排序方式: 共有15条查询结果,搜索用时 15 毫秒
1.
In this study an abiotic process was suggested to evaluate the behaviour of Pyrimethanil (antibotrytic fungicide) in real matrices. This process consists of a photodegradation of the fungicide carried out in the presence of iron(III) in three types of buffer; acetate, phosphate and citrate. The experimental results show that the nature of buffered solutions influences both the rate of disappearance of Pyrimethanil and, in the case of citrate, also the kind of by-products formed during the photodegradation process. For each case examined, the breakdown products were identified by using liquid chromatography (LC) or gas chromatography (GC), coupled with mass spectrometry (MS). The degradation pathways of the fungicide were proposed and the relative kinetic constants were evaluated. The abiotic photodegradation process shows the possibility of different pathways for Pyrimethanil degradation in environmental matrices such as the soil, plants and foodstuffs, where iron (free and/or bonded) is a natural component. 相似文献
2.
Karyotypic characterization of the great sturgeon, Huso huso, by multiple staining techniques and fluorescent in situ hybridization 总被引:1,自引:0,他引:1
F. Fontana J. Tagliavini L. Congiu M. Lanfredi M. Chicca C. Laurente R. Rossi 《Marine Biology》1998,132(3):495-501
A karyotype analysis by several staining techniques was carried out on the great sturgeon, Huso huso (Linnaeus, 1758). The karyotype (2n = 118 ± 2) was composed of 42 pairs of meta-/submetacentric chromosomes and 17 pairs of acrocentrics/microchromosomes. Constitutive
heterochromatin was mainly located at the centromeric regions of the acrocentric chromosomes. The biarmed chromosomes showed
weak C-bands. Fluorescent staining with GC-specific chromomycin A3 showed clearly recognizable fluorescent regions, whereas a more uniform base composition was revealed by the AT-specific
4,6-diamidino-2 phenylindole. After Ag-staining, nucleolar organizer regions could be observed on the short arms of two medium-sized
submetacentrics and on two acrocentrics. Digoxigenated 28S and 5S rDNA probes, prepared from Acipenser naccarii DNA and hybridized to metaphase chromosomes, showed signals on six and two chromosomes, respectively. The telomeric sequence
(TTAGGG)
n
detected by FISH was located at both ends of each chromosome. Results are discussed in relation to karyotype organization
and evolution in sturgeons.
Received: 1 April 1998 / Accepted: 21 July 1998 相似文献
3.
4.
Characterization and leaching of NiCd and NiMH spent batteries for the recovery of metals 总被引:4,自引:0,他引:4
Since NiMH and NiCd batteries are still used in the electronic devices market, a treatment and recycling plant has many advantages both from the environmental and the economic points of view. Unfortunately, there is no relationship between shape, size and chemical composition of spent batteries, consequently the characterization and the leaching method of the starting material becomes an important step of the overall treatment process in choosing the best conditions for the selective separation of the metals by hydrometallurgy. Leaching at 20 degrees C with H(2)SO(4) 2M for about 2h seems to be a good solution in terms of cost and efficiency for both battery types. The hydroxide compounds can be readily leached while Ni present as metallic form requires more aggressive conditions due to kinetic constraints. In this paper, the characterization of NiMH and NiCd spent batteries and the results of leaching tests in different conditions are reported. 相似文献
5.
A. Marin M. D. López M. A. Esteban J. Meseguer J. Muñoz A. Fontana 《Marine Biology》1998,131(4):639-645
The marine sponge Dysidea fragilis from El Mar Menor, a hypersaline coastal lagoon (Murcia, Spain), contains the furanosesquiterpenoid ent-furodysinin as the major secondary metabolite. D. fragilis emits a defensive white fluid when it is disturbed. Electron micrographs of this fluid revealed intact vesiculated cells
together with other amorphous material. Dissociated cells are more rounded in shape but maintain the same ultrastructural
features as cells observed in ultra-thin sections of the whole sponge. The defensive secretion is composed mainly of sponge
cells with abundant light vesicles. Sometimes these light vesicles appear to open into the intercellular space; this correlates
with surface blebs on these cells observed under scanning electron microscopy. The intracellular location of ent-furodysinin was confirmed by Erlich staining. In laboratory assays, we examined the role of ent-furodysinin as a feeding deterrent to generalist fish predators. It was isolated from D. fragilis and incorporated into a carrageenan-based artificial diet. The addition of ent-furodysinin to the artificial diet reduced feeding by the fish Thalassoma pavo. Similarly, fish did not feed on artificial diet above which defensive secretion of D. fragilis had been ejected with a small syringe.
Received: 4 June 1997 / Accepted: 28 January 1998 相似文献
6.
Fontana Danilo Pietrantonio Massimiliana Pucciarmati Stefano Torelli Giorgia Nadia Bonomi Chiara Masi Federica 《Journal of Material Cycles and Waste Management》2018,20(2):1199-1206
Journal of Material Cycles and Waste Management - Palladium finds a remarkable use in electronic devices and catalysts; therefore, an efficient and complete recovery from the containing secondary... 相似文献
7.
Elena Cantarello Claude E. Steck Paolo Fontana Diego Fontaneto Lorenzo Marini Marco Pautasso 《Die Naturwissenschaften》2010,97(3):265-271
Recent large-scale studies have shown that biodiversity-rich regions also tend to be densely populated areas. The most obvious explanation is that biodiversity and human beings tend to match the distribution of energy availability, environmental stability and/or habitat heterogeneity. However, the species–people correlation can also be an artefact, as more populated regions could show more species because of a more thorough sampling. Few studies have tested this sampling bias hypothesis. Using a newly collated dataset, we studied whether Orthoptera species richness is related to human population size in Italy’s regions (average area 15,000 km2) and provinces (2,900 km2). As expected, the observed number of species increases significantly with increasing human population size for both grain sizes, although the proportion of variance explained is minimal at the provincial level. However, variations in observed Orthoptera species richness are primarily associated with the available number of records, which is in turn well correlated with human population size (at least at the regional level). Estimated Orthoptera species richness (Chao2 and Jackknife) also increases with human population size both for regions and provinces. Both for regions and provinces, this increase is not significant when controlling for variation in area and number of records. Our study confirms the hypothesis that broad-scale human population–biodiversity correlations can in some cases be artefactual. More systematic sampling of less studied taxa such as invertebrates is necessary to ascertain whether biogeographical patterns persist when sampling effort is kept constant or included in models. 相似文献
8.
Brian Baily Alastair Pearson Peter Collier Dominic Fontana 《Journal of Coastal Conservation》2002,8(1):77-86
This paper discusses a research project dealing with the mapping of the intertidal vegetation of several harbours along the
southern coastline of England. It describes in detail the methods used to map the vegetation and gives examples of the results
from these studies. This paper then goes on to explain how these results are applied by the Environment Agency of England
and Wales to improve water quality in the harbours. This type of vegetation mapping is useful in monitoring the development
of the intertidal species includingSpartina, Zostera and of particular importance to this study the green algaeUlva andEnteromorpha. The work was undertaken with funding from the Environment Agency and at present has taken place over a four year period.
The data collected will be used by the Environment Agency to assess macro-algae covervalues for the intertidal area of the
harbours concerned. This forms part of the Agency's commitment to the EU Nitrates Directive and the Urban Waste Water Treatment
Directive. Some of the species mapped act as suitable indicators of water quality and are symptoms of entrophication. Other
species are of interest for nature conservation and were recorded to provide a record for longer-term trends in vegetation
patterns within the harbour. This paper aims to provide readers with an understanding of the techniques involved as well as
an evaluation of the methodology. 相似文献
9.
10.
Real‐Time Analysis of Energy Generation of a Photovoltaic System Installed in the City of Lajeado,Rio Grande do Sul 下载免费PDF全文
Luís Eduardo Fontana Alberto Benguria Bezama Camila Hasan Munique Marder Odorico Konrad 《环境质量管理》2016,26(2):105-119
Considering successive and costly increases in electricity rates, this article evaluates the generation of electricity from a photovoltaic system using solar energy, a renewable source. The solar photovoltaic system is installed at UNIVATES University Center, a public university in the state of Rio Grande do Sul, Brazil, and it is also connected to the electrical grid. Data related to the climatic conditions of the location, such as incident solar radiation, rainfall, and mean temperature, were obtained during the system's evaluation period and used along with bibliographic research on similar systems installed in southern Brazil. Our study quantified the energy produced over one calendar year (2014) and related it to the climatic variables and the conversion efficiency achieved by the system's photovoltaic modules. Our results show that there is both a strong relationship between the production of energy and climatic conditions and that the city, Lajeado, and the Brazilian state of Rio Grande do Sul, have good potential to supply energy using photovoltaic systems connected to the electrical grid. The horizontal global solar radiation average obtained in the study location was 4.14 kilowatts per square meter per day (kWh/m2/day), and the average monthly production of energy reached 243.93 kWh/m2/month, with a total of 2,927.10 kWh produced in 2014, achieving a monthly average conversion efficiency of 11.07%. This conversion efficiency is close to the value of 12.6% obtained in 2013 in a similar study of the same solar photovoltaic system conducted over a shorter time period. 相似文献