2,819 research outputs found
Review of the Ochsenius Theory for Salt Generation in the Transylvanian Basin, Romania
This short study aims to highlight contradictions in Ochsenius’s model for the basin-wide salt generation (Kara-Bogas bay desiccation). Without claiming completeness, and through numerous records cited from the specific literature, we attempt to point at crucial incoherencies in the classical evaporitic model. In our presupposition, these might have led our ancestors to conclude that basin-wide salt generation needs theoretically well-based models. This is emphatically true for the Transylvanian Basin,Romania.The selected records are basic for the specific topic. We checked their validity by logical reasoning and by literature references.As for salt generation, the classical Ochsenius model has been upheld for the generation of evaporates even though it has been known that there are records denying the exclusivity of the evaporation model. It has also been proven that deep-sea salt exists, yet terminology is reluctant to follow the new discoveries. If non-evaporitic salt generation exists, it entails that huge salt deposits may exist, which are not remnants of a desiccation process.These cannot be considered as part of the classical theory of evaporation.Former researchers left important but neglected records, which should have updated the model of Ochsenius by now. Well-documented historical observation uncovered some contradictions in the salt generation of the Transylvanian Basin, Romania.Hereby we list 10 important contradictions,which may reveal that the well-known theory of Ochsenius (i.e. drying of Kara Bogaz bay) ought to be challenged for the Transylvanian Basin
Investigation of Miocene Methane Hydrate Generation Potential in the Transylvanian Basin, Romania
In geology we often revise theoretical models; upon finding new evidence,such as the discovery of methane hydrates, the initial model will be challenged immediately. Hereby the authors put forward two postulates:1) There is a third, previously unexplored source of methane in the Transylvanian Basin, based on a new theoretical approach on methane hydrate formation; 2) The dissociation of methane hydrates creates a strong chlorinity anomaly. Based on a recent analogy with the Black Sea basin model, we apply our statements to the Transylvanian Basin. Using direct and indirect indicators and the published system tract analysis, we claim that there are substantial grounds to believe that this model of methane hydrate formation applies to the Miocene Transylvanian Basin. Due to the increase of the geothermal gradient as a result of the volcanic activity from the Eastern Carpathians, the clathrates dissociated into methane and freshwater. This process of dilution resulted in a chlorinity anomaly that can be spotted in the formation waters of several gas fields from the Transylvanian Basin
On the Nature of Intrinsic Absorption in Reddened Seyfert 1 Galaxies
We discuss the origin of the ``dusty lukewarm absorber'', which we previously
identified in the reddened Seyfert 1 galaxies NGC 3227 and Akn 564. This
absorber is characterized by saturated UV absorption lines (C IV, N V) near the
systemic velocity of the host galaxy, and is likely responsible for reddening
both the continuum and the emission lines (including those from the narrow-line
region) from these Seyferts. From a large sample of Seyfert 1 galaxies, we find
that continuum reddening (as measured by UV color) tends to increase with
inclination of the host galaxy. Furthermore, reddened, inclined Seyfert
galaxies observed at moderate to high spectral resolution all show evidence for
dusty lukewarm absorbers. We suggest that these absorbers lie in the plane of
the host galaxy at distances > 100 pc from the nucleus, and are physically
distinct from the majority of intrinsic absorbers that are outflowing from the
nucleus.Comment: 14 pages, including 2 figures, accepted for publication in the
Astrophysical Journal (Letters
International Network for Capacity Building for the Control of Emerging Viral Vector-Borne Zoonotic Diseases: Arbo-Zoonet
Arboviruses are arthropod-borne viruses, which include West Nile fever virus (WNFV), a mosquito-borne virus, Rift Valley fever virus (RVFV), a mosquito-borne virus, and Crimean-Congo haemorrhagic fever virus (CCHFV), a tick-borne virus. These arthropod-borne viruses can cause disease in different domestic and wild animals and in humans, posing a threat to public health because of their epidemic and zoonotic potential. In recent decades, the geographical distribution of these diseases has expanded. Outbreaks of WNF have already occurred in Europe, especially in the Mediterranean basin. Moreover, CCHF is endemic in many European countries and serious outbreaks have occurred, particularly in the Balkans, Turkey and Southern Federal Districts of Russia. In 2000, RVF was reported for the first time outside the African continent, with cases being confirmed in Saudi Arabia and Yemen. This spread was probably caused by ruminant trade and highlights that there is a threat of expansion of the virus into other parts of Asia and Europe. In the light of global warming and globalisation of trade and travel, public interest in emerging zoonotic diseases has increased. This is especially evident regarding the geographical spread of vector-borne diseases. A multi-disciplinary approach is now imperative, and groups need to collaborate in an integrated manner that includes vector control, vaccination programmes, improved therapy strategies, diagnostic tools and surveillance, public awareness, capacity building and improvement of infrastructure in endemic regions
Motives for choosing university and specialty applicants Ukraine (for example, students NTU "KPI")
Стаття присвячена аналізу портрета абітурієнта НТУ "ХПІ", де, крім визначення мотивів професійного вибору, самооцінки особистих здібностей, розглядаються і основні цілі навчання в НТУ "ХПІ". У статті підкреслюється, що проблема професійного самовизначення стояла перед молоддю завжди, а сьогодні вона особливо актуальна, тому що сучасні умови ринку праці ведуть до того, що більшість випускників не мають ясної життєвої перспективи. Аналізуються мотиви отримання абітурієнтами вищої освіти, мотивація вступу до НТУ "ХПІ", мотиви вибору спеціальності, період формування професійного інтересу. Проаналізовано мотиви професійного вибору абітурієнтів; період формування інтересу молодих людей до обраної спеціальності (процес самовизначення, коли здійснено вибір спеціальності, ВНЗ); специфіку вибору ВНЗ (яким за рахунком був ХПІ, хто допоміг визначитися з вибором); уявлення про процес навчання в університеті; відповідність уявлень про навчання в університеті реаліям університетського життя.This article analyzes portrait applicant NTU "KPI", where in addition to determining the reasons professional choice, self-personal skills, and discusses the main goals of training at NTU "KPI". The article highlights the problem of professional self -determination was always the youth, and today it is particularly urgent because the current labor market conditions lead to the fact that most graduates do not have a clear life perspective. Analyzed the motives of applicants receiving higher education, motivation admission to NTU "KPI" motives choice of specialty, during the formation of professional interest. Analyzed the motives of professional selection of applicants; during the formation of young people's interest to the chosen profession (the process of self-selection made when specialty Universities); the specific choice of university (how the account was HPI, who helped to choose); understanding of the learning process at the university; line ideas about university studies realities of university life
Diffusion and interface effects during preparation of all-solid microstructured fibers
All-solid microstructured optical fibers (MOF) allow the realization of very flexible optical waveguide designs. They are prepared by stacking of doped silica rods or canes in complex arrangements. Typical dopants in silica matrices are germanium and phosphorus to increase the refractive index (RI), or boron and fluorine to decrease the RI. However, the direct interface contact of stacking elements often causes interrelated chemical reactions or evaporation during thermal processing. The obtained fiber structures after the final drawing step thus tend to deviate from the targeted structure risking degrading their favored optical functionality. Dopant profiles and design parameters(e.g., the RI homogeneity of the cladding) are controlled by the combination of diffusion and equilibrium conditions of evaporation reactions. We show simulation results of diffusion and thermal dissociation in germanium and fluorine doped silica rod arrangements according to the monitored geometrical disturbances in stretched canes or drawn fibers. The paper indicates geometrical limits of dopant structures in sub-μm-level depending on the dopant concentration and the thermal conditions during the drawing process. The presented results thus enable an optimized planning of the preform parameters avoiding unwanted alterations in dopant concentration profiles or in design parameters encountered during the drawing process
Diffusion-controlled annihilation with initially separated reactants: The death of an particle island in the particle sea
We consider the diffusion-controlled annihilation dynamics with
equal species diffusivities in the system where an island of particles is
surrounded by the uniform sea of particles . We show that once the initial
number of particles in the island is large enough, then at any system's
dimensionality the death of the majority of particles occurs in the {\it
universal scaling regime} within which of the particles die at
the island expansion stage and the remaining at the stage of its
subsequent contraction. In the quasistatic approximation the scaling of the
reaction zone has been obtained for the cases of mean-field ()
and fluctuation () dynamics of the front.Comment: 4 RevTex pages, 1 PNG figure and 1 EPS figur
A Radio Study of the Seyfert Galaxy IC 5063: Evidence for Fast Gas Outflow
New radio continuum (8 GHz and 1.4 GHz) and HI 21 cm line observations of the
Seyfert 2 galaxy IC 5063 (PKS 2048-572) were obtained with the Australia
Telescope Compact Array (ATCA). The 8 GHz image reveals a linear triple
structure (~4'', 1.5 kpc) oriented perpendicular to the optical polarization
position angle. It is aligned with the inner dust lane and shows strong
morphological association with the narrow emission line region (NLR). At 21 cm,
very broad (~700 km/s) HI absorption is observed against the strong continuum
source. This absorption is almost entirely blueshifted, indicating a fast net
outflow, but a faint and narrow redshifted component is also present. In IC
5063 we see clear evidence for strong shocks resulting from the radio
plasma-ISM interaction in the central few kpc. However, the energy flux in the
radio plasma is an order of magnitude smaller than the energy emitted in
emission lines. Thus, shocks are unlikely to account solely for the global
ionization of the emission line region, particularly at large distances.
The HI emission outlines a warped disk associated with the system of dust
lanes some ~2' (~38 kpc) in radius. The lack of kinematically disturbed gas
outside the central few kpc, coupled with the disk warp and close morphological
connection of the inner dust lanes and the large-scale ionized gas, support the
idea that the gas at large radii is photoionized by the central region, while
shadowing effects are important in defining its X-shaped morphology. The
kinematics of the ionized and of the neutral gas suggests the existence of a
dark halo.Comment: 18 pages, 8 Postscript figures, 3 jpeg figures, Postscript preprint
is available from http://jhufos.pha.jhu.edu/~zlatan/papers.htm
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