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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

1st and 2nd Generation Ethanol from Biomass Crops

Capecchi, Lorenzo <1983> 18 May 2015 (has links)
In chapter 1 and 2 calcium hydroxide as impregnation agent before steam explosion of sugarcane bagasse and switchgrass, respectively, was compared with auto-hydrolysis, assessing the effects on enzymatic hydrolysis and simultaneous saccharification and fermentation (SSF) at high solid concentration of pretreated solid fraction. In addition, anaerobic digestion of pretreated liquid fraction was carried out, in order to appraise the effectiveness of calcium hydroxide before steam explosion in a more comprehensive way. In As water is an expensive input in both cultivation of biomass crops and subsequent pretreatment, Chapter 3 addressed the effects of variable soil moisture on biomass growth and composition of biomass sorghum. Moreover, the effect of water stress was related to the characteristics of stem juice for 1st generation ethanol and structural carbohydrates for 2nd generation ethanol. In the frame of chapter 1, calcium hydroxide was proven to be a suitable catalyst for sugarcane bagasse before steam explosion, in order to enhance fibre deconstruction. In chapter 2, effect of calcium hydroxide on switchgrass showed a great potential when ethanol was focused, whereas acid addition produced higher methane yield. Regarding chapter 3, during crop cycle the amount of cellulose, hemicellulose and AIL changed causing a decrease of 2G ethanol amount. Biomass physical and chemical properties involved a lower glucose yield and concentration at the end of enzymatic hydrolysis and, consequently, a lower 2G ethanol concentration at the end of simultaneous saccharification and fermentation, proving that there is strong relationship between structure, chemical composition, and fermentable sugar yield. The significantly higher concentration of ethanol at the early crop stage could be an important incentive to consider biomass sorghum as second crop in the season, to be introduced into some agricultural systems, potentially benefiting farmers and, above all, avoiding the exacerbation of the debate about fuel vs food crops.
2

Traditional crops and foods: documentation, analytical characterization, retention factors of bioactive compounds / Colture e alimenti tradizionali: documentazione, caratterizzazione analitica e ritenzione di composti bioattivi

Giambanelli, Elisa <1983> January 1900 (has links)
In recent years the interest of consumers and manufacturers on traditional foods and biodiversity has been constantly growing. The definition of traditional foods has been scientifically elaborated with different approaches, mainly based on a top-down approach. During BaSeFood, a 3 year research programme, investigations were carried out in Black sea area countries, Italy and Portugal, following a scheme of qualitative cross-cultural, on-site surveys of traditional foods and plant raw materials; the information collected has been the basis for both an extensive documentation and the selection and sampling of material to be entered in the experimental phase. A similar scheme was followed in an area of Northern Tuscany (Italy), focussing on local species and critical points in food preparation. The experimental part, was aimed at: a) evaluating the variability of local populations of the selected crops, with respect to key phytochemical compounds content; b) analyze the retention of phytochemicals following cooking/processing. Primitive wheats, mainly represented by Triticum monococcum and Triticum dicoccum, and leafy vegetables of Brassicaceae and Asteraceae families were locally collected as target species. The fate of primitive wheats phytochemicals was monitored during traditional processing of glume removal and kernel crushing, in comparison with a modern plant: besides the efficiency of the process, no relevant differences were found in bioactive compounds retention. In Brassica, retention of main phytochemical compounds was evaluated following the most common cooking methods (boiling, steaming and stir frying), also applying kinetic modelling. Retention was mainly affected by cooking method and duration, plant matrix (extractability) and the chemical nature of individual compounds. Finally, glucosinolate thermal degradation was analyzed in different binary model systems, containing broccoli, to assess the effect of added ingredients during thermal treatment. Added ingredients could play an important role on retention, however further studies are still necessary to better understand which mechanisms are involved.
3

Nutraceutical Value of Durum Wheat: Influence of Environment and Genotype in a Large Scale Experimental Trial

Di Loreto, Alessandro <1985> January 1900 (has links)
Grain quality is well known as one of the most interesting breeding objectives in Mediterranean countries. It still has great importance in wheat markets because of the increased interest of the consumers for high-quality staple food such as pasta, couscous and various types of bread. The performance of many quality characteristics depends greatly on environmental conditions and, in this context, organic agriculture could guarantee a durum wheat material with high nutraceutical value for healthy food production and special dietary uses. Among organic wheat production, KAMUT® khorasan wheat (Triticum turgidum ssp. turanicum (Jakubz.)) has attracted great attention due to its specific nutritional and functional properties (antioxidant, anti-inflammatory, and prebiotic activities). The aim of this thesis was to evaluate the environmental and climatic effects on the nutritional and nutraceutical quality of organic durum and durum-type wheat varieties. The work was subdivided into three main sections aimed at understanding the dynamic affecting the accumulation of nutritional and functional compounds in wheat caryopsis of durum and durum type wheat varieties. The first two section provide a complete characterization of KAMUT® khorasan grain. This is a distinctive study: first a collection of the same organically grown genotype collected during two decades of cultivation was characterized for nutritional and functional properties; then the investigation has shifted to the same crop harvested in a vast region (180000 km2), including several different environments. In the third section 24 old and modern durum and durum-type wheat varieties, cropped in the same location and growing season, were analyzed in order to determine and compare the phenolic composition. Results obtained gives a fundamental understanding of durum wheat grains composition in terms of nutrient and bioactive compounds.
4

Innovative techniques for sport turf managing: Agronomic and phyisiological implications / Tecniche innovative a base di prodotti biologici nella gestione di prati sportivi professionali: Implicazioni agronomiche e fisiologiche

Accorsi, Mattia <1984> 27 May 2014 (has links)
The growing substrate of the putting greens is considered a key factor for a healthy turf ecosystem. Actually detailed study on the effects of growth promoting bacteria and biostimulants on a professional sport turf are very limited. This thesis aimed to study the effectiveness of different microorganisms and biostimulants in order to improve the knowledge relative to the relationship between the beneficial microflora and root apparatus of sport turfs. The research project was divided in three principal steps: Initially, commercial products based on biostimulants and microorganisms were tested on a Lolium perenne L. essence grown in a controlled-environment. The principal evaluations were the study of the habitus of plants, biomass production and length of leaves and roots. Were studied the capacity of colonization of microorganisms within root tissues and rhizosphere. In the second step were developed two different biostimulant solutions based on effective microorganisms, mycorrhizae and humic acids. This test was conducted both on an Agrostis stolonifera putting green (Modena Golf & Country Club) in a semi-field condition and within a growth chamber on a Lolium perenne L. essence. Fungicide and chemicals applications were suspended in order to assess the effectiveness of the inoculants for nutrition and control of pests. In the last step, different microorganism mixes and biostimulants were tested on an experimental putting green in the Turf Research Center (TRC) (Virginia Tech, United States) in a real managing situation. The effects of different treatments were studied maintaining all chemicals and mechanicals managements scheduled during a sport season. Both growth-chamber and field results confirmed the capacity of microorganisms based biostimulants to promote the physiologic conditions of the plants, improve the growth of the roots and enhance the aesthetic performance of the turf. Molecular analysis confirmed the capacity of microorganisms to colonize the root tissues.
5

Studio delle proprietà idrologiche in suoli agrari

Salvatorelli, Fiorenzo <1979> 08 June 2007 (has links)
No description available.
6

New water use efficiency strategies to cope with climate change

Guerra, Elisa <1982> 10 June 2013 (has links)
Crop water requirements are important elements for food production, especially in arid and semiarid regions. These regions are experience increasing population growth and less water for agriculture, which amplifies the need for more efficient irrigation. Improved water use efficiency is needed to produce more food while conserving water as a limited natural resource. Evaporation (E) from bare soil and Transpiration (T) from plants is considered a critical part of the global water cycle and, in recent decades, climate change could lead to increased E and T. Because energy is required to break hydrogen bonds and vaporize water, water and energy balances are closely connected. The soil water balance is also linked with water vapour losses to evapotranspiration (ET) that are dependent mainly on energy balance at the Earth’s surface. This work addresses the role of evapotranspiration for water use efficiency by developing a mathematical model that improves the accuracy of crop evapotranspiration calculation; accounting for the effects of weather conditions, e.g., wind speed and humidity, on crop coefficients, which relates crop evapotranspiration to reference evapotranspiration. The ability to partition ET into Evaporation and Transpiration components will help irrigation managers to find ways to improve water use efficiency by decreasing the ratio of evaporation to transpiration. The developed crop coefficient model will improve both irrigation scheduling and water resources planning in response to future climate change, which can improve world food production and water use efficiency in agriculture.
7

Soil organic carbon dynamics under perennial energy crops

Zatta, Alessandro <1976> 10 June 2013 (has links)
The European renewable energy directive 2009/28/EC (E.C. 2009) provides a legislative framework for reducing GHG emissions by 20%, while achieving a 20% share of energy from renewable sources by 2020. Perennial energy crops could significantly contribute to limit GHG emissions through replacing equivalent fossil fuels and by sequestering a considerable amount of carbon into the soil through the large amounts of belowground biomass produced. The objective of this study is to evaluate the effects of land use change that perennial energy crops have on croplands (switchgrass) and marginal grasslands (miscanthus). For that purpose above and belowground biomass, SOC variation and Net Ecosystem Exchange were evaluated after five years of growth. At aboveground level both crops produced high biomass under cropland conditions as well as under marginal soils. At belowground level they also produced large amounts of biomass, but no significant influences on SOC in the upper layer (0-30 cm) were found. This is probably because of the "priming effect" that caused fast carbon substitution. In switchgrass only it was found a significant SOC increase in deeper layers (30-60 cm), while in the whole soil profile (0-60 cm) SOC increased from 42 to 51 ha-1. However, the short experimental periods (for both switchgrass and miscanthus), in which land use change was evaluated, do not permit to determine the real capacity of perennial energy crops to accumulate SOC. In conclusion the large amounts of belowground biomass enhanced the SOC dynamic through the priming effect resulting in increased SOC in cropland but not in marginal grassland.
8

Soil tillage and crop rotation effects on Triticum durum (Desf.) yield and mycotoxins content in its grain

Babini, Viviana <1963> 19 June 2007 (has links)
No description available.
9

Sperimentazione e modellizzazione della fenologia di colture erbacee. Il caso di studio nella stazione Agrofenologica di Cadriano

Traini, Simon <1977> 08 June 2007 (has links)
No description available.
10

Interazione fra biosintesi dei lipidi e fotosintesi in Brassicaceae oleaginose: effetto dell'epoca di raccolta e della radiazione luminosa

Bezzi, Guido <1978> 24 June 2008 (has links)
No description available.

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