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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Agrarkolonisation im Alto Beni Landschafts- und politisch-ökologische Entwicklungsforschung in einem Kolonisationsgebiet in den Tropen Boliviens /

Elbers, Jörg. January 2002 (has links)
Düsseldorf, Univ., Diss., 2002. / Computerdatei im Fernzugriff.
2

Agrarkolonisation im Alto Beni Landschafts- und politisch-ökologische Entwicklungsforschung in einem Kolonisationsgebiet in den Tropen Boliviens /

Elbers, Jörg. January 2002 (has links)
Düsseldorf, Univ., Diss., 2002. / Computerdatei im Fernzugriff.
3

Agrarkolonisation im Alto Beni Landschafts- und politisch-ökologische Entwicklungsforschung in einem Kolonisationsgebiet in den Tropen Boliviens /

Elbers, Jörg. January 2002 (has links) (PDF)
Düsseldorf, Universiẗat, Diss., 2002.
4

Spatialités maghrébines traditionnelles étude d'un cas, les Beni-Zéroual.

Tengour, Habib, January 1987 (has links)
Th. 3e cycle--Sci. des relig.--Paris 7, 1985.
5

Pastoral development in Eritrea and Eastern Sudan : implications for livestock extension programmes

Fre, Zeremamiam January 1989 (has links)
No description available.
6

Assessment and optimization of chemical industrial processes from a life cycle perspective

Cespi, Daniele <1987> 08 April 2015 (has links)
During the PhD program in chemistry, curriculum in environmental chemistry, at the University of Bologna the sustainability of industry was investigated through the application of the LCA methodology. The efforts were focused on the chemical sector in order to investigate reactions dealing with the Green Chemistry and Green Engineering principles, evaluating their sustainability in comparison with traditional pathways by a life cycle perspective. The environmental benefits associated with a reduction in the synthesis steps and the use of renewable feedstock were assessed through a holistic approach selecting two case studies with high relevance from an industrial point of view: the synthesis of acrylonitrile and the production of acrolein. The current approach wants to represent a standardized application of LCA methodology to the chemical sector, which could be extended to several case studies, and also an improvement of the current databases, since the lack of data to fill the inventories of the chemical productions represent a huge limitation, difficult to overcome and that can affects negatively the results of the studies. Results emerged from the analyses confirms that the sustainability in the chemical sector should be evaluated from a cradle-to-gate approach, considering all the stages and flows involved in each pathways in order to avoid shifting the environmental burdens from a steps to another. Moreover, if possible, LCA should be supported by other tools able to investigate the other two dimensions of sustainability represented by the social and economic issues.
7

Advanced Oxidation Processes Based on Photocatalysis for the Degradation of Organic Contaminants in Water

Saracino, Michela <1982> 27 April 2016 (has links)
Many organic pollutants are daily released into the environment or pass through the wastewater treatment plants contaminating surface and drinkable water. Part of these pollutants belongs to the category of the emerging organic contaminants since they are still unregulated or in process of regularization. They give cause of concern since they are dangerous for human health and for the survivor of a large number of living organisms. The implementation of wastewater treatment plants against the emerging contaminants is one of the challenges for the enhancement of the water quality, and advanced oxidation processes represent new technologies very promising as tertiary treatments. The research activity carried out during my PhD course focused on degradation test on aqueous solutions contaminated with different class of pollutants such as surfactants, pharmaceuticals and personal care products, both as single compound solutions and mixture of contaminants. The photocatalytic process was studied developing a new pre-industrial pilot plant and testing new TiO2-based photocatalysts in a view of a technological transfer of the photocatalytic methodology. The reuse of a photocatalyst consisting of TiO2 supported on a solid substrates was also investigated with the aim to avoid some problems related to the use of a dispersed catalyst. Photocatalytic process coupled with ultrasounds was also examined in order to speed up the decomposition of the pollutants. The disappearance of every pollutant was followed by HPLC analysis and the mineralization was assessed by the determination of total organic carbon. In the end, the energy consumption related to the processes tested on the mixture of contaminants was calculated in order to establish the best methodology to obtain good degradation rate with reasonable costs.
8

The Influence of the Environment on the Atmospheric Corrosion of Weathering Steel: Field and Laboratory Studies

Raffo, Simona <1987> January 1900 (has links)
Weathering steel (WS) describes a class of material, presenting higher corrosion resistance and enhanced mechanical properties than carbon steel when exposed to medium-aggressive environments (rural, urban and light-industrial). The chemical composition of WS, including elements such as Cu, Cr, Ni, Mn, promotes the creation of an adherent passivation layer, which opposes the entry of corrosive species and protects material from further corrosion. However, depending on the exposure environment, the evolution and the composition of patinas can strongly change; the exposure to corrosive atmospheres (i.e., marine sites and industrial/urban areas) destabilizes the patina and reduces corrosion resistance, leading WS to be more susceptible to corrosion and wash-out processes. Consequently, WS releases a certain quantity of alloying metals that could disperse in surrounding areas (soil or water); depending on their chemical form, mobility and bioavailability, some of these elements could represent an hazard to the environment and to living organisms, because of their persistence and potential chronic toxicity. In this work, the issue of atmospheric corrosion of WS was extensively investigated through field and laboratory tests, to evaluate and quantify the effects that surface treatments, exposure geometry, environmental factors and main atmospheric contaminants may have on WS corrosion. Specifically, the characterization of the composition and morphology of corrosion products formed on WS was combined with an innovative approach, that is the quantification of metal dissolution during the early years of exposure, when environmental impact could be greater, and the application of multivariate data analysis. A specific focus was made on the interaction of material with the main aggressive saline ions contained in particulate matter. This work allowed to give a more complete and comprehensive characterization of the environmental behavior of weathering steel and to point out interesting conclusion on the main environmental aspects affecting outdoor corrosion of this material.
9

Contamination Trends of Legacy and Emerging Compounds in Sediments from the Adriatic Sea

Combi, Tatiane <1987> January 1900 (has links)
Sediments are the final repositories for most pollutants, which can accumulate and remain in the sedimentary matrix for long periods of time and may accumulate through the food web, affecting marine biota, aquatic-dependent wildlife, and ultimately human health. Thus, a wide-ranging work monitoring different groups of contaminants in sediments is a key tool for a comprehensive understanding of contaminants behavior and identification of the overall environmental quality and possible threatens to the whole marine ecosystem. POPs, among which PCBs and DDTs rank first, polycyclic aromatic hyrocarbons (PAHs), and selected groups contaminants of emerging concern (CECs) (fragrances, UV filters, endocrine disruptors) were the objective of this work. First, PCB congeners were analyzed in sediment cores and recent sediments along the north-south axis of the western Adriatic Sea. Chronological records of PCB concentrations and homologue patterns were assessed, supporting the reconstruction of PCBs fluxes and total inventories. Then, the spatial distribution and fate of selected legacy and emerging compounds were investigated in surface sediments sampled along the Adriatic mud-wedge and in deep-sea regions from the southern Adriatic basin, providing the first extensive dataset and also the evaluation of potential ecotoxicological risk of target emerging contaminants in sediments from the Adriatic Sea. Finally, the analyzes of selected legacy contaminants (PCBs, DDTs and PAHs) in sediment cores from coastal and deep-sea sediments from the Adriatic Sea supported the comparison between these two areas and further reinforces the hypothesis on the transfer of contaminants from contaminated areas in the northern Adriatic to the deep southern Adriatic basin. The present thesis is the summary of the work carried out in the last three year of the PhD program “Scienze ambientali: tutela e gestione delle risorse naturali” and contains three manuscripts (two under review and one in preparation), and the main conclusions regarding this PhD research project.
10

Le massif des Beni Snassen (Maroc oriental) géologie, géographie physique, climatologie, ethnographie /

Boigey, Maurice, January 1900 (has links)
Thesis (Ph. D.)--Université de Paris. / Includes bibliographical references.

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