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排序方式: 共有151条查询结果,搜索用时 31 毫秒
101.
Ralf Srama Thomas Stephan Eberhard Grün Norbert Pailer Anton Kearsley Amara Graps Rene Laufer Pascale Ehrenfreund Nicolas Altobelli Kathrin Altwegg Siegfried Auer Jack Baggaley Mark J. Burchell James Carpenter Luigi Colangeli Francesca Esposito Simon F. Green Hartmut Henkel Mihaly Horanyi Annette Jäckel Sascha Kempf Neil McBride Georg Moragas-Klostermeyer Harald Krüger Pasquale Palumbo Andre Srowig Mario Trieloff Peter Tsou Zoltan Sternovsky Oliver Zeile Hans-Peter Röser 《Experimental Astronomy》2009,23(1):303-328
The scientific community has expressed strong interest to re-fly Stardust-like missions with improved instrumentation. We
propose a new mission concept, SARIM, that collects interstellar and interplanetary dust particles and returns them to Earth.
SARIM is optimised for the collection and discrimination of interstellar dust grains. Improved active dust collectors on-board
allow us to perform in-situ determination of individual dust impacts and their impact location. This will provide important
constraints for subsequent laboratory analysis.
The SARIM spacecraft will be placed at the L2 libration point of the Sun–Earth system, outside the Earth’s debris belts and
inside the solar-wind charging environment. SARIM is three-axes stabilised and collects interstellar grains between July and
October when the relative encounter speeds with interstellar dust grains are lowest (4 to 20 km/s). During a 3-year dust collection
period several hundred interstellar and several thousand interplanetary grains will be collected by a total sensitive area
of 1 m2. At the end of the collection phase seven collector modules are stored and sealed in a MIRKA-type sample return capsule.
SARIM will return the capsule containing the stardust to Earth to allow for an extraction and investigation of interstellar
samples by latest laboratory technologies. 相似文献
102.
VAMOS is a Magneto-Optical Filter (MOF) that can acquire nearly simultaneous Dopplergrams and magnetograms with high cadence in the K I 7699 Å line. We performed an accurate set-up of this instrument in view of its use for studying oscillations in solar magnetic regions. The optimal set-up for VAMOS was achieved and an extra result of the spectral transmission measurements was found. The MOF and Wing Selector (WS) bandpasses depend not only on the cell temperature and magnetic field but also on the radiation intensity entering the cell, when this radiation exceeds a suitable level. We call this effect The Intensity Effect. 相似文献
103.
Sebastiano Imposa Jean-Pierre Fourno Rosario Raffaele Antonio Scaltrito Luciano Scarfi 《Central European Journal of Geosciences》2009,1(4):416-423
A one-dimensional velocity model and station corrections for the Middle-Durance fault zone (south-eastern France) were computed by inverting P-wave arrival times recorded on a local seismic network of 8 stations. A total of 93 local events with a minimum of 6 P-phases, RMS 0.4 s and a maximum gap of 220° were selected. Comparison with previous earthquake locations shows an improvement for the relocated earthquakes. Tests were carried out to verify the robustness of inversion results in order to corroborate the conclusions drawn from our findings. The obtained minimum 1-D velocity model can be used to improve routine earthquake locations and represents a further step toward more detailed seismotectonic studies in this area of south-eastern France. 相似文献
104.
Richard A. Esposito Jack C. Pashin Denise J. Hills Peter M. Walsh 《Environmental Earth Sciences》2010,60(2):431-444
CO2 pilot injection studies, with site-specific geologic assessment and engineering reservoir design, can be instrumental for
demonstrating both incremental enhanced oil recovery and permanent geologic storage of greenhouse gases. The purpose of this
paper is to present the geologic and reservoir analyses in support of a field pilot test that will evaluate the technical
and economic feasibility of commercial-scale CO2-enhanced oil recovery to increase oil recovery and extend the productive life of the Citronelle Oil Field, the largest conventional
oil field in Alabama (SE USA). Screening of reservoir depth, oil gravity, reservoir pressure, reservoir temperature, and oil
composition indicates that the Cretaceous-age Donovan sand, which has produced more than 169 × 106 bbl in Citronelle Oil Field, is amenable to miscible CO2 flooding. The project team has selected an 81 ha (200 ac) 5-spot test site with one central gas injector, two producers,
and two initially temporarily abandoned production wells that are now in production. Injection is planned in two separate
phases, each consisting of 6,804 t (7,500 short tons) of food-grade CO2. The Citronelle Unit B-19-10 #2 well (Permit No. 3232) is the CO2 injector for the first injection test. The 14-1 and 16-2 sands of the upper Donovan are the target zones. These sandstone
units consist of fine to medium-grained sandstone that is enveloped by variegated mudstone. Both of these sandstone units
were selected based on the distribution of perforated zones in the test pattern, production history, and the ability to correlate
individual sandstone units in geophysical well logs. The pilot injections will evaluate the applicability of tertiary oil
recovery to Citronelle Field and will provide a large volume of information on the pressure response of the reservoirs, the
mobility of fluids, time to breakthrough, and CO2 sweep efficiency. The results of the pilot injections will aid in the formulation of commercial-scale reservoir management
strategies that can be applied to Citronelle Field and other geologically heterogeneous oil fields and the design of similar
pilot injection projects. 相似文献
105.
Iron Mountain is located in the West Shasta Mining District in California. An investigation of the generation of acid rock drainage and metals loading to Boulder Creek at Iron Mountain was conducted. As part of that investigation, a hydrograph separation technique was used to determine the contribution of ground water to total flow in Boulder Creek. During high-flow storm events in the winter months, peak flow in Boulder Creek can exceed 22.7 m3/sec, and comprises surface runoff, interflow, and ground water discharge. A hydrograph separation technique was used to estimate ground water discharge into Boulder Creek during high-flow conditions. Total ground water discharge to the creek approaches 0.31 m3/sec during the high-flow season. The hydrograph separation technique combined with an extensive field data set provided reasonable estimates of ground water discharge. These estimates are useful for other investigations, such as determining a corresponding metals load from the metal-rich ground water found at Iron Mountain and thus contributing to remedial alternatives. 相似文献
106.
Rosario Turvey 《GeoJournal》2006,67(3):207-222
Research on the practice of adopting local economic development (LED) strategies is important to understand our local world
as it is and what it might be made to be as a place for community. This article on economic development strategies (EDS) highlights
the results from a survey of 82 small communities representing the Yukon Territory and ten provinces in Canada. The purpose
was to evaluate the positive and additive effects of past local action and community initiatives so as to understand the variation
in the adoption of local economic development strategies of Canada’s small towns and local municipalities. Using a questionnaire
as instrument for data collection, the study employed hierarchical regression analysis and principal component analysis (PCA)
as method for factor extraction and composite assessment on the effects of adopting EDS for community. The PCA solution was
applied to evaluate the structure of correlation between the community characteristics as control variables in the baseline
model for regression analysis and the past local action and community initiatives as independent variables. The results of
the hierarchical regression analysis showed that local initiatives have significant and additive effects on the adoption of
EDS by small communities. The study findings offer some insights into some perspectives of ‘development from within’ to mean
the local economic development practice in Canadian communities. 相似文献
107.
José J. del Alonso Rosario M. Arias Ballesteros P. Villares Durán 《Stochastic Environmental Research and Risk Assessment (SERRA)》2007,21(3):259-272
The generation of internal lee waves (ILW) in the Strait of Gibraltar takes place in the main sill where the tidal flow interacts
with a submarine obstacle. The tidal flow is perturbed by subinertial phenomena of different nature summarized in the subinertial
currents that can inhibit the ILW generation. The authors present an attempt to randomize the problem by the introduction
of a Gaussian noise in the Taylor–Goldstein equation. The random number sets are generated from the statistical distribution
of the previously isolated random part of the subinertial currents from experimental data taken in the area during the Gibraltar
Experiment 94–96. The effect of the noise is translated into a continuous spreading of the spectrum around the solution of
the noise-free problem. A stability analysis is carried out in order to determine the single neutral modes of oscillations
and the phase space is divided onto regions of stability and instability as a function of the inflowing subinertial current.
The methodology and results could be useful for the design and timing of oceanographic surveys in straits where the ILWs occur. 相似文献
108.
Gunnar Fjeldbo Arvydas Kliore Donald Sweetnam Pasquale Esposito Boris Seidel Taylor Howard 《Icarus》1976,29(4):439-444
An analysis of the Mariner 10 dual frequency radio occultation recordings has yielded new information on the radius and atmosphere of Mercury. The ingress measurements which were conducted near 1.1° North latitude and 67.4° East longitude on the night side of the planet, gave a value for the radius of 2439.5 ± 1 km. Egress near 67.6° North latitide and 258.4° East longitude in the sunlit side yielded a radius of 2439.0 ± 1 km. The atmospheric measurements showed the electron density to be less than 103 cm?3 on both sides of the planet. From the latter result one may infer an upper limit to the dayside surface gas density of 106 molecules per cm3. 相似文献
109.
Areal Distribution of Ground Effects Induced by Strong Earthquakes in the Southern Apennines (Italy)
S. Porfido E. Esposito E. Vittori G. Tranfaglia A.M. Michetti M. Blumetti L. Ferreli L. Guerrieri L. Serva 《Surveys in Geophysics》2002,23(6):529-562
Moderate to strong crustal earthquakes are generally accompanied by a distinctivepattern of coseismic geological phenomena, ranging from surface faulting to groundcracks, landslides, liquefaction/compaction, which leave a permanent mark in thelandscape. Therefore, the repetition of surface faulting earthquakes over a geologictime interval determines a characteristic morphology closely related to seismic potential. To support this statement, the areal distribution and dimensions of effects of recent historical earthquakes in the Southern Apennines are being investigated in detail. This paper presents results concerning the 26 July 1805 earthquake in the Molise region, (I = X MCS, M = 6.8), and the 23 November 1980 earthquake in the Campania and Basilicata regions (I = X MSK, Ms = 6.9). Landslide data are also compared with two other historical earthquakes in the same region with similar macroseismic intensity. The number of significant effects (either ground deformation or hydrological anomalies) versus their minimum distance from the causative fault have been statistically analyzed, finding characteristic relationships. In particular, the decay of the number of landslides with distance from fault follows an exponential law, whereas it shows almost a rectilinear trend for liquefaction and hydrological anomalies. Most effects fall within the macroseismic area, landslides within intensity V to VI, liquefaction effects within VI and hydrologicalanomalies within IV MCS/MSK, hence at much larger distances. A possible correlation between maximum distance of effects and length of the reactivated fault zone is also noted. Maximum distances fit the envelope curves for Intensity and Magnitude based on worldwide data. These results suggest that a careful examination of coseismic geological effects can be important for a proper estimation of earthquake parameters and vulnerability of the natural environment for seismic hazard evaluation purposes. 相似文献
110.