bluuebunny/crossref_metadata_2025_split huggingface dataset:
Taguchi Approach for Optimization of Parameters that Effect Grain Size of Cast A357 Alloy
Authors: Çolak M. , Dışpınar D. 
Published: January 2018

AbstractGrain refining and modification are common foundry practice for improving properties of cast Al-Si alloys. In general, these types of treatments provide better fluidity, decreased porosity, higher yield strength and ductility. However, in practice, there are still some discrepancies on the reproducibility of the results from grain refining and effect of the refiner’s additions. Several factors include the fading effect of grain refinement and modifiers, inhomogeneous dendritic structure and non-uniform eutectic modification. In this study, standard ALCAN test was used by considering Taguchi’s experimental design techniques to evaluate grain refinement and modification efficiency. The effects of five casting parameters on the grain size have been investigated for A357 casting alloy. The results showed that the addition of the grain refiner was the most effective factor on the grain size. It was found that holding time, casting temperature, alloy type and modification with Sr were less effective over grain refinement.
Study of Thermal Properties of Cast Metal- Ceramic Composite Foams
Authors: Gawdzińska K. , Chybowski L. , Przetakiewicz W. 
Published: January 2018

Abstract
Owing to its properties, metallic foams can be used as insulation material. Thermal properties of cast metal-ceramic composite foams have applications in transport vehicles and can act as fire resistant and acoustic insulators of bulkheads. This paper presents basic thermal properties of cast and foamed aluminum, the values of thermal conductivity coefficient of selected gases used in foaming composites and thermal capabilities of composite foams (AlSi11/SiC). A certificate of non-combustibility test of cast aluminum-ceramic foam for marine applications was included inside the paper. The composite foam was prepared by the gas injection method, consisting in direct injection of gas into liquid metal. Foams with closed and open cells were examined. The foams were foaming with foaming gas consisting of nitrogen or air. This work is one of elements of researches connected with description of properties of composite foams. In author's other works acoustic properties of these materials will be presented.
Polymer Binder BioCo3 with Silicates and its Application to Microwave-Cured Moulding Sand
Authors: Grabowska B. , Kaczmarska K. , Bobrowski A. , Drożyński D. , Żymankowska-Kumon S. , Cukrowicz S. 
Published: January 2018

AbstractThe effects of silica additive (Poraver) on selected properties of BioCo3 binder in form of an aqueous poly(sodium acrylate) and dextrin (PAANa/D) binder were determined. Based on the results of the thermoanalytical studies (TG-DTG, FTIR, Py-GC/MS), it was found that the silica additive results in the increase of the thermostability of the BioCo3 binder and its contribution does not affect the increase in the level of emissions of organic destruction products. Compounds from group of aromatic hydrocarbons are only generated in the third set temperature range (420-838°C). The addition of silicate into the moulding sand with BioCo3 causes also the formation of a hydrogen bonds network with its share in the microwave radiation field and they are mainly responsible for maintaining the cross-linked structures in the mineral matrix system. As a consequence, the microwave curing process in the presence of Poraver leads to improved strength properties of the moulding sand (Rum). The addition of Poraver's silica to moulding sand did not alter the permeability of the moulding sand samples, and consequently reduced their friability. Microstructure investigations (SEM) of microwave-cured samples have confirmed that heterogeneous sand grains are bonded to one another through a binder film (bridges).
Influence of High-Temperature Treatment of Melt on the Composition and Structure of Aluminum Alloy
Authors: Grachev V. A. , Turakhodjaev N. D. 
Published: January 2018

Abstract
The aim of the current study was to examine the structure of an alloy treated at various temperatures up to 2,000-2,100 °C. Among research techniques for studying alloy structure there were the electron and optical microstructure, X-ray structure, and spectral analysis, and for studying the developed furnace geometric parameters the authors employed mathematical modeling method. The research was performed using aluminum smelting gas-fired furnaces and electric arc furnaces. The objects of the study were aluminum alloys of the brand AK7p and AK6, as well as hydrogen and aluminum oxide in the melt. For determining the hydrogen content in the aluminum alloy, the vacuum extraction method was selected. Authors have established that treatment of molten aluminum alloy in contact with carbon melt at high temperatures of 2,000-2,100 °C has resulted in facilitating reduction of hydrogen and aluminum oxide content in the melt by 40- 43% and 50-58%, respectively, which is important because hydrogen and aluminum oxide adversely affect the structure and properties of the alloy. Such treatment contributes to the formation of the extremely fine-grained microstructure of aluminum alloy.
Theory of the Stereological Analysis of Spheroid Size Distribution – Validation of the Equations
Authors: Gurgul D. , Burbelko A. , Wiktor T. 
Published: January 2018

AbstractThe paper presents validation tests for method which is used for the evaluation of the statistical distribution parameters for 3D particles’ diameters. The tested method, as source data, uses chord sets which are registered from a random cutting plane placed inside a sample space. In the sample space, there were individually generated three sets containing 3D virtual spheres. Each set had different Cumulative Distribution Function (CDF3) of the sphere diameters, namely: constant radius, normal distribution and bimodal distribution as a superposition of two normal distributions. It has been shown that having only a chord set it is possible, by using the tested method, to calculate the mean value of the outer sphere areas. For the sets of data, a chord method generates quite large errors for around 10% of the smallest nodules in the analysed population. With the increase of the nodule radii, the estimation errors decrease. The tested method may be applied to foundry issues e.g. for the estimation of gas pore sizes in castings or for the estimation of nodule graphite sizes in ductile cast iron.
Gases Emission From Surface Layers of Sand Moulds and Cores Stored Under the Humid Air Conditions
Authors: Kaźnica N. , Zych J. , Mocek J. 
Published: January 2018

Abstract
A large number of defects of castings made in sand moulds is caused by gases. There are several sources of gases: gases emitted from moulds, cores or protective coatings during pouring and casting solidification; water in moulding sands; moisture adsorbed from surroundings due to atmospheric conditions changes. In investigations of gas volumetric emissions of moulding sands amounts of gases emitted from moulding sand were determined - up to now - in dependence of the applied binders, sand grains, protective coatings or alloys used for moulds pouring. The results of investigating gas volumetric emissions of thin-walled sand cores poured with liquid metal are presented in the hereby paper. They correspond to the surface layer in the mould work part, which is decisive for the surface quality of the obtained castings. In addition, cores were stored under conditions of a high air humidity, where due to large differences in humidity, the moisture - from surroundings - was adsorbed into the surface layer of the sand mould. Due to that, it was possible to asses the influence of the adsorbed moisture on the gas volumetric emission from moulds and cores surface layers by means of the new method of investigating the gas emission kinetics from thin moulding sand layers heated by liquid metal. The results of investigations of kinetics of the gas emission from moulding sands with furan and alkyd resins as well as with hydrated sodium silicate (water glass) are presented. Kinetics of gases emissions from these kinds of moulding sands poured with Al-Si alloy were compared.
The Influence of Mg Additive on the Structure and Electrical Conductivity of Pure Copper Castings
Authors: Kranc M. , Sikora G. , Górny M. , Garbacz-Klempka A. 
Published: January 2018

AbstractThe aim of this paper was to attain defect free, pure copper castings with the highest possible electrical conductivity. In this connection, the effect of magnesium additives on the structure, the degree of undercooling (ΔTα = Tα-Tmin, where Tα - the equilibrium solidification temperature, Tmin - the minimum temperature at the beginning of solidification), electrical conductivity, and the oxygen concentration of pure copper castings have been studied. The two magnesium doses have been investigated; namely 0.1 wt.% and 0.2 wt.%. A thermal analysis was performed (using a type-S thermocouple) to determine the cooling curves. The degree of undercooling and recalescence were determined from the cooling and solidification curves, whereas the macrostructure characteristics were conducted based on a metallographic examination. It has been shown that the reaction of Mg causes solidification to transform from exogenous to endogenous. Finally, the results of electrical conductivity have been shown as well as the oxygen concentration for the used Mg additives.
Influence of the Al2O3 Solid Phase on the Kinetics of Binding Ceramic Moulds
Authors: Kolczyk J. , Zych J. , Jamrozowicz Ł. 
Published: January 2018

Abstract
The investigation results of the kinetics of binding ceramic moulds, in dependence on the solid phase content in the liquid ceramic slurries being 67, 68 and 69% - respectively, made on the basis of the aqueous binding agents Ludox AM and SK. The ultrasonic method was used for assessing the kinetics of strengthening of the multilayer ceramic mould. Due to this method, it is possible to determine the ceramic mould strength at individual stages of its production. Currently self-supporting moulds, which must have the relevant strength during pouring with liquid metal, are mainly produced. A few various factors influence this mould strength. One of them is the ceramic slurry viscosity, which influences a thickness of individual layers deposited on the wax model in the investment casting technology. Depositing of layers causes increasing the total mould thickness. Therefore, it is important to determine the drying time of each deposited layer in order to prevent the mould cracking due to insufficient drying of layers and thus the weakening of the multilayer mould structure.
Computer Simulation of the Solidification Process Including Air Gap Formation
Authors: Skrzypczak T. , Węgrzyn-Skrzypczak E. , Sowa L. 
Published: January 2018

Abstract
The paper presents an approach of numerical modelling of alloy solidification in permanent mold and transient heat transport between the casting and the mold in two-dimensional space. The gap of time-dependent width called "air gap", filled with heat conducting gaseous medium is included in the model. The coefficient of thermal conductivity of the gas filling the space between the casting and the mold is small enough to introduce significant thermal resistance into the heat transport process. The mathematical model of heat transport is based on the partial differential equation of heat conduction written independently for the solidifying region and the mold. Appropriate solidification model based on the latent heat of solidification is also included in the mathematical description. These equations are supplemented by appropriate initial and boundary conditions. The formation process of air gap depends on the thermal deformations of the mold and the casting. The numerical model is based on the finite element method (FEM) with independent spatial discretization of interacting regions. It results in multi-mesh problem because the considered regions are disconnected.
Microstructure Characteristic of TiCReinforced Cast Steel after GTAW Remelting
Authors: Sobula S. , Kwiecień A. , Olejnik E. , Pałka P. 
Published: January 2018

AbstractIn this study, low-carbon cast steel was reinforced with TiC by SHS-B method, also known as combustion synthesis during casting method. The composite zone was then subjected to surface remelting by Gas Tungsten Arc Welding (GTAW) method. The remelting operation was realized manually, at 150 A current magnitude. Microstructure, phase composition and hardness of remelted zone were investigated. XRD results reveal that the phases of the composite zone in initial state consist of TiC and Feα. Surface remelting resulted in formation of thick layers containing TiC carbides, Feα and Feγ. Microstructural examination has shown strong refinement of titanium carbides in remelted zone and complete dissolution of primary titanium carbides synthetized during casting. The average diameter of carbides was below 2 μm. The structural changes are induced by fast cooling which affects crystallization rate. The hardness (HV30) of the remelted layer was in the range between 250 HV and 425 HV, and was lower than hardness in initial state.
The Concept of Optimizing the Decopperisation of Slag Slurry in Electrical Furnace
Authors: Wędrychowicz M. , Bydałek A. W. , Wołczyński W. 
Published: January 2018

AbstractThis paper presents the idea of increasing the effectiveness of slag decopperisation in an electric furnace in the "Głogów II" Copper Smelter by replacing the currently added CaCO3with a less energy-intensive technological additive. As a result of this conversion, one may expect improved parameters of the process, including process time or power consumption per cycle. The incentives to optimize the process are the benefits of increasing copper production in the company and the growing global demand for this metal. The paper also describes other factors that may have a significant impact on the optimization of the copper production process. Based on the literature analysis, a solution has been developed that improves the copper production process. The benefits of using a new technology additive primarily include increased share of copper in the alloy, reduced production costs, reduced amount of power consumed per cycle and reduced time it takes to melt. At the conclusion of the paper, the issues raised are highlighted, stressing that mastering the slag slurry process in electric furnaces requires continuous improvement.
The effects of physical activity on chronic subclinical systemic inflammation
Authors: Tir Alba Maria Dalbello , Labor Marina , Plavec Davor 
Published: January 2018

AbstractChronic subclinical systemic inflammation (CSSI) is a pathogenic event and a common risk factor for many noncommunicable diseases like atherosclerosis, metabolic syndrome, cardiovascular disease, insulin resistance and type 2 diabetes, cancer, and obstructive lung disease. On the other hand, regular physical activity has been found to reduce this risk. Many studies of different design were conducted to assess the association between inflammatory mediators as markers of CSSI and regular physical activity. The aim of this review was to present the current level of evidence and understanding of potential mechanisms by which physical activity reduces inflammatory mediators involved in CSSI and the types of physical activity required for the expected effect. We have found that observational studies consistently report a positive association between regular physical activity and lower CSSI, but the design of these studies does not allow to infer a causal relationship. Interventional studies, in contrast, were not consistent about the causal relationship between regular physical activity and lower CSSI. The problem in interpreting these results lies in significant differences between these interventional studies in their design, sample size, study population, and intervention itself (intensity and extent, follow up, weight loss). We can conclude that the scientific community has to invest a significant effort into high-quality interventional trials focused on finding the type, intensity, and extent of physical activity that would produce the most favourable effect on CSSI.
Radiological risk assessment: an overview of the ERICA Integrated Approach and the ERICA Tool use
Authors: Prlić Ivica , Mostečak Ana , Mihić Marija Surić , Veinović Želimir , Pavelić Luka 
Published: January 2018

Abstract
The ERICA project (Environmental Risk from Ionising Contaminants: Assessment and Management) was co-funded by the European Union as part of the 6th Framework Programme (FP EURATOM). The project was carried out between 2004 and 2007 as the collective work of 15 organisations in seven European countries. Two significant outputs of the project are the ERICA Integrated Approach and the ERICA Tool. The ERICA Integrated Approach consists of three elements: assessment, risk characterisation and management. The ERICA Tool is a practical implementation of the assessment component of the ERICA Integrated Approach and has a three-tier structure. The aim of this review paper is to give a concise overview of ERICA project outputs and their structure, updates done since their first release in 2007, as well as to provide a context for their practical application in environmental radiation protection and radiological risk assessments for various engineering scenarios.
On Decay Centrality
Authors: Tsakas Nikolas 
Published: January 2018

AbstractWe establish a relationship between decay centrality and two widely used measures of centrality, namely degree and closeness. We show that for low values of the decay parameter the nodes with maximum decay centrality also have maximum degree, whereas for high values of the decay parameter they also maximize closeness. For intermediate values, we provide sufficient conditions that allow the comparison of decay centrality of different nodes and we show via numerical simulations that in the vast majority of networks, the nodes with maximum decay centrality are characterized by a threshold on the decay parameter below which they belong to the set of nodes with maximum degree and above which they belong to the set of nodes with maximum closeness. We also propose a simple rule of thumb that ensures a nearly optimal choice with very high probability.
Policy, learning and regime change: Western concepts and CEE experience
Authors: Colebatch H.K. 
Published: January 2018

Abstract
This article offers an outsider’s perspective on the place of policy in the analysis of governing in Central and Eastern Europe, both before the change from a communist to a post-communist order, and since. It explores the way in which ‘policy’ is used as a construct in both the practice of governing and the analysis of that practice. It argues that we have to recognise multiple strands – authority, structured interaction, and collective problematisation - in the construction of ‘policy’. It points to a distinction between ‘formal’ and ‘practical’ perspectives, and argues that this distinction reflects structural tensions in the process of ’putting together’ the shared understandings and relationships which make g for ‘governing’, It argues for the importance of continuing research, empirically based and theoretically informed, into the way that governing is ‘put together’ in Central and Eastern Europe, and how both participants and the governed ‘make sense’ of this process.
Transverse Hilbert schemes and completely integrable systems
Authors: Donin Niccolò Lora Lamia 
Published: January 2018

Abstract
In this paper we consider a special class of completely integrable systems that arise as transverse Hilbert schemes of d points of a complex symplectic surface S projecting onto ℂ via a surjective map p which is a submersion outside a discrete subset of S. We explicitly endow the transverse Hilbert scheme Sp
[d] with a symplectic form and an endomorphism A of its tangent space with 2-dimensional eigenspaces and such that its characteristic polynomial is the square of its minimum polynomial and show it has the maximal number of commuting Hamiltonians.We then provide the inverse construction, starting from a 2ddimensional holomorphic integrable system W which has an endomorphism A: TW → TW satisfying the above properties and recover our initial surface S with W ≌ Sp
[d].
A Start-Up’s R&D Stages and the Evolution of Financing Sources: Evidence from the Biotechnology Industry
Authors: Kang Hyunsung D 
Published: January 2018

AbstractThe co-existence of angel, independent venture capital (IVC), and corporate venture capital (CVC) in the entrepreneurial finance market raises a natural question of why a start-up finances its projects from one source over another. This question becomes more complicated to address because a start-up grows or declines dynamically. Using a life cycle theory of entrepreneurial finance, which suggests that a start-up uses several financing sources as it reaches certain thresholds in its life cycle accordingly, I explore this selection issue with my dataset on 113 biopharmaceutical start-ups. I find that these start-ups tend to finance their projects mostly from solely IVCs or CVCs rather than angels and syndicated investors combining IVCs and CVCs when they have more preclinical and phase I products in their R&D pipelines; and from CVCs or syndicated investors rather than angels and IVCs when they do more phase II and phase III products.
In vitro reconstitution and biochemical characterization of human phospholipid scramblase 3: phospholipid specificity and metal ion binding studies
Authors: Palanirajan Santosh Kumar , Sivagnanam Ulaganathan , Murugan Sowmiya , Gummadi Sathyanarayana N. 
Published: January 2018

AbstractHuman phospholipid scramblase 3 (hPLSCR3) is a single pass transmembrane protein that plays a vital role in fat metabolism, mitochondrial function, structure, maintenance and apoptosis. The mechanism of action of scramblases remains still unknown, and the role of scramblases in phospholipid translocation is heavily debated. hPLSCR3 is the only member of scramblase family localized to mitochondria and is involved in cardiolipin translocation at the mitochondrial membrane. Direct biochemical evidence of phospholipid translocation by hPLSCR3 is yet to be reported. Functional assay in synthetic proteoliposomes upon Ca2+and Mg2+revealed that, apart from cardiolipin, recombinant hPLSCR3 translocates aminophospholipids such as NBD-PE and NBD-PS but not neutral phospholipids. Point mutation in hPLSCR3 (F258V) resulted in decreased Ca2+binding affinity. Functional assay with F258V-hPLSCR3 led to ~50% loss in scramblase activity in the presence of Ca2+and Mg2+. Metal ion-induced conformational changes were monitored by intrinsic tryptophan fluorescence, circular dichroism, surface hydrophobicity changes and aggregation studies. Our results revealed that Ca2+and Mg2+bind to hPLSCR3 and trigger conformational changes mediated by aggregation. In summary, we suggest that the metal ion-induced conformational change and the aggregation of the protein are essential for the phospholipid translocation by hPLSCR3.