912 resultados para Fitted
Resumo:
In birds, parents adjust their feeding behaviour according to breeding duties, which ultimately may lead to seasonal adjustments in nutritional physiology and hematology over the breeding season. Although avian physiology has been widely investigated in captivity, few studies have integrated individual changes in feeding and physiological ecology throughout the breeding season in wild birds. To study relationships between feeding ecology and nutritional ecophysiology in Cory"s shearwater Calonectris diomedea, we weighed and took blood samples from 28 males and 19 females during the pre-laying, egg-laying, incubation, hatching and chick-rearing periods of the breeding season. In addition, we fitted 6 birds with geolocators to track their foraging movements throughout the reproductive period. Thus, we examined individual changes in (1) nutritional condition (biochemistry metabolites); (2) oxygen carrying capacity (hematology); and (3) feeding areas and foraging effort (stable isotopes and foraging movements). Geolocators revealed a latitudinal shift in main feeding areas towards more southern and more neritic waters throughout the breeding season, which is consistent with the steady increase in δ13C signatures in the blood. Geolocators also showed a decrease in foraging effort from egg-laying to hatching, reflecting the activity decrease associated with incubation duties. Plasma metabolites, body mass and oxygen carrying capacity were associated with temporal changes in nutritional state and foraging effort in relation to recovery after migration, egg formation, fasting shifts during incubation and chick provisioning. This study shows that combining physiological and ecological approaches can help us understand the influence of breeding duties on feeding ecology and nutritional physiology in wild birds.
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A new automated system for acid-base flow titrations is proposed. In the operation mode, several sample to titrant volumetric ratios are injected in an air segmented plug. Five three way solenoid valves and three acrilic junctions, assembled in a hidrodynamic injection system, were accountable for the monosegmented reagents plug formation. A turbulent flow reactor was used for a perfect mix of reagents in the plug. The detector system employed a glass combined electrode fitted in an acrilic holder. Titrations of hydrochloric, nitric and acetic acids, in several concentrations, were performed with standard sodium hidroxide, for evaluation of the efficiency of the system. The relative standard deviation of the determinations was about ±0,5% and each titration was carried out in 3-4 minutes. A Quick BASIC 4.5® program was developed for the titrator control.
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It is often reasonable to convert old boiler to bubbling fluidized bed boiler instead of building a new one. Converted boiler consists of old and new heat surfaces which must be fitted to operate together. Prediction of heat transfer in not so ideal conditions sets challenges for designers. Two converted boilers situated in Poland were studied on the grounds of acceptance tests and further studies. Calculation of boiler process was performed with boiler design program. Main interest was heat transfer in superheaters and factors affecting it. Theory for heat transfer is presented according to information found from literature. Results obtained from experimental studies and calculations have been compared. With correct definitions calculated parameters corresponded well to measured data at boiler maximum design load. However overload situations revealed to be difficult to model at least without considering changes in the combustion process which requires readjustments to the design program input values.
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Fine powders of minerals are used commonly in the paper and paint industry, and for ceramics. Research for utilizing of different waste materials in these applications is environmentally important. In this work, the ultrafine grinding of two waste gypsum materials, namely FGD (Flue Gas Desulphurisation) gypsum and phosphogypsum from a phosphoric acid plant, with the attrition bead mill and with the jet mill has been studied. The ' objective of this research was to test the suitability of the attrition bead mill and of the jet mill to produce gypsum powders with a particle size of a few microns. The grinding conditions were optimised by studying the influences of different operational grinding parameters on the grinding rate and on the energy consumption of the process in order to achieve a product fineness such as that required in the paper industry with as low energy consumption as possible. Based on experimental results, the most influential parameters in the attrition grinding were found to be the bead size, the stirrer type, and the stirring speed. The best conditions, based on the product fineness and specific energy consumption of grinding, for the attrition grinding process is to grind the material with small grinding beads and a high rotational speed of the stirrer. Also, by using some suitable grinding additive, a finer product is achieved with a lower energy consumption. In jet mill grinding the most influential parameters were the feed rate, the volumetric flow rate of the grinding air, and the height of the internal classification tube. The optimised condition for the jet is to grind with a small feed rate and with a large rate of volumetric flow rate of grinding air when the inside tube is low. The finer product with a larger rate of production was achieved with the attrition bead mill than with the jet mill, thus the attrition grinding is better for the ultrafine grinding of gypsum than the jet grinding. Finally the suitability of the population balance model for simulation of grinding processes has been studied with different S , B , and C functions. A new S function for the modelling of an attrition mill and a new C function for the modelling of a jet mill were developed. The suitability of the selected models with the developed grinding functions was tested by curve fitting the particle size distributions of the grinding products and then comparing the fitted size distributions to the measured particle sizes. According to the simulation results, the models are suitable for the estimation and simulation of the studied grinding processes.
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The driving force of boron adsorption on some tropical soils was evaluated by means of thermodynamic parameters. The batch method was employed, and the reaction was monitored at different pH values. The Langmuir equation successfully fitted the experimental results and provided reasonable isotherm parameters. Boron adsorption increased as a function of the pH of the soil solution and the concentration of added boron. The reaction was favorable and proceeded spontaneously, being strongly exoergic, as indicated by a negative free energy (deltaG) and a separation factor (K R) < 1. The boron adsorption phenomenon and the soil-solution interface were thermodinamically described using a theoretical model.
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During the last part of the 1990s the chance of surviving breast cancer increased. Changes in survival functions reflect a mixture of effects. Both, the introduction of adjuvant treatments and early screening with mammography played a role in the decline in mortality. Evaluating the contribution of these interventions using mathematical models requires survival functions before and after their introduction. Furthermore, required survival functions may be different by age groups and are related to disease stage at diagnosis. Sometimes detailed information is not available, as was the case for the region of Catalonia (Spain). Then one may derive the functions using information from other geographical areas. This work presents the methodology used to estimate age- and stage-specific Catalan breast cancer survival functions from scarce Catalan survival data by adapting the age- and stage-specific US functions. Methods: Cubic splines were used to smooth data and obtain continuous hazard rate functions. After, we fitted a Poisson model to derive hazard ratios. The model included time as a covariate. Then the hazard ratios were applied to US survival functions detailed by age and stage to obtain Catalan estimations. Results: We started estimating the hazard ratios for Catalonia versus the USA before and after the introduction of screening. The hazard ratios were then multiplied by the age- and stage-specific breast cancer hazard rates from the USA to obtain the Catalan hazard rates. We also compared breast cancer survival in Catalonia and the USA in two time periods, before cancer control interventions (USA 1975–79, Catalonia 1980–89) and after (USA and Catalonia 1990–2001). Survival in Catalonia in the 1980–89 period was worse than in the USA during 1975–79, but the differences disappeared in 1990–2001. Conclusion: Our results suggest that access to better treatments and quality of care contributed to large improvements in survival in Catalonia. On the other hand, we obtained detailed breast cancer survival functions that will be used for modeling the effect of screening and adjuvant treatments in Catalonia
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Two vegetable wastes, cork bark and grape stalks, were investigated for the removal of methylene blue from aqueous solution. The effects of contact time, dye concentration, pH, and temperature on sorption were studied relative to adsorption on a commercially-activated carbon. The highest adsorption yield was obtained within the pH range 5 to 10 for grape stalks and 7 to 10 for cork bark. The sorption kinetics of dye onto activated carbon and grape stalks was very fast. Kinetics data were fitted to the pseudo-first and second order kinetic equations, and the values of the pseudo-second-order initial rate constants were found to be 1.69 mg g-1 min-1 for activated carbon, 2.24 mg g-1 min-1 for grape stalks, and 0.90 mg g-1 min-1 for cork bark. Langmuir maximum sorption capacities for activated carbon, grape stalks, and cork bark for methylene blue estimated by the Orthogonal Distance Regression method (ODR) were 157.5 mg g-1, 105.6 mg g-1, and 30.52 mg g-1, respectively. FTIR spectra indicated that carboxylic groups and lignin play a significant role in the sorption of methylene blue. Electrostatic forces, n-p interactions, cation-p, and p-p stacking interactions contribute to methylene blue sorption onto grape stalks and cork bark. Grape stalks can be considered an efficient biosorbent and as a viable alternative to activated carbon and ion-exchange resins for the removal of methylene blue
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The objective of the thesis was to examine the possibilities in designing better performing nozzles for the heatset drying oven in Forest Pilot Center. To achieve the objective, two predesigned nozzle types along with the replicas of the current nozzles in the heatset drying oven were tested on a pilot-scale dryer. During the runnability trials, the pilot dryer was installed between the last printing unit and the drying oven. The two sets of predesigned nozzles were consecutively installed in the dryer. Four web tension values and four different impingement air velocities were used and the web behavior during the trial points was evaluated and recorded. The runnability in all trial conditions was adequate or even good. During the heat transfer trials, each nozzle type was tested on at least two different nozzle-to-surface distances and four different impingement air velocities. In a test situation, an aluminum plate fitted with thermocouples was set below a nozzle and the temperature measurement of each block was logged. From the measurements, a heat transfer coefficient profile for the nozzle was calculated. The performance of each nozzle type in tested conditions could now be rated and compared. The results verified that the predesigned simpler nozzles were better than the replicas. For runnability reasons, there were rows of inclined orifices on the leading and trailing edges of the current nozzles. They were believed to deteriorate the overall performance of the nozzle, and trials were conducted to test this hypothesis. The perpendicular orifices and inclined orifices of a replica nozzle were consecutively taped shut and the performance of the modified nozzles was measured as before, and then compared to the performance of the whole nozzle. It was found out, that after a certain nozzle-to-surface distance the jets from the two nozzles would collide, which deteriorates the heat transfer.
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Chromium (VI) removal and its reduction to chromium (III) from aqueous solution by untreated and heat-treated Quercus cerris and heat-treated Quercus suber black agglomerate cork granules was investigated. Initial screening studies revealed that among the sorbents tested, untreated Q. cerris and Q. suber black agglomerate are the most efficient in the removal of Cr(VI) ions and were selected for adsorption essays. Heat treatment adversely affected chromium adsorption and chromium (VI) reduction in Q. cerris cork. The highest metal uptake was found at pH 3.0 for Q. cerris and pH 2.0 for black agglomerate. The experimental data fitted the Langmuir model and the calculated qmax was 22.98 mg/g in black agglomerate and 21.69 mg/g in untreated Q. cerris cork. The FTIR results indicated that while in black agglomerate, lignin is the sole component responsible for Cr(VI) sorption, and in untreated Q. cerris cork, suberin and polysaccharides also play a significant role on the sorption. The SEM-EDX results imply that chromium has a homogenous distribution within both cork granules. Also, phloemic residues in Q. cerris granules showed higher chromium concentration. The results obtained in this study show that untreated Q. cerris and black agglomerate cork granules can be an effective and economical alternative to more costly materials for the treatment of liquid wastes containing chromium
Resumo:
Kaukojäähdytyksellä tarkoitetaan keskitetysti tuotetun jäähdytysenergian jakamista kiinteistöihin jakeluverkossa kiertävän kylmän veden välityksellä, eli kaukojäähdytys on ulkoistettu jäähdytysratkaisu. Jäähdytysenergiaa tarvitaan työtehon, viihtyisyyden ja sisäilman laadun parantamiseksi, sekä joidenkin prosessien tarpeisiin. Siinä missä perinteinen kiinteistökohtainen jäähdytysjärjestelmä tuottaa jäähdytysenergian sähköllä, käytetään kaukojäähdytyksessä jäähdytysenergian tuottamiseen sellaisia resursseja, jotka muuten jäisivät käyttämättä. Tästä syystä kaukojäähdytys vähentää merkittävästi hiilidioksidipäästöjä, jonka lisäksi kaukojäähdytys vähentää kylmäkoneissa käytettävien kylmäaineiden aiheuttamia kasvihuonekaasupäästöjä. Kaukolämpöverkkoa muistuttavan kaukojäähdytysverkon rakentaminen vaatii suuria investointeja. Nykyisin jakeluverkon rakenteena käytetään 2Mpuk- rakennetta, jonka todettiin olevan teknistaloudellisesti soveltuvin vaihtoehto Helsingin Energian kaukojäähdytysverkkoon. Myös PE 100 putkia voitaisiin käyttää PN 16 paineluokassa alle DN 300 kokoluokkaa vastaavissa johdoissa, ja PN 10 paineluokassa alle DN 400 johdoissa. Kaukolämpöverkon paineluokan valinta vaikuttaa oleellisesti investointikustannuksiin PE- putkilla ja joillekin alueille kannattanee rakentaa alemman paineluokan omaava erillisverkko PE- putkista. Happidiffuusion kautta PE- putkista pääsee jonkin verran happea verkkoon, mutta määrät ovat melko pieniä, eikä muitakaan teknisiä esteitä hyvin korroosiota kestävien PE- putkien käytölle ole. 2Mpuk- rakenteelle suurimman riskin aiheuttaa elementtien liitoskohdista teräsputken pinnalle pääsevä ulkopuolinen vesi. Koska kaukojäähdytysjohdot ovat lisäksi yleensä ympäristöä kylmempiä, kondensoivat ne vettä pinnallensa kaukolämpöjohdoista poiketen. Ulkopuolisen veden aiheuttamaa riskiä voitaisiin pienentää eristämällä liitoskohdat sähkömuhveilla. Verkoston rakentamiskustannuksia ja liikenteelle aiheutuvia haittoja voidaan vähentää ojattomia rakentamismenetelmiä, kuten suuntaporausta käyttämällä.
Resumo:
We introduce a method for surface reconstruction from point sets that is able to cope with noise and outliers. First, a splat-based representation is computed from the point set. A robust local 3D RANSAC-based procedure is used to filter the point set for outliers, then a local jet surface - a low-degree surface approximation - is fitted to the inliers. Second, we extract the reconstructed surface in the form of a surface triangle mesh through Delaunay refinement. The Delaunay refinement meshing approach requires computing intersections between line segment queries and the surface to be meshed. In the present case, intersection queries are solved from the set of splats through a 1D RANSAC procedure
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Polysaccharide-based drilling fluids have been often applied in horizontal wells of petroleum reservoirs in Campos, Rio de Janeiro. The present study aimed to understand the mechanism of adsorption and desorption of the drill-in fluid, xanthan, modified starch and lubricant on SiO2 by means of ellipsometry. The effect of pH and brine on the mean thickness (D) of adsorbed layer was systematically investigated. The adsorption was mainly favored under alkaline conditions. A model has been proposed to explain this effect. The adsorption isotherms determined separately for xanthan and starch on SiO2 surfaces could be fitted with the Langmuir model, which yielded similar adsorption constant values.
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Large enterprises have for many years employed eBusiness solutions in order to improve their efficiency. Smaller companies, however, have not been able to leverage these technologies due to the high level of know-how and resources required in implementing them. To solve this, novel software services are being developed to facilitate eBusiness adoption for the small enterprise with the aim of making B2Bi feasible not only between large organisations but also between trading partners of all sizes. The objective of this study was to find what standards and techniques on eBusiness and software testing and quality assurance fit best for building these new kinds of software considering the requirements their unique eBusiness approach poses. The research was conducted as a literature study with focus on standards on software testing and quality assurance together with standards on eBusiness. The study showed that the current software testing and quality assurance standards do not possess such characteristics as would make select standards evidently better fitted for building this type of software, which were established to be best developed as web services in order for them to meet their requirements. A selection of eBusiness standards and technologies was proposed to support this approach. The main finding in the study was, however, that these kinds of web services that have high interoperability requirements will have to be able to carry out automated interoperability and conformance testing as part of their operation; this objective dictates how the software are built and how testing during software development is to be done. The study showed that research on automated interoperability and conformance testing for web services is still limited and more research is needed to make the building of highly-interoperable web services more feasible.
Resumo:
Tässä diplomityössä käydään läpi IEC-60534 -standardin mukainen säätöventtiilin mitoitus kokoonpuristumattomille ja –puristuville virtauksille laskennassa tarvittavine yhtälöineen. Teoreettisessa osassa esitellään RF-letkuventtiilien rakennetta ja ominaisuuksia. Lisäksi käydään läpi putkivirtauksen perusperiaatteita. Koska letkuventtiilissä virtaavana fluidina on usein jokin liete, on työssä esitelty menetelmä lietevirtauksen aiheuttaman paine-eron laskentaan. Työssä on käsitelty myös kavitaation syntyä, laskennalliset mahdollisuudet kavitaation ennustamiseen sekä keinoja kavitaation estämiseksi. Kokeellisessa osassa suoritettiin mittauksia kolmella erikokoisella RF-letkuventtiilillä, joissa kussakin käytettiin kolmea erityyppistä letkua. Mittausten perusteella pystyttiin laskemaan kapasiteettikertoimet sekä määrittämään säätökäyrät mitatuille venttiileille ja letkutyypeille. Näistä tuloksista säätökäyrille sovitettiin yhtälöt, joiden perusteella saatiin laskettua kapasiteettikertoimien arvot myös muille venttiilikoille.
Resumo:
The aim of this work is to evaluate the use of natural zeolites to remove the NH4+ that remains in effluents from swine facilities which were submitted to physico-chemical and biological treatments. Experiments were made in batch made adding 5% (w/w) of adsorbent (0.6-1.3 and 3.0-8.0 mm) to synthetic and real swine facilities effluents. The results show that ammonium removal is influenced by adsorbent particle size and the presence of other ions in the effluent. The adsorption equilibrium was described by Langmuir as well as Freundlich isotherms and the kinetic data fitted well a pseudo-second order model.