329,069 research outputs found
NONCOMPACTION OF THE LEFT VENTRICULAR MYOCARDIUM IN CHILDREN: CLINICAL AND PHYSIOPATHOLOGIC FEATURES
No full textFazio, G; Novo, S; Zito, R; Icona, MA; Marchì, S; Mongiovì, S; Gagliano, S; Pipitone,
General Logistic Aspects
No full textA system is a collection of different elements that together produce results not obtainable by the elements alone. In this study, the system is a biodiesel- or a vegetable oil-based supply chain for energy purposes, variable under different technology level and raw material used. In this chapter, two examples of biodiesel supply chains at the industrial and the family farming scale, respectively, are outlined. In both cases, the major logistic problems are represented by transport costs and oil storability As a general rule, the higher the free fatty acid content, the lower the durability of an oil, although oils for energy purposes may be stored for longer time than oils for food uses
Economic Aspects: Assessment of Cropping Costs and Net Incomes
No full textCropping costs were assessed according to the crop techniques described in the specific scenarios of the previous chapters, concerning large-scale and family farming in South America and Africa. Estimation of costs was primarily derived from Embrapa agroeconomic section, FAOSTAT website (2009) and Mozambique Biofuels Assessment. Each entry accounts for manpower cost (even if family labour), raw materials and machinery costs (e.g., fertilization cost includes fertilizer, tractor plus fertilizer spreader cost per hour or man-days required per ha, fuel consumption, etc.), and fixed costs for administration and maintenance. For perennial crops, the establishment costs (nursery and planting) are divided by the economic lifespan of each crop, and calculated as annual equivalent cost. According to the above-described methodology, the annual costs to grow the six oil crops in large scale and family farming systems in Brazil and Mozambique are reported: they vary from a few hundreds Euros per hectare for some crops under family farming in Mozambique, to more than one thousand Euros, still in family farming, in Brazil. There is no clear relationship between cropping costs and net income, as the yield (grain or fruits) expected from each crop and the respective market prices widely vary in the two Countries. respective market prices widely vary in the two Countries: in Brazil, the two annual crops (sunflower and soybean) and perennial castorbean appear to outperform the rest of perennial species (oil palm, coconut palm and Jatropha), under large scale farming. Under family farming, net income is often negative in Brazil, if the cost of manpower is accounted for; this is particularly true in the case of the two annual species, which are intrinsically unsuited for a labour-intensive cropping. In contrast to Brazil, family farming in Mozambique exhibits more consistent, positive net incomes; the limited influence of manpower cost is clearly perceived
Identification of Suitable Plants for Oil Production in Dependence on Climate and Soil
No full textThe type of climate in a given area determines which plant species may be grown. Climatic classifications are, therefore, very important, as they allow to predict with an acceptable approximation which crops can be introduced to a new region. The Köppen Climate Classification System is most widely used for classifying the world’s climates. Its categories are based on the annual and monthly averages of temperature and precipitation. The major oil crops require specific conditions to be successfully grown. In general, the tree oil crops are palms that need warm environment such as tropical and subtropical zones, while the grain oil crops are more diffused in temperate to continental areas. Soil quality influences the growth of oil crops to a lesser degree than climate. However, soil fertility and soil characteristics significantly affect their yield. The principal soil types are: Alfisols, Andisols, Aridosols, Entisols, Gelisols, Histosols, Inceptisols, Mollisols, Oxisols, Spodosols, Ultisols and Vertisols. Their characteristics and potential for oil plant cropping are briefly reviewed
Oil Crops
No full textThe intrinsic characteristics of the oil crops which can potentially be grown in a given area are the main factor for the choice of the best suited species for that area. The oil palms (Elaeis spp.) comprise two species of the Arecaceae family, grown in commercial plantations for the production of edible oil since a long time; more recently, they are being dedicated to biodiesel production. Plants are monoecious, their fruits being drupes; they seldom are more than 8-10 m high in crop fields. The palm oil cycle starts with a long establishment phase, without any fruit yield for a few years. A modern palm plantation can yield more than 20 t/ha of fruits, which means almost 5 t of palm oil, plus additional kernel oil (around 60% of palm oil yield). Other palm species for oil production include the Macaúba or macaw palm (Acrocomia aculeata (Jacq.) Lodd. ex Mart.), which is raising a certain interest in Brazil, and the coconut palm (Cocos nucifera L.), which is grown throughout the tropics for food and industrial uses. Jatropha (Jatropha curcas L.) is a perennial, semi-evergreen shrub with glabrous, ascending branches, growing in tropical and subtropical regions, tolerating drought. The plant is poisonous, since it contains a toxin; the seed contains 27-40% of non-edible oil, which can be extracted to be directly used or further processed into biodiesel. Castorbean (Ricinus communis L.) is a fast-growing, suckering perennial shrub which can reach the size of a small tree. In the tropics, castorbean is perennial, whereas in temperate regions it cannot survive winter temperatures and is grown as an annual crop. The seed contains 40-60% of oil which is rich in unsaturated fatty acids. Sunflower (Helianthus annuus L.) is an annual herbaceous oil seed species. The plant is cropped in many warm regions of the world. It grows in the warm season, but is quite tolerant to low temperatures. At maturity, the dry fruit (achene) contains 40-50% oil. After oil pressing, the residual meal is rich in protein (about 30%), having a high value as animal feed. Soybean (Glycine max (L.) Merryl) is a leguminous species native to East Asia. Soybean is a short-day plant. Successful growth requires warm weather: optimum conditions are temperatures of 20 to 30 °C. The seed mainly contains protein (40%) and oil (20%) on a dry weight basis. The seed is normally processed into a vegetable oil, and in a defatted soybean meal which is a primary source of protein for animal nutrition. Oilseed rape (Brassica napus L. var. oleifera d.C.), is a yellow flowering member of the Brassicaceae family. Oilseed rape is typical of temperate-cold climate; in Central Europe and in the U.S. it is normally sown in the early autumn or in the early spring; the crop cycle ends in June or July. The seed is globose, small and contains about 40-45% of oil (dry weight basis) and 20-25% of protein
Optimization of Crop Farming in Dependence on the Local Preconditions
No full textThe oil crops addressed in this book can adapt to varying local conditions. However, there are major differences between cropping in large, mechanised farms and in small, labour-intensive farms (family farms). Depending on this and on the geographic area, different options may be taken into account in crop planning and in specific phases of cropping. The following survey shows the critical issues in the cropping of oil palm, coconut palm, castorbean, Jatropha, sunflower and soybean, and provides solution strategies, as well as the options for the two farming system mentioned above and for two world areas: South America, namely Brazil, and Africa. Reference to local sources is specifically indicated at the beginning of each crop. The aspects surveyed in the previously-described oil crops are: nursery, planting in the field, annual cropping operations (pruning, weeding, fertilization and plant protection) and harvest
General Characterisation and Applications of Plant Oils and Biodiesel
No full textVegetable oils or their derived product, biodiesel, are potential fuels for diesel engines, representing an alternative to fossil fuel. The suitability of the various oils and the respective biodiesels to be used in diesel engines depends on oil characteristics. The most promising crops, suitable for “short chain fuel oil” or biodiesel production are represented by seed/fruit crops, both herbaceous (annual) and tree (perennial) crops. The most suitable annual ones concerning both yield and oil characteristics are sunflower, oilseed rape and soybean; the most suitable perennial one is the oil palm, which is also the most largely grown. A first decisive factor in the choice of an oil crop is among annual and perennial species suitable for a given area. Another key issue are the physical and chemical properties of the pure plant oil, depending on the intended use: there are also climate-related parameters to be considered, as for example the melting point. The melting point indicates the temperature at which a solid material forms the first liquid droplets; this is especially important for processing or application of plant oils as biofuels. Directly related to the melting point is the iodine value, which is a measure for the amount of carbon double bonds present in the respective oil or fat, indicating the degree of saturation. Another important parameter which is crucial for the application of pure plant oil in engines is the kinetic viscosity, which is a measure of a fluid resistance to shear or tensile stress and the reciprocal value of the fluidity. The heating value or calorific value is the amount of heat released during the combustion of a specified amount of it. The cetane number is a measure of the ignitability or more exactly the ignition delay corresponding to the time period between start of injection and start of combustion. Biodiesel is a renewable fuel derived from vegetable oils which can be added at low ratio to most diesel fuels without substantially changing the fuel properties, as it shows comparable qualities as the crude oil based diesel fuel. In contrast to this, the use of pure plant oil in diesel engines is only suitable to a limited extent due to very high viscosities and poor cold flow properties. Biodiesel is chemically different from fossil diesel fuels, which leads to a number of special physical characteristics compared to the crude oil based fuel. It shows a higher viscosity, density, initial and final boiling point, cold-filter plugging point, and flash point. The lower calorific value compared to fossil diesel results in increased fuel consumption when using plant oil or biodiesel as diesel substitute. Pure plant oil and biodiesel show a significant higher flash point than fossil based diesel which is advantageous for handling the fuel especially in applications requiring high safety standards. The sulphur content of the biofuels is far lower than of standard diesel, which is another advantage as sulphur is supposed to have a negative effect on health and environment
Un nuovo testimone per le rime di Fazio degli Uberti
No full textThe paper aims to present a short fragment of a vernacular poetry manuscript (end of 14th c.), found in codex Lat. Z 478 (= 1661) of Venice's Biblioteca Nazionale Marciana. In particular, the author studies the contribution of this unknown witness to the text of the canzone Io guardo i crespi e i biondi capelli by Fazio degli Uberti, in the light of the stemma codicum Lorenzi had drawn in his recent critical edition of Fazio's poems (Pisa, 2013). Furthermore, the author examines the text transmitted by the Marcian codex of the pseudo-Boccaccian canzone Subita volontà, nuovo accidente. The essay is followed by the critical edition and by the commentary (focusing on linguistic, philological and literary aspects) of two unpublished sonnets
Introduction
No full textThere are unequivocal signs that global warming and the ensuing climate change are determined by the use of fossil fuels and represent a serious threat facing the planet. Dedicated crops are seen as one of the most interesting short-term option to replace fossil fuels and mitigate the global warming. Millions of hectares of energy crops are expected to be cultivated around the world in the next decades. Nonetheless, diverting agricultural lands to energy crops is a current subject of heated discussion, because of the possible threats to food security, and because of crop-related aspects, such as their environmental impacts, the economic sustainability and the site-specific adaptability. Nevertheless, global biofuel use is expected to increase twofold by 2015 and Brazil will remain the world’s top exporter, whereas the U.S. is expected to perform the largest increase in biofuel use per country. The most important liquid biofuels are bioethanol and biodiesel (FAME - Fatty Acid Methyl Ester) which are produced and as well as used world wide in reasonable amounts. Representatives of the following generation biofuels, such as hydrogenated vegetable oils (HVO), synthetic fuels (BtL - Biomass to Liquid), bioethanol and biodiesel from 2nd generation feedstocks (cellulose or hemi-cellulose) and Jatropha or algae are assumed to be superior to 1st generation biofuels. Beside biodiesel and bioethanol, there are several other biofuels under development, but only few of them passed the step of market launch and their availability is still limited. The most advanced technologies so far are the production of BtL-fuels by Fischer-Tropsch synthesis and HVO by hydrotreating of vegetable oils. BtL production claims to use the whole above-ground portion of ligno-cellulosic plants, but also residual material from biodiesel or bioethanol production. Hydrotreated vegetable oils (HVO) are vegetable oils which are transformed to hydrocarbons by a catalytic reaction
Environmental Impact of Oil Crops and Biofuels
No full textStudies on Life Cycle Assessment (LCA) of bioenergy chains based on dedicated crops in temperate climates show that biodiesel scenarios are generally less impacting than other possible energy chains, both in 1st generation and in 2nd generation biofuel settings. Considering the cropping techniques described for large scale farming in the previous chapters, a comparison of the environmental impacts of oil crops “from cradle to farm gate” was performed using the LCA methodology. More to this, a family farming scenario leaving manpower impact apart was calculated for comparisons with large scale farming systems. The phases and methods of LCA are described; a “cradle to farm gate” approach was adopted in the impact assessment of the oil crops. Results were standardized, i.e. reported in kg of equivalent reference substance, and normalized, i.e. weighted on the average level of emissions of one world inhabitant. Results are displayed both on both a surface (hectare) and energy (GJ) basis. The category most affected by agricultural processes is eco-toxicity of marine waters, although the primary cause of this emission is P fertilizer manufacture, which is upstream cropping. On a surface basis, the most impacting scenario was sunflower, in all considered categories, and in general both annual crops (sunflower and soybean) showed similar results. On an energy basis, the most impacting scenario was still sunflower under all impact categories, but the remaining scenarios show significant differences in comparison with the analysis on hectare basis: soybean showed emissions levels 40 to 60% lower than sunflower, although only one third of the emission per ha was allocated to oil production, the rest being spent for protein. Perennial crops showed high benefits respect to annual ones also on energy basis. A last topic addressed in this chapter is indirect land use change (ILUC). To convert land use change into consequent GHG emissions, a conversion factor must be applied. The level of GHG emissions associated with land use change will vary depending on previous land use; therefore, there is a wide range of possible conversion factors. GHG emissions are not the only impact of ILUC. Biodiversity is also adversely affected by land conversion in the form of ecosystem degradation and habitat loss. Biodiversity and ecosystems–and the services they provide are closely connected to each other and to the climate system. Biodiversity is crucial for both mitigation of and adaptation to climate change. However, the substitution of many food crops (e.g., cereals) with energy crops often requiring less fertilizers and pesticides, determines a net benefit in terms of biodiversity. Another way of limiting ILUC consequences would be shifting to second generation biofuels, which are now on the eve of diffusion in advanced countries
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