National Library of Finland DSpace Services
Not a member yet
86391 research outputs found
Sort by
Steam-induced melt infiltration method for all oxide Co3O4 based solar cells.
No full textSolar cells based on oxide materials are an attractive option for sustainable energy production offering a viable solution to climate-related issues. However, the success of all-oxide solar cells (AOSCs) is highly dependent on efficient charge extraction to prevent the recombination of photogenerated carriers, which is a primary factor contributing to their lower efficiency.
In this research work, a unique steam-induced melt infiltration (SIMI) method was introduced and studied to achieve bulk-heterojunction (BHJ) design in CO3O4-based oxide solar cells to overcome recombination losses. It is proposed that this design will overcome the losses due to the recombination of electrons and holes therefore resulting in an increased efficiency in all oxide solar cells. The work was divided into two parts. First, different parameters were studied on microscope glass slides, and second, these optimized parameters were used to build devices.
In the first part of the study, the parameters such as thickness of mesoporous titania film, concentration of metal salt Co3O4.6H2O, number of SIMI cycles, etching time for sacrificial silica layer, and capping effect were investigated and optimized to be used for building devices. The optimized parameters identified were 0.25 g/mL mp-TiO2, 1 M Co3O4·6H2O, 5 SIMI cycles, a 6h etching time, and subsequent capping with 1 M salt solution. A significant outcome of this study, confirmed by SEM imaging, was the formation of a bulk-heterojunction structure.
These optimized parameters were used for building solar cell devices on fluorine-doped tin oxide glass. These built devices (FTO glass/ c-TiO2/ mp-TiO2/ mpSiO2/ SIMI cycles/ 6h etching/ capping/ metal contact) were characterized by I-V measurements. The devices resulted in an overall low efficiency and VOC values close to zero. This study suggests that the proposed steam-induced melt infiltration method is successful in achieving bulk-heterojunction design however, other parameters need to be studied and optimized to increase the efficiency of Co3O4 based all oxide solar cells
Modelling of vertical roller mill and technical analysis
No full textThere is a growing need to reduce energy consumption, in mineral processing, and to improve the efficiency of operations. To improve the mineral processing, it is crucial to understand the breakage mechanisms in different equipment and how it impacts the product. The processing of minerals requires multiple equipment, depending on the desired characteristics for the product. The energy required for processing the material is relevant, but it is also important to minimize the stream of by-products.
The objective of the thesis was to analyze a vertical roller mill (VRM) and to use the information to improve the performance of a VRM. Most common crushers and mills were analyzed to understand what other equipment is used when minerals are processed. The VRM is efficient, quiet and produces a uniform product. In the theoretical analysis, parameters that impact the performance of the VRM were listed in two tables. The parameters can be used to modify the performance of the VRM. By modifying the performance, it is possible to adapt the mill to a changing demand.
In the experimental part of the thesis, a mill was analyzed and optimized. The mill faced some challenges that had to be addressed. Fundamental problems were found in the process and recommendations were made to improve the performance. In addition, the mill had issues producing some products, because of excessive vibrations. The vibrations have caused downtime due to excessive wear. By analyzing the mill, it was concluded that the vibrations were caused of a stick-slip effect. The stick-slip effect can be caused of an excessive roller pressure. The vibrations were minimized by decreasing the roller pressure, which improved the performance of the mill and all products could be produced normally.
Besides improving the performance of the mill, it was decided to model the grinding in the VRM. By modeling the grinding it was possible to estimate how the product changes if the raw material is modified. Dolomite is processed in the factory, which is extracted locally. From the dolomite processing a by-product is produced. There was an interest to use the by-product in the process, which would decrease waste. From the results of the model, the product did not change significantly when the by-product was added. By using the by-product the benefits would be; less waste, more efficient extraction and decreased raw material costs
Keskikosken museosillan kunnossapitosuunnitelma
No full textKeskikosken silta on mukana valtakunnallisesti merkittävien kulttuuriympäristöjen luettelossa (RKY) ja sijaitsee valtakunnallisesti merkittävällä Kymijokilaakson kulttuurimaiseman maisema-alueella. Myllykosken paperitehtaan RKY-alue liittyy kiinteästi siltaan. Museokohteena Keskikosken silta on helposti saavutettavissa. Kohteen saavutettavuutta parannetaan uusimalla opastaulut ja parantamalla viitoitusta kohteelle. Keskikosken silta otettiin museokohteeksi Kymen piirin esityksestä 1982.
Kymijoki on aina muodostanut merkittävän luonnonesteen maaliikenteelle. Pysyviä siltoja joen yli oli pitkään vain Suurella Rantatiellä lähellä Suomenlahden rannikkoa. Ensimmäinen pysyvä siltayhteys joen yläjuoksulla oli maantiesillaksi 1920-luvun lopulla muutettu Korian vanha rautatiesilta. Kymijoen yläjuoksun sillat kytkeytyvät usein alueen teollisuuteen ja niitä rakennettiin Myllykosken lisäksi myös Inkeroisiin, Voikkaalle ja Kuusankoskelle 1930- ja 40-luvuilla. Keskikosken silta rakennettiin 1949–1954 Myllykosken tehtaan ja tehdasyhteisön toiveesta korvaamaan väliaikainen tehtaan voimalaitoksen patoa hyödyntänyt siltayhteys. Silta rakennettiin teräksisenä sauvakaarisiltana, koska Kymijoen uiton oli oltava mahdollista rakennustyön aikana. Professori Ossian Hanneliuksen suunnitteleman sillan läntisen haaran vapaa aukko on 48 metriä ja itäisen haaran 35 metriä. Teräsosat ja niiden pystytys tilattiin Varkaudesta A. Ahlström Oy:ltä. Sillan rakennustyön aikana juhannuksen 1953 jälkeen tapahtui vakava onnettomuus, kun itäisen haaran palkit menettivät kovan helteen ja epäonnistuneen asennustyön vuoksi muotonsa ja sortuivat jokeen. Tämä aiheutti pitkän viivästyksen työhön, koska riittävän laadukas teräs piti tilata Keski-Euroopasta. Keskikosken silta valmistui lopulta marraskuussa 1954.
Museaalisesta näkökulmasta katsottuna sillan kunto on hyvä, mutta käyttäjien näkökulmasta sitä ympäristöineen on syytä kunnostaa kunnossapitosuunnitelman mukaisesti. Toimenpiteillä pyritään korostamaan sillan ja sen ympäristön tulkittavuutta, sekä parantamaan sen käytettävyyttä ja turvallisuutta. Suunnitelmassa on esitetty toimenpiteitä sillan ja sen lähiympäristön kehittämiseksi ja hoitamiseksi tienpitäjän ja matkailijan näkökulmasta. Suunnitelma sisältää hoitourakkaan sisällytettävät tieympäristön hoitotoimenpiteet sekä kohteen ympäristön kunnostustoimenpiteitä ja suuntaviivoja sillan korjaukselle. Hoitourakkaan sisällytettävät hoitotoimenpiteet on esitetty tiivistetysti työkohtaisessa tarkennuksessa ja kohdekortissa
Empowering Individuals with Mobility Limitations through Advanced Home Automation Technologies
No full textThis thesis explores the transformative potential of advanced home automation technologies in empowering individuals with mobility limitations. As populations age and the prevalence of mobility impairments increases, there is a growing need for innovative solutions that enhance independence, safety, and quality of life. This research investigates various home automation systems, including smart home devices, adaptive interfaces, and assistive robotics, and their applications in supporting the daily lives of individuals with mobility challenges.
This thesis focuses on a comprehensive literature review involving individuals with mobility limitations, caregivers, and experts in assistive technology. Key findings highlight the significant impact of home automation technologies in reducing physical barriers, improving accessibility, and facilitating independent living. Advanced systems such as voice-activated controls, automated lighting, and integrated health monitoring not only enhance convenience but also provide critical support in emergency situations.
Furthermore, the research identifies several challenges and barriers to the widespread adoption of these technologies, including high costs, lack of user-friendly design, and concerns about privacy and data security. Recommendations for addressing these challenges are provided, emphasizing the importance of inclusive design,
affordability, and robust security measures.
This thesis contributes to the field of assistive technology by demonstrating how advanced home automation can be effectively leveraged to empower individuals with mobility limitations. The insights gained from this research aim to inform future developments in smart home solutions, ultimately promoting greater autonomy and improved quality of life for disadvantaged people
Global minimum tax and tax incentives
No full textThis study examines the impact of global minimum tax (GMT) on the tax savings that firms derive from national tax incentives, which many governments use to stimulate economic activity. The GMT framework includes two approaches to treat such national tax rules: tax reduction treatment (TRT) and income treatment (IT). By incorporating these rules into the King and Fullerton (1984) framework, we calculate effective tax rates (EMTR and EATR) to assess the effects of these treatments. We show that while tax reduction treatment significantly reduces the tax benefits, income treatment has a more modest impact. However, in both cases, the effective tax rate on investment can remain low, primarily due to the substance-based income exclusion (SBIE) included in the rules of GMT. We also find that the effective tax rate is sensitive to inflation, staying very low or even negative at low inflation rates but increasing sharply with higher inflation.nonPeerReviewe
Lipidbindningen hos GLTP påverkar samverkan med VAP-A
No full textLipider är centrala för många biologiska funktioner och de fungerar bland annat som grundläggande komponenter i cellmembran, som energireserver och som signaleringsmolekyler. Lipidobalanser är även kopplade till exempelvis en rad olika neurodegenerativa sjukdomar. Speciellt onormala sfingolipidnivåer har kopplats till både Alzheimers och Parkinsons sjukdom. Glykolipidöverföringsproteinet (GLTP) är ett cytosoliskt lipidtransportprotein som överför glykosfingolipider in vitro. Väldigt lite är känt om den specifika funktionen hos GLTP in vivo, men det har föreslagits att GLTP skulle kunna fungera som en sensor för glukosylceramid (GlcCer)-nivåer i gränssnittet mellan det endoplasmatiska nätverket (ER) och cis-Golgiapparaten. GLTP antas även vara acylkedjelängdsspecifik och föredra GlcCer med kortare kedjor. GLTP har en ”två fenylalaniner i ett surt område” (FFAT)-domän, vilket gör att proteinet kan interagera med ER genom att binda till det vesikelassocierade membranproteinassocierade proteinet (VAP). Genom att interagera med ER genom VAP tros GLTP kunna reglera transporten av ceramidinnehållande vesklar från ER till cis-Golgi.
Syftet med detta projekt var att vidare undersöka hur GLTP interagerar med VAP i kombination med GlcCer av olika acylkedjelängder, och således erhålla mer information kring GLTP:s eventuella sensorroll. Målet var även att studera skillnader i hur GLTP samverkar med VAP-A och VAP-B. Detta undersöktes genom en bindningsanalys vars resultat visualiserades med en Western blot-analys. Sammanfattningsvis visade resultaten att då GLTP är bunden till en GlcCer så är associationen till VAP-A svagare och att GLTP generellt föredrar att binda till GlcCer-lipider med kortare acylkedjor. Resultaten visade även att GLTP binder bättre till VAP-A än till VAP-B och att VAP påverkar GLTP-GlcCer-bindningen och GLTP-GalCer-bindningen på olika sätt
Exploring The Use of LLMs In Agile Technical Documentation Writing
No full textMaintaining accurate technical documentation in a Continuous Software Development (CSD)environment is challenging and time-consuming because the frequent software changes require continuous updates to the documentation. Our work addresses this by automating the documentationupdates according to code changes. This thesis presents Autodoc, a solution that uses Large Language Models (LLMs) to automate the updating of technical documentation in response to sourcecode changes. It is developed to assist technical writers by summarizing code changes, retrievingupdated content, and allowing follow-up questions via a chat interface.Autodoc utilizes the Retrieval Augmented Generation (RAG) prompt engineering technique toretrieve existing documentation and generate updated content. Merge requests’ diff output dataserves as the basis for building both a summary engine and a chat engine, which provide comprehensive summaries and answer questions specifically related to the changes made in the request.Experiments are conducted to evaluate the solution using predefined metrics: answer relevancy,faithfulness, contextual relevancy, and summarization quality. These evaluations are performedfor the retriever and generator components, using different LLMs, embedding models, temperaturesettings, and top-k values. Additionally, qualitative evaluations are conducted by collecting userfeedback on the proposed solution’s performance and usability. Our solution achieves an averageanswer relevancy score of approximately 0.86 with OpenAI’s gpt-3.5-turbo and text-embedding-3-large. With an emotion prompting technique, this score increases to 0.94. Moreover, users providepositive feedback on the solution’s effectiveness in addressing the issue.In conclusion, our work introduces a new approach for updating technical documentation inresponse to source code changes within a CSD environment
Ukrainan sotilaallinen tukeminen : miksi länsi on epäyhtenäinen?
No full textVenäjän käynnistettyä hyökkäyksen Ukrainaan 24.2.2022 länsimaat ovat avustaneet Ukrainaa sotilaallisesti. Tämä on tapahtunut kansalliselta pohjalta, sillä Ukraina ei ole Naton jäsenvaltio. Artikkelissa formuloidaan allianssiteoreettinen malli, josta nähdään allianssin jäsenmaiden kannustin ali-investoida kansalliseen turvallisuuteen ja näiden investointien riippuvuus maan koosta.
Pienten Baltian maiden ja Pohjoismaiden tuki Ukrainalle on suhteessa bkt:hen kuitenkin ollut suurempi kuin suurten Nato-maiden. Artikkeli tarjoaa tälle selityksen kunkin jäsenmaan kansallisen turvaluokituksen avulla kahden vaiheen peliteoreettisessa mallissa ja ehdollisella sille, mitä odotuksia liittyy pelin toiseen vaiheeseen, jos Venäjä voittaa sodan vaiheessa yksi ja jos Naton kykyyn sitoutua artiklaan 5 liittyy epävarmuutta.ei tietoa saavutettavuudest
The role of the Security Council of the Russian Federation : a power tool in Russia's strategic decision-making?
No full textThis paper describes and analyses the position and role of the Security Council of the Russian Federation (SC) in the context of strategic planning and decision-making in the Russian Federation. Established in 1992, the SC was created to be the central body for coordination in the field of national security. Although its perceived position has fluctuated throughout the years, it remains an integral part of Putin’s regime.
The SC’s organisational position as subordinate to the Presidential Administration of Russia brings layers to the examination since it exemplifies the inherent hierarchy that exists in the Russian government. What is especially under analysis in this paper then is whether the SC holds some kind of power or if it is merely a façade of institutionalism in an otherwise authoritarian decision-making system.
Assessing the role of the SC is a difficult task since we know so little about its func tions beneath the surface level. It is known that it takes part in the strategic planning and decision-making process, but it is unclear how much it really affects the process and in what ways it does so. The SC seemingly has a broad remit, and the Russian constitution affords it substantial authority. Yet we have seen the SC at times subjugated to the whims of the Russian leadership in a manner that makes it seem like this governmental organ has no will of its own.ei tietoa saavutettavuudest