Keskitehoestimaattorin lisääminen diesel-sähköiseen hybridijärjestelmään

Nykyajan jatkuvasti kiristyvät päästörajoitukset ja ilmastonmuutoksen uhka ovat ajavia voimia kehittämään voimalaitosten tekniikkaa energiatehokkaampaan ja ympäristöystävällisempään suuntaan. Polttomoottoritekniikan parantaminen on tärkeä osa tätä kehitystä, mutta jo nykyisiä moottoreita voitaisiin ajaa energiate-hokkaammin käyttämällä akustoa ja älykästä säätöjärjestelmää apuna. Työssä tutkitaan simulaatioiden avulla voidaanko ulkomerellä toimivan huolto-aluksen energiatehokkuutta parantaa muokkaamalla sen tehon tuottoa keskitehoes-timaattorin ja akuston avulla.

Neuropsychological rehabilitation of memory deficits and activities of daily living in patients with Alzheimer's disease: a pilot study

Patients with Alzheimer's disease (AD) gradually lose their cognitive competence, particularly memory, and the ability to perform daily life tasks. Neuropsychological rehabilitation is used to improve cognitive functions by facilitating memory performance through the use of external aids and internal strategies. The effect of neuropsychological rehabilitation through memory training - motor movements, verbal association, and categorization - and activities of daily living (ADL) training was tested in a sample of 5 elderly out-patients (mean age: 77.4 ± 2.88 years), with mild AD (Mini-Mental State Examination score: 22.20 ± 2.17) and their caregivers. All patients had been taking rivastigmine (6-12 mg/day) for at least 3 months before being assigned to the rehabilitation sessions, and they continued to take the medication during the whole program. Just before and after the 14-week neuropsychological rehabilitation program all patients were assessed by interviewers that did not participate in the cognitive training, using the Mini-Mental State Examination, Montgomery-Alsberg Depression Rating Scale, Hamilton Anxiety Scale, Interview to Determine Deterioration in Functioning in Dementia, Functional Test, Memory Questionnaire of Daily Living for patient and caregiver, Quality of Life Questionnaire for patient and caregiver, and a neuropsychological battery. The results showed a statistically significant improvement in ADL measured by Functional Test (P = 0.04), and only a small improvement in memory and psychiatric symptoms. Our results support the view that weekly stimulation of memory and training of ADL is believed to be of great value in AD treatment, not only delaying the progress of the disease, but also improving some cognitive functions and ADL, even though AD is a progressively degenerative disease.

Review of water electrolysis technologies and design of renewable hydrogen production systems

An electric system based on renewable energy faces challenges concerning the storage and utilization of energy due to the intermittent and seasonal nature of renewable energy sources. Wind and solar photovoltaic power productions are variable and difficult to predict, and thus electricity storage will be needed in the case of basic power production. Hydrogen’s energetic potential lies in its ability and versatility to store chemical energy, to serve as an energy carrier and as feedstock for various industries. Hydrogen is also used e.g. in the production of biofuels. The amount of energy produced during hydrogen combustion is higher than any other fuel’s on a mass basis with a higher-heating-value of 39.4 kWh/kg. However, even though hydrogen is the most abundant element in the universe, on Earth most hydrogen exists in molecular forms such as water. Therefore, hydrogen must be produced and there are various methods to do so. Today, the majority hydrogen comes from fossil fuels, mainly from steam methane reforming, and only about 4 % of global hydrogen comes from water electrolysis. Combination of electrolytic production of hydrogen from water and supply of renewable energy is attracting more interest due to the sustainability and the increased flexibility of the resulting energy system. The preferred option for intermittent hydrogen storage is pressurization in tanks since at ambient conditions the volumetric energy density of hydrogen is low, and pressurized tanks are efficient and affordable when the cycling rate is high. Pressurized hydrogen enables energy storage in larger capacities compared to battery technologies and additionally the energy can be stored for longer periods of time, on a time scale of months. In this thesis, the thermodynamics and electrochemistry associated with water electrolysis are described. The main water electrolysis technologies are presented with state-of-the-art specifications. Finally, a Power-to-Hydrogen infrastructure design for Lappeenranta University of Technology is presented. Laboratory setup for water electrolysis is specified and factors affecting its commissioning in Finland are presented.

Apply of energy storages in electricity distribution networks and reserve capacity applications

The Thesis is dedicated to development of an operative tool to support decision making of battery energy storages implementation in distribution networks. The basics of various battery technologies, their perspectives and challenges are represented in the Thesis. Mathematical equations that describe economic effect from battery energy storage installation are offered. The main factors that influence profitability of battery settings have been explored and mathematically defined. Mathematical model and principal trends of battery storage profitability under an impact of the major factors are determined. The meaning of annual net value was introduced to show the difference between savings and required costs. The model gives a clear vision for dependencies between annual net value and main factors. Proposals for optimal network and battery characteristics are suggested.

Effect of auditory training on the middle latency response in children with (central) auditory processing disorder

The purpose of this study was to determine the middle latency response (MLR) characteristics (latency and amplitude) in children with (central) auditory processing disorder [(C)APD], categorized as such by their performance on the central auditory test battery, and the effects of these characteristics after auditory training. Thirty children with (C)APD, 8 to 14 years of age, were tested using the MLR-evoked potential. This group was then enrolled in an 8-week auditory training program and then retested at the completion of the program. A control group of 22 children without (C)APD, composed of relatives and acquaintances of those involved in the research, underwent the same testing at equal time intervals, but were not enrolled in the auditory training program. Before auditory training, MLR results for the (C)APD group exhibited lower C3-A1 and C3-A2 wave amplitudes in comparison to the control group [C3-A1, 0.84 µV (mean), 0.39 (SD - standard deviation) for the (C)APD group and 1.18 µV (mean), 0.65 (SD) for the control group; C3-A2, 0.69 µV (mean), 0.31 (SD) for the (C)APD group and 1.00 µV (mean), 0.46 (SD) for the control group]. After training, the MLR C3-A1 [1.59 µV (mean), 0.82 (SD)] and C3-A2 [1.24 µV (mean), 0.73 (SD)] wave amplitudes of the (C)APD group significantly increased, so that there was no longer a significant difference in MLR amplitude between (C)APD and control groups. These findings suggest progress in the use of electrophysiological measurements for the diagnosis and treatment of (C)APD.

Increased levels of glutamate in the central nervous system are associated with behavioral symptoms in experimental malaria

Cerebral malaria (CM) is a severe complication resulting from Plasmodium falciparum infection. This condition has been associated with cognitive, behavioral and motor dysfunctions, seizures and coma. The underlying mechanisms of CM are incompletely understood. Glutamate and other metabolites such as lactate have been implicated in its pathogenesis. In the present study, we investigated the involvement of glutamate in the behavioral symptoms of CM. Seventeen female C57BL/6 mice (20-25 g) aged 6-8 weeks were infected with P. berghei ANKA by the intraperitoneal route using a standardized inoculation of 10(6) parasitized red blood cells suspended in 0.2 mL PBS. Control animals (N = 17) received the same volume of PBS. Behavioral and neurological symptoms were analyzed by the SmithKline/Harwell/Imperial College/Royal Hospital/Phenotype Assessment (SHIRPA) battery. Glutamate release was measured in the cerebral cortex and cerebrospinal fluid of infected and control mice by fluorimetric assay. All functional categories of the SHIRPA battery were significantly altered in the infected mice at 6 days post-infection (dpi) (P ≤ 0.05). In parallel to CM symptoms, we found a significant increase in glutamate levels in the cerebral cortex (mean ± SEM; control: 11.62 ± 0.90 nmol/mg protein; infected at 3 dpi: 10.36 ± 1.17 nmol/mg protein; infected at 6 dpi: 26.65 ± 0.73 nmol/mg protein; with EGTA, control: 5.60 ± 1.92 nmol/mg protein; infected at 3 dpi: 6.24 ± 1.87 nmol/mg protein; infected at 6 dpi: 14.14 ± 0.84 nmol/mg protein) and in the cerebrospinal fluid (control: 128 ± 51.23 pmol/mg protein; infected: 301.4 ± 22.52 pmol/mg protein) of infected mice (P ≤ 0.05). These findings suggest a role of glutamate in the central nervous system dysfunction found in CM.

Energy Consumption of Applications on Mobile Phones

Battery consumption in mobile applications development is a very important aspect and has to be considered by all the developers in their applications. This study will present an analysis of different relevant concepts and parameters that may have impact on energy consumption of Windows Phone applications. This operating system was chosen because there is limited research even though there are related studies for Android an iOS operating systems. Furthermore, another reason is the increasing number of Windows Phone users. The objective of this research is to categorise the energy consumption parameters (e.g. use of one thread or several thread for the same output). The result for each group of experiment will be analyzed and a rule will be derived. The set of derived rules will serve as a guide for developers who intend to develop energy efficient Windows Phone applications. For each experiment, one application is created for each concept and the results are presented in two ways: a table and a chart. The table presents the duration of the experiment, the battery consumed by the experiment, the expected battery lifetime and the energy consumption, while the charts display the energy distribution based on the main threads: UI thread, application thread and network thread.

Benchmark of routing protocols regarding green considerations

In Mobile Ad-hoc Networks (MANET) the participating nodes have several roles such as sender, receiver and router. Hence there is a lot of energy consumed by the nodes for the normal working of the network since each node has many different roles. Also in MANET the nodes keep moving constantly and this in turn consumes a lot of energy. Since battery capacity of these nodes is limited it fails to fulfil the high demand of energy. The scarcity of energy makes the energy conservation in mobile ad-hoc networks an important concern. There is several research carried out on the energy consumption of mobile ad-hoc networks these days. Some of this research suggests sleep mode, transmission power control, load balancing etc. In this thesis, we are comparing various proposed energy efficient models for some of the ad-hoc protocols. We compare different energy efficient models for Optimised Linked State Algorithm (OLSR) and Ad-hoc On Demand Distance Vector (AODV). The routing protocols are compared for different parameters such as average remaining energy, number of nodes alive, payload data received and performance with different mobility speed. The simulation results helps in benchmarking the various energy efficient routing models for OLSR and AODV protocols. The benchmarking of the routing protocols can be based on many factors but this thesis concentrates on benchmarking the MANET routing protocols mainly based on the energy efficiency and increased network lifetime.

Model-based testing of software systems : functionality and performance

Software is a key component in many of our devices and products that we use every day. Most customers demand not only that their devices should function as expected but also that the software should be of high quality, reliable, fault tolerant, efficient, etc. In short, it is not enough that a calculator gives the correct result of a calculation, we want the result instantly, in the right form, with minimal use of battery, etc. One of the key aspects for succeeding in today's industry is delivering high quality. In most software development projects, high-quality software is achieved by rigorous testing and good quality assurance practices. However, today, customers are asking for these high quality software products at an ever-increasing pace. This leaves the companies with less time for development. Software testing is an expensive activity, because it requires much manual work. Testing, debugging, and verification are estimated to consume 50 to 75 per cent of the total development cost of complex software projects. Further, the most expensive software defects are those which have to be fixed after the product is released. One of the main challenges in software development is reducing the associated cost and time of software testing without sacrificing the quality of the developed software. It is often not enough to only demonstrate that a piece of software is functioning correctly. Usually, many other aspects of the software, such as performance, security, scalability, usability, etc., need also to be verified. Testing these aspects of the software is traditionally referred to as nonfunctional testing. One of the major challenges with non-functional testing is that it is usually carried out at the end of the software development process when most of the functionality is implemented. This is due to the fact that non-functional aspects, such as performance or security, apply to the software as a whole. In this thesis, we study the use of model-based testing. We present approaches to automatically generate tests from behavioral models for solving some of these challenges. We show that model-based testing is not only applicable to functional testing but also to non-functional testing. In its simplest form, performance testing is performed by executing multiple test sequences at once while observing the software in terms of responsiveness and stability, rather than the output. The main contribution of the thesis is a coherent model-based testing approach for testing functional and performance related issues in software systems. We show how we go from system models, expressed in the Unified Modeling Language, to test cases and back to models again. The system requirements are traced throughout the entire testing process. Requirements traceability facilitates finding faults in the design and implementation of the software. In the research field of model-based testing, many new proposed approaches suffer from poor or the lack of tool support. Therefore, the second contribution of this thesis is proper tool support for the proposed approach that is integrated with leading industry tools. We o er independent tools, tools that are integrated with other industry leading tools, and complete tool-chains when necessary. Many model-based testing approaches proposed by the research community suffer from poor empirical validation in an industrial context. In order to demonstrate the applicability of our proposed approach, we apply our research to several systems, including industrial ones.

Sähköajoneuvojen akkujen uusiokäyttö

Tässä kandidaatintyössä tutkittiin sähkö- ja hybridiajoneuvojen akkujen uusiokäyttöä. Tutkimus toteutettiin kirjallisuustyönä. Tavoitteena oli selvittää voidaanko sähkö- ja hybridiajoneuvojen akkuja uusiokäyttää, mitä ongelmia mahdollisesti uusiokäyttöön liittyy, minkälaisissa sovelluksissa käytettyjä akkuja voisi käyttää ja uusiokäytetäänkö kyseisenlaisia akkuja jo nykyään. Työssä esiteltiin myös yleisimpiä akkutekniikoita sekä niiden kierrätystä. Tutkimuksessa havaittiin, että akuissa on runsaasti kapasiteettia jäljellä ajoneuvokäytön jälkeen. Uusiokäytössä akku voi kestää jopa yhtä paljon käyttöä kuin ajoneuvokäytössä. Ongelmat uusiokäytössä liittyvät akkujen vaihtelevaan kuntoon ja kapasiteettiin. Ennen uusiokäyttöä akut tulisi tarkastaa ja jos mahdollista, poistaa huonokuntoiset ja vialliset kennot. Käytettyjen akkujen uusiokäyttöön soveltuvista laitteistoista on tehty muutamia prototyyppejä, jotka ovat teholtaan ja kapasiteetiltaan hyvin vaihtelevia. Sopivalla valvontajärjestelmällä varustettuna käytettyjä akkuja voitaneen käyttää myös olemassa olevissa, akkuja sisältävissä järjestelmissä. Käytettyjä akkuja voitaneen käyttää muun muassa uusiutuvan energian varastointiin, sähköverkon kulutushuippujen kompensointiin ja sähköajoneuvojen pikalatauksen puskurina. Etenkin litiumioniakkujen uusiokäyttö on järkevää, koska kierrätys ei ole kovin tehokasta ainakaan vielä.

Vanadiiniakut

Nykyään monet käyttökohteet vaativat akuilta aiempaa parempaa suorituskykyä, joten on syntynyt kasvavaa tarvetta uusien akkujen kehittämiselle erilaisista uusista materiaaleista ja uusiin valmistusmenetelmiin pohjautuen. Työn tavoitteena on selvittää kirjallisuustutkimuksena litium-vanadiini-fosfaattiakun ja vanadiini-redoksi-virtausakun ominaisuuksia, saatavuutta, sovelluskohteita ja vertailla niitä muutamaan eri litiumakkutekniikkaan. Tutkimuksen perusteella litium-vanadiini-fosfaattiakkuja ei ole vielä saatavilla kaupallisesti, joten työssä tutkittiin niitä teknisten raporttien pohjalta. Raporttien pohjalta arvioituna, parhaita ominaisuuksia litium-vanadiini-fosfaattiakuilla on erinomainen kuormituksen kesto ja korkea nimellisjännite. Sähköisissä ajoneuvoissa litium-vanadiini-fosfaattiakuilla on suurimmat mahdollisuudet erilaisissa hybridiajoneuvoissa, mutta todennäköisesti ne soveltuvat täyssähköisiin ajoneuvoihin vähintään yhtä hyvin kuin esimerkiksi litium-rauta-fosfaattiakut, jos valmistuskustannukset olisivat samalla tasolla. Vanadiini-redoksi-virtausakkua on jo markkinoilla usean valmistajan toimesta. Niiden ominaisuudet poikkeavat paljon muista akkutyypeistä ja erikoisuutena on mahdollisuus akun pikalataukseen elektrolyyttinesteet vaihtamalla. Syklien kestossa päästään myös erinomaisiin arvoihin, mutta suurimmat ongelmat ovat lyijyakkuakin matalampi energiatiheys ja tehotiheys. Vanadiini-redoksi-virtausakut soveltuvat parhaiten suuren kokoluokan sähköverkkoratkaisuihin ja sähköisissä ajoneuvoissa niiden mahdollisuudet rajoittunevat täyssähköisiin linja-autoihin ja isoihin työkoneisiin.

Akkuvarastot omakotitaloissa

Energian varastointi on noussut keskeiseksi energia-alan teemaksi viime vuosina. Erityi-sesti uusiutuvan tuotannon lisääntyminen ja energian käytön tehostaminen ovat edesautta-neet energiavarastoratkaisuiden mukaantuloa. Työssä tarkastellaan litiumrautafosfaattiak-kujen käytön kannattavuutta omakotitaloissa. Tavoitteena on selvittää, millä reunaehdoilla näiden akkujen käyttö energiavarastoina tulee kannattavaksi Lappeenrannan olosuhteissa. Kannattavuutta selvitetään litiumrautafosfaattiakkujen markkina-analyysin ja teknistalou-dellisen analyysin sekä Matlab-simulaation avulla.

Energy Management System for LVDC Island Networks

Recent developments in power electronics technology have made it possible to develop competitive and reliable low-voltage DC (LVDC) distribution networks. Further, islanded microgrids—isolated small-scale localized distribution networks— have been proposed to reliably supply power using distributed generations. However, islanded operations face many issues such as power quality, voltage regulation, network stability, and protection. In this thesis, an energy management system (EMS) that ensures efficient energy and power balancing and voltage regulation has been proposed for an LVDC island network utilizing solar panels for electricity production and lead-acid batteries for energy storage. The EMS uses the master/slave method with robust communication infrastructure to control the production, storage, and loads. The logical basis for the EMS operations has been established by proposing functionalities of the network components as well as by defining appropriate operation modes that encompass all situations. During loss-of-powersupply periods, load prioritizations and disconnections are employed to maintain the power supply to at least some loads. The proposed EMS ensures optimal energy balance in the network. A sizing method based on discrete-event simulations has also been proposed to obtain reliable capacities of the photovoltaic array and battery. In addition, an algorithm to determine the number of hours of electric power supply that can be guaranteed to the customers at any given location has been developed. The successful performances of all the proposed algorithms have been demonstrated by simulations.

Electrical Safety of Island Operated Low Voltage DC Network

Today, renewable energy technologies and modern power electronics have made it feasible to implement low voltage direct current (LVDC) microgrids (MGs) ca-pable to island operation. Such LVDC networks are particularly useful in remote areas. However, there are still pending issues in island operated LVDC MGs like electrical safety and controlled operation, which should be addressed before wide-scale implementation. This thesis is focused on the overall protection of an island operated LVDC network concept, including protection against electrical shocks, mains equipment protection and protection of photovoltaic (PV) power sources and battery energy storage systems (BESSs). The topic is approached through ex-amination of the safety hazards and the appropriate methods to protect against them, comprising considerations for earthing system selection and realisation of the protection system.