927 resultados para Two-Phase Start-up Demonstration Test
Resumo:
Globalization has increased transport aggregates’ demand. Whilst transport volumes increase, ecological values’im portance has sharpened: carbon footprint has become a measure known world widely. European Union together with other communities emphasizes friendliness to the environment: same trend has extended to transports. As a potential substitute for road transport is noted railway transport, which decreases the congestions and lowers the emission levels. Railway freight market was liberalized in the European Union 2007, which enabled new operators to enter the markets. This research had two main objectives. Firstly, it examined the main market entry strategies utilized and the barriers to entry confronted by the operators who entered the markets after the liberalization. Secondly, the aim was to find ways the governmental organization could enhance its service towards potential railway freight operators. Research is a qualitative case study, utilizing descriptive analytical research method with a normative shade. Empirical data was gathered by interviewing Swedish and Polish railway freight operators by using a semi-structured theme-interview. This research provided novel information by using first-hand data; topic has been researched previously by utilizing second-hand data and literature analyses. Based on this research, rolling stock acquisition, needed investments and bureaucracy generate the main barriers to entry. The research results show that the mostly utilized market entry strategies are start-up and vertical integration. The governmental organization could enhance the market entry process by organizing courses, paying extra attention on flexibility, internal know-how and educating the staff.
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Synchronous machines with an AC converter are used mainly in large drives, for example in ship propulsion drives as well as in rolling mill drives in steel industry. These motors are used because of their high efficiency, high overload capacity and good performance in the field weakening area. Present day drives for electrically excited synchronous motors are equipped with position sensors. Most drives for electrically excited synchronous motors will be equipped with position sensors also in future. This kind of drives with good dynamics are mainly used in metal industry. Drives without a position sensor can be used e.g. in ship propulsion and in large pump and blower drives. Nowadays, these drives are equipped with a position sensor, too. The tendency is to avoid a position sensor if possible, since a sensor reduces the reliability of the drive and increases costs (latter is not very significant for large drives). A new control technique for a synchronous motor drive is a combination of the Direct Flux Linkage Control (DFLC) based on a voltage model and a supervising method (e.g. current model). This combination is called Direct Torque Control method (DTC). In the case of the position sensorless drive, the DTC can be implemented by using other supervising methods that keep the stator flux linkage origin centered. In this thesis, a method for the observation of the drift of the real stator flux linkage in the DTC drive is introduced. It is also shown how this method can be used as a supervising method that keeps the stator flux linkage origin centered in the case of the DTC. In the position sensorless case, a synchronous motor can be started up with the DTC control, when a method for the determination of the initial rotor position presented in this thesis is used. The load characteristics of such a drive are not very good at low rotational speeds. Furthermore, continuous operation at a zero speed and at a low rotational speed is not possible, which is partly due to the problems related to the flux linkage estimate. For operation in a low speed area, a stator current control method based on the DFLC modulator (DMCQ is presented. With the DMCC, it is possible to start up and operate a synchronous motor at a zero speed and at low rotational speeds in general. The DMCC is necessary in situations where high torque (e.g. nominal torque) is required at the starting moment, or if the motor runs several seconds at a zero speed or at a low speed range (up to 2 Hz). The behaviour of the described methods is shown with test results. The test results are presented for the direct flux linkage and torque controlled test drive system with a 14.5 kVA, four pole salient pole synchronous motor with a damper winding and electric excitation. The static accuracy of the drive is verified by measuring the torque in a static load operation, and the dynamics of the drive is proven in load transient tests. The performance of the drive concept presented in this work is sufficient e.g. for ship propulsion and for large pump drives. Furthermore, the developed methods are almost independent of the machine parameters.
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The RPC Detector Control System (RCS) is the main subject of this PhD work. The project, involving the Lappeenranta University of Technology, the Warsaw University and INFN of Naples, is aimed to integrate the different subsystems for the RPC detector and its trigger chain in order to develop a common framework to control and monitoring the different parts. In this project, I have been strongly involved during the last three years on the hardware and software development, construction and commissioning as main responsible and coordinator. The CMS Resistive Plate Chambers (RPC) system consists of 912 double-gap chambers at its start-up in middle of 2008. A continuous control and monitoring of the detector, the trigger and all the ancillary sub-systems (high voltages, low voltages, environmental, gas, and cooling), is required to achieve the operational stability and reliability of a so large and complex detector and trigger system. Role of the RPC Detector Control System is to monitor the detector conditions and performance, control and monitor all subsystems related to RPC and their electronics and store all the information in a dedicated database, called Condition DB. Therefore the RPC DCS system has to assure the safe and correct operation of the sub-detectors during all CMS life time (more than 10 year), detect abnormal and harmful situations and take protective and automatic actions to minimize consequential damages. The analysis of the requirements and project challenges, the architecture design and its development as well as the calibration and commissioning phases represent themain tasks of the work developed for this PhD thesis. Different technologies, middleware and solutions has been studied and adopted in the design and development of the different components and a big challenging consisted in the integration of these different parts each other and in the general CMS control system and data acquisition framework. Therefore, the RCS installation and commissioning phase as well as its performance and the first results, obtained during the last three years CMS cosmic runs, will be
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Teaching the measurement of blood pressure for both nursing and public health nursing students The purpose of this two-phase study was to develop the teaching of blood pressure measurement within the nursing degree programmes of the Universities of Applied Sciences. The first survey phase described what and how blood pressure measurement was taught within nursing degree programmes. The second intervention phase (2004-2005) evaluated first academic year nursing and public health nursing students’ knowledge and skills results for blood pressure measurement. Additionally, the effect on the Taitoviikko experimental group students’ blood pressure measurement knowledge and skills level. A further objective was to construct models for an instrument (RRmittTest) to evaluate nursing students measurement of blood pressure (2003-2009). The research data for the survey phase were collected from teachers (total sampling, N=107, response rate 77%) using a specially developed RRmittopetus-questionnaire. Quasi-experimental study data on the RRmittTest-instrument was collected from students (purposive sampling, experimental group, n=29, control group, n=44). The RRmittTest consisted of a test of knowledge (Tietotesti) and simulation-based test (TaitoSimkäsi and Taitovideo) of skills. Measurements were made immediately after the teaching and in clinical practice. Statistical methods were used to analyse the results and responses to open-ended questions were organised and classified. Due to the small amount of materials involved and the results of distribution tests of the variables, non-parametric analytic methods were mainly used. Experimental group and control group similar knowledge and skills teaching was based on the results of the national survey phase (RRmittopetus) questionnaire results. Experimental group teaching includes the supervised Taitoviikko teaching method. During Taitoviikko students studied blood pressure measurement at the municipal hospital in a real nursing environment, guided by a teacher and a clinical nursing professional. In order to evaluate both learning and teaching the processes and components of blood pressure measurement were clearly defined as follows: the reliability of measurement instruments, activities preceding blood pressure measurement, technical execution of the measurement, recording, lifestyle guidance and measurement at home (self-monitoring). According to the survey study, blood pressure measurement is most often taught at Universities of Applied Sciences, separately, as knowledge (teaching of theory, 2 hours) and skills (classroom practice, 4 hours). The teaching was implemented largely in a classroom and was based mainly on a textbook. In the intervention phase the students had good knowledge of blood pressure measurement. However, their blood pressure measurement skills were deficient and the control group students, in particular, were highly deficient. Following in clinical practice the experimental group and control group students’ blood pressure measurement recording knowledge improve and experimental groups declined lifestyle guidance. Skills did not improve within any of the components analysed. The control groups` skills on the whole, declined statistically.There was a significant decline amongst the experimental group although only in one component measured. The results describe the learning results for first academic year students and no parallel conclusions should be drawn when considering any learning results for graduating students. The results support the use and further development of the Taitoviiko teaching method. The RRmittTest developed for the study should be assessed and the results seen from a negative perspective. This evaluation tool needs to be developed and retested.
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Tämä diplomityö on tehty HT Laser Oy:n Vieremän tehtaan hitsaustoiminnan käynnistämisen yhteydessä. Diplomityön tavoitteena oli hitsaustoiminnan käynnistämisen kustannusten minimointi ja hitsattavien tuotteiden myynti- ja valmistusprosessin luominen. Työn teoriaosassa on esitelty hitsauslaitteistolle asetettavia vaatimuksia, hitsauskustannuksiin vaikuttavia tekijöitä, tuotantojärjestelmiä, tuotannon ohjausmenetelmiä, laadunhallintaa, henkilöstöasioita, osavalmistusta, hitsauksen hinnoittelua ja tilauskäsittelyä. Ensisijaisesti työssä on tavoiteltu sujuvan ja tuloksellisen tilaus/tarjouskäsittelyprosessin luomista. Tämä on nähty edellytyksenä ongelmattomalle tuotannolle ja hyvälle toimitusvarmuudelle. Työssä on luotu malli tarjousvaiheessa läpikäytävälle esikatselmukselle, jota on esitelty kahden case -esimerkin avulla. Case -esimerkeissä on käsitelty myös tuotteiden valmistukseen ja hinnoitteluun liittyviä asioita ja ongelmia sekä näiden ratkaisuja.
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Tämä diplomityö perustuu Lappeenrannan teknillisen yliopiston Uusiutuvien energiajärjestelmien laboratorion koelaitteistoon, jolla tutkitaan voimakkaan savukaasunkierrätyksen ja kuumailmapolton soveltuvuutta pienen kokoluokan energiantuotantoprosesseihin. Työn teoriaosassa esitellään tavanomaisesta palamisesta eroavaa kuumailmapolttoa ja tarkastellaan sen ominaisuuksia. Myös työssä käytetyn tutkimusmenetelmän, numeerisen virtauslaskennan, periaatteita ja ominaisuuksia tarkastellaan. Työssä tutkitaan numeerisella virtausmallinnuksella kuumailmapolttolaitteiston virtauskentän käyttäytymistä, kun takaisin tulipesään kierrätettävän savukaasun määrä sekä tulipesän lämpöhäviöiden suuruus vaihtelevat. Virtauskentän tarkastelu on tärkeää, sillä palamisilman ja kierrätetyn savukaasun täytyy sekoittua kuumailmapolton aikaansaamiseksi. Työn virtausmallinnus suoritettiin Finflo-virtausratkaisijalla kaksiulotteisena palamisreaktioita mallintamatta. Vaikka työssä käytetyt mallit olivat kaksiulotteisia ja niissä käytettiin yksinkertaistuksia, virtausten käyttäytymisestä tulipesässä saatiin olennaista tietoa, jota voidaan mahdollisesti hyödyntää jatkotutkimuksissa.
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APROS (Advanced Process Simulation Environment) is a computer simulation program developed to simulate thermal hydraulic processes in nuclear and conventional power plants. Earlier research at VTT Technological Research Centre of Finland had found the current version of APROS to produce inaccurate simulation results for a certain case of loop seal clearing. The objective of this Master’s thesis is to find and implement an alternative method for calculating the rate of stratification in APROS, which was found to be the reason for the inaccuracies. Brief literature study was performed and a promising candidate for the new method was found. The new method was implemented into APROS and tested against experiments and simulations from two test facilities and the current version of APROS. Simulation results with the new version were partially conflicting; in some cases the new method was more accurate than the current version, in some the current method was better. Overall, the new method can be assessed as an improvement.
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Diplomityön tavoitteena oli selvittää Loviisan ydinvoimalaitoksen höyryturbiinin suoritus-kyvyn mittaamiseen käytettävissä olevia menetelmiä ja mittausjärjestelmiä. Tavoitteena oli selvittää mitkä tekijät aiheuttavat mittauksiin mittausvirheitä ja tutkia turbiineiden nykyisten mittalaitteiden epävarmuudet. Tässä diplomityössä selvitettiin millaisia standardinmukaisia testejä sekä muita varteenotettavia testejä turbiinin suorituskyvyn määrittämiseen on käytetty ja millaisia mittauksia ne vaativat. Lisäksi tutkittiin eri lähteistä millaisia mittalaitteita ja mittausjärjestelmiä voidaan käyttää turbiinin toiminnan mittauksiin. Soveltuvista mittausmenetelmistä esitettiin toimintaperiaatteet ja teoria. Kunnonvalvontaa varten esiteltiin värähtelyiden ja vääntö-momentin mittaamisen periaatteet. Epävarmuuksia arvioitiin mittalaitteiden teoreettisen epävarmuuden ja laitesijoittelun pohjalta. Työssä havaittiin, että suorituskyvyn arvioimiseksi on olemassa useita standardeja, mutta niiden mukaisiin mittauksiin tarvittaisiin nykyistä enemmän mittaustuloksia. Tarkkoja sekä luotettavia mittaustuloksia on haasteellista saada kaksifaasivirtauksesta. Mittalaitevalinnoilla ja mittalaitteiden määrää lisäämällä voidaan mittausten epävarmuutta pienentää. Loviisan ydinvoimalaitokselle ehdotettiin muutamia mittausjärjestelmiä turbiinin suoritus-kyvyn määrittämiseksi. Erityisesti turbiinin sisäiset olosuhteet tulisi määrittää nykyistä tarkemmin. Vääntömomentin mittaaminen olisi hyvä kunnonvalvonnan työkalu.
Resumo:
The purpose of this two-phase study was to define the concept of vaccination competence and assess the vaccination competence of graduating public health nurse students (PHN students) and public health nurses (PHNs) in Finland, with the goal of promoting and maintaining vaccination competence and developing vaccination education. The first phase of the study included semi-structured interviews with vaccination professionals, graduating PHN students and clients (a total of n=40), asking them to describe vaccination competence as well as the factors strengthening and weakening it. The data were analyzed through content analysis. In the second phase of the study, structured instruments were developed, and vaccination competence of PHN students (n=129) in Finland and PHNs (n=405) was assessed using a self-assessment scale (VAS) and taking a knowledge test. PHNs were used as a reference group, enabling us to determine whether a satisfactory level of vaccination competence was achieved by the end of studies, or whether it was gained through work experience vaccinating clients. The data were collected from five polytechnic institutions and seven health centers located in various parts of the country. The data were collected using instruments developed for this study, and were analyzed statistically. In the first phase, based on the results of the interviews, vaccination competence was defined as a large multi-faceted entity, including the concepts of competent vaccinator, competent implementation of the vaccination, and the outcome of the implementation. Semi-structured interviews revealed that factors strengthening and weakening vaccination competence were connected to the vaccinator, the client being vaccinated, the vaccination environment and vaccinator education. On the whole, factors strengthening and weakening vaccination were the opposite of each other. In the second phase, on the self-assessment of vaccination competence, students rated themselves as significantly lower than working professionals. On the knowledge test, the percentage of correct answers was lower for students than PHNs. When all background variables were taken into account in multivariate analysis, there was no longer a significant difference between the students and PHNs on the self-assessment. However, in multivariate analysis, the PHNs still performed better than students on the knowledge test. For this study, a satisfactory level of vaccination competence was defined as a mean of 8.0 on the self-assessment and 80% correct answers on the knowledge test. Based on these criteria, students almost reached the level of satisfactory in their overall self-assessment, and PHNs did. Both groups, however, did rank themselves as satisfactory in some sum variables. On the knowledge test the students did not achieve a level of satisfactory (80%) in their total score, though PHNs did. As before, both groups did achieve a level of satisfactory in several sum variables. Further research and development should focus on vaccination education, the testing of vaccination competence and vaccination practices in clinical practice, as well as on developing the measurement tools.
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AB STRACT This study aimed at evaluating the natural durability of Eucalyptus dunnii, Eucalyptus robusta, Eucalyptus tereticornis and Hovenia dulcis woods submitted to a deterioration test in two environments, field and forest. The test samples were buried until half of their length (150 mm). Evaluations were carried out each 45 days, totalizing a 405-day period, with three-repetition withdrawal of each species for environment, totalizing nine samples from each environment, making up 24 test samples for evaluation. After percentage calculations of mass loss and resistance degree classification, the deterioration index was adopted for decomposition evaluation and fungal decay potential determination of test samples. The study has been carried out in completely randomized design (CRD), evaluated through analysis of variance (ANOVA) with subsequent comparison of means by Turkey' s test, in a 5%-level of probability of error, along with regression analysis. Eucalyptus tereticornis wood presented lesser mass loss in both environments. Hovenia dulcis presented lesser deterioration probability in both environments. Forest environment test samples presented greater mass loss percentages and lesser deterioration index.
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Diplomityössä kartoitetaan mahdollisuuksia aukko-osuuden mittaamiseksi ydinvoimalaitosta mallintavan PWR PACTEL -koelaitteiston pystyhöyrystimen sekundääripuolella. Työ on toteutettu osana kansallista SAFIR2014-ydinturvallisuustutkimusohjelmaa. Diplomityön tavoitteena on löytää kustannuksiltaan mahdollisimman järkevä ja toimiva menetelmä aukko-osuuden määrittämiseksi. Aukko-osuuden mittaaminen on tärkeää sekundääripuolen kaksifaasivirtauksen käyttäytymisen paremman tuntemuksen lisäämiseksi. Aukko-osuusmittausdataa tarvitaan muun muassa laskentakoodien validointiin. Diplomityössä perehdytään kaksifaasivirtauksen ja aukko-osuuden fysiikkaan sekä esitellään erityyppisiä aukko-osuuden mittausmenetelmiä. Kunkin mittausmenetelmän soveltuvuutta PWR PACTEL -koelaitteistoon arvioidaan erikseen. Aukko-osuuden mittaaminen höyrystimen sekundääripuolella osoittautuu käytännössä erittäin hankalaksi. Pääasiassa tämä johtuu höyrystimen rakenteesta sekä mittausmenetelmien korkeista kustannuksista. Tämän vuoksi työssä tarkastellaan myös edellytyksiä aukko-osuuden mittaamiselle erillisessä höyrystintä mallintavassa koelaitteistossa. Mikäli aukko-osuutta haluttaisiin mitata erilliskoelaitteistossa, tulisi höyrystinmallin rakennetta, materiaaleja tai kiertoainetta muuttaa PWR PACTELin höyrystimeen verrattuna.
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The high load of nitrogen present in swine wastewater is one of the biggest management challenges of the activity. The Anammox process emerges as a good alternative for biological removal of nitrogen. This study aims to acclimate sludge collected from swine effluent treatment systems to establish the Anammox process. Two sludge samples were collected at Embrapa Swine and Poultry, Concordia - SC, Brazil, one from the bottom of an inactive anaerobic pond (inoculum A) and another from an aeration tank (inoculum B). Both were acclimated until the depletion of NO3-N, being subsequently inoculated in two reactors (Reactor A - Inoculum A and Reactor B - Inoculum B). The Reactor A showed activity after 110 days of operation, while the Reactor B needed 170 days. The difference in the start-up time could be explained by the different environmental conditions to which each sludge was submitted. FISH and PCR analyses confirmed the presence of microorganisms with Anammox activity, demonstrating that the sludge of swine wastewater treatment systems is a good source of inoculum for the development of the Anammox process.
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Potilaan hoitamisessa korostuvat mm. triagen tekeminen, potilaan voinnin seuranta ja hoitoa koskevien päätösten tekeminen nopeasti potilaan voinnin mukaan sekä potilaan jatkohoidon turvaaminen. Tämä kaksivaiheinen koulutustutkimus kohdistui päivystyshoitotyön osaamiseen. Tutkimuksen ensimmäisessä vaiheessa määriteltiin päivystyshoitotyön osaaminen ja toisessa vaiheessa arvioitiin valmistuvien sairaanhoitajaopiskelijoiden päivystyshoitotyön osaamista ja osaamiseen yhteydessä olevia tekijöitä. Osaamisen arvioinnin suorittivat opiskelijat itse ja vertailuperustana opiskelijoiden päivystyshoitotyön osaamiselle käytettiin ammatissa toimivien sairaanhoitajien päivystyshoitotyön osaamista. Tutkimuksen tavoitteena oli arvioinnin perusteella määrittää päivystyshoitotyön osaamisen nykytaso ja tehdä tarvittavat ehdotukset päivystyshoitotyön osaamisen kehittämiseen. Tutkimuksen ensimmäisessä vaiheessa (2006–2012) tiedonkeruumenetelminä oli kirjallisuuskatsaus ja asiantuntija-arviointi hyödyntäen delphi-menetelmää. Kirjallisuuskatsauksen perusteella muodostettiin päivystyshoitotyön osaamista kuvaavat pääkategoriat, yläkategoriat ja alakategoriat.Alakategoriat (n=61) annettiin asiantuntijoille (sairaanhoitajat, opettajat, ylihoitajat) arvioitavaksi.Kaksivaiheisen asiantuntija-arvioinnin perusteella muodostui 92 päivystyshoitotyön osaamista kuvaavaa alakategoriaa. Tutkimuksen toisessa vaiheessa (2007–2012) valmistuvien suomalaisten sairaanhoitaja-opiskelijoiden (N=382, n=208, vastausprosentti 55 %) päivystyshoitotyön osaamista arvioitiin tätä tutkimusta varten kehitetyllä mittarilla (Päivystyshoitotyön osaaminen -mittari). Mittari perustui tutkimuksen ensimmäisessä vaiheessa muodostettuun määrittelyyn päivystyshoitotyön osaamisesta. Osaamista mitattiin VAS-janalla (asteikko 0–100) arvon 100 ollessa optimaalinen taso, johon pyrittiin. Sairaanhoitajaopiskelijoiden tavoiteltavaksi osaamisen tasoksi asetettiin 80 olettaen opiskelijoiden osaamisen vielä kehittyvän työkokemuksen myötä. Ammatissa toimivien sairaanhoitajien (N=586, n=280, vastausprosentti 48 %) itsearvioitua osaamista käytettiin vertailuperustana opiskelijoiden osaamiselle. Aineisto analysoitiin tilastollisin menetelmin. Valmistuvien sairaanhoitajaopiskelijoiden itsearvioitu päivystyshoitotyön osaaminen oli alle tavoiteltavan osaamisen tason. Opiskelijoilla oli mielestään eniten eettistä osaamista sekä vuorovaikutus- ja yhteistyöosaamista ja vähiten päätöksenteko-osaamista ja kliinistä osaamista. Myös ammatissa toimivilla sairaanhoitajilla oli mielestään eniten vuorovaikutus- ja yhteistyöosaamista. Vähiten heillä oli ohjausosaamista ja päätöksenteko-osaamista. Sairaanhoitajilla oli tilastollisesti merkitsevästi enemmän päivystyshoitotyön osaamista kuin opiskelijoilla. Opiskelijoiden päivystyshoitotyön osaamista selitti eniten aikaisempi terveysalan tutkinto. Päivystyshoitotyön osaamisen kehittämisehdotukset kohdistuvat ammatillisen peruskoulutuksen ja täydennyskoulutuksen opetuksen sisältöihin ja määrään, opetus- ja opiskelumenetelmiin, osaamisen arviointiin sekä urasuunnitteluun. Jatkotutkimusehdotukset kohdistuvat päivystyshoitotyön osaamisen määrittelyn ja osaamista arvioivan mittarin edelleen kehittämiseen, erilaisten arviointimenetelmien kehittämiseen sekä osaamiseen yhteydessä olevien tekijöiden edelleen tutkimiseen.
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Logistics infrastructure and transportation services have been the liability of countries and governments for decades, or these have been under strict regulation policies. One of the first branches opened for competition in EU as well as in other continents, has been air transports (operators, like passenger and freight) and road transports. These have resulted on lower costs, better connectivity and in most of the cases higher service quality. However, quite large amount of other logistics related activities are still directly (or indirectly) under governmental influence, e.g. railway infrastructure, road infrastructure, railway operations, airports, and sea ports. Due to the globalization, governmental influence is not that necessary in this sector, since transportation needs have increased with much more significant phase as compared to economic growth. Also freight transportation needs do not correlate with passenger side, due to the reason that only small number of areas in the world have specialized in the production of particular goods. Therefore, in number of cases public-private partnership, or even privately owned companies operating in these sub-branches have been identified as beneficial for countries, customers and further economic growth. The objective of this research work is to shed more light on these kinds of experiments, especially in the relatively unknown sub-branches of logistics like railways, airports and sea container transports. In this research work we have selected companies having public listed status in some stock exchange, and have needed amount of financial scale to be considered as serious company rather than start-up phase venture. Our research results show that railways and airports usually need high fixed investments, but have showed in the last five years generally good financial performance, both in terms of profitability and cash flow. In contrary to common belief of prosperity in globally growing container transports, sea vessel operators of containers have not shown that impressive financial performance. Generally margins in this business are thin, and profitability has been sacrificed in front of high growth – this also concerns cash flow performance, which has been lower too. However, as we examine these three logistics sub-branches through shareholder value development angle during time period of 2002-2007, we were surprised to find out that all of these three have outperformed general stock market indexes in this period. More surprising is the result that financially a bit less performing sea container transportation sector shows highest shareholder value gain in the examination period. Thus, it should be remembered that provided analysis shows only limited picture, since e.g. dividends were not taken into consideration in this research work. Therefore, e.g. US railway operators have disadvantage to other in the analysis, since they have been able to provide dividends for shareholders in long period of time. Based on this research work we argue that investment on transportation/logistics sector seems to be safe alternative, which yields with relatively low risk high gain. Although global economy would face smaller growth period, this sector seems to provide opportunities in more demanding situation as well.
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Helicobacter pylori (HP) infection is endemic worldwide. The proposed treatment is expensive and there are few reports regarding reinfection rates in Brazil. The aim of this study was to compare the eradication rates obtained with two therapeutic options and to evaluate reinfection one year after treatment. This was a prospective randomized trial with 55 patients. Thirty-nine patients had active duodenal ulcer (DU) and 16 non-ulcer dyspepsia (NUD), and all tested positive for HP. Diagnosis was based on at least two positive tests: ultrarapid urease test, histology and/or culture. Patients were randomized to two groups: group OMC treated with 40 mg omeprazole (once a day), 500 mg metronidazole and 250 mg clarithromycin (twice daily) for 7 days, or group NA treated with 300 mg nizatidine (once a day) and 1000 mg amoxicillin (twice daily) for 14 days. Those patients in whom HP was eradicated were followed up for one year to evaluate reinfection. Twenty-five patients were randomized for OMC and 30 for NA. HP eradication occurred in 20/25 patients (80%) treated with OMC and 13/30 (43%) treated with NA (P = 0.01). After reallocation because of initial treatment failure, the overall eradication rate was 44/51 patients (86%). After an average follow-up of one year, we evaluated 34 patients (23 with DU and 11 with NUD). Reinfection occurred in 3/34 patients (7.6%). We conclude that OMC is effective for HP eradication, and that NA should not be used. Reinfection occurs in 7.6% of the patients in the first year after eradication.