Interaction of Bootstrap Reservoir and Hydraulic Pump in Aircraft Hydraulic Systems

This thesis focuses on studying system- and component-level phenomena in the fighter aircraft hydraulic power supply system in detail. The objective is to find out system-level root causes for premature failures of hydraulic pumps encountered in many modern fighter aircraft, and to study phenomena related to them. The thesis establishes a theoretically justified basis for understanding the interactions of the hydraulic system, bootstrap-type reservoir and axial piston hydraulic pump. It also presents a cost-effective and flexible method for studying system- and componentlevel phenomena in an aircraft hydraulic system by combining a theoretical approach with ground and laboratory testing.The hydraulic pump and bootstrap reservoir are studied using computer simulations to find out how interactions in the system-level operation influence the internal loads of the pump. A hydraulic pump and bootstrap-type reservoir with pipework connecting them are modelled as analytical physical models. Other parts of the hydraulic system are modelled using empirical black box-type models. The models used are verified in the laboratory using a purpose-built test rig and field measurements made with a real aircraft. Root causes of failures and phenomena causing them are identified using simulations. On the basis of this, system and component design variables which affect these phenomena are determined. The results of the study prove that premature failures of the hydraulic pump encountered in certain types of high-performance fighter aircraft are related to hydraulic system design features and their service and maintenance practices. The thesis concludes with design recommendations for bootstrap-type reservoir and pump supply and drain lines

Uskelanjoen vesistön sähkökoekalastukset vuonna 2006 ja taimenkannan (Salmo trutta L.) DNA-tutkimus

Uskelanjoen vesistö sijaitsee Salon seudulla Varsinais-Suomessa. Uskelanjoen latvahaaroja ovat Someron ja Kiikalan alueilla sijaitsevat Rekijoki, Terttilänjoki ja Hitolanjoki. Vesistön alaosassa Uskelanjokeen yhtyy Kurajoki ja Vähäjoki. Uskelanjoen vesistön valuma-alueen pinta-ala on 566 km2, josta 44 % on peltoa ja 0,6 % järviä. Uskelanjoen vesistö on aikaisempien sähkökoekalastusten perusteella luonnonvaraisen taimenen (Salmo trutta L.) esiintymisaluetta. Koekalastustulosten perusteella erityisesti Hitolanjoki sivupuroineen on alueellisesti merkittävä taimenjoki. Uskelanjoen ja Hitolanjoen taimenkanta on aikaisemmin arvioitu paikalliseksi purotaimenkannaksi, josta ei vaella yksilöitä syönnösvaellukselle mereen. Tässä tutkimuksessa pyrittiin saamaan sähkökoekalastusten avulla kokonaisvaltainen käsitys taimenkannan nykyisistä elinalueista ja merivaelluksen tehneiden yksilöiden esiintymisestä Uskelanjoen vesistössä. Helsingin yliopiston tutkija Jarmo Koskiniemen toteuttaman DNA-analyysin avulla pyrittiin selvittämään taimenkannan alkuperää ja geneettistä suhdetta eri istutus- ja luonnonkantoihin. Tämän tutkimuksen tulosten mukaan taimenta esiintyy laajalti Uskelanjoen vesistössä. Sähkökoekalastuksissa havaittiin taimenia Uskelanjoessa, Hitolanjoessa ja Terttilänjoessa. Vesistön taimenkannan havaittiin koostuvan paikallisista purotaimenista ja mereen vaeltaneista meritaimenista. DNA-analyysin mukaan Uskelanjoen vesistön taimenkanta eroaa geneettisesti vertailukannoista. Tutkimustulosten perusteella on annettu suosituksia eri toimenpiteistä Uskelanjoen vesistön luonnonvaraisen taimenkannan vahvistamiseksi ja elvyttämiseksi. Tutkimuksen kenttätyöt toteutettiin vuonna 2006 Salon seudun kalastusalueen toimesta. Työn tilaaja oli Varsinais-Suomen TE-keskuksen kalatalousyksikkö.The river Uskelanjoki watercourse is located in the Southwestern Finland. The size of the catchment area of the river Uskelanjoki watercourse is 566 km2. The catchment area is widely used by agriculture and there are only few lakes. 44 % of the catchment area is cultivated and only 0,6 % is lakes. The Uskelanjoki river flows to the Archipelago sea through the City of Salo. The river Uskelanjoki watercourse is regionally known by its natural brown trout (Salmo trutta L.) stock. Due to the previous electro-fishing results the Hitolanjoki tributary is the main habitat of the brown trout stock. The stock has been considered as a resident population without any anadromic migration behaviour. Even though some sea-migratory individuals have been discovered within the watercourse. The main purpose of this thesis was to evaluate the state and condition of the brown trout population with electro-fishing in the river Uskelanjoki watercourse. The origin of the trout stock and genetic relation to the other local stocks was evaluated with a DNA-analysis. The analysis was made by Helsinki University’s researcher Jarmo Koskiniemi. The main results were that brown trout occurs widely in the river Uskelanjoki watercourse and the brown trout stock differs genetically from the comparison stocks within the DNA-analysis. The brown trout population included resident and sea-migratory individuals. Recommendations for the conservation of the natural brown trout stock are given at the end of the thesis. The recommendations include, for example, the guidelines for fishing regulation and river habitat restoration

Fuel cells and novel thermal management advancements required for aviation

The paper considers the usage of proton exchange membrane fuel cells, gaseous H2 and cryogenic H2 fuels to solve the known thermal problems associated with electrical generation. Recent experimental H2 flight failures are reviewed, and a novel solution to control the electrolyte temperature operating range is proposed, utilising LH2, new additive manufactured evaporators/ heat exchangers and control software. The need for an IRON BIRD full scale test rig is justified prior to any further ambitious flight attempts.publishedVersionPeer reviewe

Tackling Trafficking by Targeting Sex Buyers: Can It Work?

The European legal instruments on human trafficking encourage states to tackle the demand for services of trafficked persons, for example, by making the use of services of a trafficked person a criminal offense. In Finland, buying sex from a trafficked person is a criminal offense. This article reports the results of an evaluation of the Finnish law and shows that the implementation has been inefficient. The authors argue that with an amendment of the law, the implementation could be improved but a truly efficient policy would require a total ban of sex purchase along the lines of the Swedish model.</p

Utterance-initial Duration of Finnish Non-plosive Consonants

Proceedings of the 16th Nordic Conference of Computational Linguistics NODALIDA-2007. Editors: Joakim Nivre, Heiki-Jaan Kaalep, Kadri Muischnek and Mare Koit. University of Tartu, Tartu, 2007. ISBN 978-9985-4-0513-0 (online) ISBN 978-9985-4-0514-7 (CD-ROM) pp. 160-166

Vankien poistumisluvat : yhtenäinen järjestelmä vai hajanaisia käytäntöjä?

Tutkimuksessa tarkastellaan vankien poistumislupajärjestelmää. Tavoitteena on selvittää nykyisen poistumislupajärjestelmän toimivuutta. Tutkimuksessa on käytetty poistumislupa-aineistoja vuosilta 2014-2021 ja vuodelta 2023. Tutkimuksen keskeinen päätelmä on, että poistumislupajärjestelmää koskevan lainsäädännön yksittäisiä säännöksiä tulisi tarkentaa ja varmistautua siitä, että erilaisten poistumislupien käyttö eri vankiloissa on yhdenmukaista

Kotitalouksien terveysmenojen vaikutukset toimeentuloon Suomessa – Tiivistelmä WHO:n maaraportista

Tutkimuksessa tarkastelemme terveydenhuollon palvelujen ja lääkkeiden käytöstä kotita-louksille aiheutuvaa maksutaakkaa Suomessa. Analyysit perustuvat Tilastokeskuksen ku-lutustutkimusaineistoihin vuosilta 2006, 2012 ja 2016 sekä kansainvälisiin tilastolähteisiin. Kotitalouksien maksutaakkaa mitataan suhteessa kotitalouksien maksukykyyn (katastro-faaliset terveysmenot) sekä suhteessa köyhyysrajaan (köyhdyttävät terveysmenot) käyt-täen Maailman terveysjärjestön (WHO) kehittämiä mittareita. Tuloksia verrataan muista Pohjoismaista ja Euroopan maista saatuihin tuloksiin. Lisäksi luomme katsauksen kansain-välisiin tilastoihin terveydenhuollon rahoituksesta ja tyydyttymättömistä palvelutarpeista.</p

Can people afford to pay for health care? - New evidence on financial protection in Finland (2021)

This review is part of a series of country-based studies generating newevidence on financial protection in health systems in Europe. Financialprotection is central to universal health coverage and a core dimensionof health system performance. The incidence of catastrophic healthspending in Finland is relatively high compared to other Nordic countries.It is driven mainly by out-of-pocket payments for outpatient medicines,followed by outpatient care and dental care. Unmet need for healthand dental services is also more prevalent in Finland than in many othercountries in western Europe. The factors that undermine access andfinancial protection, with a disproportionate impact on poorer and olderhouseholds, include: long-standing issues in the governance of coveragepolicy – multiple and overlapping coverage schemes, combined withregional variation in waiting times and co-payments, favour people inwork and wealthier households; complex and heavy co-payments foralmost all health services, with inadequate protection mechanisms; gapsin coverage and weaknesses in purchasing outpatient medicines; andrelatively low levels of public investment in health. To reduce unmet needand financial hardship, policy should focus on limiting co-payments foroutpatient care, especially primary care; improving protection from allco-payments for poorer households and people with high need for healthcare; and strengthening supply-side policies to promote better prescribing,dispensing and use of medicines.</p