Conellae, enigmatic structures on cephalopod shells—shapes, distribution, and formation

Conellae, enigmatic cone-shaped structures which can be found on the surface of internal moulds of cephalopod shells (predominantly of ammonoids), are regarded herein as the product of remote (biologically induced) biomineralization formed in closed-off cavities during lifetime and might be primarily composed of vaterite, aragonite, or calcite. To date conellae have been interpreted in many different ways: (i) as organisms (gastropods, cirriped crustaceans, or disciniscid brachiopods), (ii) pre-diagenetic syn vivo features, i.e., biologically controlled or induced, the product of remote biomineralization, (iii) and diagenetic, i.e., abiogenic origin and post-mortem. The proposed processes of conellae formation seem insufficient to explain conellae related phenomena. Further, their assumed primary aragonitic or calcitic mineralogy are reviewed and based on new material critically assessed. The stratigraphic range of conellae extends from the Middle Ordovician and probably to modern Nautilus. Predominantly, conellae can be found on internal moulds along the keel, ribs or nodes, umbilical shoulder, at the transition between phragmocone and body chamber, and can be associated with repaired scars. However, conellae are also common on the smooth body chambers of large macroconchs of Jurassic ammonites. Conellae, which are located on ammonite body chambers, are filled with the same material found in the body chamber and can contain small burrows, sand grains, or coprolites. Some of these conellae are partially covered with nacreous shell material. Limonitic conellae were also found on the limonitic internal moulds of orthocone nautiloids. Moreover, disciniscid brachiopods found on inoceramid bivalves were re-identified herein as conellae. A short guide for conellae identification has been provided herein

A Carbon Molecular Sieve-based Catalyst with Encapsulated Ruthenium Nanoparticles for Bio-oil Stabilization and Upgrading

Pyrolysis oil derived from biomass (bio-oil) is regarded as a potential substitute for petroleum crude for producing environmentally friendly fuels of the future. However, pyrolysis oil upgrading still remains an issue due to its complex composition, low stability, high oxygen and water contents, and low hydrogen-to-carbon ratio. Although hydrogenation was proposed as a promising technology to improve properties of pyrolysis oil, attempts to synthesize a selective and active hydrogenation catalyst have so far been unsuccessful. A major challenge is in obtaining bio-oils with stable composition that can be processed further to fuels in biorefineries. This work proposes a novel design for bio-oil stabilization catalyst with molecular sieve properties. This material consists of ruthenium nanoparticles encapsulated in an ultramicroporous carbon framework much like "berries-in-a-muffin". The hypothesis is that the most reactive bio-oil molecules (aldehydes and ketones below 5 Å that cause oligomerization) will be able to enter the pores and be hydrogenated by the ruthenium catalyst to non-reactive molecules, while other bio-oil components will not be able to access the pores and participate in chemical reactions on active sites. The stabilized bio-oil would then be ready for further hydroprocessing to produce fuels. Multistep synthesis of a carbon molecular sieve containing ruthenium nanoparticles was successfully accomplished. Transmission electron microscopy revealed that metal nanoparticles are less than 3 nm in diameter and uniformly distributed within catalyst pellets. Carbon dioxide adsorption at 273 K coupled with nitrogen adsorption at 77 K indicated that carbon porous structure is made up of ultramicropores with the total pore volume of 0.18 cm3/g and surface area of 646 m2/g. 75% of the pore volume consists of pores less than 8 Å. Adsorption of probe molecules measured by means of a tapered element oscillating microbalance (TEOM) confirmed that the catalyst possesses molecular sieve properties acting as a 5Å-molecular sieve. Slit-like pores of the carbon framework are accessible to bio-oil model compounds with minimum dimensions of 3.4-4.1 Å, such as furfural, acetaldehyde, acetone, and anisole. Water molecules as well as molecules of cyclohexanone and tetrahydrofuran (minimum dimension of 5.3 Å) are unable to adsorb on catalyst pores effectively. Estimated polarizabilities of model compounds confirm that the observed adsorption behavior is explained solely by the molecular sieve effect and does not follow from differences in interaction of the probe molecules with the carbon support. The observed catalyst pore cutoff size of 5 Å is shown to correspond to an estimated molecular size distribution in corn cob-derived bio-oil, allowing desired molecular size selectivity. This work suggests potential applications of a developed molecular sieve-based catalytic system including selective hydrogenation of light aldehydes and ketones involved in bio-oil stability issue, and selective reforming of low molecular weight oxygenates in bio-oil yielding in situ hydrogen

Instruments and attachments for electronystagmography

A portable set of instruments and devices was developed which makes it possible to record spontaneous nystagmus with open and closed eyes. Rotational, caloric, position, and pressure nystagmus under any conditions may also be recorded

Publication Trajectories of Russian Cardiologists: Ways to Attain International Visibility

In this study we investigate the publication trajectories of medical researchers in Russia. For the analysis of publication trajectories we selected all researchers which were awarded PhD in cardiology in Russia in 2005. The goal of the study was to identify the patterns of internationalization of Russian medical research on the example of cardiology. One of the important issues raised in this work is the difference in career opportunities and paths between researchers starting in the center and the periphery of national science. Scientists starting their careers not in the center are not strongly discriminated in the chances of reaching the international level. However, if the scientists of the center can start publishing in the bottom national journals, and then go to the international level, for the regionals the way to the international level is through top national journals

Chapter L’ipermodello BIM per gli allestimenti museali: programmazione visuale delle librerie parametriche

The 43rd UID conference, held in Genova, takes up the theme of ‘Dialogues’ as practice and debate on many fundamental topics in our social life, especially in these complex and not yet resolved times. The city of Genova offers the opportunity to ponder on the value of comparison and on the possibilities for the community, naturally focused on the aspects that concern us, as professors, researchers, disseminators of knowledge, or on all the possibile meanings of the discipline of representation and its dialogue with ‘others’, which we have broadly catalogued in three macro areas: History, Semiotics, Science / Technology. Therefore, “dialogue” as a profitable exchange based on a common language, without which it is impossible to comprehend and understand one another; and the graphic sign that connotes the conference is the precise transcription of this concept: the title ‘translated’ into signs, derived from the visual alphabet designed for the visual identity of the UID since 2017. There are many topics which refer to three macro sessions: - Witnessing (signs and history) - Communicating (signs and semiotics) - Experimenting (signs and sciences) Thanks to the different points of view, an exceptional resource of our disciplinary area, we want to try to outline the prevailing theoretical-operational synergies, the collaborative lines of an instrumental nature, the recent updates of the repertoires of images that attest and nourish the relations among representation, history, semiotics, sciences

DEVELOPMENT OF A WEB SERVICE FOR FORMING A SEMANTIC KERNEL OF A WEBSITE BASED ON DATA MINING METHODS

A technique has been developed for the formation of the semantic core of a site for Internet resources with already generated or dynamically generated content. A mathematical model based on data mining methods is given. For analysis and further research, an information technology is developed – a web service. The main users of this web service will be SEO specialists, for whom it will become a convenient tool. This web service relies on data mining methods and statistics on the use of search queries obtained from the Google Search interface. Integration of the data allows to qualitatively select the necessary keywords and give a list of the most optimal, relating to the subject of the site. For research, the site of the Department of Computer Science of the Azov State Technical University was selected. During the experiment, a list of keywords and phrases was obtained. The words in the list are sorted in decreasing order of performance. The automated formation of the semantic core eliminated the subjectivity of the SEO specialist when selecting words and phrases, the time spent on its formation is ten times less than the manual semantic analysis. The result set included only those words and phrases that are often used in the content and are most significant. Using Google Search to adjust the list of words allows to match words with search queries and select those for which users are looking for information. The web service has a flexible mechanism for regulating (limiting) the number of keywords in the result set. The main advantage of using this service is that only those words and phrases fall into the semantic core, in response to which there is something to offer visitors on the site

MODELING OF RUNNING CUTTERS FOR SHAPING OF IMPROVED NONINVOLUTE TOOTH GEARS

The questions of tooling design for production of advanced gears are considered. Engineering is based on the special applied development of the mathematical theory of multiparametric mappings of space. In fulfilled engineering of gear cutting tools for shaping of noninvolute gears it is provided for exclusion of distorted profiling after tool regrinds. There are proposed calculation algorithms, which may be used in dataware of respective CAD/CAM systems of maintenance for tooling backup. Among developed tools there are assembled shaping cutters with prismatic and round cutters. Compensatory possibilities of proposed assembled shaping cutters are ensured by repositioning of shaped cutting edges after their regrindings: by linear displacement of prismatic shaped cutters and angular displacement of round ones respectively