48 research outputs found

    Poincaré's philosophy of mathematics

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    The primary concern of this thesis is to investigate the explicit philosophy of mathematics in the work of Henri Poincare. In particular, I argue that there is a well-founded doctrine which grounds both Poincare's negative thesis, which is based on constructivist sentiments, and his positive thesis, via which he retains a classical conception of the mathematical continuum. The doctrine which does so is one which is founded on the Kantian theory of synthetic a priori intuition. I begin, therefore, by outlining Kant's theory of the synthetic a priori, especially as it applies to mathematics. Then, in the main body of the thesis, I explain how the various central aspects of Poincare's philosophy of mathematics - e.g. his theory of induction; his theory of the continuum; his views on impredicativiti his theory of meaning - must, in general, be seen as an adaptation of Kant's position. My conclusion is that not only is there a well-founded philosophical core to Poincare's philosophy, but also that such a core provides a viable alternative in contemporary debates in the philosophy of mathematics. That is, Poincare's theory, which is secured by his doctrine of a priori intuitions, and which describes a position in between the two extremes of an "anti-realist" strict constructivism and a "realist" axiomatic set theory, may indeed be true

    The effect of nitrogen fertilization on root characteristics of Camelina sativa L. in greenhouse pots

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    Climate change has made mandatory the introduction of new crops in Greece, such as the cultivation of camelina [Camelina sativa (L.) Crantz]. Nitrogen (N) and the development of root system are two important factors affecting crop growth and yield. Camelina has been studied mainly for its composition and oil. In the present study, root development of camelina crop was thoroughly investigated; mainly in terms of Nitrogen fertilization. Therefore, a camelina greenhouse experiment was established in Western Greece, in the region of Agrinio, in March 2019 in completely randomized design with four treatments, (control 0 ppm N, 30 ppm N, 60, ppm N and 90 ppm N). The N rates had statistically significant affected root density and root surface from 40 to 120 days after treatment (DAT) with highest values at 100 DAT and 90 ppm N, 52.54 cm of root 100 cm-3 and 27.59 cm2 of root 100 cm-3 , respectively. The root volume was significantly affected by N fertilizer from 40 to 100 DAT and highest value was 13.18 cm3 of root 100 cm-3 soil in the 90 ppm at 120 DAT. The plant leaf area was significantly affected by the highest rate of N. Yield per plant had not statistically significant difference with the 60 and with the 90 and highest weight per plant 292.25 g plant-1 in 90 ppm. In conclusion, Ν fertilization significantly affected growth or camelina’s root system after 40 DAT. Plant growth was significantly affected by fertilization and the highest yield and 1,000 seed weight were recorded with the highest amount of N

    Cannabis sativa L.: A New Promising Crop for Medical and Industrial Use

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    The cannabis plant was discovered 10,000 years ago without its exact use being known in China and Central Asia. Equally highly interested in this plant are the pharmaceutical and construction sectors. The cultivation of Cannabis sativa L. varieties containing more than 0.2% tetrahydrocannabinol (THC) has been legalized by the law 4523/2018 in Greece for the sole purpose of producing end-products of medicinal cannabis. The use of medicinal cannabis is important for dealing with chronic diseases. As far as cannabis cultivated for industrial use is concerned, there is a significant increase in the secondary services sector. The resulting fibers are used for the manufacture of ropes etc. Especially CBD is of great interest. Through surveys carried out by the Agronomy Laboratory of Agricultural University of Athens regarding the development of cannabis by applying geotextiles, radiation management, cannabidiol (CBD) content and tetrahydrocannabinol (THC), statistical data have been compiled for cannabis cultivation both pharmaceutical and textile. On the basis of the results, cannabis can be grown in Greece due to the weather conditions and, above all, sunshine, which is the main factor for the development of the plant

    Effects of Tomato Pomace Composts on Yield and Quality of Processing Tomato (Lycopersicon esculentum Mill.)

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    Organic farming encourages the use of organic waste materials as substitutes for chemical fertilizers. Tomato pomace presents an alternative to inorganic fertilizer. A field experiment was carried out to evaluate the influence of tomato pomace composts and nitrogen fertilization on agronomic and quality parameters of the processing tomato. The experiment was laid out in a randomized complete block design with three replications and five fertilization treatments (untreated, nitrogen fertilizer, tomato pomace with biocyclic humus soil, tomato pomace with manure and tomato pomace with plant residues). The results showed that the highest average fruit weight and fruit yield (163.4 t/ha) were found in plots subjected to nitrogen fertilization, while the highest total soluble solids content (4.29 °Brix), and L* and a* colour parameters, important quality parameters to processing tomato industry, were obtained through the application of tomato pomace mixed with biocyclic humus soil making organic tomatoes suitable for processing tomato industry
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