983 resultados para Sizes
Resumo:
The landforms that appears in granite slabs of the megaliths, that localize in the NW part of Catalonia, had studied for quantify their increase values. The results allow of distinguish between pre and postmegalithical landforms. Some premegalithical gnammas are 5000 years old or more and has developed actually. Had been calculate 1cm/1000 yaers deepening rates for gnammas and between 0,4 and 3 com/1000 years for the alveoles according to postmegalithical ladforms sizes. The size cannot be used for age approach in another postmegalithical landforms (pitting, ‘pseudorejones’ and speleothems)
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Rockfish species are considered important to the ecology of rocky-reef communities which constitute a key habitat in many coastal marine protected areas (MPAs). These species, which are commercially valuable for artisanal fisheries in the Mediterranean, display particular biological traits that could render them vulnerable to fishing. In this study we monitored the artisanal fisheries of scorpaenids (Scorpaena spp.) in the MPA of Cap de Creus (northwestern Mediterranean) in order to estimate the status of their populations, to link captures with the reproduction of these species, and to evaluate the potential impact that artisanal fishing may have on them. Data from onboard sampling with artisanal fishermen and from fisheries statistics (total landings) were used. Total landings and catch per unit of effort (CPUE) follow a clearly seasonal cycle, with a prominent peak during the summer months coinciding with their spawning season, which may be due to mating behavior prior to fertilization. Although maximum sizes are bigger inside the MPA than in non-protected areas situated close by, a significant percentage of individuals caught inside the MPA are below their size at sexual maturity. Although rockfish seem to be favored by the partial protection of the MPA, the allowed artisanal fisheries are probably impacting the reproduction of these species
Resumo:
Tässä diplomityössä tutkittiin hitsaamalla valmistettavan kerrossihtilevyn soveltuvuutta eri sellutehtaan laitteisiin mekaanisen kuormituskokeen, korroosiokokeen ja syrjäytyskokeiden avulla. Tutkimusympäristönä käytettiin puukuitupesuria, sillä kerrossihtilevyrakenteen todennäköisimpiä käyttökohteita ovat erilaiset massan pesuun tarkoitetut laitteet. Mekaanisen kuormituksen kokeessa tarkasteltiin kerrossihtilevyn staattista ja dynaamista kuormituksen kestoa painevaihteluiden avulla pesurin koelokerossa ja verrattiin sitä porattuun reikälevyyn. Kokeessa käytetyn kerrossihtilevyversion todettiin olevan huomattavasti porattua saman paksuista reikälevyä heikompi dynaamisen kuormituksen alaisena. Syrjäytyskokeilla määritettiin syrjäytysnopeus erilaisilla reiänhalkaisijoilla ja –jaoilla sekä tutkittiin väriaineen avulla sokeiden tukikannasten vaikutusta syrjäytyspesun homogeenisuuteen levyn pinnassa. Syrjäytysnopeuden todettiin heikentyvän vapaan reikäpinta-alan pienentyessä. Väriaineellisissa kokeissa ei havaittu tukikannasten merkittävästi alentavan syrjäytysnopeutta. Korroosiokokeilla tutkittiin ja vertailtiin laser- ja vastuspistehitsien korroosionkestokykyä kloridipitoisissa olosuhteissa lämpötilan säätelyn mahdollistavan olosuhdekaapin avulla. Laserhitsauksessa parametrien ei havaittu vaikuttavan merkittävästi hitsin herkistymislämpötilaan. Vastuspistehitsaamalla on mahdollista saavuttaa laserhitsien korroosionkesto.
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In der Leistungselektronik spielt die Kenntnis des Wärmevrhaltens einer Platine eine sehr große Rolle. Die immer größeren Leistungsdichten unterstreichen die Wichtigkeit des Kenntnisses des Wärmeverhaltens. In der Platine funktionieren die Leistungskomponenten und Kupferlagen die große Ströme tragen als Leistungsquellen. Das Isolationsmaterial zwischen den Kupferlagen limitiert die maximale Temperatur der Platine. Dieses bringt eine Grentzung für den maximalen Strom der durch die Platine geführt werden kann. In dieser Arbeit wurden die maximalen Stromdichten im Worst-Case-Szenario einer Platine untersucht. Dafür wurde eine Testplatine entworfen und für die Testplatine ein thermisches Modell konstruiert. Die Effekte von Kühlung wurden auch untersucht. Die Bestimmtheit des Modells wurde mit Messungen überprüft.
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Tämän diplomityön tavoitteena oli kartoittaa kunnossapidon nykytilaa metsäteollisuuden voimalaitoksissa. Asiaa selvitettiin kvalitatiivisena tutkimuksena, jossa haastateltiin kunnossapidon vastuuhenkilöitä. Tutkimuksen kohteeksi valittiin kahdeksan erikokoista voimalaitosta, jotka edustivat suurimpia Suomessa toimivia metsäteollisuuden konserneja. Työssä käsiteltiin tiedon ja materiaalin hallintaa, kunnossapidon suunnittelua ja organisointia sekä taloudellisia vaikutuksia. Tulokset on esitetty yleisessä muodossa ilman laitoskohtaista erittelyä. Metsäteollisuus toimii hyvin globaaleilla markkinoilla, joilla kilpailu on kiristynyt viime vuosina. Tehokkuutta on pyritty parantamaan kaikilla sektoreilla ja tämä näkyy muutoksena monilla kunnossapidon osa alueilla. Merkittävä muutos oli kunnossapitotoimintojen eriyttäminen omaksi yhtiöksi, joka oli toteutettu yhtiön strategisena valintana puolella tehtaista. Tutkimuksessa kävi myös ilmi, että henkilökunnan koulutukseen panostamalla tietojärjestelmiä voidaan hyödyntää tehokkaammin. Varastoon sidotun pääoman pienentäminen on merkinnyt materiaalilogistiikan tärkeyden korostumista tavoiteltaessa parempaa käyttövarmuutta. Kun lisäksi teollisuuden investointien määrät ovat viime vuosina laskeneet, on kunnossapidon ja etenkin sen suunnittelun rooli kasvanut.
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In the context of the evidence-based practices movement, the emphasis on computing effect sizes and combining them via meta-analysis does not preclude the demonstration of functional relations. For the latter aim, we propose to augment the visual analysis to add consistency to the decisions made on the existence of a functional relation without losing sight of the need for a methodological evaluation of what stimuli and reinforcement or punishment are used to control the behavior. Four options for quantification are reviewed, illustrated, and tested with simulated data. These quantifications include comparing the projected baseline with the actual treatment measurements, on the basis of either parametric or nonparametric statistics. The simulated data used to test the quantifications include nine data patterns in terms of the presence and type of effect and comprising ABAB and multiple baseline designs. Although none of the techniques is completely flawless in terms of detecting a functional relation only when it is present but not when it is absent, an option based on projecting split-middle trend and considering data variability as in exploratory data analysis proves to be the best performer for most data patterns. We suggest that the information on whether a functional relation has been demonstrated should be included in meta-analyses. It is also possible to use as a weight the inverse of the data variability measure used in the quantification for assessing the functional relation. We offer an easy to use code for open-source software for implementing some of the quantifications.
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In this work, aqueous suspensions of aluminas with different particle sizes were evaluated. The effect of pH on the electrosteric stabilization using PMAA-NH4 (ammonium polymethacrylate) as deflocculant was studied. The amount of deflocculant was optimized and rheologic properties were determined at four different pH values. Sedimentation was also evaluated. For suspensions with pH 4, an electrostatic mechanism of stabilization was observed, probably due to a flat adsorption of PMMA- on the alumina surface, leading to a small efficiency in relation to steric stabilization. For a suspension with pH 12, the steric mechanism of stabilization prevails. Suspensions with pH 7 and 9 present a higher flocculation degree. In relation to particle size, A-1000 samples present a smaller particle size, leading to a smaller interparticle distance (IPS), making stabilization more difficult.
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Characterization of the thermal decomposition of polyurethane (PUR) foams was performed by Fourier-transformed infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). Three main weight loss paths were observed by TGA, the residue being lower than 3 wt.% for 3 different PUR foams analyzed. FT-IR spectra indicated CO2, CO, NH3 and isocyanides as main decomposition products. PUR foams of different cell sizes were immersed in a slurry of the parent glass ceramic of composition Li2O-ZrO2-SiO2-Al 2O3 (LZSA) and submitted to heat treatment. The LZSA cellular glass ceramics obtained after sintering and crystallization resembled the original morphology of the PUR foams.
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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.
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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.
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The aim of this work was to prepare and characterize spray-dried nanocapsule-coated microparticles obtained in one step, using indomethacin as a hydrophobic drug model and poly(e-caprolactone) or Eudragit® RS100, as polymers. Nanocapsule-coated microparticles showed micrometric mean sizes (10 - 15 µm) and a reduced surface area (75 - 85 m²g-1) compared to the raw material (214 m²g-1). Microparticles coated with Eudragit® RS100-nanocapsules showed a better control of the drug release. The release profiles fit to the monoexponetial model and to the Power Law. The mechanism of the indomethacin release from the microparticles is non-Fickian and depends on the particles desagglomeration.
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The aim of this study was to verify the influence of the apparent molecular size of aquatic humic substances on the effectiveness of coagulation with ferric chloride. Coagulation-filtration tests using jar test and bench-scale sand filters were carried out on samples of water with true color of approximately 100 Hazen units, prepared with aquatic humic substances of different molecular sizes (F1: < 0.45 µm, F2: 100 kDa - 0.45 µm, F3: 30 - 100 kDa and F4': < 30 kDa). For the water samples with lower apparent molecular size fractions, greater dosages of coagulant was needed to remove the color around 5.0 Hanzen units, mainly because these water samples contain higher concentrations of fulvic acids, which exhibited a larger number of negatively-charged groups.
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This work reports the development of polymeric nanocapsules containing lipoic acid prepared by interfacial deposition of poli(ε-caprolactona). The suspensions showed acid pH and encapsulation efficiencies from 77 to 90%. Zeta potential values were from -7.42 to -5.43 mV and particle sizes were lower than 340 nm with polidispersion lower than 0.3. The stability of nanocapsules within 28 days was evaluated in terms of pH, lipoic acid content, diameter, size distribution, zeta potential and measurements of relative light backscattering. The stability of formulations containing free lipoic acid was also evaluated. Nanoencapsulation drastically improved the physico-chemical stability of lipoic acid.
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The pheromones of the weevils has been the most studied and used so far for Coleoptera species. The majority of reported weevil pheromones is produced by males and usually attract both sexes. The identified pheromone compounds are classified in two categories: ten-carbon compounds with terpenoid branching and compounds of various sizes, apparently of fatty-acid origin. These pheromone structural categories are consistent within subfamilies. This review aims to give an overview of the aggregation pheromones identified for Curculionidae pests, describing the relationship of the molecules structural pattern among subfamilies, and propose an identification key based on the structure of the pheromone components.
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The catalytic performance of Mg,Al-mixed oxides (MO20, MO25 and MO33) derived from hydrotalcites was evaluated in the Knoevenagel reaction between benzaldehyde and phenylsulfonylacetonitrile at 373 and 383 K. The best results were obtained for the sample MO20 that presented the highest basic sites density and external area and the smallest crystallite sizes. The relative amount of basic sites with weak to intermediate strength also played an important role on catalytic performance. By increasing the catalyst content from 1 to 5 wt.% at 383 K, a complete conversion of the reactants is attained, producing α-phenylsulfonylcinnamonitrile with a selectivity of 100%.