bluuebunny/crossref_metadata_2025 huggingface dataset:
Les anomalies thermiques du climat aux moyennes et hautes latitudes de l'hémisphère Nord (The thermic fluctuations of the climate in the middle and high latitudes of the northern hemisphere)
Authors: Petit-Renaud Gérard
Published: February 2015

Abstract. - The climatic anomalies are defined from particular means chosen for reference, as the deviations which are more than twice the standard deviation of normalized distributions. The study of a few severe winters in Europe shows the same positive anomaly of pressure field more or less centered over Island and a lack of correlation with the North-East of the american continent.
Camaçari : une certaine désillusion urbaine (Camaçari : an example of urban disappointment)
Authors: Rivière d'Arc Hélène
Published: February 2015

Résumé. - Camaçari est un exemple de ville nouvelle brésilienne qui n'a pas réussi. La raison de cet échec est qu'elle n'a pas pu attirer les ouvriers du complexe pétrochimique voisin, pour lesquels elle avait été prévue. Sa population se compose surtout de chômeurs et de pauvres d'origine rurale.
Stratégies industrielles au Brésil (Brazil's strategies for industrialisation)
Authors: Théry Hervé
Published: February 2015

Résumé. - Pour expliquer l'apparition d'une série de nouveaux foyers industriels au Brésil il faut à la fois saisir la place de ce pays dans la nouvelle division internationale du travail et les concevoir comme l'aboutissement de plusieurs logiques (technique, politique, financière), le résultat de négociations entre des partenaires multiples. Plus que des «pôles de développement » ce sont des exemples de convergences d'intérêts et le point de départ de mutations sociales et spatiales de grande ampleur.
Le développement industriel des pays andins. Réalités et difficultés (The industrial development of andin countries. Realities and difficulties)
Authors: Collin Delavaud Anne
Published: February 2015

Resumen. - Los parses andinos han conocido a partir de la decada de los 70 un desarrollo industrial sin precedente. Cada pais de esta región a intentado de recuperar su retrazo, sobre todo en lo que concierne el fomento y la infrastructura básica. Asi se ha construido numéros as represas de irrigacion y de centrales hydroelectricas, unas refinerias de petroleo y redes de oleoductos, carreteras, aeropuertos regionales y aun locales, terminales maritimos y puertos fluviales en Amazonia.

En el marco del Grupo Andino, esos paises han experimentado unas formas originales de integracion. Unos programas de desarrollo industrial fueron inaugurados en los sectores siderurgicos, petrochimicos y particularmente automobiles, aún con los paises los menos industrializados como Bolivia y Ecuador. Pero a un esfuerzo real en el principio de los anos 70 ha contestado el duro choque de la crisis mundial. Sin parar la corriente legislativa integracionista, la recesion a demorado todos los programas industriales por falta de inversiones. Actualmente, las grandes ambiciones del Pacto Andino son abandonadas, pero el Grupo Andino persevera hacia una integraciõn de proyectos regionales y locales mucho más pequeños pero mas adaptados y realistas. Se puede notar que sin Venezuela y el norte de Colombia, los paises del Grupo Andino no fueron realmente concernados por la nueva distribución industrial mundial.
Ventilation/perfusion SPECT/CT in patients with pulmonary emphysema
Authors: Schreiter V. , Steffen I. , Huebner H. , Bredow J. , Heimann U. , Kroencke T. J. , Poellinger A. , Doellinger F. , Buchert R. , Hamm B. , Brenner W. , Schreiter N. F.
Published: February 2015

The purpose of this study was to evaluate the reproducibility of a new software based analysing system for ventilation/perfusion single-photon emission computed tomography/ computed tomography (V/P SPECT/CT) in patients with pulmonary emphysema and to compare it to the visual interpretation. Patients, material and methods: 19 patients (mean age: 68.1 years) with pulmonary emphysema who underwent V/P SPECT/CT were included. Data were analysed by two independent observers in visual interpretation (VI) and by software based analysis system (SBAS). SBAS PMOD version 3.4 (Technologies Ltd, Zurich, Switzerland) was used to assess counts and volume per lung lobe/per lung and to calculate the count density per lung, lobe ratio of counts and ratio of count density. VI was performed using a visual scale to assess the mean counts per lung lobe. Interobserver variability and association for SBAS and VI were analysed using Spearman's rho correlation coefficient. Results: Interobserver agreement correlated highly in perfusion (rho: 0.982, 0.957, 0.90, 0.979) and ventilation (rho: 0.972, 0.924, 0.941, 0.936) for count/count density per lobe and ratio of counts/count density in SBAS. Interobserver agreement correlated clearly for perfusion (rho: 0.655) and weakly for ventilation (rho: 0.458) in VI. Conclusions: SBAS provides more reproducible measures than VI for the relative tracer uptake in V/P SPECT/CTs in patients with pulmonary emphysema. However, SBAS has to be improved for routine clinical use.
Fundamental edge broadening effects during focused electron beam induced nanosynthesis
Authors: Schmied Roland , Fowlkes Jason D , Winkler Robert , Rack Phillip D , Plank Harald
Published: February 2015

The present study explores lateral broadening effects of 3D structures fabricated through focused electron beam induced deposition using MeCpPt(IV)Me3 precursor. In particular, the scaling behavior of proximity effects as a function of the primary electron energy and the deposit height is investigated through experiments and validated through simulations. Correlated Kelvin force microscopy and conductive atomic force microscopy measurements identified conductive and non-conductive proximity regions. It was determined that the highest primary electron energies enable the highest edge sharpness while lower energies contain a complex convolution of broadening effects. Moreover, it is demonstrated that intermediate energies lead to even more complex proximity effects that significantly reduce lateral edge sharpness and thus should be avoided if desiring high lateral resolution.
Natural phenolic metabolites with anti-angiogenic properties – a review from the chemical point of view
Authors: Sun Qiu , Heilmann Jörg , König Burkhard
Published: February 2015

Considering the many secondary natural metabolites available from plants, phenolic compounds play a particularly important role in human health as they occur in significant amounts in many fruits, vegetables and medicinal plants. In this review natural phenolic compounds of plant origin with significant anti-angiogenic properties are discussed. Thirteen representatives from eight different natural or natural-like phenolic subclasses are presented with an emphasis on their synthesis and methods to modify the parent compounds. When available, the consequence of structural variation on the pharmacological activity of the molecules is described.
Sustained Remission in Tumor Necrosis Factor Inhibitor–treated Patients with Rheumatoid Arthritis: A Population-based Cohort Study
Authors: Einarsson Jon Thorkell , Geborek Pierre , Saxne Tore , Kapetanovic Meliha C.
Published: February 2015

Objective.

To study frequency, possible baseline predictors, timing, and duration of sustained remission [SR; defined as 28-joint Disease Activity Score (DAS28) < 2.6 for at least 6 mos] in patients with established rheumatoid arthritis (RA) treated with different tumor necrosis factor (TNF) inhibitors [etanercept (ETN), infliximab (IFX), adalimumab (ADA)]. In addition, the aim was to compare (head-to-head) the effectiveness of individual drugs in patients receiving their first anti-TNF treatment.

Methods.

All anti-TNF–treated patients with RA included in the observational South Swedish Arthritis Group register were eligible. We identified the patients’ first SR periods (time between first visit after treatment initiation with DAS28 < 2.6 and subsequent visit with DAS28 ≥ 2.6). Baseline predictors of SR in biologic-naive patients were studied using multivariate regression models. Remission duration and timing of remission start was estimated with Kaplan-Meier curves.

Results.

Of the 2416 patients included, 382 (15.8%) fulfilled the criteria for SR. Median estimated duration of SR was 5.25 years. Predictors for SR were male sex, low Health Assessment Questionnaire, low DAS28, methotrexate (MTX) treatment, and the calendar year of treatment start. OR for achieving SR within the first 12 months of treatment were 1.86 for ETN (95% CI 1.33–2.61) compared to IFX. HR for 4 years of SR were 1.32 for ETN (95% CI 1.01–1.74) and 1.84 for ADA (95% CI 1.23–2.78), with IFX as the reference drug.

Conclusion.

SR was uncommon in patients with RA treated with anti-TNF in clinical practice. However, patients remained in SR for a substantial period of time. Concomitant MTX treatment predicts remission. ETN and ADA were more likely in reaching SR.
2014 Update of the Canadian Rheumatology Association/Spondyloarthritis Research Consortium of Canada Treatment Recommendations for the Management of Spondyloarthritis. Part I: Principles of the Management of Spondyloarthritis in Canada
Authors: Rohekar Sherry , Chan Jon , Tse Shirley M.L. , Haroon Nigil , Chandran Vinod , Bessette Louis , Mosher Dianne , Flanagan Cathy , Keen Kevin J. , Adams Karen , Mallinson Michael , Thorne Carter , Rahman Proton , Gladman Dafna D. , Inman Robert D.
Published: February 2015

Objective.

The Canadian Rheumatology Association (CRA) and the Spondyloarthritis Research Consortium of Canada (SPARCC) have collaborated to update the recommendations for the management of spondyloarthritis (SpA).

Methods.

A working group was assembled and consisted of the SPARCC executive committee, rheumatologist leaders from SPARCC collaborating sites, Canadian rheumatologists from across the country with an interest in SpA (both academic and community), a rheumatology trainee with an interest in SpA, an epidemiologist/health services researcher, a member of the CRA executive, a member of the CRA therapeutics committee, and a patient representative from the Canadian Spondylitis Association. An extensive review was conducted of literature published from 2007 to 2014 involving the management of SpA. The working group created draft recommendations using multiple rounds of Web-based surveys and an in-person conference. A survey was sent to the membership of the CRA to obtain an extended review that was used to finalize the recommendations.

Results.

Guidelines for the management of SpA were created. Part I focuses on the principles of management of SpA in Canada and includes 6 general management principles, 5 ethical considerations, target groups for treatment recommendations, 2 wait time recommendations, and recommendations for disease monitoring. Also included are 6 modifications for application to juvenile SpA.

Conclusion.

These recommendations were developed based on current literature and applied to a Canadian healthcare context. It is hoped that the implementation of these recommendations will promote best practices in the treatment of SpA.
Remission in Rheumatoid Arthritis: Working Toward Incorporation of the Patient Perspective at OMERACT 12
Authors: van Tuyl Lilian H. , Sadlonova Martina , Davis Bev , Flurey Caroline , Goel Niti , Hewlett Sarah E. , Hill Catherine L. , Hoogland Wijnanda , Kirwan John R. , van Schaardenburg Dirkjan , Scholte-Voshaar Marieke , Smolen Josef S. , Stamm Tanja , Wells George A. , Boers Maarten
Published: February 2015

Objective.

The treatment of rheumatoid arthritis (RA) should target patient-relevant outcomes, making patient perspective on remission essential. In 2010, patients, physicians, health professionals, and researchers at the Outcome Measures in Rheumatology (OMERACT) conference developed an ambitious research agenda to study the concept of remission. Qualitative research has since helped us understand the concept of remission from the patient perspective.

Methods.

During OMERACT 12, the OMERACT working group on patient perspective on remission in RA elaborated on data generated to date and discussed the methodological challenges ahead. Challenges included (1) selection of domains, (2) choice of a patient remission definition or a single domain to add to the current remission definition, and (3) the importance of pain in defining remission from a patient perspective.

Results.

Focus in the coming years will be on increasing our understanding by identifying the most important domains from the patient perspective regarding remission and investigating how these domains can be measured. Investigation into the Rheumatoid Arthritis Impact of Disease questionnaire, disease flare, as well as the concordance of domains from our ongoing remission survey is appropriate. More data and further discussions are needed to decide on the next steps.

Conclusion.

Progress summarized over 4 years highlights the main methodological challenges discussed within the working group on patient perspective on remission in RA during OMERACT 12.
The role of perception in yeísmo: A preliminary study with Catalan-speaking listeners
Authors: Rost Bagudanch Assumpció
Published: February 2015

Yeísmo, as a change in progress in the Spanish phonological system, has been studied from various perspectives, especially from dialectology and articulatory phonetics. However, the role of the listener in its origins and spread has been scarcely analysed. In fact, it is necessary to focus on the side of the listener to detect if the articulatory similarity of sounds [ʎ] and [j] can be perceptively ambiguous and, thus, confounded. The present work wants to examine this topic in order to determine how the innovative neutralization could initiate. With this purpose we have carried out a perception study which consisted of three different tests: the first one worked as control test and the other two were used to find out if the change could be related to signal reception problems or to opacities in the input segmentation. In these experiments, we have used samples from a Spanish speaker who upholded /ʎ/ and /ʝ/ distinction (second test) and from a yeísta speaker (third test).

Despite our concern is to analyse the dephonologization of /?/ in Spanish, there is an important obstacle to achieve our goal: it is quite difficult to find Spanish speakers that do preserve the phonological distinction between /ʎ/ and /ʝ/ in the same way Spanish system once did. Therefore, we must rely on compared grammar: the judges of the perception tests were 20 Catalan speakers, a language that keeps this phonological contrast.

The results display that 30 % of the stimulus from Spanish speakers were misinterpreted. In addition, data suggest that the presence of an adjacent palatal vowel and the occurrence in an unstressed position may favour the confusion and, hence, the recategorization process.
Dataveillance in the Workplace
Authors: Connolly Regina
Published: February 2015

The work environment is changing in response to market pressures, and the psychological contract that previously typified many employer and employee work relationships is coming under distinct threat as pervasive Internet-based technologies now enable management to monitor employees' email, computer interactions, and general work productivity. Although in some cases management may have legitimate reasons to monitor employees' actions, it is becoming increasingly evident that the use of these technologies has the potential to negatively impact employee productivity and morale, and in some cases employee health and wellbeing. This chapter outlines some of the emerging issues relating to workplace surveillance from the employees' perspective, as well as the motivation behind management's decision to employ technologies in order monitor their employees.
Privacy, Security, and Identity Theft Protection
Authors: Francia III Guillermo A. , Hutchinson Frances Shannon , Francia Xavier Paris
Published: February 2015

The proliferation of the Internet has intensified the privacy protection and identity theft crises. A December 2013 report by the U.S. Department of Justice indicates that 16.6 million persons were victims of identity theft with direct and indirect losses amounting to almost $24.7 billion in 2012 (Harrell & Langton, 2013). These startling and apparently persistent statistics have prompted the United States and other foreign governments to initiate strategic plans and to enact several regulations in order to curb the crisis. This chapter surveys recently enacted national and international laws pertaining to identity theft and privacy issues. Further, it discusses the interplay between privacy and security, the various incentives and deterrence for privacy protection, and the prospects for the simulation of the social and behavioral aspects of privacy using the agent-based modeling.
Identity Management Systems
Authors: Bhatt Reema , Gupta Manish , Sharman Raj
Published: February 2015

Identity management is the administration of an individual's access rights and privileges in the form of authentication and authorization within or across systems and organizations. An Identity Management system (IdM) helps manage an individual's credentials through the establishment, maintenance, and eventual destruction of their digital identity. Numerous products, applications, and platforms exist to address the privacy requirements of individuals and organizations. This chapter highlights the importance of IdM systems in the highly vulnerable security scenario that we live in. It defines and elaborates on the attributes and requirements of an effective identity management system. The chapter helps in establishing an understanding of frameworks that IdM systems follow while helping the reader contrast between different IdM architecture models. The latter part of this chapter elaborates on some of today's most popular IdM solutions.
A Dynamic Subspace Anomaly Detection Method Using Generic Algorithm for Streaming Network Data
Authors: Zhang Ji
Published: February 2015

A great deal of research attention has been paid to data mining on data streams in recent years. In this chapter, the authors carry out a case study of anomaly detection in large and high-dimensional network connection data streams using Stream Projected Outlier deTector (SPOT) that is proposed in Zhang et al. (2009) to detect anomalies from data streams using subspace analysis. SPOT is deployed on 1999 KDD CUP anomaly detection application. Innovative approaches for training data generation, anomaly classification, false positive reduction, and adoptive detection subspace generation are proposed in this chapter as well. Experimental results demonstrate that SPOT is effective and efficient in detecting anomalies from network data streams and outperforms existing anomaly detection methods.
Detecting Botnet Traffic from a Single Host
Authors: García Sebastián , Zunino Alejandro , Campo Marcelo
Published: February 2015

The detection of bots and botnets in the network may be improved if the analysis is done on the traffic of one bot alone. While a botnet may be detected by correlating the behavior of several bots in a large amount of traffic, one bot alone can be detected by analyzing its unique trends in less traffic. The algorithms to differentiate the traffic of one bot from the normal traffic of one computer may take advantage of these differences. The authors propose to detect bots in the network by analyzing the relationships between flow features in a time window. The technique is based on the Expectation-Maximization clustering algorithm. To verify the method they designed test-beds and obtained a dataset of six different captures. The results are encouraging, showing a true positive error rate of 99.08% with a false positive error rate of 0.7%.
The Advantages of PsychoSpiritual Psychotherapy
Authors: Caparros Elizabeth
Published: February 2015

The purpose of this chapter is to educate those interested in the value of understanding psychological theories and how they may contribute to the mental and emotional healing of individuals, personally, socially, spiritually, and universally. It also examines some principles that relate to one's search for meaning.
Effects of High Temperature Treatment on the Mechanical Properties of Basalt Fiber Reinforced Aluminous Composites
Authors: Jogl Marcel , Reiterman Pavel , Holčapek Ondřej , Koťátková Jaroslava
Published: February 2015

Article presents the results of an experimental program aimed at investigating of the mechanical properties of composites based on aluminous cement with the addition of basalt fibres, which could be used in the manufacture of components resistant to high temperatures, including the retention of mechanical properties. Silica composites based on Portland cement and silica aggregates are not able to resist the effects of high temperatures [1], therefore a heat resistant mixtures in this experiment includes only components that are able to resist the effects of high temperatures.
Performance of Stabilized and Non-Stabilized PVA Nanofiber Textiles Subjected to Tension
Authors: Rácová Zuzana , Prošek Zdeněk , Topič Jaroslav , Tesárek Pavel , Indrová Kateřina , Nežerka Václav , Ryparová Pavla
Published: February 2015

Nanofiber textiles became indispensible in medicine and many other industries because of their unique properties. Recently, the pioneering works suggested their use also in a building industry in the form of moisture barriers. For a better chemical stability and resistance to air humidity it is suitable to stabilize the spun textiles. Our study is focused on the influence of the physical-chemical stabilization, also called crosslinking, on the mechanical properties of nanofiber textiles in tension, namely stiffness, strength and ductility. During the process of crosslinking the individual fibers bond in nodes, ensuring a better spatial integrity. However, the presented results indicate that the stabilized nanofiber textiles exhibit significantly lower ductility while their ultimate strength is lower only by about 10 %.
Impact of Anisotropy on the Elastic Modulus of Basic Woven Fabric Structure
Authors: Šimić Penava Diana , Penava Željko , Knezić Željko
Published: February 2015

Anisotropy is the characteristic which is typical for most materials, especially woven fabrics. Influence of direction of tensile force action on the properties of the fabric is big and frequently tested. The woven fabric can be defined as orthogonal elastomer. The values of elastic modulus of woven fabrics for different angles of extension direction were analyzed. Three types of fabric samples of different weaves (plain, twill, sateen) and the same raw material composition were tested under tensile forces in seven directions oriented with 15° increment with respect to the weft direction. Elastic modulus of woven fabrics was determined experimentally in the laboratory. Based on the experimentally obtained values, theoretically calculated elastic modulus for arbitrarily chosen fabric directions was calculated. A good agreement between experimental results and the calculated obtained values of the elastic modulus was shown, so the theoretical equations can be used with high accuracy to calculate the elastic modulus of the fabric in various directions. Therefore, the measurements need to be implemented when the tensile force acting on the fabric only in the warp (90°), weft (0°) and at angle of 45°.
The Analyses of Pure Shear Behaviour of E-Glass Woven Fabrics by Picture Frame Test
Authors: Šimić Penava Diana , Penava Željko , Krolo Joško
Published: February 2015

This paper describes an experimental study on the pure shear properties of E-Glass woven fabric by picture frame test. During shear deformation, the fabric yarns experience large angular change between warp and weft yarns. The picture frame test is one of the fundamental methods to characterize the in-plane shear behaviour of woven fabrics and can produce a quite uniform shear deformation state in the fabric sheet. Tests are conducted on two different size of EGlass specimens 40x40 mm and 80x80 mm. For a double increase the specimen size, the values of shear force and axial load are also almost double increase at the maximum displacement and shear angle.
Static and Dynamic Experimental Stress-Strain Analysis of Axles Loaded by Rotation Bending
Authors: Černý Ivo , Čipera Martin
Published: February 2015

Safety assessment of railway axles is based on fatigue strength design. During the design overall lifetime, railway axles undergo a very high number of loading cycles under rotating bending. Due to safety and reliability reasons, fatigue strength design has to be very carefully evaluated. Both theoretical modelling and extensive experimental fatigue testing including full scale tests have to be performed, whereas such tests have to be performed correctly with a high precision. In the paper, problems of dynamic forces during fatigue tests of railway axles are pointed out. Though static calibration can be carried out with a very high precision, dynamic forces can cause a significant redistribution of static stresses along the axle. An example is given and discussed.
Identification of Coupled Mode Shapes Based on Complex Mode Indicator Function
Authors: Huňady Róbert , Hagara Martin , Schrötter Martin
Published: February 2015

Paper deals with the identification of coupled mode shapes by experimental modal analysis. Main attention is focused on the using of Complex Mode Indicator Function that is based on singular value decomposition of frequency response function matrix and allows to separate coupled and also closed modes. In the paper there is described experimental modal analysis at which digital image correlation method is used to measure responses of a circular plate. The measurement was evaluated in program Modan 3D that is being developed by the authors.
Driver Seat Differential Pneumatic System with Air Damping
Authors: Kohl Ondrej , Pešík Lubomír , Skarolek Antonin
Published: February 2015

The paper shows a possibility of the tuning mechanical system by means of two pneumatic springs in a differential configuration connected with a throttle valve. The springs are inserted into the lead mechanism and connected to its parts, and to its supporting platform. The vibrations, transferred from the kinematic excitation of the base, are intended to be minimized. The vibration isolation by means of pneumatic springs is available in many technical systems, e.g. in supports of heavy machinery as well as in systems characterized by the human interaction, such as driver seats, ambulance couchettes, etc. The pneumatic springs provide the option of adaption of the stiffness, and herewith the adaption of the natural frequency of the system according to the exciting frequency. In cases of application of the object vibration isolation, they can change the load characteristics in a relative large range. In the studied case of the differential spring configuration, the springs are connected with an air pipe to the throttle valve. The air being exchanged during the motion period comes through the valve, the cross-section of which determines the time delay of the pneumatic sub-system thus creating a hysteresis of load characteristic of the spring support. This brings an additional, controllable damping to such a system that is profitable in most vibration isolation cases.
Analysis of Differential Method Used for the Evaluation of Uniform Residual Stresses by the Ring-Core Method
Authors: Šarga Patrik , Menda František , Trebuňa František , Kováč Ladislav
Published: February 2015

Despite the significant advantages of the Ring-Core method over the hole-drilling method, the Ring-Core method is still less common. Recent developments at our department showed the full potential of the method when using the adequate calibration coefficients. In this paper the differential method, a quick and easy method for uniform residual stress evaluation is described and the influence of its relaxation coefficients on the specimen’s dimensions is obtained.
Damage and Localized Corrosion in Steam Turbines
Authors: Cerny Miroslav
Published: February 2015

In the presented paper the system for determination of pits due to alloy corrosion in steam turbines is described. For two-dimensional task the number of pits in different areas is determined by microscopy technique with image analysis.
Development of the Bus Sandwich Roof Experimental and Numerical Approach
Authors: Doubrava Karel , Novotný Ctirad
Published: February 2015

This paper describes the design verification process of a new bus roof. The aim was to obtain a roof with comparable or better mechanical properties and likely dropped weight. The sandwich roof is developed in the framework of the project when properties matching real roof were compared to test samples. Different core materials and faces have been investigated. The experimental results serve to verify the suitability of the proposed FEM modelling for the future use on global structure roof numerical model.
Numerical Modelling and Experimental Measurement of Lifting Platform Construction for Car Relocation
Authors: Petrů Michal , Lepšík Petr , Novák Ondřej , Lufinka Aleš
Published: February 2015

Numerical modelling and experimental measurements led to the assessment of stress of structural nodes of scissor lifting platform, which is used for relocation of cars from a production line. It also led to optimization of producing process. Immediate load of scissor lifting platform by a car on stand causes additional bending moment that must be captured in a scissor mechanism. At the beginning the experimental measurements on the real lifting platform were made for obtaining of dependence of displacement, velocity and acceleration on time which was almost 1.5±0.1 g. Then dynamical analysis using a numerical method Runge Kutta 4th order of lifting platform were created. Model analysis showed that the initial immediate acceleration of lifting platform at start and immediate deceleration at stop lead to dynamic shocks. These dynamic shocks are due to long term operation dangerous because they permanently load not only pivots but also other parts – bearings and joining parts. A resonance may occur as well. In particular, dynamic shocks caused damage of structural nodes. Immediate load of scissor lifting platform by a car on stand causes additional bending moment. It is not appropriate in terms of long-term operation. Recommended load lifting platform should be symmetrical.
Measurement of Aircraft Propeller Dynamic Loading
Authors: Rosa Jindřich , Cagáň Jan
Published: February 2015

Aircraft Propeller Testing Laboratory of VZLÚ Praha-Letňany has been performed strain measuments on rotating parts, especially on aircraft propellers, for more than five decades. The means of signal recording and its processing have been changed during this age, following technical trends in electrical enginering, but a resistance strain gauge has remained the only one sensor easy practicable for the measurement. The article describes the contemporary state-of-the art and presents some examples of signal evaluation to obtain the data required for purpose of design and certification.
Experimental Analysis of Gear Loading in Planetary Transmission
Authors: Berka Ondřej , Lopot František , Dub Martin
Published: February 2015

This paper is focused on examination of teeth loading in rotating gears during standard operation and describes the applied approach and device developed. One of the closely examined items in planetary transmission testing is the gearing. The tooth load of each wheel in planetary transmission is monitored individually. In large devices, also the load across the width of the tooth is assessed by the Khβ coefficient.
Experimental and Numerical Investigation of Response of Sandwich Composite Beam Subjected to Low-Velocity Impact
Authors: Mandys Tomáš , Laš Vladislav , Kroupa Tomáš , Zemčík Robert
Published: February 2015

This paper deals with the progressive failure analysis of sandwich composite beam loaded with transversely low-velocity impact. A user defined material model was used for modeling of the non-linear orthotropic elastic behavior of composite skin. The non-linear behavior of foam core was modeled using Low-Density Foam material model. The numerical model was validated using performed experiment and the results in terms of deflection and contact force time dependencies are mutually compared.
Uncertainties of the Evaluation of the Hole Drilling Residual Stress Measurement According to the ASTM E837 Standard
Authors: Švantner Michal , Skála Jiří
Published: February 2015

The paper deals in hole drilling residual stress measurement method. The basic principles of measurement and evaluation by the uniform stress and Integral methods are described. The uncertainties of the residual stress evaluation procedure based on the ASTM E837 standard are analyzed. Examples of residual stress evaluation and comparison of different ASTM E837 standard editions are presented.
Modal Parameter Analysis for Underdamped Mechanical Systems
Authors: Nangolo Fillemon Nduvu , Klimenda František
Published: February 2015

There are many ways to model and to analyze discrete event systems. In general these systems lead to a non-linear characteristic equation description in linear algebra. This paper presents an analytical method for solving the characteristic equation of higher order, which arise when solving ordinary differential equations of motion of rigid body systems with 2 ≤ p° ≤ 10 degrees of freedom. The objective of this work was to express the characteristic equation in the form of product quadratic polynomial, from which the modal components could be found. To validate the model, the modal parameters extraction technique – Ibrahim Time Domain (ITD) – was used to extract modal parameters from artificial data developed in MATLAB environment. The extracted modal components were compared to those obtained from the analytical model.
Experimental Tests and FEM Simulations of Flank Breakage on Tooth of Gears with Respect to Different Nitrided Depths
Authors: Petr Karel , Dynybyl Vojtěch , Křepela Jan
Published: February 2015

This article deals with the reasons for gear failure - Flank breakage on tooth of spur gears with helical and straight involute gears. Gear flank breakage can be observed on edge zone-hardened gears. The creation of flank and tooth breakage and FEM simulation of flank breakage on tooth are described in this article. In the article are also described and short photo documentation from real load tests on mechanically closed stand for testing of gearing with helical gears and different nitrided depth.
Experimental and Numerical Analysis of Vibration of the Test Stand
Authors: Petrů Michal , Ševčík Ladislav
Published: February 2015

Sound effect derives a pair of highly loaded machinery parts-motion screw and nut. Loaded pair is used in non-standard environments of high voltage electrical equipment in electrical substations. The non-standard environment is seen in the movement of this pair immersed in transformer oil deeply below the surface. Transformer oil has no good mechanical lubricating properties because it does not contain sulfur. Loaded pair cannot be lubricated, because there would be oil contamination and deterioration of its electro-insulating properties. The causes were sought in the structure of the machine, frame stiffness, mechanical strength machine and used materials. The aim of the research with help experimental and numerical study was to define the cause and eliminate sound effect coming from the device.
Use of MBD Programs in Solving General Unbalance Simple Mechanical System
Authors: Svoboda Martin , Soukup Josef , Petrenko Alena
Published: February 2015

The contribution solves the effect of the construction, operation and excitation asymmetry of the simple spatial model. The model can be used for simulation of the vibration of the vehicles (road and rail). The solution was performed by experiments and numerical methods. The mathematical model was developed to reliable describe the experimental simple spatial model. The model was verified by experimental results.
Vibration and Noise Reduction Analysis of Sheet Metal Structures with Damping Layer
Authors: Petřík Jan , Kulhavý Petr , Pašek Miloslav , Šašek Jakub
Published: February 2015

Vibration reduction in term of lower acoustic noise level increases e.g. the passenger comfort, fulfills acoustic manufacturing standards, decreases the transportation influence on the environment etc. The basic sheet metal structure is complemented with damping layer which absorbs the vibration energy. The frequency response experiment analysis of the component structure with damping material helps to validate the separate material models used for predictive simulations.
Utilisation Possibilities of PhotoStress Method in Determination of Residual Stresses
Authors: Frankovský Peter , Trebuňa František , Ostertag Oskar , Šarga Patrik , Delyová Ingrid , Kostka Ján
Published: February 2015

The presented paper demonstrates the determination of residual stresses by means of PhotoStress® method. The identification was performed on a drilled and subsequently loaded sample of a split ring. Through drilling and subsequent loading of the sample we were able to simulate residual stresses throughout the surface of the split ring. Using the values of residual stresses, a gradient of residual stresses was specified. The 3 mm thick split ring was laser-cut from a non-alloyed fine-grained structural steel sheet suitable for welding, i.e. steel 11 523. It was coated with 3.125 mm thick photoelastic coating PS-1A with fringe constant.
Failure Probability of Structure and its Model
Authors: Kesl Petr , Plánička František
Published: February 2015

The Simulation Based Reliability Assessment SBRA Method is a probabilistic method using the Monte Carlo simulation [1,3]. Substance of that method consists in repeated calculations of relatively simple equations, where entering variables (dimensions of the body, mechanical properties, loads, etc.) can be constant or defined by histograms, respectively. Probability of failures of the model and the steel beam were determined using Anthill software [3].
Probabilistic Verification of Structures with Respect to Durability
Authors: Marková Jana
Published: February 2015

General principles on probabilistic approach to structural verification with respect to durability are provided in the international standard ISO 13823 which is currently being implemented into the system of Czech standards. The operational use of the new procedures in practice would require specification of probabilistic durability criteria, physical models of material deteriorations, and theoretical models of basic variables. It appears that the probabilistic methods of optimisation may provide valuable background information facilitating determination of appropriate criteria for durability.
Theory of Hole-Drilling Strain-Gage Method for the Using of Semiconductor Strain Gauges
Authors: Vítek Karel
Published: February 2015

When determining stress states by the hole-drilling method, it is necessary to take into account the experiment performance accuracy. The drilled holes eccentricity appears as a frequent imperfection, which influences essentially the reliability of their stress state assessment. This paper presents the hole-drilling measurement method corresponding to the E 837 standard method, but, at the same time, it is more universal. This method transforms the full stress tensor of the drilled hole position by the regression coefficients and describes the state of strains released in the hole surrounding, based on the hole center distance and its depth. The regress coefficients are not defined in the method concretely for the rosette but they are universal both for the isotropic Hooke’s materials and for the other measuring elements. The method defines the way for the processing of the released strains measured with a defined measuring element and involves naturally the influence of the drilled hole eccentricity and so it is possible, in the hole-drilling method, to apply measuring elements more simply, without determining their specified regression coefficients. Modification of Decomposition theory for semiconductor hole drilling rosette with a greater sensitivity is advantageous.
Non-Destructive Testing of Composite Gypsum Material Properties – Long Time Measurement
Authors: Plachy Tomáš , Svoboda Tomáš , Topič Jaroslav , Prošek Zdeněk , Nežerka Václav , Tesárek Pavel
Published: February 2015

The paper presents results of long-time investigation of mechanical properties of composite gypsum material using nondestructive technique. The gypsum block was put to the façade of the building for four years. Then it was removed and cut to smaller specimens, which were investigated. The matrix of 6 × 4 specimens of dimensions 40 × 40 × 160 mm were cut from the block after its removal from the façade. After 6 and 9 years, the Young’s moduli and shear moduli of these specimens were determined from the transversal, longitudinal and torsional vibrations using the impulse excitation method.
Probabilistic Parametrical Assessment of FRC Specimens
Authors: Šolc Martin , Brož Petr
Published: February 2015

Significant progress has been made in the last years towards understanding the short and long – term performances of fibre reinforced cementitious materials and this has resulted in a number of novel and innovative uses. One of the main problems concerns the great quantity of random parameters– the placement of fibres, their orientation and quantity in a determined section etc. In consequence, full – probabilistic methods could be recommended for the analysis and evaluation of FRC. It can be assumed that for some structures probabilistic parameters derived from actual material tests could be used. A series of 9 specimens with the same reinforcement was used for a standard 4-point bending test. Using the obtained results, probabilistic normal distributions for the necessary input data were defined. The diagram of the experiment can then be recalculated probabilistically using the method SBRA. The ductility of the material can be expressed energetically. The final result is a histogram of the flexural toughness of the specimen that can be used for further calculations and evaluations.
Non-Destructive Testing during the Hardening of Alkali-Activated Slag
Authors: Topolář Libor , Rypák Peter , Šamárková Kristýna , Rovnaník Pavel
Published: February 2015

Non-destructive acoustic analysis methods, Impact-echo method as a traditional and the Acoustic Emission method as nontraditional method for civil engineering, were used for experiment. This paper reports the experiment during hardening and drying of specimens of alkali activated slag mortars. Alkali activated slag is a material having a great potential to be used in practice. The main drawback of this material is a high level of autogenous and especially drying shrinkage, which causes a deterioration of the mechanical properties. The aim of this paper is introduce the effect of method used and time curing on the microstructure of alkali activated slag mortars. An understanding of microstructure–performance relationships is the key to true understanding of material behaviours.
Use of Digital Image Correlation to Track Strain Evolution in Compressed Masonry Piers
Authors: Antoš Jakub , Nežerka Václav , Tesárek Pavel
Published: February 2015

In order to develop a constitutive material model and to verify its consistency when implemented in a computational code, it is necessary to understand the material and to carry out a comprehensive experimental analysis. This can be a challenging task in the case of composite materials and structures, such as masonry, when using conventional measurements. Strain gauges and allow recording strains at a limited number of discrete points and do not provide sufficient amount of data, thus increasing the cost of the analysis. From that reason a full-field non-contact measurements, such as Digital Image Correlation (DIC), became very popular and valuable for analysis of structures subjected to mechanical loading and precise detection of the onset of strain localization. The presented study deals with tracking the strain localization using DIC in the case of masonry piers loaded by the combination of bending and compression. In such case the strain localizes into more compliant mortar joints while the complete collapse occurs when the masonry blocks fail to transfer tensile stress due to transversal expansion. The obtained data will be used for the validation of a finite element model to predict the behavior of masonry structures.
Experimental Verification of a Computing Model
Authors: Melcer Jozef
Published: February 2015

The finite element method and Component element method are widely used in modeling nowadays. Also the classical computing models especially discrete computing models give very good results. Often some assumptions must be adopted in the process of creation of computing models especially within creation of bridge computing models. In such a case the experimental tests are needed to verify the validity of adopted assumptions. The presented paper describes the adopted assumptions and methodology of their experimental verification. It mutually compares the experimentally and numerically obtained results and makes findings for practical applications.
Do we still Need an Experiment at All?
Authors: Holý Stanislav , Hrubý Zbyněk
Published: February 2015

This contribution is carrying similar title as former published two ones [1,2] , as until today there is some discussion about relationship of numerical simulation a experiment during structure construction,. What is better and what is more trustworthy. Looking at motto we see that any of the separate application cannot fulfill recent requirements for high quality, warranted life time and lower mass of structures together with economic approach (short term of design).
Dependence of Load Bearing Capacity on Homogeneity of Steel Fiber Distribution
Authors: Rydval Milan , Huňka Petr , Kolisko Jiří
Published: February 2015

Load-bearing capacity of fine grained cement-based composite materials UHPFRC depends on the homogeneity of the steel fiber distribution at cross section. The homogeneity of the steel fiber distribution has significant effect to the mechanical properties of UHPFRC elements, especially at tensile strength in bending. The load-bearing capacity depending on the homogeneity of steel fibers at the permanent formwork slabs made from UHPFRC is shown in this paper.
Finite Element Transient Dynamic Analysis of Laminated Composite Plates
Authors: Žmindák Milan , Soukup Josef , Rychlíková Lenka , Skočilas Jan
Published: February 2015

In recent years, the requirements on the plane and space structures have been growing. The essential aim is to minimize weight and increase the strength and carrying capacity of these structures. One of the possible solutions is application of the layered structure composed from the composite materials. These materials represent the most effective utilization of potential possibilities of mass and energy savings not only from material point of view, but also with respect to structure usage. The article presents the Finite element method (FEM) solution of the displacement, velocity and acceleration distributions in the composite plates. The plate is unidirectional composite consisting of carbon fibers embedded in the epoxy matrix. FEM software ANSYS 11.0 has been used for analysis.
Methods of Non-Destructive Assessment of Timber
Authors: Klapálek Pavel , Melzerová Lenka
Published: February 2015

As a preparation for further research of timber this paper was made and the purpose of this paper is to summarize and describe the currently used non-destructive assessment methods of a timber structures used in modern civil engineering. The principle of each method is shortly introduced and the reader is familiarized with tools necessary for the assessment and output parameters provided by the method.