932 resultados para Realized volitility


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The aim of this study was to evaluate the possible impacts caused in the soil and in the percolate in lysimeters of drainage with application of different rates of swine wastewater (SW) during the cycle of soybean culture and to assess the productivity of it. The experiment was conducted at the Agricultural Engineering Experimental Center of UNIOESTE. The soil was classified as typical Distroferric Red Latosol. There were twenty-four drainage lysimeters in the area in which the soybean was cultivated, cultivar CD 214. Four SW depths (0; 100; 200 and 300 m³ ha-1) were applied to the soil seven days before the sowing in a single application combined with two mineral fertilizations in the sowing (with and without recommended fertilization during sowing), and three repetitions per treatment. It was realized three collections of percolate in each experimental portion, the first was conducted 40 days after sowing (DAS); the second at 72 DAS, and the third at the end of crop cycle (117 DAS). It was evaluated in the percolate the pH, calcium, magnesium, potassium, phosphorus, and total nitrogen. Based on the results, it was possible to observe that the level of K, P and N in the soil increased according tothe increase of SW rates. The levels of K and P in the percolate were higher for higher rates of SW. The productivity was not influenced by the application of SW or by fertilization.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This study was conducted to evaluate and compare the behavior of the heating inside poultry shed through gas hood and underfloor heating. The experiment was conducted in poultry shed belonging to the Federal Institute of Education, Science and Technology of Triângulo Mineiro Region, Uberlândia city – state of Minas Gerais (MG), Brazil. The dimensions of the shed are 24 meters long and 9.6 meters wide and with a ceiling height of 3.2 meters. The temperature was measured with an optical thermometer of Minipa brand, MT 350 model. It was used, to the analysis of temperature behavior, the public domain software FEMM 4.2, which uses finite elements techniques, with data collected from two lots. Underfloor heating is made using hot water flowing through a serpentine type system, which is installed below the bed; this hot water is from solar heaters. An energetic and economic assessment of the warming shed for raising chickens was realized. From the results obtained with the simulations, it may observe that the heating through the floor provides a more homogeneous distribution of temperature when compared with the hood heating. The flow of heat is upwards supplying, thus, the greatest need of heating of the bird, which is the pectoral part.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The purpose of this research was to evaluate the K2O distribution uniformity by surface drip irrigation at Universitat Politecnica de Valencia, Valencia, Spain (39º 29′ N, 0º 23′ W, 20 m). The irrigation was performed by drip lines with not-compensated emitters, spaced 0.3 m. The fertigation was realized using a fertilizer injector pump of electric action with injection of 0.25 h. The experimental design used completely randomized blocks with five treatments and four replications. The treatments consisted of injection in five distances, located at 10; 20; 30; 40; 50 m of the first drip line. Samples were collected in emitters located at the start, at 1/3, at 2/3 and at the end of the drip lines. The nutrient concentration was determined by flame spectrophotometry. The Christiansen's uniformity coefficients (CUC), of distribution (DUC), of statistical (SUC) and of emission (eUC) were estimated. The K2O concentration and distribution decreased linearly with the increase of the injection distance. In all treatments, the CUC, SUC and DUC were described as 'excellent'. The eUC was described as 'recommended' only at smaller injection distances.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The search for the use of water with high levels of efficiency has motivated the use of drip irrigation in several agricultural systems. However, for the efficiency be ensured, it is necessary that the water distribution in the soil profile must to be known in more details. As it is a highly variable process, function of the local characteristics, is essential the study of each case. The objective of this research was evaluating the water distribution in the soil profile, from drippers installed in surface and 0.15 m below the soil surface. The experiment was realized in the Technical Center of Irrigation (TCI) of the State University of Maringá - PR. The water monitoring in the soil profile was done with TDR probes installed in a box containing sandy soil, at the depths from 0.05 to 0.80 m; and 0.05 to 0.35 m of lateral spacing, at intervals of 0.05 m, totalizing 30 probes. The treatments were differentiated in relation of the installation depth of the emitters (0.0 and 0.15 m) and flow (1, 2, 4, 6, and 8 L h-1). The irrigation time was 8 hours continuous with reading of the TDR probes each 30 minutes. The results allowed concluding that the wet area with the emitter positioned on the soil surface was directly proportional to the flow increase. For the underground dripper, this area was substantially smaller and the water losses by percolation were higher, mainly to the flows higher than 4 L h-1, which provided to unacceptable water losses that should be avoided.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Ammattikorkeakoulut ovat osa suomalaista innovaatiojärjestelmää. Niiden tärkeimpiä tuotteita ovat laadukkaat tutkinnot, joilla tuotetaan Suomen kilpailukyvyn kannalta olennaista osaavaa työvoimaa. Koulutusinnovaatioiden avulla ammattikorkeakoulut voivat parantaa opetuksen ja oppimisen laatua ja edistää opiskelijoiden parempaa osaamista. Tässä tutkimuksessa tarkasteltiin Kymenlaakson ammattikorkeakoulua innovatiivisena oppimisyhteisönä Hokkasen (2001) hahmotteleman innovatiivisen oppimisyhteisön profiilitekijöiden mukaisesti. Tutkimuksen tavoitteena oli selvittää, millainen innovatiivinen oppimisyhteisö KyAMK:ssa toteutuu opettajien kokemana, ja miten innovatiivisen oppimisyhteisön piirteitä voitaisiin edistää mainitussa organisaatiossa. Aineisto kerättiin haastattelemalla kymmentä KyAMK:n Tekniikan ja liikenteen toimialan opettajaa. Tulokset osoittivat Kymenlaakson ammattikorkeakoulun johdon sallivan innovatiiviset koulutuksen kehittämiseen tähtäävät toimet, mutta johto ei proaktiivisesti ohjannut ja kannustanut niihin. Ammattikorkeakouluopettajien pedagogisen autonomian todettiin olevan suurta. Tästä huolimatta kaivattiin yhteisöllisyyteen tukevia toimintamalleja, joiden avulla organisaatiossa oleva monialaisen työyhteisön innovaatiopotentiaali voitaisiin valjastaa opetuksen kehittämiseen ja organisaatiolta puuttuvan toiminnan kokonaiskuvan ja -ymmärryksen kehittämiseen. Osana yhteisöllisyyden kehittämistä aineistosta nousi esiin kehittämisehdotuksena pitkäjänteisemmän verkostoitumisen toteuttaminen niin organisaation sisällä kuin ulkopuolisten sidosryhmien kanssa.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The use of intensity-modulated radiotherapy (IMRT) has increased extensively in the modern radiotherapy (RT) treatments over the past two decades. Radiation dose distributions can be delivered with higher conformality with IMRT when compared to the conventional 3D-conformal radiotherapy (3D-CRT). Higher conformality and target coverage increases the probability of tumour control and decreases the normal tissue complications. The primary goal of this work is to improve and evaluate the accuracy, efficiency and delivery techniques of RT treatments by using IMRT. This study evaluated the dosimetric limitations and possibilities of IMRT in small (treatments of head-and-neck, prostate and lung cancer) and large volumes (primitive neuroectodermal tumours). The dose coverage of target volumes and the sparing of critical organs were increased with IMRT when compared to 3D-CRT. The developed split field IMRT technique was found to be safe and accurate method in craniospinal irradiations. By using IMRT in simultaneous integrated boosting of biologically defined target volumes of localized prostate cancer high doses were achievable with only small increase in the treatment complexity. Biological plan optimization increased the probability of uncomplicated control on average by 28% when compared to standard IMRT delivery. Unfortunately IMRT carries also some drawbacks. In IMRT the beam modulation is realized by splitting a large radiation field to small apertures. The smaller the beam apertures are the larger the rebuild-up and rebuild-down effects are at the tissue interfaces. The limitations to use IMRT with small apertures in the treatments of small lung tumours were investigated with dosimetric film measurements. The results confirmed that the peripheral doses of the small lung tumours were decreased as the effective field size was decreased. The studied calculation algorithms were not able to model the dose deficiency of the tumours accurately. The use of small sliding window apertures of 2 mm and 4 mm decreased the tumour peripheral dose by 6% when compared to 3D-CRT treatment plan. A direct aperture based optimization (DABO) technique was examined as a solution to decrease the treatment complexity. The DABO IMRT technique was able to achieve treatment plans equivalent with the conventional IMRT fluence based optimization techniques in the concave head-and-neck target volumes. With DABO the effective field sizes were increased and the number of MUs was reduced with a factor of two. The optimality of a treatment plan and the therapeutic ratio can be further enhanced by using dose painting based on regional radiosensitivities imaged with functional imaging methods.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Att övervaka förekomsten av giftiga komponenter i naturliga vattendrag är nödvändigt för människans välmående. Eftersom halten av föroreningar i naturens ekosystem bör hållas möjligast låg, pågår en ständig jakt efter kemiska analysmetoder med allt lägre detektionsgränser. I dagens läge görs miljöanalyser med dyr och sofistikerad instrumentering som kräver mycket underhåll. Jonselektiva elektroder har flera goda egenskaper som t.ex. bärbarhet, låg energiförbrukning, och dessutom är de relativt kostnadseffektiva. Att använda jonselektiva elektroder vid miljöanalyser är möjligt om deras känslighetsområde kan utvidgas genom att sänka deras detektionsgränser. För att sänka detektionsgränsen för Pb(II)-selektiva elektroder undersöktes olika typer av jonselektiva membran som baserades på polyakrylat-kopolymerer, PVC och PbS/Ag2S. Fast-fas elektroder med membran av PbS/Ag2S är i allmänhet enklare och mer robusta än konventionella elektroder vid spårämnesanalys av joniska föroreningar. Fast-fas elektrodernas detektionsgräns sänktes i detta arbete med en nyutvecklad galvanostatisk polariseringsmetod och de kunde sedan framgångsrikt användas för kvantitativa bestämningar av bly(II)-halter i miljöprov som hade samlats in i den finska skärgården nära tidigare industriområden. Analysresultaten som erhölls med jonselektiva elektroder bekräftades med andra analytiska metoder. Att sänka detektionsgränsen m.hj.a. den nyutvecklade polariseringsmetoden möjliggör bestämning av låga och ultra-låga blyhalter som inte kunde nås med klassisk potentiometri. Den verkliga fördelen med att använda dessa blyselektiva elektroder är möjligheten att utföra mätningar i obehandlade miljöprov trots närvaron av fasta partiklar vilket inte är möjligt att göra med andra analysmetoder. Jag väntar mig att den nyutvecklade polariseringsmetoden kommer att sätta en trend i spårämnesanalys med jonselektiva elektroder.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Tutkimuksen tavoitteena oli selvittää yleisellä tasolla aikuiskoulutuksen roolia kunnossapidon muutosjohtamisen vahvistajana. Työn tuloksia on tarkoitus käyttää kunnossapidon johtamisen ylemmän ammattikorkeakoulutuksen (YAMK) kehittämisessä Jyväskylän ammattikorkeakoulussa. Tutkimuksen teoriaosassa selvitettiin organisaatiomuutoksen ja muutosjohta-misen käsitteitä, aikuiskoulutusta, sekä teollisuuden kunnossapitoa, rajoittuen sen perustehtävän johtamiseen ja kehittämiseen. Tämän lisäksi teoriaosassa kartoitettiin muutosjohtamisen haasteita, niin yleisesti kuin kunnossapidon ai-hepiirissä. Työn empiirisessä osassa selvitettiin 15 kunnossapidon ammattilaisen, kun-nossapidon johtamisen YAMK- opiskelijoiden, kokemuksia kunnossapidon organisaatiomuutoksista, muutosjohtamisesta sekä opiskelijoiden osaamistar-peista koskien kunnossapidon muutosjohtamista. Tutkimuksen tulokset osoittivat, että kunnossapidon organisaatiomuutosten johtamisen haasteet ovat samankaltaisia yleisesti tunnistettujen muutosjohta-misen haasteiden kanssa. Käytännössä kirjallisuudessa korostetut organisaa-tiomuutoksen johtamisen hyvät käytänteet toteutuvat kunnossapidon organi-saatiomuutoksissa satunnaisesti. Lisäksi tutkimuksessa tunnistettiin kunnos-sapidon opiskelijoiden keskeisiä muutosjohtamisen osaamistarpeita. Tutki-muksen tulos korostaa muutosjohtajan roolin tärkeyttä organisaatiomuutoksen läpiviemisessä. Lisäksi tutkimuksessa esiteltiin aktivoivan opetuksen periaat-teiden mukainen johtamismalli, jonka avulla pyritään vahvistamaan kunnossa-pidon johtajien ja asiantuntijoiden kykyä toimeenpanna kunnossapidon hyviä käytänteitä nykyistä tehokkaammin.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This bachelor’s thesis is a part of the research project realized in the summer 2011 in Lappeenranta University of Technology. The goal of the project was to develop an automation concept for controlling the externally excited synchronous motor. Thesis concentrates on the testing planning and testing the system. Testing plan was made for three sectors: For the PLC program testing, for the communication testing and for the whole system testing. PLC program was tested with white box and destructive methods. Communication testing was done by switching maximum com-munication speed and checked if communication was reliable. Whole system testing included among other things speed and torque controlling. The system was tested with exploratory testing also. This enabled more reliable and broader testing than with systematical testing only.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This bachelor’s thesis is a part of the research project realized in the summer 2011 in Lappeenranta University of Technology. The goal of the project was to create an automation concept for controlling an electrically excited synchronous motor. This thesis concentrates on the setup and requirements specification part of the concept. The setup consists of ABB AC500 as the PLC master device, DCS800 as an exciter and ACS800 as a frequency converter. The ACS800 frequency converter uses permanent magnet synchronous machine software to control the stator’s magnetic field, the DC drive handles the excitation and the AC500 PLC master controls the communication and functionality of the system. The requirements specification briefly explains the general over-view of the concept, the use and functionality of the PLC program and the requirements needed for the whole concept and the PLC program to work as intended.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Incident and near miss reporting is one of the proactive tools of safety management. By analyzing incidents and near misses and by corrective actions, severe accidents can potentially be avoided. Near miss and incident reporting is widely used in many riskprone industries such as aviation or chemical industry. In shipping incident and near miss reporting is required by the mandatory safety management system International Safety Management Code (ISM Code). However, in several studies the conclusion has been that incidents are reported poorly in the shipping industry. The aim of this report is to highlight the best practices for incident reporting in shipping and to support the shipping industry in the better utilization of incident reporting information. The study consists of three parts: 1) voluntary, shared reporting systems in shipping (international experiences), 2) interview study at four shipping companies in Sweden and in Finland (best practices), 3) expert workshop on incident reporting (problems and solutions). Preconditions for a functional reporting system are an existing no blame culture, commitment of the top management, feedback, good communication, training and an easy-to-use system. Although preconditions are met, problems can still appear, for example due to psychological, interpersonal or nationality-related reasons. In order to keep the reporting system functioning, the shipping company must be committed to maintain and develop the system and to tackle the problems. The whole reporting process from compiling, handling and analyzing a report, creating corrective actions and implementing them has to be handled properly in order to gain benefits from the reporting system. In addition to avoiding accidents, the functional reporting system can also offer other benefits by increasing safety awareness, by improving the overall safety and working conditions onboard, by enhancing team work and communication onboard and between ships and the land-based organization of shipping companies. Voluntary shared reporting systems are supported in the shipping industry in principle, but their development in the Baltic Sea is still in its infancy and the potential benefits of sharing the reports have not been realized. On the basis of this study we recommend that a common reporting system be developed for the Baltic Sea area which all the ships operating in the area could use regardless of their flag. Such a wider system could prevent some of the problems related to the current national systems. There would be more incident cases available in the database and this would support anonymity and thus encourage shipping companies to report to a shared database more frequently. A shared reporting system would contribute to the sharing of experiences and to the wider use of incident information in the shipping industry.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Bone strain plays a major role as the activation signal for the bone (re)modeling process, which is vital for keeping bones healthy. Maintaining high bone mineral density reduces the chances of fracture in the event of an accident. Numerous studies have shown that bones can be strengthened with physical exercise. Several hypotheses have asserted that a stronger osteogenic (bone producing) effect results from dynamic exercise than from static exercise. These previous studies are based on short-term empirical research, which provide the motivation for justifying the experimental results with a solid mathematical background. The computer simulation techniques utilized in this work allow for non-invasive bone strain estimation during physical activity at any bone site within the human skeleton. All models presented in the study are threedimensional and actuated by muscle models to replicate the real conditions accurately. The objective of this work is to determine and present loading-induced bone strain values resulting from physical activity. It includes a comparison of strain resulting from four different gym exercises (knee flexion, knee extension, leg press, and squat) and walking, with the results reported for walking and jogging obtained from in-vivo measurements described in the literature. The objective is realized primarily by carrying out flexible multibody dynamics computer simulations. The dissertation combines the knowledge of finite element analysis and multibody simulations with experimental data and information available from medical field literature. Measured subject-specific motion data was coupled with forward dynamics simulation to provide natural skeletal movement. Bone geometries were defined using a reverse engineering approach based on medical imaging techniques. Both computed tomography and magnetic resonance imaging were utilized to explore modeling differences. The predicted tibia bone strains during walking show good agreement with invivo studies found in the literature. Strain measurements were not available for gym exercises; therefore, the strain results could not be validated. However, the values seem reasonable when compared to available walking and running invivo strain measurements. The results can be used for exercise equipment design aimed at strengthening the bones as well as the muscles during workout. Clinical applications in post fracture recovery exercising programs could also be the target. In addition, the methodology introduced in this study, can be applied to investigate the effect of weightlessness on astronauts, who often suffer bone loss after long time spent in the outer space.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Tässä diplomityössä on käsitelty ydinvoimalaitoksen rakentamisprosessin aikaista viran-omaistoimintaa, viranomaisten vaatimuksia sekä rakentamiseen liittyvää riskienhallintaa julkisesti saatavissa olevan materiaalin pohjalta. Ensin on käyty läpi johdannon ja tavoitteiden lisäksi ydinvoiman historiaa ja nykyhetkeä Suomessa. Tämän jälkeen työssä on käsitelty riskienhallintaa sekä siihen liittyvää yleistä teoriaa. Teoria toimii lisätukena viranomaisvaatimusten tarkastelussa sekä niiden toimien ymmärtämisessä. Ennen viranomaisvaatimuksia on tarkasteltu kuitenkin itse viranomaisia, niiden välisiä kytköksiä sekä sitä, mitkä eri viranomaiset vaikuttavat ydinvoimalaitoksen rakentamiseen. Tässä osiossa on tarkasteltu myös politiikan vaikutusta viranomaistoimintaan. Viranomaisten toimintaa ja vaatimuksia käsittelevässä osiossa on käyty läpi yleisesti ydinvoimalaitokseen liittyviin toimituksiin kuuluvat vaatimukset sekä yksityiskohtaisempia vaatimuksia aihealueittain. Tässä osiossa on myös käsitelty esimerkkejä Olkiluoto 3 –projektissa tehdyistä havainnoista ja toteutuneista riskeistä. Tämän jälkeen työssä on tehty tarvittavat johtopäätökset tutkimuskysymyksiin läpikäydyn materiaalin pohjalta. Johtopäätöksissä on myös käsitelty ydinvoimalaitokseen liittyvään toimitukseen sisältyviä riskejä sekä niiden hallintaa. Viranomaistyöstä korostuivat läpikäydyssä materiaalissa erityisesti suomalaisen viranomaistoiminnan tinkimättömyys ja korkea vaatimustaso. Tärkeimmiksi seikoiksi työssä nousivat ydinvoimalaitoksen rakentamiseen olennaisena osana kuuluva korkea turvallisuuskulttuuri sekä sen seurauksena yritysten toimivat johtamisjärjestelmät. Lisäksi hyvin tehty esi- ja perussuunnittelu helpottavat projektin eri osa-alueita. Huomioimalla nämä kolme seikkaa pystytään ydinvoimalaitoksen rakentamisen ja käytön aikaisia riskejä hallitsemaan tehokkaimmalla tavalla.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This thesis examines the existence and nature of momentum effect in European equity indices. A set of predefined indicators is used to compose momentum portfolios and different holding periods are used to test the strategies over variable time periods as well as under different economical conditions. The data consists of daily closing prices of STOXX Europe 600 index and its 18 super sector indices. Over the study period we follow the performances of a long position in the Winner portfolio, a position in the market neutral zero-cost portfolio and also a position in the risk-controlled zero-cost portfolio. The investment ratio of the risk-controlled zero-cost portfolio is negatively correlated with the realized market volatility. The results show that momentum effect is present in European industries and is most prominent in the short-term. Indicators that are based on short-term performance tend predict the over- and underperformers for the 1-month holding period more reliably than any other indicator/holding period combination. The examination of the strategies under different economical conditions shows that the market neutral approach can create significant returns in times of recession but in times of economic boom the long position in Winner portfolio outperforms the market neutral portfolio by an extensive margin.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Pasvik monitoring programme was created in 2006 as a result of the trilateral cooperation, and with the intention of following changes in the environment under variable pollution levels. Water quality is one of the basic elements of the Programme when assessing the effects of the emissions from the Pechenganikel mining and metallurgical industry (Kola GMK). The Metallurgic Production Renovation Programme was implemented by OJSC Kola GMK to reduce emissions of sulphur and heavy metal concentrated dust. However, the expectations for the reduction in emissions from the smelter in the settlement Nikel were not realized. Nevertheless, Kola GMK has found that the modernization programme’s measures do not provide the planned reductions of sulfur dioxide emissions. In this report, temporal trends in water chemistry during 2000–2009 are examined on the basis of the data gathered from Lake Inari, River Pasvik and directly connected lakes, as well as from 26 small lakes in three areas: Pechenganikel (Russia), Jarfjord (Norway) and Vätsäri (Finland). The lower parts of the Pasvik watercourse are impacted by both atmospheric pollution and direct wastewater discharge from the Pechenganikel smelter and the settlement of Nikel. The upper section of the watercourse, and the small lakes and streams which are not directly linked to the Pasvik watercourse, only receive atmospheric pollution. The data obtained confirms the ongoing pollution of the river and water system. Copper (Cu), nickel (Ni) and sulphates are the main pollution components. The highest levels were observed close to the smelters. The most polluted water source of the basin is the River Kolosjoki, as it directly receives the sewage discharge from the smelters and the stream connecting the Lakes Salmijarvi and Kuetsjarvi. The concentrations of metals and sulphates in the River Pasvik are higher downstream from the Kuetsjarvi Lake. There has been no fall in the concentrations of pollutants in Pasvik watercourse over the last 10 years. Ongoing recovery from acidification has been evident in the small lakes of the Jarfjord and Vätsäri areas during the 2000s. The buffering capacity of these lakes has improved and the pH has increased. The reason for this recovery is that sulphate deposition has decreased, which is also evident in the water quality. However, concentrations of some metals, especially Ni and Cu, have risen during the 2000s. Ni concentrations have increased in all three areas, and Cu concentrations in the Pechenganickel and Jarfjord areas, which are located closer to the smelters. Emission levels of Ni and Cu did not fall during 2000s. In fact, the emission levels of Ni compounds even increased compared to the 1990s.