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31.
Anaerobically stabilized sludge from wastewater treatment is always a challenge from the environmental aspect of management. The agrarian environmental surroundings present a possibility for swift and efficient utilization of compost from anaerobically stabilized sludge in order to increase the quality of the biological product. With intensification of the composting procedure by means of the microbiological consortium Geocell‐1 (Cellvibrio sp., Pseudomonas fluorescens with the addition of micro‐ and macro‐elements), the results show that the compost obtained from stabilized sludge after inoculation is significantly improved in terms of moisture reduction (39–43%), while in the control compost, this value is significantly higher with 61%. The results of the pathogenic effect show a significant reduction in the number of fecal coliform (<1 × 103) and Enterococcus bacteria (<1 × 104) in the inoculated (treated) compost. With a slight decrease in the concentration of limiting factors such as As, Cd, Cu, a quality biological product can be achieved, which can be safely deposited on soil. The phytotoxicological germination test with white mustard (Sinapis alba) shows a higher number of sprouting plants with a mixture of treated compost and standard soil for flowers 1:1 and 1:4 compared to the control group.  相似文献   
32.
The precise orbit determination antennas of F3/C and GRACE-A satellites are from the same manufacturer, but are installed in different configurations. The current orbit accuracy of F3/C is 3 cm at arcs with good GPS data, compared to 1 cm of GRACE, which has a larger ratio of usable GPS data. This paper compares the qualities of GPS observables from F3/C and GRACE. Using selected satellites and time spans, the following average values for the satellite F3/C and satellite A of GRACE are obtained: multipath effect on the pseudorange P1, 0.78 and 0.38 m; multipath effect on the pseudorange P2, 1.03 and 0.69 m; occurrence frequency of cycle slip, 1/29 and 1/84; standard error of unit weight, 4 and 1 cm; dynamic–kinematic orbit difference, 10 and 2 cm. For gravity determination using F3/C GPS data, a careful selection of GPS data is critical. With six satellites in orbit, F3/C’s large amount of GPS data will make up the deficiency in data quality.  相似文献   
33.
Seismic characterization and monitoring of Fucino Basin (Central Italy)   总被引:1,自引:1,他引:0  
The Fucino basin (Central Italy) is one of the largest intramountain alluvial plain in the Apennines range. It has a tectonic origin related to the presence of important systems of faults located in its northern and eastern edges. Some of these faults are still active and capable of generating strong seismic events. Site effects related to the soft soils filling the basin can be very important. In this paper we show the preliminary results of a seismic network installed in the Fucino area in order to collect information about site amplification effects and geometry of the basin. We analyze ambient seismic vibrations and recordings of about 150 local earthquakes mainly related to the seismic sequence of the April 6th 2009 Mw 6.3 L’Aquila event. Moreover the strongest events of L’Aquila sequence were analyzed at the three permanent strong-motion stations operating in the area. Using standard spectral techniques we investigate the variation of resonance frequencies within the basin. The ground motion recorded in the Fucino plain is mainly characterized by strong energy at low-frequencies (f < 1 Hz) affecting both horizontal and vertical components. This is particularly evident for stations deployed in correspondence of very thick deposits of sedimentary filling, where a significant increase of ground-motion amplitude and duration is likely caused by locally generated surface waves. The amplification at low-frequencies (<1 Hz) on the horizontal components can reach up a factor of 10 in comparison to nearby stiff sites. However, we found evidences of seismic amplification phenomena also for stiff sites surrounding the basin, including stations of the Italian strong motion network. The independent geological information and the shallow shear-velocity profiles available for the basin can be combined with resonance frequencies for deriving representative geological sections to be used as base for future numerical 2D–3D modeling of the basin.  相似文献   
34.
The Agua Negra drainage system (30 12′S, 69 50′ W), in the Argentine Andes holds several ice‐ and rock‐glaciers, which are distributed from 4200 up to 6300 m a.s.l. The geochemical study of meltwaters reveals that ice‐glaciers deliver a HCO3?? Ca2+ solution and rock‐glaciers a SO42?? HCO3?? Ca2+ solution. The site is presumably strongly influenced by sublimation and dry deposition. The main processes supplying solutes to meltwater are sulphide oxidation (i.e. abundant hydrothermal manifestations), and hydrolysis and dissolution of carbonates and silicates. Marine aerosols are the main source of NaCl. The fine‐grained products of glacial comminution play a significant role in the control of dissolved minor and trace elements: transition metals (e.g. Mn, Zr, Cu, and Co) appear to be selectively removed from solution, whereas some LIL (large ion lithophile) elements, such as Sr, Cs, and major cations, are more concentrated in the lowermost reach. Daily concentration variation of dissolved rare earth elements (REE) tends to increase with discharge. Through PHREEQC inverse modelling, it is shown that gypsum dissolution (i.e. sulphide oxidation) is the most important geochemical mechanism delivering solutes to the Agua Negra drainage system, particularly in rock‐glaciers. At the lowermost reach, the chemical signature appears to change depending on the relative significance of different meltwater sources: silicate weathering seems to be more important when meltwater has a longer residence time, and calcite and gypsum dissolution is more conspicuous in recently melted waters. A comparison with a non‐glacierized semiarid drainage of comparable size shows that the glacierized basin has a higher specific denudation, but it is mostly accounted for by relatively soluble phases (i.e. gypsum and calcite). Meltwater chemistry in glacierized arid areas appears strongly influenced by sublimation/evaporation, in contrast with its humid counterparts. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
35.
For a long time the Moslavačka Gora Massif in Croatia has been regarded as a major outcrop of Variscan crystalline basement of the South Tisia block. However, new geochronological data indicate that this massif consists of a Cretaceous S-type granite pluton intruding a Cretaceous low-pressure/high-temperature (LP/HT) metamorphic envelope. The age of the LP/HT metamorphism is estimated at ~90–100 Ma using the method of electron microprobe based monazite dating. The Central Granite was dated at 82 ± 1 Ma (LA-SF-ICP-MS zircon age). The metamorphic complex comprises mainly felsic anatexites and orthogneisses of granitic composition, some metapelites (paragneisses and mica schists) and amphibolites. Zircons from three different samples of metagranite were dated at 486 ± 6, 483 ± 6, and 491 ± 1 Ma, suggesting that most of the metamorphic complex represents an Early Ordovician granitic series. The Cretaceous regional metamorphism culminated in granulite facies conditions of ~750°C and 3–4 kbar. A retrograde metamorphic event at lower amphibolite facies conditions overprinted the metamorphic complex. This event is probably related to the intrusion of the Central Granite. The southeastern sector of the massif was additionally affected by post-granitic, predominantly NE oriented shearing at greenschist facies conditions. As yet there is no clear evidence for Variscan events in the Moslavačka Gora Massif. Mineral relics of a medium-pressure amphibolite facies metamorphism are preserved in amphibolites. They are older than the Cretaceous LP/HT regional metamorphism, but their age is presently unknown. Some indications for a Permian regional metamorphic event are provided by inherited zircons in the Central Granite that have been dated with a Permian age, and by Permian monazite relics in metapelites. The Cretaceous high heat flow regime recorded in the Moslavačka Gora Massif is unique in the subcrop of the Pannonian Basin and may be a local feature triggered by a mafic intrusion in the lower crust.  相似文献   
36.
The dynamics between sediment erosion and accumulation at an alluvial basin margin affected by changes in the surface hydrology are explored using scaled analogue models produced in a flume. The presented results differ from previous counterparts in that accumulation or erosion has not been forced at a spreading outlet, but occurred at a slope change produced by previously accumulated sediment. Cyclical upstream incision produced by increased stream discharge generated incised valleys, and these were subsequently filled by sediment carried by less efficient streams generated during the low discharge period. High resolution mapping using 2.5 mm contour maps allowed the study of sediment accumulation and terrain modelling. The results of three selected experiments are analysed. The only variable explored was discharge. The basin margin was simulated by a ramp inserted in a low sloping flume, consisting of two segments of different slopes selected to emulate high and low efficiency flume fans produced elsewhere. Water and fine‐medium sand entered the ramp along a narrow (0.1 m) channel and flow expanded but without occupying the complete 1.2 m flume width. Flows were highly concentrated and noncohesive. Fan‐like accumulation (slope: 0.11) began during low discharge (LD) periods at the ramp slope break, and proceeded upstream, onlapping quickly at first, but shifting to mostly progradation at the end of the period. High discharges (HD) usually generated two or three incised channels at the beginning of the period, but one of them prevailed and rapidly eroded parts of the LD fan and moved the sediment to a more distal low‐sloping fan (slope: 0.045). Both LD and HD fans passed downstream into a system of small parallel channels resembling a braided alluvial plain ending in sediment lobes. The mapping of the accumulated sediment during the various periods allowed calculation of sediment budgets for the entire flume. The stratal architecture of the deposits was investigated along five parallel trenches cut after experiment termination. The regression analysis of depositional profiles at fan‐like features (expanding flow) and at braided plains (parallel flow) indicated that these fan‐like systems are linear and dependent on applied discharge, while the latter showed an exponential decrease of slope downstream, with a starting value set up by the fan slope. Two main types of stratigraphic units were generated, the LDST and HDST (system tracts). The LDST has a nonerosive base over ‘bedrock’ and the previous HDST, filling proximal erosional topography and prograding as well, generating an onlap–downlap array. Its geometry is highly variable and dependent on pre‐existing topography. The HDST base is an important erosive surface comparable to sequence boundaries. However, there are places without erosion due to a marginal position with respect to the main stream. Indeed, the results suggest that the three‐dimensional variability of erosion and depositional processes might produce very different architectures along the same basin margin.  相似文献   
37.
Résumé Dans ce travail on fait l'étude minéralogique des matériaux sédimentaires de deux formations du Tertiaire continental de la Péninsule Ibérique: la masse miocène du Tertiaire de Castille et l'ensemble miocène — oligocène du Tertiaire d'Estrémadoure.Des résultats obtenus par l'étude des minéraux lourds, on deduit: 1. la provenance des matériaux et leurs caractéristiques; 2. on etablit, pour le Tertiaire de Castille, des cycles locaux dans le procès général sédimentaire; 3. on définit deux formations: autochtone et allochtone, dans l'ensemble sédimentaire de l'Estrémadoure; 4. on reconnait des possibles variations paléoclimatiques.  相似文献   
38.
A long sequence of earthquakes causing few casualties and considerable damage in a wide zone struck Central Italy starting on September 26, 1997. Theearthquakes are characterized by normal faulting mechanism, with a NE-SW(anti-Apenninic direction) tension axis. In this paper we analyze the accelerometric recordings collected by the accelerograph stations belonging to the National Accelerograph Network. About 10 stations were triggered by the mainshocks of the sequence. In particular, a small size foreshock and the two mainshocks that occurred on September,26 (00:33(GMT) MW = 5.7 and 09:40 MW = 6.0) have been recorded by two digital 3-C accelerometers located at near source distances (within 30 km from the faults). These records are relevant to investigate the detail of therupture kinematics, due to the close epicentral distance and azimuthallocation relative to the fault orientation and geometry. Using a trial and error approach we modeled the source mechanism through the fit of the arrival times, the apparent source time duration, the main polarization features and the entire waveforms of the recorded signals, in order to get some insight on the rupture evolution, the location of the fracture origin point and the fault geometry. Based on this fault kinematic model, inferences on fault slip distribution are obtained by modeling the S acceleration waveform, comparing the ray theory synthetics with 1–5 Hz band filtered ground velocity records.The final model shows that the seismic ruptures occurred along two adjacent,sub-parallel, low angle dipping normal faults. Ruptures bothnucleated from the fault bottom and propagated up-dip, showing differentrupture velocity and length. The presence of a transfer zone (barrier)can be suggested by the mainshocks rupture evolution. This transfer zonehas probably controlled the amplitude increase of local stressreleased by the first rupture at its NW edge which triggered about 9 hourslater the second rupture. The inferred model was used to compute the predictedground acceleration in the near source range, using a hybridstatistical-deterministic approach.A similar trial and error method has been also applied to the October 14, 199715:23 earthquake (MW = 5.6). The inferred kinematic model indicates a rupture nucleating from the faultbottom and propagating up-dip, toward the SE direction. Thus the three mainshocks ruptured distinct fault segments, adjacent and slightly offsetfrom one to another.  相似文献   
39.
The Rupnica locality became the first protected geosite in Croatia in 1948 owing to a well‐exposed phenomenon of columnar jointing developed in albite rhyolite. According to the geochemical signature, melt that originated at mid‐crustal depths (10–15 km) reached a shallow emplacement level as a high‐temperature lava. Non‐destructive statistical analysis conducted at the geosite revealed that relatively narrow (29.4 ± 6.3 cm) predominantly four‐ and five‐sided columns, tightly packed striae (4.8 ± 2.1 cm) and small‐amplitude wavy sets of columns (wavelength of 32.5 ± 6.7 cm) dominate the exposed part of the Rupnica. A number of features quantified through this statistical approach, together with petrography, geochemistry and the geology of the geosite's surroundings, suggest the rapid cooling of a (sub)surface acidic lava body and the behaviour of the evolving volcanic system, developing columnar jointing under the combined influence of large‐scale constitutional supercooling and thermal contraction processes.  相似文献   
40.
This paper reports on site characterization for a set of accelerometric stations of the RAN (Italian accelerometric network) with specific attention to the shear wave velocity profile. The latter is indeed of primary importance for the usability of the accelerometric database. Surface wave analysis has been chosen as the primary investigation method since it offers the possibility of reaching the required accuracy with reasonable costs. A range of different techniques, both of the active-source and passive-source types, has been adopted to cope with the objectives of the characterization in relation to specific geological settings. Quality assessment of experimental data has been implemented to check the consistency of the measurements also with respect to the fundamental hypotheses of the method. Strategies to improve the reliability and robustness of the surface wave data inversion were exploited in order to mitigate problems arising from solution non-uniqueness and influence of higher modes in the propagation. Comparisons with independent borehole tests, available at some specific sites, confirm the reliability of the results. Although the research program covered only a subset of the network, the obtained results show the importance of specific experimental investigations aimed at estimating the shear wave velocity profile. Indeed the results lead to a re-classification of several sites with respect to the preliminary classification based on surface geology. Within this context, four selected case histories are reported in the present paper.  相似文献   
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