bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite Element Analysis of Head-Form Impacting Laminated Glass for Automotive Windscreens
Authors: Min Yan , Cao Zeng Chen , Li Shuang
Published: February 2016

Based on GB/T 5137.1-2002 experiment specification, the finite element model of head-form impacting laminated glass for automotive windscreens is set up in this paper. According to Finite Element Analysis results of laminated glass with different structure and further analyzing impact property and mechanism of laminated glass , the influence rule of the structure of the laminated glass on the mechanical behavior is discussed. (H)
A Quadratic Contact Element Passing the Patch Test
Authors: Nguyen Duc Tue , Rauchs Gast , Ponthot Jean Philippe
Published: February 2016

For the two dimensional contact modeling, the standard node-to-segment quadratic contact elements are known to exhibit oscillations of the contact pressure. This situation is particularly critical when using the penalty method with a high penalty parameter because the amplitude of the oscillations increase with increasing penalty parameter. The aim of this article is to present a method for removing the oscillations of contact pressure observed while using quadratic contact element. For this purpose, the nodal forces at the slave and at the master nodes need to be evaluated appropriately. One possibility is to develop a suitable procedure for computing the nodal forces. In that sake, we selected the approach first proposed in [35] in an appropriate manner. After presenting the improved quadratic contact element, some numerical examples are illustrated in this paper to comparethe standard quadratic node-to-segment element with the proposed element. The examples show that the proposed element can strongly reduce the oscillating contact pressure for both plane and curved contact surfaces.
Numerical Models of Vacancy Diffusion Based on Crystal Structure
Authors: Krośniak Michał , Pałka Paweł , Boczkal Grzegorz
Published: February 2016

The paper discusses influence of main structural factors, as the type of crystal structure and net constant, on macroscopic features of self-diffusion and interdiffusion, in an attempt to provide a consistent description of diffusion that would involve all relevant physical effects, such as Kirkendall effect, dependence of diffusion on vacancy concentration, crystallography, and concentration of individual elements.Basing on the model structure, which is a Simple Regular net along with a corresponding Wigner-Seitz cell, the principal assumptions of the proposed model are presented as well as its implications, in order to determine general relations, which can further be used in numerical calculations involving diffusion streams. Subsequently, example calculations are performed for a simplified case of a two-dimensional Simple Regular net.The conclusions reached through this line of reasoning are then extrapolated to more complicated cases of diffusion – FCC, BCC, and HCP nets – which makes possible to relate particular material structures with diffusion rates. The connection of Wigner-Seitz cells with diffusion constitutes a good demonstration of dependence of the diffusion stream on the crystallographic orientation as well on the corresponding diffusion anisotropy for complex networks.
Research of Chemical Composition Influence on the Mechanical and Electrical Properties of Al-Mg-Si Wires
Authors: Smyrak Beata , Gniełczyk Marek , Jurkiewicz Bartosz , Knych Tadeusz , Korzeń Kinga , Jabłoński Michał , Mamala Andrzej , Nowak Andrzej
Published: February 2016

The subject of the work focuses on hardened-precipitation type alloys Al-Mg-Si which constitute the primary component material used to build homogeneous electric wires, type AAAC (All Aluminium Alloy Conductor). The material in consideration is a well-known and well-studied alloy, particularly in terms of the possibilities for using it in thermal treatment processes. However, the subject literature does not present a comprehensive recognition of the effect of heat treatment parameters on the set of mechanical and electrical properties in wires grade 6101. In particular, the study presents the results of experiments that show the possibility of controlling the AlMgSi wire properties by means of selecting the heat treatment parameters for simultaneously obtaining a high tensile strength and high electrical conductivity. Hence, the research described in this paper focuses mostly on determining the impact of the Mg and Si content on the electrical and mechanical properties of wires of Al-Mg-Si wire alloys.
Metallographic Studies of Selected Eneolithic and Bronze Age Artifacts from Poland
Authors: Suchy Józef Szczepan , Garbacz-Klempka Aldona , Adamczak Kamil , Kowalski Łukasz , Kozana Janusz , Perek-Nowak Małgorzata , Szucki Michał , Piękoś Marcin
Published: February 2016

This work presents the results of metallographic studies performed on four Eneolithic and Bronze Age artifacts from Poland. All of them are of none archaeological context therefore its academic value is strongly reduced. The aim of this work is to deal with such a reduced data in a way of improving and verifing current state of knowledge about the artifacts. In order to achieve this goal elemental composition (XRF), microstructure analysis (SEM-EDS), macrostructure analysis (optical microscopy) and 3D scanning were performed.
Structure and Properties Studies of Rapidly Solidified Al-Mn Alloys
Authors: Kula Anna , Blaz Ludwik , Lobry Patrycja
Published: February 2016

Rapid solidification (RS) combined with plastic consolidation by hot extrusion was used to produce Al alloys with additions of varied concentration of Mn. RS flakes were manufactured using an inert gas atomizing of the molten alloy and the spray deposition on the water-cooled cooper roll. Rods of 7mm in diameter were received using cold pressing of RS-flakes, vacuum degassing and hot extrusion procedures. Mechanical properties of as extruded materials were tested in hot compression at temperature range 293K - 773K. It was found that the flow stress was reduced monotonically with deformation temperature for all tested materials. RS alloys exhibit higher mechanical properties than those produced by conventional metallurgy methods. Higher mechanical properties of RS materials are ascribed to beneficial particles morphology obtained due to the rapid solidification. Development of fine Al6Mn particles was observed in all tested RS-materials.
Powder Metallurgy and Precious Metals: State of the Art and Future Developments
Authors: Grande Marco Actis , Forno Ilaria
Published: February 2016

Precious metals are widely used in a variety of different industry mainly for their inertness and their intrinsic value. This latter, is also the reason to pursue time and material saving technologies, reducing scraps and metal losses. Powder Metallurgy offers some interesting and effective alternative to traditional precious metals forming, aiming either to a performance improvement (in terms of cost, time, complexity) or to a cost reduction. The ever increasing availability of metal based alloys with advanced features, supplied in powder form, opens the doors to the use of alternative sintering techniques, borrowed from smelting sectors.
Powder Metallurgy applied to precious metals processing makes it possible to create both unconventional shapes and so-far unexplored alloys, using techniques already introduced in other ferrous and non ferrous metals processing. In this paper Field Assisted Sintering Techniques (FAST), Metal Injection Moulding (MIM) and Additive Manufacturing of precious powders are examined as avant-garde processes to obtain near net shape metal parts.
Metallurgy at KGHM Polish Copper SA
Authors: Kwapisiński Piotr
Published: February 2016

Metallurgy of KGHM Polska Miedź S.A. is one of the world leaders in the production of copper. It is the result of high volume and quality production of copper and silver, as well as the use of modern technology direct to copper process in flash smelting furnace in HMG II. Soon this will be also the case for HMG I. The intention is to modernise, and upgrade technological processes within all the smelters to increase effectiveness, also to decrease production costs, and improve contamination of environment. In the year 2014 production of electrolytic copper increased about 2% in respect to 2013, and reached the record value 577 thousands ton. Production of silver increased 8% attaining value of 1256 ton. These perfect results were obtained through optimisation of smelting processes from one side, and rising the content of own concentrates, and foreign batches with higher content of precious metals. Production of metallic gold in 2014 was equal to 2,5t. Moreover KGHM is the third world producer of rhenium. They produce also lead technical and refined, as well as selenium, nickel sulphate, and platinum-palladium concentrate. The KGHM is also substantial producer of sulphuric acid, what is the direct effect of very efficient technology of desulphurisation of exhausts in the used metallurgical processes. The challenge for future is to increase retrieving of elements associated with copper production on every phase of the production. Due to the use of new technologies one expects also to achieve improved retrieving of other metals. Since 20% of KGHM revenue comes from silver, this is an important position in the overall balance of corporation focused mainly on copper exploitation. This is also why KGHM develops co-operations with scientific centres on the level bigger than laboratory (i.e. demo and/or pilot scales). The corporation is directly involved in research and development (subsidised national and international projects), while the value of these projects exceeds 200 mln PLN. There were created several collaborations with academic institutions targeting improvement of retrieval of energy from exploration processes, increase automation, remote control mining, and others. All of them are state of the art, and very modern technologies. KGHM must stay innovative, to preserve its market advantage. Metallurgy itself using own implemented technologies, resumes extended efforts to explore fully the richness of elements associated with the main metals.
Functional Model of Monitoring System of Laboratory Tests for Individual Production Supervised in the ERP
Authors: Zaba Krzysztof , Gałda Bartosz
Published: February 2016

The aim of the study is the functional analysis of management system for laboratory tests in control of the manufacturing process, based on standard functionality of the SAP R/3 as an example of ERP systems.
World Class Manufacturing Methodology as an Example of Problems Solution in Quality Management System
Authors: Łyp-Wrońska Katarzyna
Published: February 2016

The article presents the methodology of World Class Manufacturing (WCM) used in one of the factory the mechanical engineering industry. The company has factories all over the world, while in Poland produces on average 800 ready-made machines by a year. The article presents the following pillars WCM: S (Safety) CD (Cost Deployment), Fl (Focused Improvement), AA (Autonomous Activity), PM (Professional Maintenance), QC (Quality Control), L & CS (Logistics & Customer Service), EEM (Early Equipment Management), EPM (Early Product Management), PD (People Development), E (Environment). Each pillar uses methods and tools. By using the methodology of WCM in the factory has reduced losses and improved the quality of the products.
Evaluation of Local Material Flow during Complex Deformation Conditions on the Basis of Multi Scale Analysis
Authors: Szyndler Joanna , Madej Lukasz
Published: February 2016

Development of the multiscale numerical model of innovative incremental forming process, dedicated for manufacturing complex components for the aerospace industry is the main aim of the work. Description of the incremental forming concept based on division of large die into a series of small anvils subsequently pressed into the material is presented within the paper. Particular attention is put on material behavior at both, macro and micro scale levels, respectively. A Finite Element Method (FEM) supported by Digital Material Representation (DMR) concept was used during the investigation. Results in the form of strain distributions and shapes of grains obtained from different sample areas after incremental forming process are presented within the paper.
Study of the Structural Properties and Segregation of Alloying Elements in Strips from the TRC Line
Authors: Ściężor Wojciech , Mamala Andrzej , Kwaśniewski Paweł , Kowal Radosław , Grzebinoga Justyna
Published: February 2016

Twin roll casting (TRC) technology is becoming increasingly popular because of the opportunity to receive aluminum strips which may serve as input for direct cold rolling processes. Furthermore, these strips have a favourable combination of mechanical and electric properties as well as dimensional tolerances. TRC line strips show segregation of alloying elements and structure providing a combination of casting structure and wrought alloy. As part of this study, the structure of the strips from the TRC line has been analyzed as well as the segregation of the alloying elements.
Rheological Resistance of CuAg15 Alloy Wires
Authors: Sieja-Smaga Eliza , Korzeń Kinga , Kawecki Artur , Smyrak Beata , Kiesiewicz Grzegorz , Knych Tadeusz , Mamala Andrzej , Kwaśniewski Paweł
Published: February 2016

The paper presents the results of studies on obtaining the alloy and generating a set of very high mechanical and electrical properties of wires. The paper also presents the results of testing the rheological resistance in the form of stress relaxation tests carried out on the wires after various thermomechanical treatment processes. The optimum parameters of the thermo-mechanical treatment of the alloy were determined, enabling obtaining the most favorable mechanical and electrical properties of wires. The relationships of the influence of the material and its deformation on the changes in the mechanical and electrical properties of wires were determined. In addition, a microstructural analysis was carried out of casts and wires using scanning electron microscopy. Cast material was subject to observation and the material at successive stages of heat treatment.
Analysis of the Antimicrobial Copper Alloys Registered by the Environmental Protection Agency
Authors: Walkowicz Monika , Osuch Piotr , Knych Tadeusz , Mamala Andrzej , Smyrak Beata , Bocheńska Sabina
Published: February 2016

The paper raises the issue of antimicrobial copper and its alloys constituting a promising solution for the constantly increasing problem of dangerous hospital-acquired infections. The major aim of the presented work is a precise analysis of antimicrobial copper alloys approved by The Environmental Protection Agency (EPA) in accordance with the Unified Numbering System, taking into account their European and international equivalent symbols as well – CEN and ISO, respectively. The analysis focuses mostly on the copper alloy types which the EPA list is composed of, their prices as well as materials and technological properties.
New Aluminum Base Materials for Use on Electrical Purposes
Authors: Grzebinoga Justyna , Mamala Andrzej , Knych Tadeusz , Kwaśniewski Paweł , Ściężor Wojciech , Kiesiewicz Grzegorz , Kawecki Artur , Kowal Radosław , Sieja-Smaga Eliza , Jurkiewicz Bartosz
Published: February 2016

Modern power industry expects new, dedicated aluminum based alloys with non-standard properties, including increased resistance to temperature. Materials exhibiting higher thermal resistance allow to increase operating temperature of electrical conductors, which results in the increase of their current carrying capacity. Commonly known and used in such applications are alloys from the AlZr group. Despite their advantages scientists from around the world are searching for new alternatives. In this paper authors present research results on Al-Mo and Al-Ag alloys with particular interest to the analysis of the molybdenum addition to the aluminum in the amount of 0.05, 0.1, 0.2% and silver addition in the amount of 0.05, 0.1, 0.15% by mass on the mechanical and electrical properties of obtained alloys. Tests were also carried out for reference material which is high-purity aluminum and the AlZr alloy, both in the as cast state temper. Results showed a significant change of temperature coefficient of resistance in Al-Ag alloys compared to Al, which leads to possible increase of the Joule’a heat without the raise of conductors temperature limit. On the other hand, above-average heat resistance of alloys from the Al-Mo group of materials was achieved during the trials. On that basis authors state that Al-Ag alloys may be used for the production of ACSS conductors and Al-Mo alloys for TACSR or TACIR type of conductors.This study was performed under a project financed by NCBiR within the INNOTECH II program.
Mathematical Methods in Quantum Molecular Dynamics
Authors: Hagedorn George A. , Lasser Caroline , Le Bris Claude
Published: February 2016

This report summarizes the 2015 Oberwolfach meeting on mathematical methods in quantum molecular dynamics. Over decades this field has hosted considerable research activity from different disciplines, such as mathematics, chemistry, and physics. The workshop has aimed at bringing together these scientists for mutual benefit.
Free Probability Theory
Authors: Guionnet Alice , Speicher Roland , Voiculescu Dan-Virgil
Published: February 2016

The workshop brought together leading experts, as well as promising young researchers, in areas related to recent developments in free probability theory. Some particular emphasis was on the relation of free probability with random matrix theory.
Numerical Approaches for Linear Left-invariant Diffusions onSE(2), their Comparison to Exact Solutions, and their Applications in Retinal Imaging
Authors: Zhang Jiong , Duits Remco , Sanguinetti Gonzalo , ter Haar Romeny Bart M.
Published: February 2016

Left-invariant PDE-evolutions on the roto-translation groupSE(2)(and their resolvent equations) have been widely studied in the fields of cortical modeling and image analysis. They include hypo-elliptic diffusion (for contour enhancement) proposed by Citti & Sarti, and Petitot, and they include the direction process (for contour completion) proposed by Mumford. This paper presents a thorough study and comparison of the many numerical approaches, which, remarkably, are missing in the literature. Existing numerical approaches can be classified into 3 categories: Finite difference methods, Fourier based methods (equivalent toSE(2)-Fourier methods), and stochastic methods (Monte Carlo simulations). There are also 3 types of exact solutions to the PDE-evolutions that were derived explicitly (in the spatial Fourier domain) in previous works by Duits and van Almsick in 2005. Here we provide an overview of these 3 types of exact solutions and explain how they relate to each of the 3 numerical approaches. We compute relative errors of all numerical approaches to the exact solutions, and the Fourier based methods show us the best performance with smallest relative errors. We also provide an improvement of Mathematica algorithms for evaluating Mathieu-functions, crucial in implementations of the exact solutions. Furthermore, we include an asymptotical analysis of the singularities within the kernels and we propose a probabilistic extension of underlying stochastic processes that overcomes the singular behavior in the origin of time-integrated kernels. Finally, we show retinal imaging applications of combining left-invariant PDE-evolutions with invertible orientation scores.
3D Reconstruction of the Poggio Sommavilla Territory (Sabina Tiberina, Rieti- Italy) A new approach to the knowledge of the archeological evidences
Authors: Verga Flaminia , Fabbri Federica
Published: February 2016

The area object of this paper is located in the Middle Tiber Valley and comprises a wide stretch of land within the loop of the river Tiber between the municipalities of Magliano Sabina and Ponzano. A study about this region was published in the volume 44 of the Series Forma Italiae, as it has played an important role in the reconstruction of the cultural and historical aspects of the Sabine Tiber Valley in ancient time. Its geological structure has produced a characteristic wavy landscape wich has determined the country life from time to time. Therefore, the 3D reconstruction of this area appears an important aid to the knowledge of the territory shape and its evolution. In fact the 3D model of this area has been developed in order to better understand its geological, hydrographical and anthropological conformation.
Assessment of real aging in selection process of replacement materials for stone monuments conservation.
Authors: Concha Lozano Nicolas , Lafon Dominique , Eterradossi Olivier , Gaudon Pierre
Published: February 2016

Reconstruction of monuments often raises the question of stones replacement. It must be aesthetically durable, which means the stone must age like the original one. This study presents an image processing chain, from capture to visualisation, to compare stones at different states of aging: recently extracted from quarry, weathered on old buildings, and cleaned on monuments recently restored. This tool includes: (1) a digital still camera calibration, (2) a chromatic adaptation transform and (3) a resizing process. To test it, a case study was conducted to assess the compatibility of three types of limestone. This graphical tool helps the selection of replacement materials by visual comparison between several possible stones in order to select them by aging properties and visual resemblance.
La comunicación de la Arqueología Virtual
Authors: Gómez Merino José Luis
Published: February 2016

Virtual Archaeology started as 3D reconstructions, but 3D images are published inserted in the Media. Those who edit these Media have the control of Virtual Archaeology, so we aim that 3D designers should know the programs to publish Virtual information on Internet and other uses such interactive programs for Museums or Education.
Tecnologías ópticas aplicadas a la visualización y presentación 3D de patrimonio. Caso práctico de la Virgen del Rebollet de Oliva
Authors: Granero Luis , Díaz Francisco , Millet Francisco , Domínguez Rubén , Sanjuán Yolanda
Published: February 2016

This article will present an application case of different optical technologies to the study and analysis of artworks. It will present the results of the capture of the geometry of an statue of the “Virgen del Rebollet” using 3D digitizing technology based on the fringe pattern projection technique, as well as the colorimetric capture via using the RGB pattern projection technique, a process that is integrated in the general process of 3D digitizing. Also, it will be presented the results of the final process for the 3D presentation, using stereoscopic vision systems, that are actually well-known due to its increasingly use for entertainment applications, that are a innovative element for the diffusion and analysis of artworks.
Recreación Virtual de la Necrópolis de Lomo Gordo (San Bartolome de Tirajana, Gran Canaria)
Authors: Martín Rodríguez Ernesto
Published: February 2016

On September the 7th 1988, during the expansion project of highway GC-1 between Tarajalillo and Pasito Blanco (San Bartolomé de Tirajana, Gran Canaria), an extensive burial site belonging to the first inhabitants of the island was discovered. After 20 years stored, these remains are currently undergoing an analysis taking advantage of new technological possibilities.
Generation of automatic stippling illustrations from photographs for documenting archaeological pieces
Authors: Arroyo Germán , Martín Domingo , Luzón María Victoria
Published: February 2016

Hand-made stippling has been used frequently in the process of drawing illustrations for documenting archaeological pieces. This is due to the fact that this technique represents in an efficient way shapes, tones, and textures, by means of distributing dots on the paper. The process of stippling has needed traditionally the ability of an artist, who usually produces the illustration from photographs. In this paper, a program that generates stippling illustrations of high quality is presented. The developed interface makes possible that any user can generate illustrations without the need of artistic abilities. The program is able to work in realtime, allowing the user interacts with the program. We have developed several artistic techniques in high level tasks that allow to improve the final results.
Arquitectura de barro. Reconstrucción gráfica del hábitat del inicio de la Edad del Bronce en el interior peninsular.
Authors: Fernández Moreno José Javier , Almeida Olmedo José Ramón
Published: February 2016

The results of the excavation of two archaeological sites from the Bronze Age in the province of Soria bring forward valuable information on the structure and town planning of the villages set up on high grounds in the second and third millennium BC, which are the oldest villages known in the upper area Duero river.

The building materials found on the sites tell us on the architectural solutions used in those villages. Their distribution, as well as the outlay of the household objects allow for an interpretation of the organization of the villages and the specialization of activities in relation to the different rooms.
In this way, one is provided with relevant information for a virtual reconstruction of these villages, complying with archaeological findings and integrating them into a digital model of the area.
Fotogrametría de bajo coste para la modelización de edificios históricos
Authors: Pérez García José Luis , Mozas Calvache Antonio T. , Cardenal Escarcena Francisco Javier , López Arenas Andrés
Published: February 2016

In recent times the methodologies and tools used for study and documentation of cultural heritage has undergone remarkable progress, we have a wide range of possibilities to tackle these tasks. However, some of these new possibilities, such as digital photogrammetric stations or laser scanner system facilitate and significantly improve the work and obtained products but it has fairly high costs, which in many cases not allow its use. This paper shows different techniques of low cost photogrammetry to obtain very interesting products with an acceptable accuracy for the study, documentation and modeling of historical documents.
Avances hacia una nueva metodología de trabajo en proyectos arqueológicos: El caso de la Villa Romana de La Ontavia (Terrinches, Ciudad Real)
Authors: Benítez de Lugo Enrich Luis , López-Menchero Bendicho Víctor Manuel
Published: February 2016

The growing international need for new tools to facilitate the comprehensive management of archaeological heritage -ie the coordinated processes of research, conservation and presentation of archaeological remains- opens the door for the use of new techniques in some cases based on the use of ICT and, in other cases, based in the use of elements "a priori" more traditional but equally effective, such as volumetric reconstructions. The project being developed now in the Roman villa of La Ontavia (Terrinches, Ciudad Real) intends to advance the development of new techniques and working methods more in tune with the needs of the comprehensive management of cultural heritage in the XXI century.
La Fuente de Foncalada (Oviedo): Aplicación de métodos gráficos e infográficos de análisis compositivo y metrológico a la formulación de una hipótesis de Anastilosis Virtual del Monumento
Authors: Borge Cordovilla Francisco José
Published: February 2016

In this work, the application to Foncalada´s fountain of the graphic methodology of compositive analysis tested by the author, and already applied to certain monuments of the Asturian Upper-medieval stage, allows to appreciate the proportional relationships between the different parts of the monument, defining a similar and common development, allowing, in this way, the formulation of a hypothesis of the complete reconstruction of the monument; since it allows to formulate, in hypothesis, the total proportions of the pond, which leads us to determine the specific location of the place of closing or culmination of it, revealing itself as a powerful recovery tool of the archaeological exploration.
Continuous measurements at the urban roadside in an Asian megacity by Aerosol Chemical Speciation Monitor (ACSM): particulate matter characteristics during fall and winter seasons in Hong Kong
Authors: Sun C. , Lee B. P. , Huang D. , Jie Li Y. , Schurman M. I. , Louie P. K. K. , Luk C. , Chan C. K.
Published: February 2016

Abstract. Non-refractory submicron aerosol is characterized using an Aerosol Chemical Speciation Monitor (ACSM) in the fall and winter seasons of 2013 on the roadside in an Asian megacity environment in Hong Kong. Organic aerosol (OA), characterized by application of Positive Matrix Factorization (PMF), and sulfate are found to be dominant. Traffic-related organic aerosol shows good correlation with other vehicle-related species, and cooking aerosol displays clear mealtime concentration maxima and association with surface winds from restaurant areas. Contributions of individual species and OA factors to high NR-PM1 are analyzed for hourly data and daily data; while cooking emissions in OA contribute to high hourly concentrations, particularly during mealtimes, secondary organic aerosol components are responsible for episodic events and high day-to-day PM concentrations. Clean periods are either associated with precipitation, which reduces secondary OA with a lesser impact on primary organics, or clean oceanic air masses with reduced long-range transport and better dilution of local pollution. Haze events are connected with increases in contribution of secondary organic aerosol, from 30 to 50 % among total non-refractory organics, and the influence of continental air masses.
Secondary organic aerosol formation from isoprene photooxidation during cloud condensation–evaporation cycles
Authors: Brégonzio-Rozier L. , Giorio C. , Siekmann F. , Pangui E. , Morales S. B. , Temime-Roussel B. , Gratien A. , Michoud V. , Cazaunau M. , DeWitt H. L. , Tapparo A. , Monod A. , Doussin J.-F.
Published: February 2016

Abstract. The impact of cloud events on isoprene secondary organic aerosol (SOA) formation has been studied from an isoprene ∕ NOx ∕ light system in an atmospheric simulation chamber. It was shown that the presence of a liquid water cloud leads to a faster and higher SOA formation than under dry conditions. When a cloud is generated early in the photooxidation reaction, before any SOA formation has occurred, a fast SOA formation is observed with mass yields ranging from 0.002 to 0.004. These yields are 2 and 4 times higher than those observed under dry conditions. When the cloud is generated at a later photooxidation stage, after isoprene SOA is stabilized at its maximum mass concentration, a rapid increase (by a factor of 2 or higher) of the SOA mass concentration is observed. The SOA chemical composition is influenced by cloud generation: the additional SOA formed during cloud events is composed of both organics and nitrate containing species. This SOA formation can be linked to the dissolution of water soluble volatile organic compounds (VOCs) in the aqueous phase and to further aqueous phase reactions. Cloud-induced SOA formation is experimentally demonstrated in this study, thus highlighting the importance of aqueous multiphase systems in atmospheric SOA formation estimations.
An exemplary case of a bromine explosion event linked to cyclone development in the Arctic
Authors: Blechschmidt A.-M. , Richter A. , Burrows J. P. , Kaleschke L. , Strong K. , Theys N. , Weber M. , Zhao X. , Zien A.
Published: February 2016

Abstract. Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by GOME-2 on board the MetOp-A satellite over Arctic sea ice in polar spring. These plumes are often transported by high-latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. However, only few studies have focused on the role of polar weather systems in the development, duration and transport of tropospheric BrO plumes during bromine explosion events. The latter are caused by an autocatalytic chemical chain reaction associated with tropospheric ozone depletion and initiated by the release of bromine from cold brine-covered ice or snow to the atmosphere. In this manuscript, a case study investigating a comma-shaped BrO plume which developed over the Beaufort Sea and was observed by GOME-2 for several days is presented. By making combined use of satellite data and numerical models, it is shown that the occurrence of the plume was closely linked to frontal lifting in a polar cyclone and that it most likely resided in the lowest 3 km of the troposphere. In contrast to previous case studies, we demonstrate that the dry conveyor belt, a potentially bromine-rich stratospheric air stream which can complicate interpretation of satellite retrieved tropospheric BrO, is spatially separated from the observed BrO plume. It is concluded that weather conditions associated with the polar cyclone favoured the bromine activation cycle and blowing snow production, which may have acted as a bromine source during the bromine explosion event.
Random uncertainties of flux measurements by the eddy covariance technique
Authors: Rannik Üllar , Peltola Olli , Mammarella Ivan
Published: February 2016

Abstract. Large variability is inherent to turbulent flux observations. We review different methods used to estimate the flux random errors. Flux errors are calculated using measured turbulent and simulated artificial records. We recommend two flux errors with clear physical meaning: the flux error of the co-variance, defining the error of the measured flux as one standard deviation of the random uncertainty of turbulent flux observed over an averaging period of typically 30 min to 1 hour duration; and the error of the flux due to the instrumental noise. We suggest that the numerical approximation by Finkelstein and Sims (2001) is a robust and accurate method for calculation of the first error estimate. The method appeared insensitive to the integration period and the value 200 s sufficient to obtain the estimate without significant bias for variety of sites and wide range of observation conditions. The error proposed by Wienhold et al. (1995) is a good approximation to the total flux random uncertainty provided that independent cross-covariance values far from the maximum are used in estimation as suggested in this study. For the error due to instrumental noise the method by Lenschow et al. (2000) is useful in evaluation of the respective uncertainty. The method was found to be reliable for signal-to-noise ratio, defined by the ratio of the standard deviation of the signal to that of the noise in this study, less than three. Finally, the random uncertainty of the error estimates was determined to be in the order of 10 to 30 % for the total flux error depending on the conditions and method of estimation.
An integrated approach to monitor the calibration stability of operational dual-polarization radars
Authors: Vaccarono Mattia , Bechini Renzo , Chandrasekar Venkatachalam , Cremonini Roberto , Cassardo Claudio
Published: February 2016

Abstract. The stability of the weather radar calibration is a mandatory aspect for quantitative applications, such as rainfall estimation, short-term weather prediction and initialization of numerical atmospheric and hydrological models. Over the years, calibration monitoring techniques based on external sources have been developed, specifically the calibration using the Sun, and the calibration based on ground clutter returns. In this paper, these two techniques are integrated and complemented with a self-consistency procedure and an intercalibration technique. The aim of the integrated approach is to implement a robust method for online monitoring, able to detect significant changes in the radar calibration. The physical consistency of polarimetric radar observables is exploited using the self-consistency approach, based on the expected correspondence between the dual-polarization power and phase measurements in rain. This technique allows to provide a reference absolute value for the radar calibration, from which eventual deviations may be detected using the other procedures. In particular, the ground clutter calibration is implemented on both polarization channels (horizontal and vertical) and for each radar scan, allowing to monitor the polarimetric variables and promptly recognize hardware failures. The Sun calibration allows to monitor the calibration and sensitivity of the radar receiver, in addition to the antenna pointing accuracy. It is also applied using observations collected during the standard operational scans, but requires longer integration times (several days) in order to accumulate a sufficient amount of data. Finally, an intercalibration technique is developed and performed to compare co-located measurements collected in rain by two radars on overlapping regions. The integrated approach is performed on the C-band weather radar network in northwestern Italy, during July–October 2014. The set of methods considered is shown to provide a robust online tool to monitor the stability of the radar calibration. The attainable accuracy for the calibration of the radar reflectivity is about 1 dB, which is considered adequate for most quantitative applications.
Detection and origin of different types of annual laminae in recent stalagmites from Zoolithencave, southern Germany: Evaluation of the potential for quantitative reconstruction of past precipitation variability
Authors: Riechelmann Dana Felicitas Christine , Fohlmeister Jens , Tjallingii Rik , Jochum Klaus Peter , Richter Detlev Konrad , Brummer Geert-Jan A. , Scholz Denis
Published: February 2016

Abstract. An arrangement of three stalagmites from Zoolithencave (southern Germany) was analysed for different types of annual laminae using both microscopic and geochemical methods. The speleothems show visible laminae (consisting of a clear and a brownish, pigmented layer pair) as well as fluorescent and elemental laminae. The age of the speleothems was constrained to 1800 to 1970 AD by 14C-dating of a charcoal piece below the speleothems, detection of the 14C bomb peak, as well as counting of annual laminae. Dating by the 230Th/U-method was impossible due to detrital contamination. On the annual time-scale, the variability of Mg, Ba, and Sr is controlled by Prior Calcite Precipitation (PCP) resulting in lower values during the wet season (autumn/winter) and vice versa. Yttrium and P are proxies for soil activity and are enriched in the brownish, pigmented layers. However, Y and P are also influenced by detrital content superimposing the soil activity signal. Aluminium and Mn are proxies for detrital content. Lamina thickness shows a significant correlation with the amount of precipitation of previous December and current January, February, March, April, May, and December (DJFMAMD) recorded at the nearby meteorological station Bamberg. Thus lamina thickness is a proxy for past precipitation, which is confirmed by the good agreement with a precipitation reconstruction based on tree-ring width from the Bavarian forest. This highlights the potential of these speleothems for climate reconstruction at annual resolution.
Climate model emulation in an integrated assessment framework: a case study for mitigation policies in the electricity sector
Authors: Foley A. M. , Holden P. B. , Edwards N. R. , Mercure J.-F. , Salas P. , Pollitt H. , Chewpreecha U.
Published: February 2016

Abstract. We present a carbon-cycle–climate modelling framework using model emulation, designed for integrated assessment modelling, which introduces a new emulator of the carbon cycle (GENIEem). We demonstrate that GENIEem successfully reproduces the CO2 concentrations of the Representative Concentration Pathways when forced with the corresponding CO2 emissions and non-CO2 forcing. To demonstrate its application as part of the integrated assessment framework, we use GENIEem along with an emulator of the climate (PLASIM-ENTSem) to evaluate global CO2 concentration levels and spatial temperature and precipitation response patterns resulting from CO2 emission scenarios. These scenarios are modelled using a macroeconometric model (E3MG) coupled to a model of technology substitution dynamics (FTT), and represent different emissions reduction policies applied solely in the electricity sector, without mitigation in the rest of the economy. The effect of cascading uncertainty is apparent, but despite uncertainties, it is clear that in all scenarios, global mean temperatures in excess of 2 °C above pre-industrial levels are projected by the end of the century. Our approach also highlights the regional temperature and precipitation patterns associated with the global mean temperature change occurring in these scenarios, enabling more robust impacts modelling and emphasizing the necessity of focusing on spatial patterns in addition to global mean temperature change.
Classification and quantification of pore shapes in sandstone reservoir rocks with 3-D X-ray micro-computed tomography
Authors: Schmitt Mayka , Halisch Matthias , Müller Cornelia , Fernandes Celso Peres
Published: February 2016

Abstract. Recent years have seen a growing interest in the characterization of the pore morphologies of reservoir rocks and how the spatial organization of pore traits affects the macro behavior of rock–fluid systems. With the availability of 3-D high-resolution imaging, such as x-ray micro-computed tomography (µ-CT), the detailed quantification of particle shapes has been facilitated by progress in computer science. Here, we show how the shapes of irregular rock particles (pores) can be classified and quantified based on binary 3-D images. The methodology requires the measurement of basic 3-D particle descriptors (length, width, and thickness) and a shape classification that involves the similarity of artificial objects, which is based on main pore network detachments and 3-D sample sizes. Two main pore components were identified from the analyzed volumes: pore networks and residual pore ganglia. A watershed algorithm was applied to preserve the pore morphology after separating the main pore networks, which is essential for the pore shape characterization. The results were validated for three sandstones (S1, S2, and S3) from distinct reservoirs, and most of the pore shapes were found to be plate- and cube-like, ranging from 39.49 to 50.94 % and from 58.80 to 45.18 % when the Feret caliper descriptor was investigated in a 10003 voxel volume. Furthermore, this study generalizes a practical way to correlate specific particle shapes, such as rods, blades, cuboids, plates, and cubes to characterize asymmetric particles of any material type with 3-D image analysis.
Refliukso simptomų indekso klausimyno lietuviškos versijos kultūrinė adaptacija ir validizacija
Authors: Šiupšinskienė Nora , Adamonis Kęstutis , Belafsky Peter , Aukštakalnienė Asta , Norkienė Sigutė
Published: February 2016

Darbo tikslas buvo parengti lietuvišką refliukso simptomų indekso (RSI) klausimyno versiją ir įvertinti psichometrines klausimyno savybes, tiriant pacientus, sergančius gastroezofaginio refliukso ligos laringofaringine forma (GERL LF). Lietuviška RSI klausimyno versija buvo paruošta pagal standartinius, griežtus klausimynų vertimo ir adaptavimo procedūros reikalavimus, verčiant klausimyną iš anglų kalbos į lietuvių ir iš lietuvių atgal į anglų, pirminių versijų testavimą Jungtinėse Amerikos Valstijose (JAV), komiteto peržiūras ir galutinės lietuviškos RSI klausimyno versijos psichometrinių savybių testavimą. Tyrime dalyvavo keturios suaugusių asmenų grupės: RSI klausimyno atgalinio lietuviško- angliško vertimo dviejų pirminių versijų testavimas atliktas JAV Balso ir rijimo centre ištyrus 30 balso pacientų; bandomasis lietuviškos RSI versijos tyrimas atliktas Lietuvos universitetinėje ligoninėje įvertinus 20 pacientų atsakymus; galutinės lietuviškos RSI versijos psichometrinės savybės patikrintos ištyrus 25 otorinolaringologinius pacientus, kuriems GERL LF diagnozuota atsižvelgiant į būdingus klinikinius požymius ir nustatytą erozinį ar histologinį ezofagitą. Kontrolinę grupę sudarė 27 sveiko balso panašaus amžiaus savanoriai. Koreliacija tarp originalios ir abiejų pirminių atgalinio vertimo RSI versijų JAV pacientų grupėje buvo labai patikima (r=0,99 ir r=0,98 (p<0,0001). Nustatytas geras galutinės lietuviškos RSI klausimyno versijos bendrasis vidinis nuoseklumas (Kronbach‘o a=0,87) ir klausimyno stabilumas (koreliacijos koeficientas tarp pirmo ir pakartotinio tyrimo buvo 0,99). GERL LF grupės RSI vidurkis reikšmingai skyrėsi nuo kontrolinės grupės rodmenų: atitinkamai 18,2 ±7,1 ir 3,8±4,4 balų (p<0,0001). Patologinis RSI (≥13) nustatytas 88 proc. ir panašiai - patologinis refliukso radinių indeksas (≥7) diagnozuotas 84 proc. GERL LF grupės pacientų. Pagal ROC kreivės duomenis, didesnis nei 10 balų RSI įvertis tiksliausiai skyrė GERL LF pacientus nuo sveikų – bendrasis teisingai suklasifikuotų asmenų procentas buvo 92,3. Lietuviška RSI klausimyno versija yra paprastas, patikimas ir pagrįstas metodas, padedantis diagnozuoti GERL LF.
Dose Up-Titration Of Neurohormone Blockers For Chronic Heart Failure Treatment In Real Clinical Practice: Data From Single University Centre
Authors: Kavoliūnienė Aušra , Maciulevičiūtė Goda , Sadeckaitė Rasa , Vasiljevaitė Kristina
Published: February 2016

Objective. To describe treatment peculiarities of ambulatory chronic heart failure patients’ in one of Lithuania’s university centres, participating in European Society of Cardiology EURObservation Research Programme (EORP) Heart Failure Long- Term Registry. Methods. 240 ambulatory patients with chronic heart failure were entered in European Society of Cardiology EURObservation Research Programme (EORP) Heart Failure Long-Term Registry from our university centre between May 2011 and March 2013. Follow-up data were collected after 12 months. Registered data about heart failure treatment were included to this study. Statistical analysis was performed with SPSS 22 program. Results. In our centre 67,1% of patients received angiotensin converting enzyme inhibitors at target doses, one third (34,3%) had not reached target doses due to symptomatic hypotension. Beta blockers were up-titrated to target doses for 82,5% of patients and the main reasons for failure to reach their target dose were: symptomatic bradycardia (12,7%), symptomatic hypotension (10,7%). Mineralocorticoid receptor antagonists were up-titrated to a target doses just for half of the patients – 52,1% and the most frequent reason for not reaching target doses was hyperkalemia (15,4%). Conclusions. Angiotensin converting enzyme inhibitors, beta-blockers and mineralocorticoid receptors antagonists, except angiotensin receptor blockers, were prescribed in a guideline-recommended doses. The main reasons why the target doses of neurohormone blockers have not been achieved were symptomatic hypotension for angiotensin converting enzyme inhibitors, symptomatic bradycardia for beta-blockers and hyperkalemia for mineralocorticoid receptors antagonists.