Using an ultrasonic technique under pressure, we investigated the dependence of elastic properties of propylene glycol, dipropylene glycol and tripropylene glycol on the concentration of hydrogen ...bonds and the mass of molecules. Studies were carried out up to 1.8 GPa in the glassy state and at isobaric heating during the glass-liquid transition. Propylene glycol in glassy state has the highest modules, and its interaction potential is more central than in di- and tripropylene glycol. Both the shear modulus G and the bulk modulus B are practically identical for glassy di- and tripropylene glycol.
Over the last 25 years, researchers, mostly paleontologists, have developed a system of rank-free, phylogenetically defined names for the primary clades of turtles. As these names are not considered ...established by the PhyloCode, the newly created nomenclatural system that governs the naming of clades, we take the opportunity to convert the vast majority of previously defined clade names for extinct and extant turtles into this new nomenclatural framework. Some previously defined names are converted with minor adjustments. We also define a number of new clade names to close apparent nomenclatural gaps. In total, we establish 113 clade names, of which 79 had already received phylogenetic definitions and 34 are new.
Marine reptile occurrences are rare in the Lower Jurassic Series outside of Europe. Here we describe diverse marine reptile faunas from the Lower Jurassic Series (Pliensbachian and Toarcian stages, ...including the Toarcian–Aalenian boundary interval) of Eastern Siberia. The taxonomic composition of Toarcian marine reptile assemblages of Siberia highlight their cosmopolitan nature, with the presence of taxa previously known nearly exclusively from coeval strata of Europe, such as ichthyosaurians Temnodontosaurus and Stenopterygius, microcleidid plesiosaurians (including the genus Microcleidus), rhomaleosaurids and basal pliosaurids. The palaeogeographic reconstruction places these faunas to the palaeopolar region, north of the 80th northern parallel and up to the palaeo north pole (upper value within the 95% confidence interval for some of the localities). The materials include remains of both mature and juvenile (or even infant, judging by their very small size and poor ossification) animals, indicating a possibility that these polar seas may serve as a breeding area. The diversity and abundance of plesiosaurians and ichthyosaurians, along with a lack of thalattosuchian remains (considering their wide distribution elsewhere at low latitudes), is an additional argument that plesiosaurians and neoichthyosaurians were able to live and reproduce in a polar environment. There is no certainty whether these animals lived in polar seas permanently, or whether they were taking seasonal migrations. However, given the polar night conditions at high latitudes, the latter seems more plausible, and both these scenarios are further indirect evidence that these groups likely had a high metabolism.
As glasses are nonergodic systems, their properties should depend not only on external macroparameters, such as P and T, but also on the time of observation and thermobaric history. In this work, ...comparative ultrasonic studies of two groups of molecular propylene carbonate glasses obtained by quenching from a liquid at pressures of 0.1 and 1 GPa have been performed. Although the difference in the densities of the different groups of glasses is small (3–5%), they have significantly different elastic properties: the difference in the respective bulk moduli is 10–20%, and the difference in the respective shear moduli is 35–40% (!). This is due to the “closure of nanopores” in the glass obtained at 1 GPa. The pressure and temperature derivatives of the elastic moduli for these groups of glasses are also noticeably different. The glass-transition temperatures of glasses from different groups differ by 3–4 K. The character of absorption of ultrasound waves near the glass-transition temperature also differs for different groups of glasses. The differences in the behaviors of these groups of glasses disappear gradually above the glass-transition temperature, in the region of a liquid phase. Glasses with a wide diversity of physical properties can be obtained using various paths on the (T,P) diagram.
This paper is devoted to the description of a new species of xinjiangchelyid turtle - Annemys variabilis sp. nov. - represented by thousands of isolated bones and several more complete specimens from ...the Middle Jurassic (Bathonian) Itat Formation of the Berezovsk coal mine, Krasnoyarsk Territory, western Siberia, Russia. The description is based on a sample of the best-preserved specimens. The new species differs from other Annemys spp. by a combination of cranial and shell characters. The basisphenoids (about 200 specimens) of A. variabilis demonstrate variation in 12 characters, some of which are reported in turtles for the first time. About 20 shell characters of A. variabilis are subject to ontogenetic or interindividual variation. Some of these characters are variable in other Annemys spp. and other xinjiangchelyids. The formula of the cervical vertebrae (2(3()4()5()6()7()8) or (2(3()4()5()6()7()8( with two opisthocoelous vertebrae (2 and 3), four or five amphicoelous vertebrae (4-7 or 4-8), and one procoelous vertebra is unique for this species among xinjiangchelyids, which were previously known to have only amphicoelous cervicals. Other characters of the non-shell postcranium correspond to those of other xinjiangchelyids. Of the three phylogenetic analyses performed in this study, Analysis 1 does not support the monophyly of either Xinjiangchelyidae or Annemys, Analysis 2 shows paraphyly of Xinjiangchelyidae and monophyly of the Annemys clade (A. latiens, A. levensis, A. variabilis and A. wusu), and Analysis 3 supports monophyly of the Annemys clade with A. latiens, A. levensis and A. variabilis, only in the majority rule consensus tree. The diversity of the turtle assemblage of the Itat Formation is re-assessed as containing 2-3 taxa (A. variabilis =Testudines indet. 2, Testudines indet. 1 and 3), which is in agreement with similar diversities seen in some other Middle Jurassic Asian turtle assemblages. The known record of Annemys spp. is restricted to the northern part of Asia.
https://zoobank.org/urn:lsid:zoobank.org:pub:E836F02F-21DD-4A36-ACBB-4170A6CD46AD
We study the design of different majority voters based on a commercial 65 nm CMOS technology, propose the test system and discuss the experimental results of heavy ion irradiation campaign and the ...proposed relative efficiency criterion for choosing the voter for a given TMR strategy.
Currently, the demand for surface treatment methods like plasma electrolytic polishing (PeP)-a special case of electrochemical machining-is increasing. This paper provides a literature review on the ...fundamental mechanisms of the plasma electrolytic polishing process and discusses simulated and experimental results. The simulation shows and describes a modelling approach of the polishing effect during the PeP process. Based on the simulation results, it can be assumed that PeP can be simulated as an electrochemical machining process and that the simulation can be used for roughness and processing time predictions. The simulation results exhibit correlations with the experimentally-achieved approximation for roughness decrease. The experimental part demonstrates the results of the PeP processing for different times. The results for different types of roughness show that roughness decreases exponentially. Additionally, a current efficiency calculation was made. Based on the experimental results, it can be assumed that PeP is a special electrochemical machining process with low passivation.
Although fossils of Trionychidae are found as far back as the Early Cretaceous, their evolutionary history, including the origin of the crown clade, is poorly understood. Here, we use a microCT scan ...of the skull of 'Trionyx' kyrgyzensis from the late Early Cretaceous (Albian) of Kyrgyzstan as the basis for a thorough redescription of the cranial morphology of this species. New information includes the pattern of cranial circulation, which is comparable to all extant trionychids. A unique combination of cranial and postcranial characters of 'Trionyx' kyrgyzensis allows us to establish for it a new genus Petrochelys gen. nov. The data regarding Petrochelys kyrgyzensis are incorporated into a phylogenetic analysis. When Petrochelys kyrgyzensis is analysed without including additional, extinct taxa, it is placed in a highly derived position within the extant Nilssonia. However, the addition of five Cretaceous-Palaeogene taxa breaks up hypothesized long branches and results in more basal positions for Petrochelys kyrgyzensis within recovered trees. All results support the hypothesis that Petrochelys kyrgyzensis is a crown trionychid and a member of Trionychinae. Our findings highlight the importance of including multiple extinct taxa in phylogenetic analyses prior to using any of those taxa as calibration points in divergence dating estimates.
http://zoobank.org/urn:lsid:zoobank.org:pub:592B98BF-87DF-48A8-8AA2-543AAD21FC95
PDF
