Damage Evolution During Fatigue in Structural Materials

AbstractEarly stages of damage evolution in cyclic loading are described and discussed. The importance of the role of cyclic plastic strain in damage evolution is emphasized and the relation between stress and strain in cyclic straining is clarified. The principal stages of damage evolution in fatigued crystalline structural material are identified. The basic characteristic and theories of fatigue crack initiation are sketched and confronted with experimental observations. Early fatigue crack growth is characterized and quantitatively described. The relation between the growth of short cracks and fatigue life in the form of Manson-Coffin law is established

Evaluation of transgenic Prunus domestica L., clone C5 resistance to Plum pox virus

Plum pox virus (PPV) is one of the most devastating diseases of Prunus species. Since few sources of resistance to PPV have been identified, transgene-based resistance offers a complementary approach to developing PPV-resistant stone fruit cultivars. C5, a transgenic clone of Prunus domestica L., containing the PPV coat protein (CP) gene, has been described as highly resistant to PPV in greenhouse tests, displaying characteristics typical of post-transcriptional gene silencing (PTGS). Moreover, C5 trees exposed to natural aphid vectors in the field remained uninfected after 4 years while susceptible transgenic and untransformed trees developed severe symptoms within the first year. In our study, a high and permanent infection pressure of PPV was provided by bud grafting of inoculum in the field trial of clone C5 conducted in the Czech Republic, in which PPV-infected and healthy control trees were used. Moreover, trees with combined inoculations by PPV, ACLSV and PDV were also used in the trial. The presence of the viruses throughout the tree tissues, the relative titre of the viruses and symptoms on C5 trees have been monitored over the years. The resistance stability of C5 clones under permanent infection pressure is discussed.Keywords: PPV, C5, resistance, real-time PC

CLASSIFICATIONS OF INNOVATIONS: APPROACHES AND CONSEQUENCES

Abstract TABAS, J., BERANOVÁ, M., POLÁK, J.: Classifi cation of innovations: approaches and consequences. Acta univ. agric. et silvic. Mendel. Brun., 2011, LIX, No. 2, pp. 399-406 Currently, innovations are perceived as a life blood of businesses. The inevitable fact is that even if the innovations have a potential to transform the companies or all the industries, the innovations are high risky. Even though, the second fact is that in order to companies' development and their survival on the markets, the innovations have become the necessity. In the theory, it is rather diffi cult to fi nd a comprehensive defi nition of innovation, and to settle down a general defi nition of innovation becomes more and more diffi cult with the growing number of domains where the innovations, or possible innovations start to appear in a form of added value to something that already exist. Defi nition of innovation has come through a long process of development; from early defi nition of Schumpeter who has connected innovation especially with changes in products or production processes, to recent defi nitions based on the added value for a society. One of possible approaches to defi ne the content of innovation is to base the defi nition on classifi cation of innovation. In the article, the authors provide the analysis of existing classifi cations of innovations in order to fi nd, respectively in order to defi ne the general content of innovation that would confi rm (or reject) their defi nition of innovation derived in the frame of their previous work where they state that innovation is a change that leads to gaining profi t for an individual, for business entity, or for society, while the profi t is not only the accounting one, but it is the economic profi t. The article is based especially on the secondary research while the authors employ the method of analysis with the aim to confront various classifi cation-based defi nitions of innovation. Then the methods used are especially comparison, analysis and synthesis. added value, classifi cation of innovations, competitive advantage, defi nition of innovation, innovatio

Cyclic Plastic Response and Damage in Materials for High Temperature Applications

In this contribution, the methods allowing to study the sources of cyclic stress and early fatigue damage at room and elevated temperatures are presented and used to reveal details of the mechanisms of cyclic plastic straining and fatigue damage evolution in austenitic steels and nickel superalloys.Анализ кривых гистерезиса показывает, что при различной температуре имеют место характерные изменения зависимости между циклическими пластическими деформациями и напряжениями в нержавеющей стали и суперсплавах. Соответствующее изменение микрорельефа поверхности при мягком нагружении зафиксировано с помощью сканирующей и томографической электронной микроскопии с высоким разрешением. Проанализированы механизмы локализации циклической деформации, образования поверхностного микрорельефа, инициирования усталостных трещин и роста коротких трещин.Аналіз кривих гістерезису показує, що за різних температур відбуваються характерні зміни залежності між циклічними пластичними деформаціями і напруженнями в нержавіючій сталі і суперсплавах. Відповідні зміни мікрорельєфу поверхні за м’якого навантаження зафіксовано за допомогою сканувальної і томографічної електронної мікроскопії з високим розділенням. Проаналізовано механізми локалізації циклічної деформації, утворення поверхневого мікрорельєфу, ініціювання тріщин від утомленості і росту коротких тріщин

Multiaxial elastoplastic cyclic loading of austenitic 316L steel

Cyclic stress-strain response and fatigue damage character has been investigated in austenitic stainless steel 316L. Hollow cylindrical specimens have been cyclically deformed in combined tension-compression and torsion under constant strain rate condition and different constant strain and shear strain amplitudes. In-phase and 90° out-of-phase cyclic straining was applied and the stress response has been monitored. Cyclic hardening/softening curves were assessed in both channels. Cyclic softening followed for higher strain amplitudes by long-term cyclic hardening was observed. Cyclic stress-strain curves were determined. Study of the surface damage in fractured specimens revealed the types and directions of principal cracks and the sources of fatigue crack initiation in slip bands

Snakes Represent Emotionally Salient Stimuli That May Evoke Both Fear and Disgust

Humans perceive snakes as threatening stimuli, resulting in fast emotional and behavioral responses. However, snake species differ in their true level of danger and are highly variable in appearance despite the uniform legless form. Different snakes may evoke fear or disgust in humans, or even both emotions simultaneously. We designed three-step-selection experiments to identify prototypical snake species evoking exclusively fear or disgust. First, two independent groups of respondents evaluated 45 images covering most of the natural variability of snakes and rated responses to either perceived fear (n = 175) or disgust (n = 167). Snakes rated as the most fear-evoking were from the family Viperidae (Crotalinae, Viperinae, and Azemiopinae), while the ones rated as the most disgusting were from the group of blind snakes called Typhlopoidea (Xenotyphlopinae, Typhlopinae, and Anomalepidinae). We then identified the specific traits contributing to the perception of fear (large body size, expressive scales with contrasting patterns, and bright coloration) and disgust (thin body, smooth texture, small eyes, and dull coloration). Second, to create stimuli evoking a discrete emotional response, we developed a picture set consisting of 40 snakes with exclusively fear-eliciting and 40 snakes with disgust-eliciting features. Another set of respondents (n = 172) sorted the set, once according to perceived fear and the second time according to perceived disgust. The results showed that the fear-evoking and disgust-evoking snakes fit mainly into their respective groups. Third, we randomly selected 20 species (10 fear-evoking and 10 disgust-evoking) out of the previous set and had them professionally illustrated. A new set of subjects (n = 104) sorted these snakes and confirmed that the illustrated snakes evoked the same discrete emotions as their photographic counterparts. These illustrations are included in the study and may be freely used as a standardized assessment tool when investigating the role of fear and disgust in human emotional response to snakes

Media reporting: facts, nothing but facts?

This IRIS Special examines the principles of accuracy, objectivity and fairness in news and current affairs coverage by European media organisations. The issue is explored from a number of perspectives, including from that of media organisations, the Council of Europe, the European Court of Human Rights, member states, and judicial and regulatory bodies. It also includes chapters on a number of Council of Europe member states, discussing the regulatory framework that impacts upon this issue, including national legislation, case law, regulatory codes, and regulatory enforcement

Charge separation relative to the reaction plane in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}= 2.76 TeV

Measurements of charge dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudo-rapidity range $|\eta| < 0.8$ are presented as a function of the collision centrality, particle separation in pseudo-rapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge dependent azimuthal correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286

Eo-Alpine metamorphism and the ‘mid-Miocene thermal event’ in the Western Carpathians (Slovakia): New evidence from multiple thermochronology

A combination of zircon (U–Th)/He (ZHe), apatite fission track (AFT) and apatite (U–Th)/He (AHe) dating methods is applied to constrain the metamorphic and exhumation history of the Tatric part of the Branisko Mountains in the Western Carpathians. ZHe ages from the basement samples prove the basement experienced a very low-grade to low-grade Eo-Alpine metamorphic overprint in mid-Cretaceous times. Miocene AFT and AHe ages found in the basement and in the Palaeogene sediments conclusively demonstrate that the Branisko Mts experienced a ‘mid-Miocene thermal event’. This thermal event had a regional character and was related to magmatic and/or burial heating that exposed the sediment and basement samples to ~ 120–130°C and ~ 100–190°C, respectively