TDDFT study of time-dependent and static screening in graphene

Time-dependent density functional theory (TDDFT) within the random phase approximation (RPA) is used to obtain the time evolution of the induced potential produce by the sudden formation of a C 1s core hole inside a graphene monolayer, and to show how the system reaches the equilibrium potential. The characteristic oscillations in the time-dependent screening potential are related to the excitations of π and σ+π plasmons as well as the low energy 2D plasmons in doped graphene. The equilibrium RPA screened potential is compared with the DFT effective potential, yielding good qualitative agreement. The self energy of a point charge near a graphene monolayer is shown to demonstrate an image potential type behavior, Ze/(z−z0), down to very short distances (4 a.u.) above the graphene layer. Both results are found to agree near quantitatively with the DFT ground state energy shift of a Li+ ion placed near a graphene monolayer

The Karst Dinarides are Composed of Relics of a Single Mesozoic Platform: Facts and Consequences

Croatian geological literature during the mid nineteen-eighties and nineties was marked by the appearance of a new geotectonic concept of the Dinarides proposing that the recent, very complex structural setting is a direct consequence of a specific palaeogeographic relationship during the Mesozoic, i.e. the proposed existence of two carbonate platforms separated by a long-lasting deep marine area (interplatform trough). Although the idea was very interesting and provoked discussion, resulting in the questioning of formerly established concepts, detailed analysis of available data indicate that the Karst Dinarides (External Dinarides) were formed by the destruction of a single, although morphologically considerably variable shallow water carbonate platform. This platform was in some periods very dynamic because of its palaeogeographic position during the Mesozoic, resulting in many periods of large-scale facies differentiation, especially during the Late Cretaceous. The final disintegration of the platform area culminated in the formation of flysch trough(s) in the latest Cretaceous and Palaeogene and the subsequent uplift of the Dinarides. Recently there have been some misunderstandings resulting from the imprecise use of newly established terms, which are, by circular logic, used to connect recent geotectonic relationships with Mesozoic palaeogeography without adequate material proof. Therefore, the terms Dinaricum and Adriaticum should be redefined and used only for description of the recent tectonic pattern, without implying a palaeogeographic component, since during the Mesozoic they represented a single entity. Additional confusion is added by different names used for the same shallow water carbonate platform. Probably the best, although not the ideal name is the most frequently used one: the Adriatic Carbonate Platform. Its duration may be estimated from the Late Lias to the Late Cretaceous, representing the most important part of a thick carbonate succession in the Karst Dinarides (ranging from Carboniferous to Eocene)

Palaeogeographic Variability and Depositional Environments of the Upper Jurassic Carbonate Rocks of Velika Kapela Mt. (Gorski Kotar Area, Adriatic Carbonate Platform, Croatia)

Synsedimentary tectonics caused significant differentiation of sedimentary environments of the Adriatic Carbonate Platform during the Kimmeridgian. The most important changes have been recorded in W and central Croatia: along the NW part in present day W Istria there was an emergence with bauxite deposits, while along the NE margin of the platform, in the Karlovac area, a former emerged area was submerged. Penecontemporaneously between these areas, in the wider area of Velika Kapela Mt., a shallow intraplatform trough was formed, characterised by deposition of dark mudstones with nodules and thin layers of cherts and thin interbeds of tuffs in the upper part of the succession. Occurrences of planktonic foraminifera, radiolarians, calcisphaeres and rare ammonites indicate the sporadic influence of the open sea. Along the margins of the trough, peri-reefal environments were established, with flourishing developments of different reef-building organisms – hydrozoans, stromatoporoids, corals and bryozoans. Reefs were continuously destroyed, and in this way derived material was reworked and transported towards the trough slopes. An enormous quantity of this material caused progradation towards the deeper central part of the area, which was gradually infilled and narrowed. In the final phase, the trough was completely infilled, and peri-reefal environments gradually disappeared, since they were covered by ooid bars, culminating in the establishment of shallow environments over the entire area. A similar situation was recorded in another contemporaneous, also tectonically formed environment – the Lemes trough, stretching from the vicinity of Bihac in NW Bosnia towards the south into Croatia, into E Lika and N Dalmatia. This trough had direct communication with the open Tethys realm, and thin-bedded and platy limestones with chert and pelagic organisms, including common ammonites, were deposited within it. The Lemes trough was also surrounded by coral–hydrozoan reefs, and it was infilled by the same depositional processes as the neighbouring trough in the area of Velika Kapela Mt., and finally covered by shallow-water deposits. Although both troughs were probably formed by the same tectonic act, and had approximately the same duration – during the Kimmeridgian and Early Tithonian – they differ according to their palaeogeographic and facies characteristics. The trough investigated in the Velika Kapela Mt. was isolated, surrounded by shallow-marine platform environments, and had only temporary, indirect contact with the open sea. The Lemes trough had a continuous connection with the open sea, as indicated by the relatively rich assemblages of pelagic organisms, especially ammonites, and is characterised by abundant cherts. However, both troughs are characterised by similar depositional sequences: both are underlain and overlain by shallow-water carbonate deposits, and they represent a consequence of a specific depositional event caused by tectonic deformation (formation of pull-apart basins) within the inner part of the Adriatic Carbonate Platform

The Origin and Importance of the Dolomite-Limestone Breccia Between the Lower and Upper Cretaceous Deposits of the Adriatic Carbonate Platform: An Example from Cicarija Mt. (Istria, Croatia)

On the NE slopes of Cicarija Mt. (N Istria) a 120-150 m thick complex composed of dolomite-limestone breccia crops out between the Lower and Upper Cretaceous deposits. This studied breccia sequence is of post-sedimentary, tectogenic-diagenetic origin. It was formed by polyphase tectonic fracture of the Upper Albian to Lower Cenomanian early- and late-diagenetic dolomite succession with relics of recrystallized limestone, which enabled very important subsequent diagenetic alteration. This included partial dissolution, dedolomitization, recrystallization and calcitization of the fine-grained, crushed dolomite matrix, and centripetal dissolution of dolomite fragments and their cementation by calcite and ferroan calcite cements, as well as the partial collapse of fragments from the roofs of dissolution cavities and limited late-diagenetic silicification (the silica surplus originating from layers of diagenetic quartz from underlying Upper Albian deposits). Such a complex pattern of different events resulted in the high variability of breccia characteristics over relatively small distances, especially near more intensively tectonized zones. The contemporaneous stratigraphic level (Lower to Upper Cretaceous transition) in other parts of the Adriatic Carbonate Platform is also characterised by predominantly late-diagenetic dolomites with relics of limestones (including local occurrences of early-diagenetic dolomites) which are, in more tectonized areas, late-diagenetically altered into tectogenic-diagenetic breccias

Sensitivity of gypsy moth neurosecretory neurons to acute thermal stress

In gypsy moth caterpillars exposed to a temperature of 35°C (for 1, 12 and 24 h and caterpillars that were exposed to elevated temperature for 12 h and were allowed to recover for 12 h at 23°C), changes in the brain protein profiles and morphometric characteristics of A1’ medial and L2 lateral protocerebral neurosecretory neurons were analyzed. In all groups, protein bands with a molecular mass corresponding to that of members of heat-shock protein families were detected, indicating that acute exposure to this temperature likely induced the synthesis of HSP. Increased morphometric parameters of A1’ neurons and the large amount of neurosecretory material in the neuron body implicate that the temperature of 35°C is not in the temperature range that exerts stimulatory effects on growth and survival. Changes in the morphometric characteristics of L2 neurosecretory neurons from the lateral part of the protocerebrum, and retention of neurosecretory material in their cytoplasm indicate a low level of secretion

Biogenic amines in protocerebral A2 neurosecretory neurons of Lymantria dispar L. (Lepidoptera:Lymantriidae): Response to trophic stress

The number, morphometric parameters and amount of aminergic neurosecretory product of protocerebral A2 neurosecretory neurons were investigated in the fifth instar of Lymantria dispar caterpillars, following a suitable or unsuitable trophic regime. Caterpillars originated from two populations (Quercus rubra or Robinia pseudoacacia forest) and were differently adapted to trophic stress, i.e. feeding on locust tree leaves - unsuitable host plant. The number of neurosecretory neurons was higher in the caterpillars originated from Robinia population than in Quercus population, regardless of feeding. A2 neurosecretory neurons, nuclei and their nucleoli were larger in caterpillars fed with unsuitable leaves in both populations. There was more aminergic product in the A2 neurosecretory neurons of the caterpillars fed with unsuitable leaves independently of population origin