Automated Detection of Human Users in Twitter

AbstractThis paper compares Suppport Vector Machine (SVM) classification and a number of clustering approaches to separate human from not human users in Twitter in order to identify normal human activity. These approaches have similar F1 accuracy scores of 90% with both experienc- ing difficulties in classifying human users behaving abnormally. A second stage classification step was then used to further separate not human users into brands, celebrities and promoters / information achieving an average F1 accuracy of 74%. These accuracies were achieved by reducing the size of the feature space using stepwise feature selection and category balancing from manual inspection of classification results

Lubricious TiSi(V)N coatings for extreme temperature application deposited by Deep Oscillation Magnetron Sputtering (DOMS) mode

Development of new self-lubricant coating systems with control of the lubricous species diffusion have enormous potential to be used in the protection of surfaces in components for machining. In the last years, vanadium rich coatings have been introduced as possible candidates for self-lubrication due to their optimum tribological properties. This work is devoted on the study of V additions on the morphology, structure and on the tribological properties of TiSiN films deposited by HiPIMS in Deep Oscillation Magnetron Sputtering (DOMS) mode. Two different peak powers were used on the deposition of coatings in order to produce films with different morphology. The tribological properties of coatings were evaluated at room temperature against Al2O3 balls on a pin-on-disc apparatus. Increasing of peak power showed to change the cross section morphology of films from columnar type to compact structure. V additions improved the tribological properties of TiSiN coatings.This research is sponsored by FEDER funds through the program COMPETE – Programa Operacional Factores de Competitividade – and by national funds through FCT – Fundação para a Ciência e a Tecnologia, under the projects: PTDC/EMETME/ 122116/2010 and PTDC/EMS-TEC/1805/2012. The authors acknowledge the Master student Melkamu A. Mekicha (co-author of this paper) from the International Joint European Master in Tribology of Surfaces and Interfaces (TRIBOS) program, doing his thesis in the mechanical engineering department of the University of Coimbra, for his special dedication on the development of this research

Different environmentaly-friendly strategies for loading waterborne polyurethane and polyurethane-urea dispersions

The environmental awareness has increased the research and development of eco-friendly green synthesis routes for many different applications, such as the waterborne polymer systems. Among others, waterborne polyurethanes (WBPU) and waterborne polyurethane-ureas (WBPUU) have gained attention due to their versatility in terms of composition and properties, making them suitable in a wide range of applications [1]. WBPU and WBPUU synthesis process is based on the incorporation of internal emulsifiers covalently bonded to the polymer obtaining stable water dispersions over months. Furthermore, the waterborne character of the dispersions provides the opportunity of incorporating water dispersible nanoentities and water soluble additives, enhancing or even providing additional properties. In this context, the use of renewable derivatives opens the possibility of enhancing the environmentally-friendly character. Among them, cellulose nanocrystals (CNC) are presented as a suitable candidate for the preparation of nanocomposites, considering their unique properties in the nanoscale dimension, provided by their high length/diameter aspect ratio and high specific mechanical properties [2]. Otherwise, the incorporation of natural water soluble additives has focused attention on extracts obtained from plants, consisting in biologically active compounds [3], whose antimicrobial character can determine the antimicrobial behavior of the WBPU and WBPUU. Therefore, in this work, different strategies have been analyzed for the preparation of WBPU-CNC nanocomposites and WBPUU-plant extracts varying their content as well as their incorporation route.info:eu-repo/semantics/publishedVersio

Avoided energy cost of producing minerals: The case of iron ore

There is growing concern about the decline of the ore grade in mines and the increased energy usage for processing and refining metals. In the limit, where no concentrated deposits exist, minerals must be obtained from bare rock. A method for quantitatively assessing the “free bonus” granted by nature in providing concentrated minerals in mines and thus assessing the quality of the different resources is estimating how much energy is needed to concentrate the minerals, as they are already in mines, from bare rock. This bonus granted by nature reduces the costs of human mining and metallurgical processes, as well as the mining effort required of future generations. In this study, the concentration of high-iron-content minerals in common rocks was investigated via a computational model developed using the HSC software. As expected, the range of results for the specific energy for the concentration of iron from common rocks was considerably higher than the energy required by modern processes. This reveals the need to value current iron deposits and the challenge of developing sustainable methods of metal production to satisfy the needs of the present and future generations

Development of waterborne polyurethane-ureas added with plant extracts: Study of different incorporation routes and their influence on particle size, thermal, mechanical and antibacterial properties

Polyurethane-ureas are a versatile family of polymers which can be employed in a wide range of applications. Among them, waterborne polyurethane-urea (WBPUU) dispersions are gaining relevance in the field of environmentally-friendly products since their productive process adopts green synthesis routes, avoiding the use of organic solvents. Furthermore, their waterborne character can be exploited to incorporate several water compatible ingredients able to confer functional properties to the final materials. Among them, plant extracts, which are known to have relevant bioactivities, can be viewed as interesting candidates. Therefore, in this work, two extracts known to present antimicrobial activity (Melissa officinalis L. and Salvia officinalis L.) were obtained by the infusion method and incorporated into the WBPUU (1, 3 and 5 wt%) following different incorporation routes comprising its adding during different phases of the productive process (post-, in-situ and pre- methods). Thereafter films were prepared by solvent-casting and characterized from the viewpoint of physicochemical, thermal, mechanical, thermomechanical and antibacterial properties and morphologically. The studied incorporation routes resulted in different intercalation mechanisms that varied from extract positioned among the polyurethane-urea nanoparticles (post-method) to extract partially embedded inside them (in-situ and pre-methods), which produced stiffening or flexibilizing effects in the produced films, enhancing in general the antimicrobial characteristics of films after 4 days of incubation comparing with base WBPUU, especially when the extract is embedded.Financial support from the Basque Government (IT-776-13), the Spanish Ministry of Economy and Competitiveness (MINECO) (MAT2016-76294-R), POCI-01-0145-FEDER-006984 (LA LSRE-LCM) funded by ERDF through POCI-COMPETE2020 and FCT and NORTE-01-0145-FEDER-000006, funded by NORTE 2020, under PT2020 through ERDF is gratefully acknowledged. We also wish to acknowledge the “Macrobehaviour- Mesostructure-Nanotechnology” SGIker units from the University of the Basque Country, for their technical support. A.S-E thanks the University of the Basque Country for Ph.D. grant (PIF/UPV/12/201).Financial support from the Basque Government (IT-776-13), the Spanish Ministry of Economy and Competitiveness (MINECO) (MAT2016-76294-R), POCI-01-0145-FEDER-006984 (LA LSRE-LCM) funded by ERDF through POCI-COMPETE2020 and FCT and NORTE- 01-0145-FEDER-000006, funded by NORTE 2020, under PT2020 through ERDF is gratefully acknowledged. We also wish to acknowledge the “Macrobehaviour- Mesostructure-Nanotechnology” SGIker units from the University of the Basque Country, for their technical support. A.S-E thanks the University of the Basque Country for Ph.D. grant (PIF/UPV/12/201).info:eu-repo/semantics/publishedVersio

Aplicação de um estimulante do vingamento dos frutos em olival

A oliveira apresenta habitualmente floração abundante. Contudo, muitas flores não se desenvolvem completamente, ocorrendo a sua queda logo após a floração. Segue-se uma fase em que ocorre queda massiva de pequenos frutos. Em 2010 decorreram dois ensaios de campo onde se avaliou o efeito de um fertilizante foliar no vingamento, produção de azeitona e estado nutritivo das árvores. O produto contém boro, molibdénio solúvel em água, polissacáridos e ácido fólico. As caldas foram aplicadas no fim da floração. Um ensaio decorreu num olival adulto da cultivar Santulhana, na localidade de Calvelhe em Bragança. Um segundo ensaio decorreu num olival de 8 anos da cultivar Cobrançosa localizado próximo de Valpaços. Em Calvelhe, o número médio de frutos vingados por ramo foi igual entre tratamentos (0,58). No olival de Valpaços, a produção média de azeitona em grupos de seis árvores foi de 13,8 e 13,7 kg nos tratamentos fertilizado e não fertilizado, respectivamente, sem diferenças estatísticas entre si. A análise foliar revelou concentrações de azoto, boro, fósforo, potássio e cálcio mais elevadas na modalidade fertilizada, sem que o fertilizante contenha estes nutrientes com excepção para o boro. O fertilizante não teve efeito positivo no vingamento na medida em que o número de frutos que persiste parece ser sobretudo regulado pelos fotoassimilados disponíveis na planta. Contudo, o fertilizante melhorou as condições nutritivas gerais das árvores, o que poderá favorecer a indução da floração, a qualidade das flores e o vingamento na estação de crescimento seguinte. The olive usually presents abundant flowering. However, in a tree there are many staminate flowers which fall shortly after full bloom. ln the next step a massive drop of small fruits occurs. Two field experiments were carried out in 2010 to evaluate the effect of a foliar spray on fruit set, olive yield and tree nutritional status. The fertilizer contains boron, water-soluble molybdenum, polysaccharides and folie acid. The spray was applied at the end of flowering. One of the trials occurred in a mature orchard CV. Santulhana in Calvelhe, near Bragança city. A second trial was installed in a young (8 years) orchard CV. Cobrançosa near Valpaços. ln Calvelhe, the average number of fruits that persisted per shoot was similar between treatments (0.58). ln Valpaços, the mean olive yields per groups of six trees were 13.8 and 13.7 kg in fertilized and unfertilized treatments, respectively, without statistical differences between them. Leaf analysis revealed nitrogen, boron, phosphorus, potassium and calcium concentrations higher in the fertilized plot in comparison to the unfertilized treatment, despite the fertilize r does not contain these nutrients except boron. The fertilize r did not have a positive effect on fruit set, in 50 far as the number of fruits that persist seems to be regulated by the available carbohydrates in the tree. However, the fertilizer seems to have improved the overall nutritional status of the plants, which may favor the crop of the next year

Optical demultiplexer device operating in the visible spectrum

In this paper, we present results on the use of multilayered a-SiC:H heterostructures as a device for wavelength-division demultiplexing of optical signals. These devices are useful in optical communications applications that use the wavelength division multiplexing technique to encode multiple signals into the same transmission medium. The device is composed of two stacked p-i-n photodiodes, both optimized for the selective collection of photo generated carriers. Band gap engineering was used to adjust the photogeneration and recombination rate profiles of the intrinsic absorber regions of each photodiode to short and long wavelength absorption in the visible spectrum. The photocurrent signal using different input optical channels was analyzed at reverse and forward bias and under steady state illumination. A demux algorithm based on the voltage controlled sensitivity of the device was proposed and tested. An electrical model of the WDM device is presented and supported by the solution of the respective circuit equations

Dried brewers’ grain as a replacement for soybean meal on nutrient digestibility and rumen parameters of cattle

The objective of this study was to determine the effect of replacing soybean meal with dried brewers’ grains (DBG) in intake and digestibility of the nutrients and the ruminal parameters of cattle. Four ruminal cannulated Jersey oxen with initial body weight of 662.7 ± 85.5 kg were distributed in a 4x4 Latin square design. The treatments were levels of 0%, 33%, 66% and 100% DBG replacing soybean meal in the diet. Dry matter (DM) and crude protein (CP) intake were not influenced by the treatments. There were linear increases in ether extract (EE), neutral detergent fibre (NDF) and acid detergent fibre (ADF) intakes because of higher levels of these nutrients in diets with DBG. Non-fibre carbohydrate (NFC) and total digestible nutrient (TDN) intake showed a decreasing linear effect. Dry matter and NFC digestibility decreased linearly with rising DBG levels, while EE, CP, NDF and ADF digestibilities were not affected. Ruminal pH was not influenced by DBG levels in the diet. There was a quadratic effect in ammonia nitrogen (NH3-N) concentration in the rumen, with the maximum occurring at a level of 36.7% DGB. The replacement of soybean meal with DBG in cattle diets did not alter DM intake and ruminal pH, but reduced TDN intake.Keywords: Ammonia nitrogen, by-product, digestibility, intake, p

A novel hybrid material with calcium and strontium release capability

The preparation of PDMS–TEOS–CaO hybrid materials by sol–gel techniques has been widely described in previous works. Calcium nitrate is the most common source of calcium used in these preparations. However, to remove possible toxic nitrate by-products a thermal treatment is necessary at temperatures above 500 1C, which leads to the degradation of the polymeric components of the hybrids. Strontium has already shown some promising results in the therapeutic area, being used in cases of osteoporosis and low bone density. In this study a new potential bioactive hybrid material was prepared, by sol–gel techniques, using calcium acetate as a novel calcium source. Also, for the first time, incorporation of strontium in a PDMS–TEOS hybrid system was evaluated. Samples were characterized before and after immersion in Kokubo’s Simulated Body Fluid (SBF) by SEM, EDS, ICP and FT-IR spectroscopy