2,841 research outputs found
Transmission of force through particulate systems with restricted geometry
Particle systems may be characterised by a knowledge
of the dimensions of the individual particles. By using
the Feret's diameter distribution and the random
filament distribution of an iron powder the characterisation
of a system of the powder particles, constrained in a
cylindrical die, has been achieved. The Monte Carlo method
has been used to simulate the transmission of force
through the model created by this characterisation.
The results of 500 Monte Carlo simulations have been used
to produce a description of the force due to one surface
particle at various points in the system. Using this diagram
together with a knowledge of the spatial distribution of the
surface particles and the dimensions of the die it was
possible to produce: (1) curves of side wall pressure vs. depth in the die for
various loads; (2) curves of applied to transmitted pressure for various height:diameter ratios; (3) curves of friction loss at the walls vs. depth for different height:diameter ratios.
The differences between the experimentally determined values
and the values predicted on the basis of the model have been
explained in terms of the assumptions made, and suggestions made
as to how these may be eliminated
Assessment of phytotoxicity of potable water treatment plant sludge-bound compost pellets on seed germination of radish (Raphanus sativus L.)
Maintenance of compost pellet stability highly depends on the binding materials used. Potable water treatment plant sludge (WTPS) has the potential to be used as a binding material due to its high content of clay, organic matter, and nutrients. Compost and WTPS may contain heavy metals, toxic compounds, salts, and growth inhibitors and they may be phytotoxic to the plants. The present study aimed to assess the phytotoxicity of different pelleted compost using a seed germination bioassay of Raphanus sativus L. Pellet aqueous extracts (PAEs) were prepared from four types of compost pellets (T1: commercial compost pellet, T2: commercial integrated pellet, T3: WTPS-bound compost pellet, T4: WTPS-bound integrated pellet). The dilution sequence of PAEs at 50% and 100% concentrations were tested for seed germination in Petri dishes in a randomized design with three replicates. pH, EC, and selected heavy metal concentrations (Al3+, Zn2+, Cu2+, and Cr6+) were determined in PAEs. Relative Seed Germination % (RSG%), Relative Radicle Growth % (RRG%), and Germination Index (GI) were calculated for all the treatments after 72 hours. RSG%, RRG%, and GI showed negative correlation with EC. PAEs of T2 showed high phytotoxicity, while T4 showed less phytotoxicity at the 100% concentration level, whereas other treatments did not show any signs of phytotoxicity. All the PAEs at 50% concentration level were free from phytotoxicity. Hence, 10% WTPS on a w/w basis can be used as a binding material in pelletizing loose compost
Horizontal and vertical movements of starry smooth-hound Mustelus asterias in the northeast Atlantic
Commercial landings of starry smooth-hound Mustelus asterias in northern European seas are increasing, whilst our knowledge of their ecology, behaviour and population structure remains limited. M. asterias is a widely distributed demersal shark, occupying the waters of the southern North Sea and Irish Sea in the north, to at least the southern Bay of Biscay in the south, and is seasonally abundant in UK waters. There are no species-specific management measures for the northeast Atlantic stock, and the complexity of its population structure is not yet fully understood. To address this issue, we deployed both mark-recapture and electronic tags on M. asterias to gain novel insights into its horizontal and vertical movements. Our data suggest that the habitat use of M. asterias changes on a seasonal basis, with associated changes in geographical distribution, depth utilisation and experienced temperature. We report the first direct evidence of philopatry for this species, and also provide initial evidence of sex-biased dispersal and potential metapopulation-like stock structuring either side of the UK continental shelf. Investigations of finer-scale vertical movements revealed clear diel variation in vertical activity. The illustrated patterns of seasonal space-use and behaviour will provide important information to support the stock assessment process and will help inform any future management options
Development of a rapid and simple approach for kid carcass evaluation by vídeo image analysis.
objective of this work is the development of a simple and cost-effective video image analysis
(VIA) system to evaluate kid carcass in small slaughter units. To achieve this objective a trial was
conducted with 42 kid carcasses (6.6±2.6 kg) and models to predict carcass composition from VIA
were established. While the carcasses were hanging in the gambrel an image of the dorsal view
of each carcass was obtained with a digital camera (Sony, DCR-TRV460). For imaging, carcasses
were placed in front of a non-glare black surface and illuminated with standard lighting. The
camera was placed perpendicular to the carcass long axis. A total of 44 geometric measurements
(linear and area) were obtained after carcass image analysis with the ImageJ 1.39J software
Comparison of aerobic capacity determined by the lactate minimum test among guard, forward and forward-center positions in basketball players
To aim of this study was to verify the aerobic capacity by lactate minimum test (LM) among different positions in professional basketball players. Twelve high performance basketball players (12 Major National Leagues, 26.7± 3.2 years) were evaluated by LM. The method of lactate elevation consisted of 6 maximum sprints of 35 m separated by 10 s of recovery each (Running Anaerobic Sprint Test). The progressive phase in LM consisted of 4 periods of 3 min each at 8, 10, 11 and 12 Km/h. After lactate elevation phase and progressive periods, 25μL samples of blood were collected to determine peak lactate (PL) concentration and relative lactate minimum concentration (LACc) respectively. The running speed at the LM was taken when the gradient of the line was zero. Anova one-way statistical was utilized to compare the intensity corresponding LM, LACc and PL (p≤0.05). The velocity (Km/h) of LM did not differ among positions: Guard LM= 9.46±0.17 Km/h; Forward LM= 9.60±0.68 Km/h and Forward-Center LM= 9.64±0.25 Km/h. The LACc did not differ: Guard LM= 3.55±0.51 mmol/L; Forward LM= 3.48±1.63 mmol/L and Forward-Center LM= 4.00±0.43 mmol/L. No changes occurred in PL: Guard LM= 8.35±1.41 mmol/L; Forward LM= 8.16±1.47 mmol/L and Forward-Center LM= 8.76±1.20 mmol/L. The aerobic capacity determined by LM did not differ among guard, forward and forward center basketball players
Haematological and biochemical parameters in Churra-da-Terra-Quente ewes from the northeast of Portugal
Hematological and biochemical parameters, including plasma electrolytes and thyroid hormones, were determined in 73 clinically healthy Churra-da-Terra-Quente ewes, a typical breed from the northeast of Portugal. The hemogram values were: erythrocytes 9.8±1.51012/L; haemoglobin 118.1±19.1g/L; haematocrit 40.8±5.9%; leukocytes 5.7±1.8109/L; and platelets 544.3±177.2109/L. The thrombin time was 17.3±1.7 seconds. The values of biochemical parameters were: total protein 76.4±6.1g/L; glucose 2.87±0.60mmol/L; total cholesterol 1.65±0.33mmol/L; aspartate aminotransferase 155.9±49.2U/L; alanine aminotransferase 23.2±9.6U/L; γ-glutamyl transferase 48.0±18.7U/L; total alkaline phosphatase 121.6±76.1U/L; glutamate dehydrogenase 6.4±3.7U/L; urea 7.32±2.22mmol/L; creatinine 123.0±54.1μmol/L; total calcium 2.53±0.25mmol/L; phosphorus 2.10±0.46mmol/L; magnesium 1.01±0.09mmol/L; sodium 152.04±3.65mmol/L; potassium 4.7±0.4mmol/L; ionized calcium 1.32±0.07mmol/L; total thyroxine 111.75±42.29nmol/L; total triiodothyronine 1.01±0.28nmol/L; free T4 11.93±1.78pmol/L; free T3 4.22±1.33pmol/L; and thyroid-stimulating hormone 0.18±0.19μIU/mL. Although differences among the Churra-da-Terra-Quente breed and other breeds may occur, the hematological and biochemical parameters, plasma electrolytes, and thyroid hormones, for this indigenous breed, were generally situated within the reference intervals previously reported for sheep
Environmental assessment of viticulture waste valorisation through composting as a biofertilisation strategy for cereal and fruit crops
Composting is a solid waste management alternative that avoids the emission of methane associated with its disposal in landfill and reduces or eliminates the need for chemical fertilisers if compost is applied. The main objective of this study was to analyse the environmental burdens of composting as a way to achieve a more circular valorisation of wine waste. To do so, with the purpose of identifying optimal operational conditions and determining the “hotspots” of the process, the life cycle assessment (LCA) methodology was used. The consumption of diesel fuel in machinery was determined to be the main critical point in the environmental effects of the system, followed by the transport and distribution of the compost. After the application of compost instead of mineral fertilisers, corn, tomato and strawberry crops would have a better environmental performance in most impact categories. In this sense, a maximum improvement of 65% in terrestrial ecotoxicity is achieved in strawberry cultivation. In light of the results obtained, it is demonstrated that composting is a suitable way of organic waste valorisation according to Circular Economy principles
E-Commerce System
This paper presents the development of an E-commerce System (ECS) for users. ECS is able to manage the details of users who have registered to the system. Not only that but also this system can manage order details that are user has ordered. In addition, this system provides calculation service payment for items that are in the cart. The users of ECS are the customer and the admin. This system was developed using the MERN stack and MongoDB as the database platform
Spatial diet overlap and food resource in two congeneric mullet species revealed by stable isotopes and stomach content analyses
Food partitioning among coexisting species in different habitats remains an important research topic in trophic ecology. In this work, we combined carbon and nitrogen stable isotope ratios and stomach content analyses to investigate differences in diet and niche overlap of two congeneric juvenile mullet species (Mugil curema and Mugil liza) coexisting in a marine surf-zone and an estuarine zone in southern Brazil (29oS). These habitats have contrasting levels of food availability, especially in terms of prey diversity, with higher microalgae diversity in the estuary than in the marine surf-zone. In these contrasting conditions, we predicted that both mullet species will have (a) higher niche overlap and smaller niche breadth at the marine surf-zone due to the common exploration of highly abundant surf-zone diatoms and (b) lower niche overlap and higher niche breadth inside the estuary due to selective feeding on more diverse food resources. Isotope niche areas (measured as standard ellipse areas) were higher in the estuary (6.10 and 6.18) than in the marine surf-zone (3.68 and 3.37) for both M. curema and M. liza, respectively. We observed an overlap of 52% in isotopic niches of both species in the marine surf-zone and none in the estuary. We also found contrasting patterns in the diet composition between species according to the habitat. At the marine surfzone, diatoms of the classes Bacillariophyceae and Coscinodiscophyceae dominated (> 99%) the food content of both mullet species. In contrast, green algae, cyanobacteria, dinoflagellates and flagellates comprised the diet of both species in the estuary. These results could be explained by spatial differences in food availability (especially regarding diversity of microalgae) between both habitats. At the marine site, both species explored the most abundant microalgae available (mostly the surf-zone diatom Asterionellopsis cf. guyunusae and fragments of Coscinodiscus), whereas in the estuary both species shifted their diets to explore the greater diversity of microalgae resources. Overall, our findings revealed that niche partitioning theory could not fully predict changes in breadth and overlap of food niches of estuarine dependent fish species with complex life cycles encompassing marine to estuarine systems with contrasting food availabilities
Evaluación de reservas corporales de grasa de vacas lecheras a través de un sistema de análisis de imagen
publishedTomo I . Sección: Sistemas Ganaderos-Economía y Gestión. Sesión: Producción de leche. Ponencia nº 3
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