Two-dimensional Einstein manifolds in geometrothermodynamics

We present a class of thermodynamic systems with constant thermodynamic curvature which, within the context of geometric approaches of thermodynamics, can be interpreted as constant thermodynamic interaction among their components. In particular, for systems constrained by the vanishing of the Hessian curvature we write down the systems of partial differential equations. In such a case it is possible to find a subset of solutions lying on a circumference in an abstract space constructed from the first derivatives of the isothermal coordinates. We conjecture that solutions on the characteristic circumference are of physical relevance, separating them from those of pure mathematical interest. We present the case of a one-parameter family of fundamental relations that -- when lying in the circumference -- describe a polytropic fluid

An extensive K-bentonite as an indicator of a super-eruption in northern Iberia 477 My ago

Zircon and monazite ID-TIMS U-Pb dating of four Lower Ordovician altered ash-fall tuff beds (K-Bentonites) in NW Iberia provided coetaneous ages of 477.5±1, 477±1.3 Ma, 477.2±1.1 Ma and 477.3±1 Ma, with a pooled concordia age of 477.2±0.74 Ma. A conservative estimation of the volume and mass of the studied K-bentonite beds (using data from the Cantabrian Zone) returns a minimum volume for the preserved deposits of ca. 37.5 km3 (Volcanic Explosivity Index - VEI = 6, Colossal). When considering other putative equivalent beds in other parts of Iberia and neighbouring realms the volume of ejecta associated to this event would make it reach the Supervolcanic-Apocalyptic status (VEI=8, >1000 km3). Contrary to most cases of this kind of gargantuan eruption events, the studied magmatic event took place in relation to continental margin extension and thinning and not to plate convergence. We speculate that a geochronologically coincident large caldera event observed in the geological record of NW Iberia could be ground zero of this super-eruption

Обширные отложения K-бентонитов как индикатор супервзрыва в северной Иберии на уровне 477 миллионов лет назад

Zircon and monazite ID-TIMS U-Pb dating of four Lower Ordovician altered ash-fall tuff beds (K-Bentonites) in NW Iberia provided coetaneous ages of 477.5±1, 477±1.3 Ma, 477.2±1.1 Ma and 477.3±1 Ma, with a pooled concordia age of 477.2±0.74 Ma. A conservative estimation of the volume and mass of the studied K-bentonite beds (using data from the Cantabrian Zone) returns a minimum volume for the preserved deposits of ca. 37.5 km3 (Volcanic Explosivity Index - VEI = 6, Colossal). When considering other putative equivalent beds in other parts of Iberia and neighboring realms the volume of ejecta associated to this event would make it reach the Supervolcanic-Apocalyptic status (VEI=8, >1000 km3). Contrary to most cases of this kind of gargantuan eruption events, the studied magmatic event took place in relation to continental margin extension and thinning and not to plate convergence. We speculate that a geochronologically coincident large caldera event observed in the geological record of NW Iberia could be ground zero of this super-eruption

Thermodynamic modelling of metamorphic processes: state of the art in pseudosection approach

Understanding global-scale orogenic processes related to supercontinents, and their relationship to the secular evolution of the Earth's lithosphere, represent important challenges for Earth scientists today. The record of these processes is preserved in the microstructures, mineral assemblages and mineral compositions of lithospheric rocks exhumed to the Earth's surface. Given a well-characterized microstructural evolution, thermodynamic modelling is the key to quantifying changes in pressure and temperature, with the rate of these changes being provided by rock-forming and accessory mineral-based geochronology. Thus, metamorphic rocks provide Pressure–Temperature–time–deformation (P–T–t–d) data that help to parameterize orogenic processes

Thermodynamic modelling of metamorphic processes: state of the art in pseudosection approach

Understanding global-scale orogenic processes related to supercontinents, and their relationship to the secular evolution of the Earth’s lithosphere, represent important challenges for Earth scientists today. The record of these processes is preserved in the microstructures, mineral assemblages and mineral compositions of lithospheric rocks exhumed to the Earth’s surface. Given a well-characterized microstructural evolution, thermodynamic modelling is the key to quantifying changes in pressure and temperature, with the rate of these changes being provided by rock-forming and accessory mineral-based geochronology. Thus, metamorphic rocks provide Pressure– Temperature–time–deformation (P–T–t–d) data that help to parameterize orogenic processes

Characterization of viroplasm formation during the early stages of rotavirus infection

Abstract Background During rotavirus replication cycle, electron-dense cytoplasmic inclusions named viroplasms are formed, and two non-structural proteins, NSP2 and NSP5, have been shown to localize in these membrane-free structures. In these inclusions, replication of dsRNA and packaging of pre-virion particles occur. Despite the importance of viroplasms in the replication cycle of rotavirus, the information regarding their formation, and the possible sites of their nucleation during the early stages of infection is scarce. Here, we analyzed the formation of viroplasms after infection of MA104 cells with the rotavirus strain RRV, using different multiplicities of infection (MOI), and different times post-infection. The possibility that viroplasms formation is nucleated by the entering viral particles was investigated using fluorescently labeled purified rotavirus particles. Results The immunofluorescent detection of viroplasms, using antibodies specific to NSP2 showed that both the number and size of viroplasms increased during infection, and depend on the MOI used. Small-size viroplasms predominated independently of the MOI or time post-infection, although at MOI's of 2.5 and 10 the proportion of larger viroplasms increased. Purified RRV particles were successfully labeled with the Cy5 mono reactive dye, without decrease in virus infectivity, and the labeled viruses were clearly observed by confocal microscope. PAGE gel analysis showed that most viral proteins were labeled; including the intermediate capsid protein VP6. Only 2 out of 117 Cy5-labeled virus particles colocalized with newly formed viroplasms at 4 hours post-infection. Conclusions The results presented in this work suggest that during rotavirus infection the number and size of viroplasm increases in an MOI-dependent manner. The Cy5 in vitro labeled virus particles were not found to colocalize with newly formed viroplasms, suggesting that they are not involved in viroplasm nucleation.</p

Base Case Analysis of a HYSOL Power Plant

Concentrating solar power (CSP) plants are regarded as an alternative solution for electricity generation. The main drawback of this technology is related to the intermittent and seasonal nature of the solar irradiation. As a consequence, most CSP plants have a reduced capacity factor and difficulties to supply electricity on demand to the grid. The integration of energy back-up systems may contribute to increasing power generation capacity and stability. Several options are being developed at present which are based on the incorporation of Thermal Energy Storage (TES) and also the use of auxiliary fuels. HYSOL is a new concept in CSP technology that relies on the integration of a molten salt TES system operating in hybrid mode with a biogas turbine with a Heat Recovery System (HRS). This paper illustrates the methodology and first results obtained during the development of the static model, considering a Base Case of HYSOL configuration. The study of this Base Case allows evaluating the impact of HYSOL technology, providing preliminary plant information and defining the required tools to be used in the project

Insectos dañinos al patrimonio documental de archivos y bibliotecas: diagnóstico de dos casos en la República de Cuba y la República Argentina

The “bibliophagous” group of insects finds their food source in libraries and archives, mostly feeding on the cellulose in the books, the glue used to bind them and mold. A diagnosis was made of the impact caused by bibliophagous insects on the National Archives of the Republic of Cuba and on the Library at the La Plata Museum in Argentina. As a result, two types of damage caused by insects were detected: the ones that dig holes in galleries and pierce book spines, and those that scrape the surface or feed on book binding glue or mold. The first group includes beetles of the order Coleoptera, and beetles of the families Anobiidae and Dermestidae. The second group includes insects of the orders Blattaria (cockroaches), Isoptera (termites), Psocoptera (booklice) and Zygentoma (silverfish)

Fullerene based devices for molecular electronics

We have investigated the electronic properties of a C_60 molecule in between carbon nanotube leads. This problem has been tackled within a quantum chemical treatment utilizing a density functional theory-based LCAO approach combined with the Landauer formalism. Owing to low-dimensionality, electron transport is very sensitive to the strength and geometry of interfacial bonds. Molecular contact between interfacial atoms and electrodes gives rise to a complex conductance dependence on the electron energy exhibiting spectral features of both the molecule and electrodes. These are attributed to the electronic structure of the C_60 molecule and to the local density of states of the leads, respectively.Comment: 4 pages, 2 figures, to appear in Physica

Interpersonal Violence and Psychotic-Like Experiences: The Mediation of Ideas of Reference, Childhood Memories, and Dissociation

Previous studies have demonstrated the relationship between the accumulation of situations involving interpersonal violence (IV) and psychotic-like experiences. This study explored whether IV is related to aberrant salience (AS), using a sequential mediation model that included memories of relationship with parents (submission, devaluation, and threat; Early Life Experiences Scale (ELES)), ideas of reference (IR), and dissociative symptoms (absorption and depersonalization), and whether the patient/nonpatient condition moderated this effect. The sample was made of 401 participants (including 43 patients with psychotic disorders) aged 18 to 71 years (Mage = 30.43;SD= 11.19). Analysis of a serial multiple mediator model revealed that IR, ELES, absorption, and depersonalization fully mediated the effect of IV on AS, explaining 39% of the variance, regardless of the patient/nonpatient condition. The indirect paths, which place IR and dissociation (especially absorption, the variable to which the IR and ELES lead) in a primordial position for being related to AS, are discussed. This continuum model could be useful for understanding processes related to the onset of psychosis unmoderated by the patient/nonpatient condition