Ethnic migration between area groups in England and Wales     

James Raymer  Corrado Giulietti 《Area》2009,41(4):435-451

Minority ethnic populations in England and Wales have been increasing steadily as a share of the total population since the 1991 Census. In this paper, we are interested in how internal migration has changed as a possible consequence. Our analysis focuses on the movements between 12 area groups, as defined by the Office for National Statistics, and addresses the following three research questions: (1) how has internal migration in England and Wales evolved from 1991 to 2004; (2) what are the main differences in the movements between the White (majority) population and the ethnic minority population; and (3) how do migration patterns differ when ethnicity, education and employment statuses are considered together? The data come from the 1991 to 2004 National Health Service Central Registers, the 1999–2004 patient registers and the 2001 Census. We find strong stability in the migration patterns of the total population over time. However, large differences appear when the flows are disaggregated by ethnicity and further by education and employment. Education level is an important factor influencing the migration patterns for the White population, whereas employment status is a much more important factor for the ethnic minority population.  相似文献   

Massive antigravity field and incomplete black hole evaporation     

Corrado Massa 《Astrophysics and Space Science》2008,314(1-3):23-24

If gravity is a mixture of the ordinary attractive force carried by the massless graviton, and of a repulsive force carried by a particle with nonzero mass, an evaporating black hole might leave a stable remnant.  相似文献   

Evaluating debris-flow and anthropogenic disturbance on 10Be concentration in mountain drainage basins: implications for functional connectivity and denudation rates across time scales     

Francesco Brardinoni  Reto Grischott  Florian Kober  Corrado Morelli  Marcus Christl 《地球表面变化过程与地形》2020,45(15):3955-3974

We examine the sensitivity of ¹⁰Be concentrations (and derived denudation rates), to debris-flow and anthropogenic perturbations in steep settings of the Eastern Alps, and explore possible relations with structural geomorphic connectivity. Using cosmogenic ¹⁰Be as a tracer for functional geomorphic connectivity, we conduct sampling replications across four seasons in Gadria, Strimm and Allitz Creek. Sampling sites encompass a range of structural connectivity configurations, including the conditioning of a sackung, all assessed through a geomorphometric index (IC). By combining information on contemporary depth of erosion and sediment yield, disturbance history and post-LGM (Last Glacial Maximum) sedimentation rates, we constrain the effects of debris-flow disturbance on ¹⁰Be concentrations at the Gadria sites. Here, we argue that bedrock weakening imparted by the sackung promotes high depth of erosion. Consequently, debris flows recruit sediment beyond the critical depth of spallogenic production (e.g., >3 m), which in turn, episodically, due to predominantly muogenic production pathways, lowers ¹⁰Be concentration by a factor of 4, for at least 2 years. In contrast, steady erosion in Strimm Creek yields very stable ¹⁰Be concentrations through time. In Allitz Creek, we observe two- to fourfold seasonal fluctuations in ¹⁰Be concentrations, which we explain as the combined effects of water diversion and hydraulic structures on sediment mixing. We further show that ¹⁰Be concentration correlates inversely with the IC index, where sub-basins characterized by high concentrations (long residence times) exhibit low IC values (structurally disconnected) and vice versa, implying that, over millennial time scales a direct relation exists between functional and structural connectivity, and that the IC index performed as a suitable metric for structural connectivity. The index performs comparably better than other metrics (i.e., mean slope and mean normalized channel steepness index) previously used to assess topographic controls on denudation rates in active unglaciated ranges. In terms of landscape evolution, we argue that the sackung, by favouring intense debris-flow activity across the Holocene, has aided rapid postglacial reshaping of the Gadria basin, which currently exhibits a topographic signature characteristic of unglaciated debris-flow systems. © 2020 John Wiley & Sons, Ltd.  相似文献   

A new limit on time dependence of the gravitational constant from gravity modified quantum electrodynamics     

Corrado Massa 《Astrophysics and Space Science》1993,209(2):307-308

The time variation of the gravitational constantG is discussed in the light of the gravity modified form of quantum electrodynamics. From the experimental upper limit |a/| < 5 × 10^–15 yr^–1 on the time variation of the electromagnetic fine structure constant one finds |/G| < 5 × 10^–13 yr^–1.  相似文献   

Inheritance of Jurassic rifted margin architecture into the Apennines Neogene mountain building: a case history from the Lucretili Mts. (Latium, Central Italy)     

Andrea Bollati  Sveva Corrado  Maurizio Marino 《International Journal of Earth Sciences》2012,101(4):1011-1031

The western Lucretili Mts. in the central Apennines (Latium, Italy) have been recently re-mapped in great detail and are the subject of combined stratigraphic, sedimentological and structural investigations. In this paper, we present a new stratigraphic interpretation of the Jurassic paleogeography of western Lucretili Mts., where a rift-derived intrabasinal paleo-high of the Alpine Tethys has been identified for the first time by means of facies analysis and biostratigraphic dating. Recognised facies associations, combined with dated stratigraphic sections, allow to define the morphology of the structural paleo-high and to identify the associated gravity-driven deposits (olistoliths) accumulated in the surrounding basin. Furthermore, we investigated the modes of interaction between Jurassic extensional structures and the subsequent contractional patterns developed during the Tertiary mountain building. In detail, the role played during Apennines tectonics by the paleo-escarpments bounding the paleo-high and by the surrounding olistoliths has been analysed. The paleo-escarpments either acted as focussing features for ENE-directed frontal thrust ramp localisation and were offset with small shortening amounts or reactivated as NNE striking high angle transpressional faults or preserved the original geometries as a result of variable orientation of paleo-escarpments with respect to the Neogene compressive stress field (with ENE oriented sigma1). Newly formed ENE striking tear faults connect these either inherited or neo-formed discontinuities. This complex stratigraphic and structural pattern is substantially different from the previous interpretations of this portion of the central Apennines based on a hypothesised layer-cake stratigraphy deformed by neo-formed Neogene thrusts. This contribution strengthens the importance of integrating facies analyses and structural investigations to detect the influence of pre-orogenic structures on compressive structural patterns, in an area where commercial seismic lines are not available and cannot help in reconstructing the subsurface geometries.  相似文献   

A field‐scale infiltration model accounting for spatial heterogeneity of rainfall and soil saturated hydraulic conductivity     

Renato Morbidelli  Corrado Corradini  Rao S. Govindaraju 《水文研究》2006,20(7):1465-1481

This study first explores the role of spatial heterogeneity, in both the saturated hydraulic conductivity K_s and rainfall intensity r, on the integrated hydrological response of a natural slope. On this basis, a mathematical model for estimating the expected areal‐average infiltration is then formulated. Both K_s and r are considered as random variables with assessed probability density functions. The model relies upon a semi‐analytical component, which describes the directly infiltrated rainfall, and an empirical component, which accounts further for the infiltration of surface water running downslope into pervious soils (the run‐on effect). Monte Carlo simulations over a clay loam soil and a sandy loam soil were performed for constructing the ensemble averages of field‐scale infiltration used for model validation. The model produced very accurate estimates of the expected field‐scale infiltration rate, as well as of the outflow generated by significant rainfall events. Furthermore, the two model components were found to interact appropriately for different weights of the two infiltration mechanisms involved. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Relativistic Cosmology with Zero Deceleration Parameter     

Corrado Massa 《Astrophysics and Space Science》1997,253(2):285-289

The possibility that the deceleration parameter q might be a null constant is discussed; such possibilitiy is interesting because solves the horizon problem and the flatness problem with no need of inflation. A simple way to get q = const = 0 is explored: the way assumes Einstein's field equations without cosmological term and introduces a massless scalar field V with negative energy density. Both in the early and in the present universe one finds the Whitrow-Randall relation Gut² = const 1 G gravitational coupling, u mass-energy density, t cosmic time). The interaction between the V-field and the ordinary matter is briefly discussed; as possible consequence of this interaction the true value of the Hubble parameter might be one half the observed value. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

The dynamics of a double-cell hydrothermal system in triggering seismicity at Somma-Vesuvius: results from a high-resolution radon survey (revisited)     

Corrado Cigolini 《Bulletin of Volcanology》2010,72(6):693-704

Data collected at Somma-Vesuvius during the 1998–1999 radon surveys have been revisited and reinterpreted in light of recent geophysical and geochemical information. The duration of selected radon anomalies, together with the decay properties of radon, have been used to estimate the permeability and porosity of rocks of the deep hydrothermal system. The current local cyclic seismicity is explained by means of a double convective-cell model. Convective cells are separated by a low-permeability horizon located at about 2–2.5 km below sea level. Fluids convecting within the upper cells show temperatures ranging 300–350°C. Rock permeabilities in this sector are estimated on the order of 10⁻¹² m², for porosities (ϕ) of about 10⁻⁵ typical of a brittle environment where fluid velocities may reach ∼800 m/day. Fluid temperatures within the lower cells may be as high as 400–450°C, consistent with supercritical regimes. The hydrodynamic parameters for these cells are lower, with permeability k ∼ 10⁻¹⁵ m², and porosity ranging from 10⁻⁶ to 10⁻⁷. Here, fluid motion toward the surface is controlled by the fracture network within a porous medium approaching brittle–ductile behaviour, and fluid velocities may reach ∼1,800 m/day. The low-permeability horizon is a layer where upper and lower convecting cells converge. In this region, fluids (convecting both at upper and lower levels) percolate through the wallrock and release their brines. Due to self-sealing processes, permeability within this horizon reaches critical values to keep the fluid pressure near lithostatic pressure (for k ∼ 10⁻¹⁸ m²). Deep fluid pressure buildups precede the onset of hydrothermally induced earthquakes. Permeability distribution and rock strength do not exclude that the next eruption at Somma-Vesuvius could be preceded by a seismic crisis, eventually leading to a precursory phreatic explosion. The coupling of these mechanisms has the potential of inducing pervasive failure within rocks of the hydrothermal shell, and may be a prelude to a magmatic eruption. It is finally emphasised that the integrated analysis of seismic and geochemical data, including radon emissions, could be successfully used in testing temperature distributions and variations of porosity and permeability in active geothermal reservoirs.  相似文献   

Non‐impact origin of the crater‐like structures in the Gilf Kebir area (Egypt): Implications for the geology of eastern Sahara     

Letizia ORTI  Mario DI MARTINO  Marco MORELLI  Corrado CIGOLINI  Enrico PANDELI  Alessandra BUZZIGOLI 《Meteoritics & planetary science》2008,43(10):1629-1639

Abstract— Several small crater‐like structures occur in Gilf Kebir region (SW Egypt). It has been previously suggested that they could be the result of meteoritic impacts. Here we outline the results of our geological and geophysical survey in the area. The proposed impact origin for these structures is not supported by our observations and analyses, and we suggest an alternative interpretation. The crater‐like structures in Gilf Kebir area are likely related to endogenic processes typical of hydrothermal vent complexes in volcanic areas which may reflect the emplacement of subvolcanic intrusives.  相似文献   

Geoinformatics in morphological study of River Paglia,Tiber River basin,Central Italy     

Corrado Cencetti  Pierluigi De Rosa  Andrea Fredduzzi 《Environmental Earth Sciences》2017,76(3):128

This work reports the results of a geomorphological study on the River Paglia (Tiber basin, Central Italy), to analyse the historical evolution of the riverbed/floodplain system in its lower valley reaches, upstream the confluence of River Tiber. A morphological–sedimentological approach has been used, starting with an historical analysis and a survey of the forms and sediments in the riverbed/alluvial plain system, in order to reconstruct the current evolutionary trend and to identify the causes and processes leading to changes in natural trends. This approach is not in contrast to the hydrologic–hydraulic one, normally applied in engineering fields, but it is integrated with it in a complementary and parallel manner, in order to achieve the complete knowledge of the river system, result of an investigation multidisciplinary, aimed to define its physical state. Historical data (cartographic documents, digital terrain models—DTM, topographic surveys, aerial photographs, etc.) indicate clear-cut narrowing and deepening of the active channel, manifested after the Second World War and due to the considerable changes which affected the entire fluvial system (from the recovery of land for agriculture near the river, to sediments taken from its bed over the past few decades). The result is a state of great disequilibrium, which is shown in the passage from a braided morphology, observed in the 1950s, to a single channel with low sinuosity (wandering type). This type of morphology is certainly more unstable: in fact, the narrowing and deepening of fluvial sections provide a better hydraulic efficiency for the upstream, so the peak discharge does not overflow. Such peak discharge arrives downstream, next to the confluence with the Tiber River, not laminated, causing serious flooding effects. An increased vulnerability is observed in the last reach, in the areas pertaining to the river, where most of the industrial-economic activities are concentrated and where transportation infrastructures of nationwide importance (Italy’s most important motorway, the A1, and the Rome–Florence–Milan high-speed rail links) are located. The evolution of the Paglia (which is not substantially different from that of many streams in Italy and in general throughout Europe) is affected by severe anthropic constraints and intense exploitation of resources, which have produced a state of disequilibrium approaching irreversibility in an already vulnerable system. Finally, some suggestions for the correct management of the river system are pointed out, with the aim of mitigating the flood risk in the lower Paglia valley.  相似文献