Miracle-dz/UniFAR-FTUs huggingface dataset:
Self-study manual for introduction to computational fluid dynamics

Mechanical Engineering and Production Technology Riihimäki Author Andrey Nabatov Year 2017 Subject Self-study manual for introduction to computational fluid dynamics Supervisor(s) Esa Murtola ABSTRACT Computational Fluid Dynamics (CFD) is the branch of Fluid Mechanics and Computational Physics that plays a decent role in modern Mechanical Engineering Design process due to such advantages as relatively low cost of simulation comparing with conduction of real experiment, an opportunity to easily correct the design of a prototype prior to manufacturing of the final product and a wide range of application: mixing, acoustics, cooling and aerodynamics. This makes CFD particularly and Computational Physics in general the tools, desirable to know for every Mechanical Engineering product developer.Computational Fluid Dynamics (CFD) is the branch of Fluid Mechanics and Computational Physics that plays a decent role in modern Mechanical Engineering Design process due to such advantages as relatively low cost of simulation comparing with conduction of real experiment, an opportunity to easily correct the design of a prototype prior to manufacturing of the final product and a wide range of application: mixing, acoustics, cooling and aerodynamics. This makes CFD particularly and Computational Physics in general the tools, desirable to know for every Mechanical Engineering product developer. This project is aimed to provide the Mechanical Engineering department of HAMK with sufficient study material for a potential course in the future that will introduce HAMK Mechanical Engineering students to Computational Fluid Dynamics. The study material contains parts of theory, describing the ideas behind derivation of governing equations of Fluid Dynamics, their discretization methods, fundamental algorithms of CFD, part of boundary layer theory essential for CFD and turbulence RANS models, which is the required minimum to study prior to the main practical part, consisting of a link to open-source CFD tutorials for ANSYS FLUENT and a simple example done in Mathcad 15, illustrating the work of algorithms and mathematics, covered in theory. There is also an introduction to the Pi-theorem and its applications in the separate chapter, which provides students with a toolbox for a proper analysis of results, gained from several simulations.
Silicon Quantum Dots in a Dielectric Matrix for All-Silicon Tandem Solar Cells

We report work progress on the growth of Si quantum dots in different matrices for future photovoltaic applications. The work reported here seeks to engineer a wide-bandgap silicon-based thin-film material by using quantum confinement in silicon quantum dots and to utilize this in complete thin-film silicon-based tandem cell, without the constraints of lattice matching, but which nonetheless gives an enhanced efficiency through the increased spectral collection efficiency. Coherent-sized quantum dots, dispersed in a matrix of silicon carbide, nitride, or oxide, were fabricated by precipitation of Si-rich material deposited by reactive sputtering or PECVD. Bandgap opening of Si QDs in nitride is more blue-shifted than that of Si QD in oxide, while clear evidence of quantum confinement in Si quantum dots in carbide was hard to obtain, probably due to many surface and defect states. The PL decay shows that the lifetimes vary from 10 to 70 microseconds for diameter of 3.4 nm dot with increasing detection wavelength.
Dynamics of CO2 price drivers

Using data from Phase II-III of the European Union Emission Trading Scheme, we characterize CO2 prices interrelation with energy prices (gas, electricity and coal), carbon allowances substitute prices and with economic activity index. We estimate a vector autoregressive model and the responses of CO2 prices to impulses in other variables, observing duration and direction of the impact. Our main findings include significant positive impact of returns in CO2 of peak electricity, gas, and economy index, and CO2 returns itself. The impact is visible during ten days in case of an electricity innovation, and during one day in case of gas. A shock in economy index prices has 2 days impact, and finally a substitute good for carbon licences in the European market does not have a significant impact.
Impact of Brexit : Firm Exit and Loss of Variety

The impact of Brexit is investigated using two computable general equilibrium (CGE) models, featuring conventional constant-returns-to-scale (CRS) technology and increasing-returns-to-scale (IRS) technology with firm heterogeneity, a la Melitz. The imposition of trade barriers would trigger a significant contraction of the bilateral trade between the United Kingdom (UK) and the rest of the European Union (EU). While a CRS CGE model predicts that the trade barriers would benefit or only marginally harm the UK fs welfare, the IRS model predicts a larger loss through firm exit and loss of varieties, comparable to the expected saving of the UK fs contribution to the EU budget. Among the UK industries, the textiles and apparel, steel and metal, and automotive and transportation equipment sectors would suffer most severely from their sharp fall in exports.
MAGNETIC CIRCUIT WITH LARGE BLOCKS FROM NdFeB MAGNETS FOR SUSPENDED MAGNETIC SEPARATORS

The article provides the results acquired during the development of a magnetic circuit equipped with magnetic blocks assembled from NdFeB magnets with gradually increasing height. It presents the knowledge from the application of the new method of assembling these blocks and the achieved values of maximum magnetic induction in dependence on the distance from the surface of the blocks both for their different heights and for the different designs of the magnetic circuit in comparison with the values obtained for similar magnetic circuits with ferrite magnets.
Mode-mixity in beam-like geometries: global partitioning with cohesive zones

In-service adhesive joints and composite laminates are often subjected to a mixture of mode I (tensile opening) and mode II (in-plane shear) loads. It is generally accepted that the toughness of such joints can vary depending on the relative amounts of mode I and mode II loading present. From a design perspective, it is therefore of great importance to understand and measure joint toughness under a full range of mode-mixities, thus obtaining a failure locus ranging from pure mode I to pure mode II. The pure mode toughnesses (I, II) can be measured directly from experimental tests, the most common tests being the double cantilever beam (DCB) for mode I and end loaded split (ELS) for mode II. Unfortunately, the analysis of a mixed mode test is not straightforward. In any mixed mode test, one must apply a partition in order to estimate the contributions from each mode. The particular test under study in this work is the fixed ratio mixed mode test (FRMM) with a pure rotation applied to the top beam (fig. 1). In this test, a range of mode-mixities can be obtained by varying γ, where γ = h1/h2. This test is normally analysed using analytical or numerical methods, each of which suffers from a number of uncertainties. The present work attempts to shed some light on both analytical and numerical approaches and ultimately develop a testing protocol and recommendations for the accurate determination of mode-mixity in the FRMM test and other similar beam-like geometries.
Modelling Household Debt and Financial Assets: A Bayesian Approach to a Bivariate Two-Part Model

In this paper, we contribute to the empirical literature on household finances by introducing a Bayesian bivariate two-part model. With correlated random effects, the proposed approach allows for the potential interdependence between the holding of assets and debt at the household level and also encompasses a two-part process to allow for differences in the influences of the independent variables on the decision to hold debt or assets and the influences of the independent variables on the amount of debt or assets held. Finally, we also incorporate joint modelling of household size into the framework to allow for the fact that the debt and asset information is collected at the household level and hence household size may be strongly correlated with household debt and assets. Our findings endorse our joint modelling approach and, furthermore, confirm that certain explanatory variables exert different influences on the binary and continuous parts of the model.
Paleoenvironmental reconstruction of a Late Quaternary lagoon system in southern Brazil (Jaguaruna region, Santa Catarina state) based on multi‐proxy analysis

This paper provides a paleoenvironmental reconstruction of a Late Quaternary lagoon system in the Jaguaruna region of Santa Catarina state, southern Brazil. Integrated results of bulk sedimentary organic matter characterization (δ13C, δ15N and C/N), microfossil (pollen and diatom) and grain‐size analysis from three shallow cores (∼2.5 m depth) allowed us to propose an evolving paleogeographic scenario in this coastal region for the last ca. 5500 cal a BP. The lagoonal system in this area was more extensive during the mid‐Holocene than today, with a gradual and continuous lagoon–sea disconnection until the present. We add to the debate regarding relative sea‐level (RSL) variations for the Brazilian coast during the Holocene and discuss the importance of sedimentary dynamics for interpreting changes in coastal ecosystems. The multi‐proxy analysis suggests that changes in coastal ecosystems could be directly related to local sedimentary processes, which are not necessarily linked to RSL fluctuations and/or to climatic variations. Copyright © 2011 John Wiley & Sons, Ltd.
Business Cycle, Banking Market Structure and Capital Buffer

Based on the panel data of 40 Chinese commercial banks from 2004 to 2014, this paper tests empirically the relationship among business cycle, banking market structure and capital buffer using the method of GMM. The results show that in China: capital buffers fluctuate over the business cycles countercyclicality, and market concentration shows a negative relationship with the capital buffers. The decrease of market concentration enforces the countercyclical behavior of capital buffers.
Primary School Children’s Internet Skills : A Report on Performance Tests of Operational, Formal, Information, and Strategic Internet Skills

The performance levels of fundamental (i.e., operational and formal) and advanced (i.e., information and strategic) Internet skills and their potential predictors were assessed among a sample of Dutch primary school children. The findings suggest that primary school children possess sufficient levels of fundamental but not advanced Internet skills and, hence, might not be able to make best use of important opportunities the Internet has to offer. Children employed very ineffective and inefficient search strategies and did not combine information to make beneficial decisions. Contrary to previous survey research findings, no performance differences among boys and girls were revealed when using actual performance tests. Training programs to support advanced Internet skills among primary school children should be considered.
User Perceptions About Self-efficacy, Features and Credibility as Antecedents to Flow on Social Networking Sites

Increasing engagement with other users and online content is an important goal for digital and social media managers. Through such involvement educators, brands, and organizations seek to achieve desired outcomes. Thus, in the current study, the concept of flow (intense involvement and engagement) is of interest as the focal dependent variable. An online survey (N = 888) was used to measure three potential antecedents to flow: perceptions about self-efficacy, social networking site credibility and site features. The findings indicated that self-efficacy predicted flow for social networking site users when they experienced positive perceptions about site features and credibility. This outcome underscores the value of user-friendly site features, and beliefs about site credibility in facilitating optimal involvement with social networking site content.
Bidding Revealed: An Empirical Analysis of Selling Hydropower through Elspot

In the deregulated Nordic electricity market, power producers bid to sell tomorrow's power in the day-ahead auction Elspot. This thesis presents an empirical analysis of bids submitted by three medium to large sized Norwegian reservoir hydropower producers over four two-week periods in 2011. Being price takers, the producers maximize their profits by bidding their marginal cost, which is dependent on both known and unknown variables. Additionally, producers must abide by both external market restrictions and internal technical and hydrological restrictions when bidding. Patterns in the submitted bids are found and explanations for the bidding behavior are given. Furthermore, suboptimalities and potential irrationalities in the bidding are revealed. A two-stage stochastic mixed-integer linear program generating optimal bids is developed to assist in the analysis. The hydropower producers do not optimize their bidding, yet often come close to the optimal result.
Characterization of fracture systems using precise array locations of earthquake multiplets: An example at Deception Island volcano, Antarctica

[1] Volcano-tectonic earthquakes are common seismic events in active volcanic areas. The stress produced by volcanic processes is released through fracturing of the shallow crust. Very often, these earthquakes occur in multiplets with similar waveforms, a fact which indicates common source characteristics. In this work, we introduce a method that uses array techniques to calculate precise relative locations of earthquake multiplets. We use the relative slowness estimate method to determine accurately the apparent slownesses and propagation azimuths of the earthquakes relative to a selected master event. We also obtain precise estimates of the S-P delays. This information is used to calculate precise relative locations by ray tracing in an Earth model. We applied this method to determine the characteristics of the fractures activated during the 1999 seismic series at the Deception Island volcano, Antarctica. We selected a set of 17 earthquake multiplets, initially located in a small (4 × 4 km) region a few km NE of the array site. We estimated precise locations for 14 of the clusters. In most cases, hypocenters were distributed in well-defined planar geometries. We found the best fitting planes, which we interpreted as fractures in the medium. For two clusters, the method spatially separated the earthquakes into two subgroups. Thus, we obtained two planes for each of these clusters, resulting in a total of 16 fracture planes. This is the first time that the orientations of fracture planes related to a seismic series have been obtained using a seismic array. We performed several tests to check various aspects in relation to the stability of the method and concluded that the results were robust. The dip angles indicate that the planes are mostly subvertical, while the strike angles clearly show a NW-SE trend for most of the planes and a few planes with NE–SW trends. The geometry and position of these planes suggest that the 1999 seismic series was influenced by regional tectonics, although the origin of the destabilization of the system may be related to the reactivation of a shallow magma chamber.
Radical scavenging and antioxidant activity of Hibiscus rosasinensis extract

Free radicals induce numerous diseases by lipid peroxidation, protein peroxidation and DNA damage. It has been reported that numerous plant extracts have antioxidant activities to scavenge free radicals. In the present study, the antioxidant properties of crude extract ofHibiscus rosasinensis were examined, using different in vitro analytical methodologies, such as total antioxidant activity determination by ferric thiocyanate, hydrogen peroxide scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS+ radical cation) radical cation scavenging activity and superoxide anion radical scavenging by riboflavin-methionine-illuminate system. Butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and α-tocopherol were used as the reference antioxidant radical scavenger compounds. The crude extract inhibited 94.58% peroxidation of linoleic acid emulsion at 20 μg/ml concentration, while the standard antioxidants BHA, BHT and α-tocopherol indicated an inhibition of 93.75, 96.66 and 83.33% at 60 μg/ml concentration, respectively. The hydrogen peroxide radical, DPPH radical, ABTS+ radical cation(s) and superoxide anion radical scavenging activities of crude extract were also compared to BHA, BHT and α-tocopherol as references antioxidant compounds. The present study shows that the crude extract is an effective natural antioxidant component. Key words: Hibiscus rosasinensis, antioxidant activity, free radical scavenging activity.
INTERNAL STRUCTURE OF A VERMICULAR IRONSTONE AS DETERMINED BY X-RAY COMPUTED TOMOGRAPHY SCANNING

Ironstones or petroplinthites are common materials in soils under humid tropical climate, generally defined as the result of Fe oxide accumulation in areas where the water table oscillates, and may exhibit considerable morphological variability. The aim of this study was to examine the internal structure and porosity of an ironstone fragment from a Petroferric Acrudox in Minas Gerais, Brazil, by computed tomography (CT) and conventional techniques. The sample analyzed had total porosity of 59.5 %, with large macropores in the form of tubular channels and irregular vughs, the latter with variable degrees of infilling by material released from the ironstone walls or the soil matrix. The CT scan also showed that the ironstone has wide variation in the density of the solid phase, most likely due to higher concentrations or thick intergrowths of hematite and magnetite/maghemite, especially in its outer rims. The implications of these results for water retention and soil formation in ironstone environments are briefly discussed.
Precise aftershock distribution and crustal structure in and around the northern focal area of the 2008 Iwate-Miyagi Nairiku Earthquake

The 2008 Iwate-Miyagi Nairiku Earthquake (Mj 7.2) occurred on June 14, 2008, at the eastern flank of the Ou backbone range, in the central part of northern Honshu, Japan. In the northern part of the focal area, seismic reflection/refraction experiments conducted in 2006 and 2007 revealed a series of west-dipping faults. To investigate the relation between these faults and aftershocks, we conducted a high-density seismic array observation across the northern focal area. The arrival times of earthquakes were used in a joint inversion for earthquake locations and velocity structure. The Vp structure shows tilted blocks and the block boundaries coincide with the revealed west-dipping faults. These faults were interpreted to have formed during the Miocene extension. The aftershock distribution shows a concentration on a plane dipping westward approximately 40° beneath the eastern margin of the Ou backbone range. The zone of aftershock concentration can be correlated to the known range-bounding fault inferred from seismic profiling and does not coincide with the known active reverse fault (Dedana fault). These results indicate the significance of the potential source fault located along the boundary of the Ou backbone range.
Gender Segregation in IT Occupations

The explanatory power of four theories about gender segregation is tested for IT-occupations in the Netherlands, which are studied for a period of four decades. Theories on occupational choices explain women's low participation in computer science, allthough entry requirements changed tremendously. Theories about employers' hiring practices explain the post-war recruitment of men in the female-dominated programmer's occupation, but not that employers went beyond gender boundaries because of labor shortage. Theories about the segregation code explain hierarchical gender relations. Yet, these have changed because of women's inroads into IT-occupations and because of the high proportion of women among non-professional users. Social closure theories explain why the professional community tries to keep a male image. Female computer professionals pay for their inroads into the high status and skilled male-dominated occupations by adapting to the male pattern of working hours and the male-dominated attitudes and by postponing maternity.
Size-uneven competition and resource availability: A factorial experiment on seedling establishment of three Mediterranean species

Abstract A factorial experiment was conducted in order to test whether the ranking of competitive ability at seedling stage is affected by different resource availability and competition asymmetry levels. Seedlings of three Mediterranean species (Rhamnus alaternus, Ampelodesmos mauritanicus and Cistus incanus) were grown at two competition intensities with different water and nutrient levels. Plants responses were expressed as mortality, biomass production and plant architecture. Data were also analysed by an index of competitive response intensity. A clear ranking of competitive response was observed, with Rhamnus > Ampelodesmos > Cistus. Competition was affected both by water and nutrient availability, but none of these factors modified competitive ranking. Seedling competition behaviour appeared to be related to species successional roles.
Prediction and disorderliness of hub proteins

Protein-Protein Interaction (PPI) networks are important as they provide clues about the functions of individual proteins as well as enable system level analyses of cellular processes. Predicting hub proteins, the highly connected proteins in PPI networks, is a challenging computational problem. This paper proposes a method for predicting hub proteins from sequence information with 76% accuracy, 84% sensitivity and 71% specificity. In this method, a biodiversity measure, Shannon Index, is used along with an amino acid attribute Transfer Free Energy to Surface (TFES) to distinguish hub proteins from non-hub proteins. Also an analysis of disorderliness in hub proteins revealed that some amino acids have higher composition in hub than in non-hub.
Mitochondrial genetic diversity and phylogenetic relationships of Siberian flying squirrel (Pteromys volans) populations

Abstract Siberian flying squirrel, an endangered species in South Korea, is distributed through major mountain regions of South Korea. The number of Siberian flying squirrel (Pteromys volans) in South Korea has decreased and their habitats are fragmented and isolated because of anthropogenic activities. So far no molecular genetic data has, however, been available for their conservation and management. To obtain better information concerning genetic diversity and phylogenetic relationships of the Siberian flying squirrel in South Korea, we examined 14 individuals from South Korea, 7 individuals from Russia, and 5 individuals from northeastern China along with previously published 29 haplotypes for 1,140 bp of the mtDNA cytochrome b gene. The 14 new individuals from South Korea had 7 haplotypes which were not observed in the regions of Russia and Hokkaido. The level of genetic diversity (0.616%) in the South Korean population was lower than that in eastern Russia (0.950%). The geographical distribution of mtDNA haplotypes and reduced median network confirmed that there are three major lineages of Siberian flying squirrel, occupying; Far Eastern, northern Eurasia, and the island of Hokkaido. The South Korean population only slightly distinct from the Eurasia, and eastern Russian population, and is part of the lineage Far Eastern. Based on these, we suggest that the South Korean population could be considered to belong to one partial ESU (Far Eastern) of three partial ESUs but a different management unit. However, the conservation priorities should be reconfirmed by nuclear genetic marker and ecological data.