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1.
Arena U Di Gregorio F Amorese C Mastellone ML 《Waste management (New York, N.Y.)》2011,31(7):1494-1504
A comparison between the most promising design configurations for the industrial application of gasification based, plastics-to-energy cogenerators in the 2-6 MWe range is presented. A pilot scale bubbling fluidized bed air gasifier, having a feeding capacity of 100 kg/h, provided experimental data: the syngas complete composition, the characterization of the bed material, the entrained fines collected at the cyclone and the purge material from the scrubber. Mass and energy balances and material and substance flow analyses have been therefore drawn to assess and compare design solutions utilizing two mixed plastic wastes (MPW) obtained from separate collection of plastic packaging, after different levels of pre-treatments. The related techno-economic performances have been finally estimated on the basis of the manufacturer’s specifications. The study concludes that the MPW obtained after a very simple pre-treatment and fed to a gasifier coupled with a steam turbine is the solution that currently offers the higher reliability and provides the higher internal rate of return for the investigated range of electrical energy production. 相似文献
2.
J. Juri Ayub D.E. Di Gregorio H. Velasco H. Huck M. Rizzotto F. Lohaiza 《Journal of environmental radioactivity》2009
The 7Be wet deposition has been intensively investigated in a semiarid region at San Luis Province, Argentina. From November 2006 to May 2008, the 7Be content in rainwater was determined in 58 individual rain events, randomly comprising more than 50% of all individual precipitations at the sampling period. 7Be activity concentration in rainwater ranged from 0.7 ± 0.3 Bq l−1 to 3.2 ± 0.7 Bq l−1, with a mean value of 1.7 Bq l−1 (sd = 0.53 Bq l−1). No relationship was found between 7Be content in rainwater and (a) rainfall amount, (b) precipitation intensity and (c) elapsed time between events. 7Be ground deposition was found to be well correlated with rainfall amount (R = 0.92). For the precipitation events considered, the 7Be depositional fluxes ranged from 1.1 to 120 Bq m−2, with a mean value of 32.7 Bq m−2 (sd = 29.9 Bq m−2). The annual depositional flux was estimated at 1140 ± 120 Bq m−2 y−1. Assuming the same monthly deposition pattern and that the 7Be content in soil decreases only through radioactive decay, the seasonal variation of 7Be areal activity density in soil was estimated. Results of this investigation may contribute to a valuable characterization of 7Be input in the explored semiarid ecosystem and its potential use as tracer of environmental processes. 相似文献
3.
Di Gregorio DE Huck H Aristegui R De Lazzari G Jech A 《Journal of environmental radioactivity》2004,76(3):273-281
Gamma-ray spectra from more than 50 samples of food products available in stores of Buenos Aires city were measured using a germanium detector. Activity concentrations of 137Cs up to 10 Bq/kg were found in tea and yerba mate manufactured in Apóstoles, Argentina. Further measurements of tea leaves, yerba mate leaves and soils, all coming from a cultivated area in that region, also show the presence of 137Cs contamination. The results suggest that the area was fertilized with a product that originated in a region affected by the fallout from the Chernobyl nuclear plant accident. 相似文献
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5.
Gilad Heinisch Aldo Corriero Antonio Medina Francisco J. Abascal Jose-Miguel de la Serna Robert Vassallo-Agius Antonio Belmonte Ríos Antonio García Fernando de la Gándara Christian Fauvel Christopher R. Bridges Constantinos C. Mylonas Saadet F. Karakulak Isik Oray Gregorio De Metrio Hanna Rosenfeld Hillel Gordin 《Marine Biology》2008,154(4):623-630
Atlantic bluefin tuna (BFT; Thunnus thynnus) is a migrating species straddling the North Atlantic Ocean and Mediterranean Sea. It is assumed that this species is divided
into a western and an eastern stock, which spawn in the Gulf of Mexico and the Mediterranean Sea, respectively. To learn more
about the reproductive behavior of the eastern BFT stock, we tracked gonadal development in adult fish that were sampled between
April and July during three consecutive years (2003–2005). Sampling campaigns were carried out using common fishing methods
at selected locations within the Mediterranean Sea, namely Levantine Sea, Malta, and Balearic Islands. An additional sampling
point, Barbate, was situated northwest of the Straits of Gibraltar along the Atlantic coast. Morphometric parameters such
as the total body mass (M
B) and the weights of the gonads (M
G) were recorded, and the respective gonadosomatic index (GSI) values were calculated. The data collected revealed two important
trends: (1) GSI values are higher in fish caught in the eastern rather than the western locations across the Mediterranean
Sea, and (2) the GSI reaches maximum values between late May and early June in Levantine Sea (eastern Mediterranean Sea),
and only 2 and 4 weeks later in the central (Malta) and western (Balearic Islands) locations, respectively. The advanced gonadal
development in BFT correlates well with higher sea surface temperatures. Our findings also distinguish the northern Levantine
Sea BFT population (mean M
B 78.41 ± 4.13 kg), and the Barbate BFT population with the greatest M
B (all fish sampled > 100 kg). These data reflect a situation in which the eastern Mediterranean basin may function as a habitat
for young BFT, until they gain a larger M
B and are able to move to the Atlantic Ocean. However, the existence of genetically discrete BFT populations in the Mediterranean
Sea cannot be ruled out. 相似文献
6.
Growth, age and somatic production of the benthic predator Odontocymbiola magellanica were studied in Golfo Nuevo (42°S 65°W), on the South American Atlantic shelf. Stable oxygen isotope ratios confirmed semiannual
formation of internal and external shell growth marks. Mean shell length (SL) of females was 115 and 112 mm for males, while
population modal shell-free wet mass (SFWM) was 62.8 g. A Gompertz growth function (SL∞ = 200 mm, K = 0.197, t
0 = 5.486) fitted 113 pairs of size-at-age data (12 shells) best. O. magellanica is a long-lived species, reaching up to 20 years of age. The maximum individual somatic production of 29.3 g SFWM per year
is attained at 145 mm SL, which corresponds to about 12 years of age. The life span of this volutid seems to be twice compared
with other large gastropods. O. magellanica is a valuable and exploitable resource regarding its large size and somatic production, but on the other hand, its slow growth,
late maturity and direct development makes it extremely vulnerable to overexploitation. 相似文献
7.
Risk assessment approach for untreated wastewater using the QUAL2E water quality model 总被引:4,自引:0,他引:4
McAvoy DC Masscheleyn P Peng C Morrall SW Casilla AB Lim JM Gregorio EG 《Chemosphere》2003,52(1):55-66
This paper presents a novel approach for assessing the risk of consumer product ingredients in surface waters that receive untreated wastewater. The approach utilizes the water quality simulation model QUAL2E for predicting the impact caused by conventional pollutants, as well as the exposure concentration of consumer product ingredients. This approach invokes an impact zone concept whereby the receiving water can be thought of as a natural wastewater treatment system. After the river has recovered via self-purification, the ecosystem is then assessed by traditional risk assessment methods. This approach was validated using data collected from the Balatuin River, which is located in the Philippines. Results from this study support the use of QUAL2E for assessing the risk of consumer product ingredients in riverine systems receiving untreated wastewater. 相似文献
8.
Baumann Matthias Israel Christoph Piquer-Rodríguez María Gavier-Pizarro Gregorio Volante José Norberto Kuemmerle Tobias 《Regional Environmental Change》2017,17(4):1179-1191
Regional Environmental Change - The dry forests of Latin America are among the most dynamic deforestation frontiers in the world and are important carbon and biodiversity reservoirs. Our knowledge... 相似文献
9.
Olivia Gregorio Emma L. Berdan Genevieve M. Kozak Rebecca C. Fuller 《Behavioral ecology and sociobiology》2012,66(10):1429-1436
Reinforcement occurs when reduced hybrid fitness leads to the evolution of a stronger prezygotic isolation. Populations sympatric with closely related species, where hybridization occurs, are predicted to have stronger mate preferences than allopatric populations. The reinforcement of male mate preference is thought to be rarer than the reinforcement of female preference, but this inference may be biased by the lack of studies on male preference. We tested male mate preferences from sympatric and allopatric populations of two closely related species of killifish: Lucania goodei and Lucania parva. We found that sympatric males had greater preferences for conspecific females than allopatric males. Furthermore, conspecific preferences in allopatric populations were weakest when these populations were geographically distant (>50?km) from those of heterospecifics. Our data suggest that reinforcement has contributed to male conspecific preference and speciation in Lucania. 相似文献
10.
Buccinanops cochlidium is a common edible snail from Argentinean shallow waters, which is being consumed locally in north Patagonia. Nevertheless,
there are no policies for their fisheries management. This study provides information about the reproductive cycle and size
at first maturity of B. cochlidium from San José Gulf, Argentina. In this species, the testes seemed to develop mature sperm all year round without a resting
period although resorption was registered after periods of high evacuation (June–November). The occurrence of parasperm in
a nassariid species is reported for the first time in this study. Females showed a clear seasonality, without a resting period,
and proliferation of oogonia throughout the year. Evacuation of mature oocytes measuring over 220 μm occurred mainly in October.
Oocyte evacuation was associated with minimum seawater temperature and increasing daylength. Males developed a penis of functional
size and mature gametes in their testes at 37 mm in shell length (SL) but only began to mate at 65 mm in SL. Females matured
at 80 mm in SL, considering gonad maturity, mating behaviour and oviposition altogether. Female SL at first gonadal maturity
is close to the male maximum SL. The present results are useful when planning fishery policies aiming to prevent the overexploitation
of the resource, if an extensive fishery targeting on this species is developed. In case of this, we propose a fishery based
on an artisanal diving collection of individuals over 82 mm in SL, and avoiding to catch gravid females. 相似文献