ceramic and cermet components with the mechanical properties. The present article is aimed to review some of the most commonly used AM techniques for the fabrication of ceramics and cermets. This has been followed by a brief discussion on the microstructural developments during different AM-based techniques. In addition, an overview of the challenges and future perspectives, mainly associated with the necessity towards developing a systematic structure-property correlation in these materials has been provided based on three factors viz. the efficiency of different AM-based fabrication techniques (involved in ceramic and cermet research), an interdisciplinary research combining ceramic research with microstructural engineering and commercialisation of different AM techniques based on the authors’ viewpoints.

Ethical Challenges of Organ Transplantation

This collection features comprehensive overviews of the various ethical challenges in organ transplantation. International readings well-grounded in the latest developments in the life sciences are organized into systematic sections and engage with one another, offering complementary views. All core issues in the global ethical debate are covered: donating and procuring organs, allocating and receiving organs, as well as considering alternatives. Due to its systematic structure, the volume provides an excellent orientation for researchers, students, and practitioners alike to enable a deeper understanding of some of the most controversial issues in modern medicine.

631 Designing an Oral and Maxillofacial Trauma Assessment Proforma for Dental Core Trainees in Northern Ireland

Aim The dental core training (DCT) scheme is an optional postgraduate training pathway for dental graduates who have completed their foundation training and wish to undergo further specialist training. The majority of posts available in Northern Ireland (NI) are within oral and maxillofacial surgery (OMFS) units and include on-call commitment. Dental core trainees (DCTs) are expected to examine and assess OMFS trauma patients and often have limited experience of this prior to post commencement. This project outlines the development of an OMFS trauma assessment proforma designed for DCTs working in NI. Method An initial OMFS trauma proforma was designed alongside senior staff. This was introduced to 6 DCTs and 2 trust SHOs within a tertiary OMFS unit. 34 proformas were recorded within month 1, following which a feedback survey was completed by the 8 trainees. A revised proforma was redistributed and 33 recorded over month 2, followed by a repeat feedback survey. Results The revised proforma was found to be successful amongst trainees within the unit to act as an aid memoir and provide systematic structure to trauma examination. 100% of trainees recorded the revised proforma as useful. As a result, the proforma was introduced as part of the national induction programme for new DCTs commencing training posts in NI. Conclusions Progressing from general practice dentistry to the role of an OMFS DCT can be a challenging transition for many trainees. The proforma aids to guide junior clinicians in how to structure and record oral and maxillofacial trauma whilst ensuring thorough and comprehensive examination.

On subfamily structure of the Cupedidae (Coleoptera, Archostemata): data from paleontology and an approach to solving conflicting classifications

This paper demonstrates some of main differences between the systematic constructions based mostly on paleontological research and constructions involving the other approaches. Some reasons for these differences are discussed, together with an approach to solve contradictions between the conflicting hypotheses. The multiple (multidimensional) parallelism gives a possibility to solve many problems of phylogenetic interrelations due to reconstructions based on coincidence of patterns of changes (series of interconnected facts) traced in different aspects of evolutionary processes. This principle originates in the ideas by Jean Agassiz and Ernst Haeckel defined as the principle of triple parallelism. Other aspects of the evolution can be added to the morphology, embryology, and paleontology, initially included in this method. The molecular method is one of such aspects. It is shown that the potential resolution of the morphological and molecular approaches in some cases could be rather restricted, particularly applying ancient groups with main evolutionary transformations passed far in the past. The infraorder Cupediformia and suborder Archostemata in general are examples of such cases. It is advisable in the current research period that has followed the previous interpretation of the systematic structure of the family Cupedidae recognizing three subfamilies with not quite distinct hiatus between them (Cupedinae, Ommatinae and Triadocupedinae). Some recent morphological and molecular approaches proposed to divide the Cupedidae into two separate families on the basis of incomplete information accessible after study of only modern representatives, as most events in the family evolution occurred during the Palaeozoic and Mesozoic, and these events are scarcely possible to trace without considering fossils. As the principle of multiple parallelism cannot be currently used for archostematans to the full extent of its power, it is necessary to choose the paleontological method of phylogenetic reconstruction as crucial. This approach is preferable for groups that are well-documented through very diverse fossils, and for which only few of its remnants of the past diversity reached the modern epoque.