1,337 research outputs found
Comparison of two soil tillage treatments for winter barley-soybean growing based only on residual nitrogen after soybean
The winter barley crop growing has not been adequately researched regarding soil tillage systems, especially in crop rotation with the soybean, both crops gaining importance as food or fodder. Also, productivity of such crop rotation in low nitrogen environment is especially interesting for organic crop growing, where mineral nitrogen fertilization is not allowed. The research on two soil tillage systems, the conventional one, based on mouldboard ploughing (PLOW) and reduced soil tillage, based on discharrowing (DISC), with no other nitrogen source except symbiotic soybean bacterial fixation, was conducted at the experimental site Bokšić (Croatia), during the seasons 2004/05 and 2005/06. Results showed low but stable yields of winter barley, between 2.1 and 2.6 t ha-1, where PLOW treatment recorded lower yield than DISC in 2005, and usual soybean yields (between 2.8 and 3.4 t ha-1), with higher soybean grain yields for PLOW only in 2006. The absolute mass and hectolitre mass did not show any statistical differences among treatments either
GARNETS OF MICA-SCHISTS FROM CRNI VRH AND RESAVSKI HUMOVI (SERBIA)
Metamorphic rocks of the Crni Vrh and Resavski Humovi area belong to the north-northwestern part of the Serbo-Macedonian Composite Terrane and consist of different types of mica-schists, gneisses and amphibolites. Mica-schists are composed of biotite, muscovite, garnet, staurolite, kyanite, small quantity of Kfeldspar, acid plagioclase and quartz. Accessory minerals are apatite, zircon, tourmaline and ilmenite. Garnets in mica-schists from both localities occur as subhedral to anhedral porphyroblasts from 0.2 to 10mm in size. Most garnets are oriented parallel to the dominant foliation. Garnets from the Crni Vrh mica-schists contain more spesartine component than garnets from Resavski Humovi, while almandine component show opposite tendency. The difference between those garnets is clearly visible, as well as zonality expressed through the increase of almandine component from center to the grain rim. The spesartine component as mentioned above, shows the opposite tendency. Using different geothermometers and geobarometers it was found that mica-schists from Crni Vrh were formed at temperatures from 550-600°C and pressures from 6-6.2 kbar, while micaschists from Resavski Humovi developed at slightly lower temperatures (520-560°C) and at some higher pressures (7-7.3 kbar)
High School Class for Gifted Pupils in Physics and Sciences and Pupils` Skills Measured by Standard and Pisa Test
The ``High school class for students with special abilities in physics`` was
founded in Nis, Serbia in 2003. The basic aim of this project has been
introducing a broadened curriculum of physics, mathematics, computer science,
as well as chemistry and biology. We present analysis of the pupils` skills in
solving rather problem oriented test, as PISA test, and compare their results
with the results of pupils who study under standard curricula. Analysis of
achievement data should clarify what are benefits of introducing in school
system track for gifted students. Additionally, item analysis helps in
understanding and improvement of learning strategies efficacy.Comment: 6 pages, Talk given at 7th International Conference of the Balkan
Physical Union, Alexandruoplos, Greece, 9-13 September 2009. To be published
in AIP Conf.Pro
Varieties of state capital:What does foreign state-led investment do in a globalized world?
Existing studies have scrutinized the rise of states as global owners and investors, yet we still lack a good understanding of what state investment does in a globalized economy, especially in host states. Comparative capitalisms research has analyzed foreign state investment as a potential source of patient capital for coordinated and mixed-market economies. However, this patient capital framework cannot explain the recent surge of protectionist sentiments, even among the "good hosts" of state-led investment. Therefore, we go beyond the patient capital argument and develop a novel framework centered on the globalized nature of foreign state investment. We create and empirically illustrate a novel typology based on different modes of cross-border state investment-from financial to strategic-and different categories of host states. Our results provide a new pathway to study the rise and effects of cross-border state investment in the 21st century
Endoscopic snare polypectomy of a pedunculated adenocarcinoma of the duodenal bulb arising from a hyperplastic polyp
Primary non-ampullary adenocarcinoma
of the duodenum is a rare occurrence,
arising mainly from adenomatous polyps
[1].We report the first case of a pedunculated
adenocarcinoma of the duodenal
bulb, arising from a hyperplastic polyp,
treated with endoscopic snare polypectomy.peer-reviewe
A new method for complexity determination by using fractals and its applications in material surface characteristics
In this article, a new method for complexity determination by using fractals in combination with an artificial intelligent approach is proposed and its application in laser hardening technology is detailed. In particular, nanoindentation tests were applied as a way to investigate the hardness properties of tool steel alloys with respect to both marginal and relevant changes in laser hardening parameters. Specifically, process duration and temperature were considered, together with nanoindentation, later related to surface characteristics by image analysis and Hurst exponent determination. Three different Machine Learning algorithms (Random Forest, Support Vector Machine and k-Nearest Neighbors) were used and predictions compared with measures in terms of mean, variability and linear correlation. Evidences confirmed the general applicability of this method, based on integrating fractals for microstructure analysis and machine learning for their deep understanding, in material science and process engineering
MACHINE LEARNING TOOLS IN THE ANALYZE OF A BIKE SHARING SYSTEM
Advanced models, based on artificial intelligence and machine learning, are used here to analyze a bike-sharing system. The specific target was to predict the number of rented bikes in the Nova Mesto (Slovenia) public bike share scheme. For this purpose, the topological properties of the transport network were determined and related to the weather conditions. Pajek software was used and the system behavior during a 30-week period was investigated. Open questions were, for instance: how many bikes are shared in different weather conditions? How the network topology impacts the bike sharing system? By providing a reasonable answer to these and similar questions, several accurate ways of modeling the bike sharing system which account for both topological properties and weather conditions, were developed and used for its optimization
Modelling the Surface Roughness of Steel after Laser hardening by using 2D Visibility Network, Convolutional neural Networks and Genetic Programming
The surface characterization of materials after Robot Laser Hardening (RLH) is a technically demanding procedure. RLH is commonly used to harden parts, especially when subject to wear. By changing their surface properties, this treatment can offer several benefits such as lower costs for additional machining, no use of cooling agents or chemicals, high flexibility, local hardening, minimal deformation, high accuracy, and automated and integrated process in the production process. However, the surface roughness strongly depends on the heat treatment and parameters used in the process. This article used a network theory approach (i.e., the visibility network in 2D space) to analyze the surface roughness of tool steel EN100083-1 upon RLH. Specifically, two intelligent methods were merged in this investigation. Firstly, a genetic algorithm was applied to derive a relationship between the parameters of the robot laser cell and topological surface properties. Furthermore, convolutional neural networks allowed the assessment of surface roughness based on 2D photographic image
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