bluuebunny/crossref_metadata_2025 huggingface dataset:
First record of Inocutis tamaricis in Romania with comments on its cultural characteristics
Authors: Chinan Vasilică C. , Fusu Lucian , Mânzu Ciprian C.
Published: May 2015

Inocutis tamaricis is a lignicolous basidiomycete associated exclusively with Tamarix species. The first Romanian record of this species is reported from Constanţa city near the Black Sea coast where it was detected on Tamarix tetrandra. We noticed that in pure culture it forms swollen hyphae in the aerial mycelium, which have not been reported so far for I. tamaricis.
Variability of pollen aperture heteromorphism in annual pansies (Viola Section Melanium)
Authors: Magrini Sara , Scoppola Anna
Published: May 2015

Pollen heteromorphism is frequent in the section Melanium of the genus Viola, in which over 80% of the species produces pollen morphs with 3 to 6 apertures. Some authors have pointed out that many factors can affect the proportion of the different pollen types in perennial species, and that this proportion can change among populations. This work focuses on the study of the polymorphic pollen assemblage of three annual pansies: Viola arvensis, V. kitaibeliana, and V. hymettia, and on the assessment of its variability both within a population and within the same plant. In all the species, with both large and small flowers, 3-, 4- and 5-aperturate pollen grains were observed, with a large prevalence of 4-aperturate types. No pollen grains with 6 apertures were found. No significant variability of the pollen assemblage among flowers of the same plant was observed. In addition, in these three Viola species the frequencies of the various pollen morphs are also fairly constant among plants of the same population.
Re-evaluation of the Panicum capillare complex (Poaceae) in Croatia
Authors: Király Gergely , Alegro Antun
Published: May 2015

The Panicum capillare complex includes several taxa, among them P. capillare L., which is usually considered to be an established alien throughout Europe, whereas other species are recorded only as casuals. A new representative of the complex, P. riparium H. Scholz was described from Germany in 2002, and shortly after its description was recorded in several countries on the continent. In the course of herbarium revisions and recent field studies the authors documented several localities of the species in Croatia as well. The paper presents a new key for the determination of Croatian species of the complex and anticipates the invasion of P. riparium in the sub-Mediterranean regions of the Balkan Peninsula.
Morphometric variation and taxonomic identification of thirteen wild rose populations from Tunisia
Authors: Cheikh-Affene Zohra Ben , Haouala Faouzi , Harzallah-Skhiri Fethia
Published: May 2015

Thirteen populations of wild roses (Rosa L.) growing in northern and central Tunisia have been used for studies on the discrimination between accessions and populations. Thirty-eight morphological characters related to the branches, prickles, leaves and corymbs were measured on the collected accessions to study the phenotypic diversity among and within species. Principal component and hierarchical cluster analyses (PCA and HCA) separated rose accessions into two distinctive groups and eight subgroups. A taxonomic interpretation of the morphological variability has shown that Tunisian rose populations belong to two sections (Synstylae and Caninae) of the genus Rosa. Moreover, they have been identified as seven separated taxa: R. sempervirens L., R. sempervirens var. submoshata Rouy., R. sempervirens var. prostrata Lindl. belonging to Synstylae section and R. canina L., R. agrestis Savi., R. micrantha Smith. and R. dumetorum Thuill. belonging to Caninae section. PCA and HCA proved that morphological characters used in taxonomic identification such as styles form, leaf and leaflets length, number of flowers by corymb, leaflet serration, presence of glands in leaflet, peduncle, receptacle and sepal have a high value of discrimination, and have been very successful in morphological identification.
Morphology and anatomy of Hedysarum pannosum (Boiss.) Boiss. (Fabaceae)
Authors: Dural Huseyin , Citak Burcu Yilmaz
Published: May 2015

The aim of this paper is to investigate morphological, anatomical, palynological, fruit and seed micromorphological properties of Hedysarum pannosum (Boiss.) Boiss. A detailed description of the species is reported for the first time in this study. The morphological features of the species have been compared with the results of previous investigations. Anatomical studies have been carried out on cross-sections of roots, stems, leaflets and petioles. The anatomical results show that the plants have secondary growth roots, protruding stems, amphistomatic and equifacial leaves with tannin, triangular shaped petioles. Hedysarum pannosum pollen are tricolpate, prolate and pollen exine ornamentation is reticulate. Fruits have trichomes on their setae and tomentose trichomes have papillae. Seeds are reniform and they have rugolo-reticulate ornamentation.
The influence of concrete shrinkage on durability of reinforced structural members
Authors: Flaga K.
Published: May 2015

The aim of the paper was to present the author’s novel approach to the problem of the influence of concrete shrinkage on the static-strength performance of reinforced structures. The problem of concrete shrinkage has been known in concrete technology for years, mainly in the theoretical and experimental aspects. However, there are few works in which the effect of concrete shrinkage in real reinforced structural members and structures is shown. In the present article the author performs an analysis of these effects on a macro-scale, useful in the assessment of the influence of concrete shrinkage on limit states of bearing capacity and serviceability of reinforced concrete structures. An important distinction is made between shrinkage stresses imposed in RC members by external and internal (reinforcement induced) constraints and residual shrinkage stresses inside members (massive especially) resulting from non-stationary and non-linear moisture fields. The article concludes with a way of calculating the necessary, near-surface anti-shrinkage reinforcement in such members.
Interfacial transition zone of cement paste-reactive aggregate in cement-zeolite mortars
Authors: Owsiak Z. , Czapik P.
Published: May 2015

Alkali-aggregate reaction is an expansive chemical reaction between the alkalis present in cement paste and minerals contained in aggregates. Mineral admixtures can mitigate the detrimental processes caused by this reaction. One of the minerals that reduce the effects of the alkali-aggregate reaction is natural zeolite. This study attempts to explain the process that takes place in the zone surrounding reactive gravel in the cement mortar made with an addition of natural zeolite. Mortar bar expansion tests were performed and a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer was used to observe the paste-aggregate interfacial zone. The results confirmed the influence of the zeolite on the reduction in reactive aggregate-based mortar expansion. The microstructure of the aggregatepaste interfacial region was described and particular sub-zones varying in terms of calcium, sodium, potassium and silicon contents were determined.
Analysis of the microcracking process with the Acoustic Emission method with respect to the service life of reinforced concrete structures with the example of the RC beams
Authors: Goszczyńska B. , Świt G. , Trąmpczyński W.
Published: May 2015

The study presents the analysis of the process of crack formation and crack width growth in statically determinate and hyperstatic reinforced concrete beams with the IADP acoustic emission method. The beams were subjected to the monotonic, variable with unloading, and variable cyclic loading schemes. The criteria of structural damage were established to account for the structure durability
Application of stress based NDT methods for concrete repair bond quality control
Authors: Garbacz A.
Published: May 2015

Adhesion in repair systems is one of the most important factors affecting their durability. Elaboration of a reliable nondestructive test method to perform an adhesion mapping is one of the most important tasks. A majority of NDT methods applicable for the assessment of concrete structures are based on the propagation of various types of stress waves. In this paper, the influence of the repair material type (polymer-cement or polymer) and quality of the concrete substrate (roughness, microcracking, not cleaned surface) upon propagation of stress waves in a repair system was studied in view of developing a reliable NDT procedure for the field assessment of bond quality in concrete repairs.
Non-destructive and semi-destructive diagnostics of concrete structures in assessment of their durability
Authors: Hoła J. , Bień J. , Sadowski Ł. , Schabowicz K.
Published: May 2015

This paper proposes a comprehensive classification of test methods for the diagnosis of concrete structures. The main focus is on the ranges of suitability of the particular methods and techniques for assessing the durability of structures, depending on the principal degradation mechanisms and their effects on this durability. The survey covers non-destructive testing (NDT) methods, which do not in any way breach the integrity of the tested structures, and semi-destructive testing (SDT) methods requiring material samples to be taken or any other minor breach of structural integrity. An original taxonomy of physical, chemical and biological diagnostic methods, useful in assessment of concrete structures durability, is proposed. Equipment specific for selected advanced testing methods is presented as well as exemplary test results.
Evaluation of phenomenological model parameters using density dependent laws for prediction of mechanical response of cellular materials
Authors: Butt H.S.U. , Xue P. , Hou B.
Published: May 2015

Cellular materials have found wide-spread attention in structural applications involving impact energy absorption. The choice of the most suitable density of a cellular material, for a particular impact application, is based on its mechanical response, which may be obtained through experimental tests and/or models. A current study is focused on prediction of a mechanical response of a wide range of densities of a cellular material using available experimental data of very few densities. Best fitting-parameters of four selected phenomenological models, to fit the available experimental response of three distinct aluminum foam densities, are evaluated. The relationship between the best-fitting parameters and density of the foam is established by using two types of functions. The first function is based on a power law relationship between each parameter and foam density ρ, while the second function assumes each parameter as a linear combination of ρn and ρ, where n is any real number. The former function is found reasonable in the cases of both parameter interpolation and extrapolation while the latter is found reasonable for a parameter interpolation only. The findings of a current study emphasize for a conscious approach during selection of density dependent laws for phenomenological model parameters to avoid any erroneous or misleading design decision.
Utilizing the energy of kinetic friction for the metallization of ceramics
Authors: Chmielewski T. , Golański D. , Włosiński W. , Zimmerman J.
Published: May 2015

The paper is concerned with the metallization of ceramic materials using the friction-welding method in which the mechanism of the formation of a joint involves the kinetic energy of friction. The friction energy is directly transformed into heat and delivered in a specified amount precisely to the joint being formed between the metallic layer and the substrate material. The paper describes the ceramic metallization process, which has been developed by the present authors based on the friction-welding method.

The stress and temperature fields induced in the joint during the metallization process were determined using the finite element method with the aim to optimize the process parameters. The results were verified experimentally. The structures of the metallic coatings thus obtained were examined and the results are discussed in the paper.
A correction in feedback loop applied to two-axis gimbal stabilization
Authors: Zych C. , Wrońska-Zych A. , Dudczyk J. , Kawalec A.
Published: May 2015

A two-axis gimbal system can be used for stabilizing platform equipped with observation system like cameras or different measurement units. The most important advantageous of using a gimbal stabilization is a possibility to provide not disturbed information or data from a measurement unit. This disturbance can proceed from external working conditions. The described stabilization algorithm of a gimbal system bases on a regulator with a feedback loop. Steering parameters are calculated from quaternion transformation angular velocities received from gyroscopes. This data are fed into the input of Proportional Integral Derivative (PID) controller. Their input signal is compared with earned value in the feedback loop. The paper presents the way of increasing the position’s accuracy by getting it in the feedback loop. The data fusion from a positioning sensor and a gyroscope results in much better accuracy of stabilization.
Integrated mathematical model of competence-based learning-teaching process
Authors: Różewski P. , Zaikin O.
Published: May 2015

The competence-based learning-teaching process is a significant approach to the didactical process organization. In this paper the mathematical model of the competence-based learning-teaching process is proposed. The model integrates three models: a knowledge representation model (based on the ontological approach), a motivation model (as a behavioral-incentive model) and a servicing model (in a form of the queuing model). The proposed integrated model allows to control the learning-teaching process on different levels of management. The learning-teaching process can be interpreted as competence-based due to Open and Distance Learning (ODL) philosophy. We assume that the competence is a result of fundamental, procedural and project knowledge acquisition in accordance to the incoming European Qualification Framework.
Deliberations about three-phase PLL technologies applied to a grid control of the renewable power system
Authors: Liu L. , Liu C.
Published: May 2015

An efficient phase locked loop (PLL) method is very important to improve the grid-connected efficiency and the locked speed of frequency, phase, and voltage. However, most of literatures only introduce one PLL or one modified PLL method. There are many grid faults due to the grid connection to the renewable power generating system. A comparison and analysis is very important to select the most effective PLL technology for the grid-connected control of the renewable power system. Three PLL technologies are compared at different grid faults, such as single phase voltage drop, two phase voltage drop, frequency deviation, and voltage distortion. Simulation results indicated that different PLL methods have different locked performances at different grid faults.
Feedback stabilization of one-dimensional parabolic systems related to formations
Authors: Sano H.
Published: May 2015

This paper is concerned with the problem of stabilizing one-dimensional parabolic systems related to formations by using finitedimensional controllers of a modal type. The parabolic system is described by a Sturm-Liouville operator, and the boundary condition is different from any of Dirichlet type, Neumann type, and Robin type, since it contains the time derivative of boundary values. In this paper, it is shown that the system is formulated as an evolution equation with unbounded output operator in a Hilbert space, and further that it is stabilized by using an RMF (residual mode filter)-based controller which is of finite-dimension. A numerical simulation result is also given to demonstrate the validity of the finite-dimensional controller
Visualization support for the analysis of properties of interestingness measures
Authors: Susmaga R. , Szczęch I.
Published: May 2015

The paper considers a particular group of rule interestingness measures, called Bayesian confirmation measures, which have become the subject of numerous, but often exclusively theoretical studies. To assist and enhance their analysis in real-life situations, where time constraints may impede conducting such time consuming procedures, a visual technique has been introduced and described in this paper. It starts with an exhaustive and non-redundant set of contingency tables, which consists of all possible tables having the same number of observations. These data, originally 4-dimensional, may, owing to an inherent constraint, be effectively represented as a 3-dimensional tetrahedron, while an additional, scalar function of the data (e.g. a confirmation measure) may be rendered using colour.

Dedicated analyses of particular colour patterns on this tetrahedron allow to promptly perceive particular properties of the visualized measures. To illustrate the introduced technique, a set of 12 popular confirmation measures has been selected and visualized. Additionally, a set of 9 popular properties has been chosen and the visual interpretations of the measures in terms of the properties have been presented.
Control of Traffic Driven Epidemics in Weighted Networks by Immunizing Edges
Authors: Chang Zinan , Shao Fei
Published: May 2015

Many immunization strategies have been proposed to control the epidemic spreading which mainly focus on how to immunize the nodes. A novel and efficient strategy to control the traffic driven epidemic spreading in weighted networks is proposed in this paper. By immunizing the edges according to different weights, our control strategies cannot only reduce the epidemic spreading velocity and enhance the critical epidemic threshold, but also maintain the integrity of the weighted networks. Simulations show that the control strategy by immunizing edges according to the product of the strengths of two nodes of the edge proved to be more efficient.
Evaluation of the Software Industry Competitiveness in Jilin Province Based on Factor Analysis
Authors: Meng Pinchao , Yin Weishi , Li Yanzhong
Published: May 2015

In this paper 12 economic indices of the software industry in 30 cities/provinces in China are used to set up an evaluation system for the competitiveness of the regional software industry. By using the statistical analysis method of factor analysis, an evaluation model of the comprehensive competitiveness of the software industry for each city/province is built. Taking Beijing and Shanghai as examples, the comprehensive competitiveness and problems of the software industry in Jilin province are compared and analyzed.
Privacy Preservation of a Group and Secure Data Storage in Cloud Environment
Authors: Govinda K. , Sathiyamoorthy E.
Published: May 2015

Cloud computing has become a victorious archetype for data storage, as well as for computation purposes. Greater than ever it concerns user’s privacy, so that data security in a cloud is increasing day by day. Ensuring security and privacy for data organization and query dispensation in the cloud is important for superior and extended uses of cloud based technologies. Cloud users can barely have the full benefits of cloud computing if we can ensure the real user’s privacy and his data security concerns this approach along with storing thin-skinned personal information in databases and software spread around the cloud. There are numerous service suppliers in WWW (World Wide Web), who can supply each service as a cloud. These cloud services will switch over data with a supplementary cloud, so that when the data is exchanged between the clouds, the problem of confidentiality revelation exists. So the privacy revelation problem concerning a person or a corporation is unavoidably open when releasing or data distributing in the cloud service. Confidentiality is a significant issue in any cloud computing environment. In this paper we propose and implement a mechanism to maintain privacy and secure data storage for group members or a community in cloud environment.
QoS Guaranteed Intelligent Routing Using Hybrid PSO-GA in Wireless Mesh Networks
Authors: Sarasvathi V. , Iyengar N. Ch. S. N. , Saha Snehanshu
Published: May 2015

In Multi-Channel Multi-Radio Wireless Mesh Networks (MCMR-WMN), finding the optimal routing by satisfying the Quality of Service (QoS) constraints is an ambitious task. Multiple paths are available from the source node to the gateway for reliability, and sometimes it is necessary to deal with failures of the link in WMN. A major challenge in a MCMR-WMN is finding the routing with QoS satisfied and an interference free path from the redundant paths, in order to transmit the packets through this path. The Particle Swarm Optimization (PSO) is an optimization technique to find the candidate solution in the search space optimally, and it applies artificial intelligence to solve the routing problem. On the other hand, the Genetic Algorithm (GA) is a population based meta-heuristic optimization algorithm inspired by the natural evolution, such as selection, mutation and crossover. PSO can easily fall into a local optimal solution, at the same time GA is not suitable for dynamic data due to the underlying dynamic network. In this paper we propose an optimal intelligent routing, using a Hybrid PSO-GA, which also meets the QoS constraints. Moreover, it integrates the strength of PSO and GA. The QoS constraints, such as bandwidth, delay, jitter and interference are transformed into penalty functions. The simulation results show that the hybrid approach outperforms PSO and GA individually, and it takes less convergence time comparatively, keeping away from converging prematurely.
Atmospheric Chemistry and Climate in the Anthropocene / Chemia Atmosferyczna I Klimat W Antropocenie
Authors: Crutzen Paul J. , Wacławek Stanisław
Published: May 2015

Humankind actions are exerting increasing effect on the environment on all scales, in a lot of ways overcoming natural processes. During the last 100 years human population went up from little more than one to six billion and economic activity increased nearly ten times between 1950 and the present time. In the last few decades of the twentieth century, anthropogenic chlorofluorocarbon release have led to a dramatic decrease in levels of stratospheric ozone, creating ozone hole over the Antarctic, as a result UV-B radiation from the sun increased, leading for example to enhanced risk of skin cancer. Releasing more of a greenhouse gases by mankind, such as CO2, CH4, NOx to the atmosphere increases the greenhouse effect. Even if emission increase has held back, atmospheric greenhouse gas concentrations would continue to raise and remain high for hundreds of years, thus warming Earth’s climate. Warming temperatures contribute to sea level growth by melting mountain glaciers and ice caps, because of these portions of the Greenland and Antarctic ice sheets melt or flow into the ocean. Ice loss from the Greenland and Antarctic ice sheets could contribute an additional 19-58 centimeters of sea level rise, hinge on how the ice sheets react. Taking into account these and many other major and still growing footprints of human activities on earth and atmosphere without any doubt we can conclude that we are living in new geological epoch named by P. Crutzen and E. Stoermer in 2000 - “Anthropocene”. For the benefit of our children and their future, we must do more to struggle climate changes that have had occurred gradually over the last century.
Innovation in Study of Physical and Technical Measurements. Czech-Polish Cooperation of Universities / Innowacje Studiów Fizyczne I Techniczne Metody Pomiarowe. Czesko-Polska Współpraca Uniwersytetów
Authors: Kříž Jan , Hyšplerová Lidmila , Trnková Lucie , Lyčka Antonín , Vybíral Bohumil , Hlúbik Jan , Ziembik Zbigniew , Dołhańczuk-Śródka Agnieszka , Wacławek Maria
Published: May 2015

In the Faculty of Science (University of Hradec Králové) the innovative program in chemistry for the study specialization Physico-technical Measurements and Computer Technology was developed. The innovation of chemistry filed study has been focused especially on increase in competitiveness and in graduates employment. Design of innovation enables graduates applying for the position of experts in physical measurements and informatics and at the same time they expand their competence in the service of the physico-chemical instrumentation in industrial ecology. Because Faculty of Science is not equipped yet in expensive instrumentation for nuclear spectrometry, cross-border cooperation with the Faculty of Natural and Technical Sciences (University of Opole) has been started. In the area of teaching about non-traditional energy sources the cross-border cooperation with the Department of Automation and Renewable Energy Sources, Faculty of Electrical Engineering (Czestochowa University of Technology) has been initiated. Well-developed system of cooperation with companies, which are equipped with the latest technology of environmental protection, was created. In the exchange system Polish students attended for practicing in these companies. The aim of the contribution is to describe one of the means of innovation of chemistry field study in the frame of bachelor study specialization oriented in physics and computer technology. We believe that the new approach will lead to increase in graduate competitiveness as well as to development of their motivation to study and better understanding of regulation principles of chemical processes and patterns.
Study of Extraction Equilibria in the Reaction of Alkaline Hydrolysis of Activated Amino Acid Esters / Badanie Równowag Ekstrakcji W Reakcji Zasadowej Hydrolizy Aktywowanych Estrów Aminokwasów
Authors: Doroshkevich Victor S. , Baranova Oksana V. , Shendrik Aleksandr N. , Doroshkevich Aleksandr S. , Lygina Olena S. , Lyubchyk Svitlana B.
Published: May 2015

Correlation between observed kinetic effects of phase-transfer catalytic reaction of the alkaline hydrolysis of 4-nitrophenyl ester of N-benzyloxycarbonylglycine-4 in the two-phase system chloroform-borate buffer pH = 10 and a content of ionic forms of catalyst was investigated. The phosphonium salts QX (X = Cl¯, Br¯, I¯) shows high catalytic reactivity. Dependence of the reaction kinetics discussed in the framework of the extraction mechanism with a competitive extraction of a nucleophile ОН¯, nucleofuge 4-NO2C6H4O¯ and anion X¯ of the phase-transfer catalyst.
Beer as Olfactory Attractant in the Fight Against Harmful Slugs Arion Lusitanicus Mabille 1868 / Piwo Jako Atraktant W Zwalczaniu Szkodliwego Ślimaka Z Gatunku Arion Lusitanicus Mabille 1868
Authors: Piechowicz Bartosz , Grodzicki Przemysław , Piechowicz Iwona , Stawarczyk Kinga
Published: May 2015

In 2012-2013 a series of laboratory and field experiments were carried out to check out, if beers can be used as olfactory attractants in the fight against harmful slugs Arion lusitanicus. Six brands of lager beer were used for olfactory analysis (Goolman Premium, Harnas Jasne Pełne, Tatra Mocne, Kasztelan Niepasteryzowane, Lezajsk Niepasteryzowane, Wojak Jasny Pelny). During laboratory and field tests it was evidenced that beers of all types were more attractive for slugs than water.
Stress Equations for Adhesive in Twodimensional Adhesively Bonded Joints/ Równania Naprężn W Plaskich Dwuwymiarowych Spoinach Klejowych
Authors: Rapp Piotr
Published: May 2015

The subject of this paper is formulation of shear stress equations for plane twodimensional adhesive layers present in adhesively bonded joints. The adherends are assumed to have the same thickness and be made of an isotropic material. The shape of the adherends in the joint plane is arbitrary. The adhesive joint can be subjected to a shear stress arbitrarily distributed on the adherends surfaces as well as normal and shear stresses arbitrarily distributed along the adherends edges. A set of two partial differential equations of the second order with shear stresses in the adhesive as unknowns has been formulated. For a particular case of rectangular joints a set of 12 base functions has been derived; their appropriate linear combinations uniquely define shear stresses in the adhesive for a joint loaded arbitrarily by a set of axial forces, bending moments and shear forces.
Stability of Selected PAHs in Sewage Sludge/ Stabilność Wybranych Wwa W Osadach Ściekowych
Authors: Włodarczyk-Makuła Maria
Published: May 2015

The aim of the investigations was to estimate the half-life of selected PAHs in sewage sludge. Five hydrocarbons selected from 16 PAHs- EPA were chosen. In this study, the quantity changes in the concentration 3- and 4-ring of PAHs in sewage sludges were investigated. Sewage sludges were stored under aerobic conditions for 12 weeks. At the same time the sewage sludges with the added sodium azide, in order to deactivate the microorganisms (abiotic samples), were also stored. Gas chromatography-mass spectrometry was used to qualify and quantify PAHs in 2-week intervals. Sewage sludges were taken from a municipal wastewater treatment plant. Under experimental conditions the half-lives of individual compounds were diversed. In biotic samples halflife of hydrocarbons was in the range of 19 to 368 days. Half-life of PAHs in abiotic sewage sludges was in the range of 31 to 2961 days. The most persistent were phenanthrene.
Shakedown of Composite Frames Taking into Account Plastic and Brittle Fracture of Elements
Authors: Alawdin Piotr , Bulanov George
Published: May 2015

In the paper the mathematical model of the optimization problem of limit and shakedown analysis for composite plane frames, containing elastic-plastic and brittle elements under low-cyclic loading, is proposed. It is assumed that the load varies randomly within the specified domain, and limited plastic redistribution of forces in such structures occurs. An example of the shakedown analyses of the composite frame is given.
Numerical Analysis of Deflections of Multi-Layered Beams
Authors: Biliński Tadeusz , Socha Tomasz
Published: May 2015

The paper concerns the rheological bending problem of wooden beams reinforced with embedded composite bars. A theoretical model of the behaviour of a multi-layered beam is presented. The component materials of this beam are described with equations for the linear viscoelastic five-parameter rheological model. Two numerical analysis methods for the long-term response of wood structures are presented. The first method has been developed with SCILAB software. The second one has been developed with the finite element calculation software ABAQUS and user subroutine UMAT. Laboratory investigations were conducted on sample beams of natural dimensions in order to validate the proposed theoretical model and verify numerical simulations. Good agreement between experimental measurements and numerical results is observed.
Comparison Of Patterns Of Convergence Among “Emerging Markets” Of Central Europe, Eastern Europe And Central Asia
Authors: Poznańska Joanna , Poznański Kazimierz
Published: May 2015

Based on analysis of economic growth indicators for 1989-2014, this article distinguishes the “emerging markets” of Central and Eastern Europe (with Russia included), from the other economies that fall in the broad ‘emerging markets’ category. Following the post–1989 reforms, the countries of the region share many of the same typical institutional features as other “emerging economies”, but not necessarily the associated economic outcomes. What characterizes “emerging economies” is that they grow fast enough to systematically close the distance dividing them from the advanced economies, creating convergence. Departing from this pattern, Central and Eastern Europe (and Russia) have so far fallen short in terms of the growth rates, and the region as a whole has not made much progress in catching up. By more than doubling its national product Poland is the only notable exception in the region, although Slovenia may fit in the same category. At the other extreme, some of the economies actually lost two decades in terms of reducing the gaps, and some even fell further behind (e.g., Serbia, Ukraine). These findings have potentially serious implications for economic theory in general and for the presumption that globalization processes act as a unifying developmental force.
Evaluation of Spring Wheat Genotypes (Triticum Aestivum L.) for Heat Stress Tolerance Using Different Stress Tolerance Indices
Authors: Khan A.A. , Kabir M.R.
Published: May 2015

Twenty five spring wheat genotypes were evaluated for terminal heat stress tolerance in field environments in the Agro Ecological Zone-11 of Bangladesh, during 2009-2010 cropping season. The experiments were conducted at Wheat Research Centre, Bangladesh Agricultural Research Institute, using randomized block design with three replicates under non-stress (optimum sowing) and stress (late sowing) conditions. Seven selection indices for stress tolerance including mean productivity (MP), geometric mean productivity (GMP), tolerance (TOL), yield index (YI), yield stability index (YSI), stress tolerance index (STI) and stress susceptibility index (SSI) were calculated based on grain yield of wheat under optimum and late sowing conditions. The results revealed significant variations due to genotypes for all characters in two sowing conditions. Principal component analysis revealed that the first PCA explained 0.64 of the variation with MP, GMP, YI and STI. Using MP, GMP, YI and STI, the genotypes G-05 and G-22 were found to be the best genotypes with relatively high yield and suitable for both optimum and late heat stressed conditions. The indices SSI, YSI and TOL could be useful parameters in discriminating the tolerant genotypes (G-12, G-13, and G-14) that might be recommended for heat stressed conditions. It is also concluded from the present studies that biomass, grain filling rate and spikes number m-2 are suitable for selecting the best genotypes under optimum and late sowing conditions because these parameters are highly correlated with MP, GMP, YI and STI. However, high ground cover with long pre heading stage and having high grain filling rate would made a genotype tolerant to late heat to attain a high grain yield in wheat.
Drought Tolerance Studies in Wheat (Triticum Aestivum L.)
Authors: Mahpara S. , Hussain S.T. , Farooq J.
Published: May 2015

Wheat is a foremost staple food crop of Pakistan and plays a vital role for stability of country's economy and people's food requirement. Shortage of water has remained a consistent problem for the farmers over past few years and different agronomic techniques have been introduced into the limelight. But there is an immense scope of making some genetic manipulations to improve/enhance the drought tolerance of wheat. It has been observed by many researchers that yield in drought stress conditions, is a fine fusion of the traits like days taken by crop to reach physical maturity, water use efficiency, crop water use and harvest index. Drought being one of the main limiting factors of wheat production should be highly preferred in the future wheat improvement programs.
Political Criteria vs. Political Conditionality: Comparative analysis of Slovenian and Croatian European Union accession processes
Authors: Bojinović Fenko Ana , Urlić Ana
Published: May 2015

This study analyses the differences in content and procedure in the application of political criteria and political conditionality in the EU accession processes of Slovenia and Croatia. The article ascertains that with regard to substance, the Commission and EU member states did apply political criteria more extensively and meticulously to Croatia in comparison to Slovenia, but mainly due to the difference in the states’ initial assessment of preparedness for EU membership and the application of the principle of own merits. Empirical results, however, show that the differences in political conditionality did not only stem from Croatia’s post-conflict conditions, but also from the EU’s experience of the 2004 and 2007 enlargements and the concern about the EU’s absorption capacity. As for the accession process procedure, the latter has increasingly empowered the Commission rather than EU member states, which bears relevance for future (Western Balkans) enlargements
Prediction of natural frequencies of laminated
curved panels using refined 2-D theories in the
spectral collocation method
Authors: Hossein Mohazzab Amir , Dozio Lorenzo
Published: May 2015

This paper presents a versatile and efficientmodeling
and solution framework for free vibration analysis
of composite laminated cylindrical and spherical panels
modeled according to two-dimensional equivalent singlelayer
and layerwise theories of variable order.Aunified formulation
of the equations of motion is adopted which can
be used for both thin and thick structures. The discretization
procedure is based on the spectral collocation method
and is presented in a compact matrix form which can be
directly and easily implemented. The convergence and accuracy
of the proposed approach is evaluated for panels
having different boundary conditions, thickness and shallowness
ratios, and lamination layups.
Curved composite beam with interlayer slip
loaded by radial load
Authors: Ecsedi István , Lengyel Ákos József
Published: May 2015

Elastic two-layer curved composite beam with
partial shear interaction is considered. It is assumed that
each curved layer separately follows the Euler-Bernoulli
hypothesis and the load slip relation for the flexible shear
connection is a linear relationship. The curved composite
beam at one of the end cross sections is fixed and the other
end cross section is subjected by a concentrated radial
load. Two cases are considered. In the first case the loaded
end cross section is closed by a rigid plate and in the second
case the radial load is applied immediately to it. The
paper gives solutions for radial displacements, slips and
stresses. The presented examples can be used as benchmark
for the other types of solutions as given in this study.
Isogeometric treatment of large deformation contact and debonding problems with T-splines: a review
Authors: Dimitri Rossana
Published: May 2015

Within a setting where the isogeometric analysis
(IGA) has been successful at bringing two different research
fields together, i.e. Computer Aided Design (CAD)
and numerical analysis, T-spline IGA is applied in this
work to frictionless contact and mode-I debonding problems
between deformable bodies in the context of large deformations.
Based on the concept of IGA, the smooth basis
functions are adopted to describe surface geometries and
approximate the numerical solutions, leading to higher accuracy
in the contact integral evaluation. The isogeometric
discretizations are here incorporated into an existing
finite element framework by using Bézier extraction, i.e. a
linear operator which maps the Bernstein polynomial basis
on Bézier elements to the global isogeometric basis. A
recently released commercial T-spline plugin for Rhino is
herein used to build the analysis models adopted in this
study.

In such context, the continuum is discretized with cubic
T-splines, as well as with Non Uniform Rational B-Splines
(NURBS) and Lagrange polynomial elements for comparison
purposes, and a Gauss-point-to-surface (GPTS) formulation
is combined with the penalty method to treat the
contact constraints. The purely geometric enforcement of
the non-penetration condition in compression is generalized
to encompass both contact and mode-I debonding
of interfaces which is approached by means of cohesive
zone (CZ) modeling, as commonly done by the scientific
community to analyse the progressive damage of materials
and interfaces. Based on these models, non-linear relationships
between tractions and relative displacements
are assumed. These relationships dictate both the work of
separation per unit fracture surface and the peak stress
that has to be reached for the crack formation. In the generalized
GPTS formulation an automatic switching procedure
is used to choose between cohesive and contact models,
depending on the contact status. Some numerical results
are first presented and compared in 2D for varying
resolutions of the contact and/or cohesive zone, including
frictionless sliding and cohesive debonding, all featuring
the competitive accuracy and performance of T-spline IGA.
The superior accuracy of T-spline interpolations with respect
to NURBS and Lagrange interpolations for a given
number of degrees of freedom (Dofs) is always verified.
The isogeometric formulation is also extended to 3D bodies,
where some examples in large deformations based on
T-spline discretizations show an high smoothness of the
reaction history curves.
Design and Optimization of a Composite Canard Control Surface of an Advanced Fighter Aircraft under Static Loading
Authors: Shrivastava Sachin , Mohite P.M.
Published: May 2015

The minimization of weight and maximization of payload is an ever challenging design procedure for air vehicles. The present study has been carried out with an objective to redesign control surface of an advanced all-metallic fighter aircraft. In this study, the structure made up of high strength aluminum, titanium and ferrous alloys has been attempted to replace by carbon fiber composite (CFC) skin, ribs and stiffeners. This study presents an approach towards development of a methodology for optimization of first-ply failure index (FI) in unidirectional fibrous laminates using Genetic-Algorithms (GA) under quasi-static loading. The GAs, by the application of its operators like reproduction, cross-over, mutation and elitist strategy, optimize the ply-orientations in laminates so as to have minimum FI of Tsai-Wu first-ply failure criterion. The GA optimization procedure has been implemented in MATLAB and interfaced with commercial software ABAQUS using python scripting. FI calculations have been carried out in ABAQUS with user material subroutine (UMAT). The GA's application gave reasonably well-optimized ply-orientations combination at a faster convergence rate. However, the final optimized sequence of ply-orientations is obtained by tweaking the sequences given by GA's based on industrial practices and experience, whenever needed. The present study of conversion of an all metallic structure to partial CFC structure has led to 12% of weight reduction. Therefore, the approach proposed here motivates designer to use CFC with a confidence.
Nonlinear forced vibration response of smart two-phase nano-composite beams to external harmonic excitations
Authors: Mareishi Soraya , Kalhori Hamed , Rafiee Mohammad , Hosseini Seyedeh Marzieh
Published: May 2015

This paper presents an analytical solution for nonlinear free and forced vibration response of smart laminated nano-composite beams resting on nonlinear elastic foundation and under external harmonic excitation. The structure is under a temperature change and an electric excitation through the piezoelectric layers. Different distribution patterns of the single walled aligned and straight carbon nanotubes (SWCNTs) through the thickness of the beam are considered. The beam complies with Euler-Bernoulli beam theory and von Kármán geometric nonlinearity. The nonlinearity is due to the mid-plane stretching of the beam and the nonlinear stiffness of the elastic foundation. The Multiple Time Scales perturbation scheme is used to perform the nonlinear dynamical analysis of functionally graded carbon nanotube-reinforced beams. Analytical expressions of the nonlinear natural frequencies, nonlinear dynamic response and frequency response of the system in the case of primary resonance have been presented. The effects of different parameters including applied voltage, temperature change, beam geometry, the volume fraction and distribution pattern of the carbon nanotubes on the nonlinear natural frequencies and frequency-response curves are presented. It is found that the volume fractions of SWCNTs as well as their distribution pattern significantly change the behavior of the system.
Free vibration behavior of laminated composite stiffened elliptic parabolic shell panel with cutout
Authors: Sahoo Sarmila
Published: May 2015

In this paper free vibration behavior of laminated composite stiffened elliptic parabolic shell has been analyzed in terms of natural frequency and mode shape. Finite element method has been applied using an eight-noded curved quadratic isoparametric element for shell with a three noded curved beam element for stiffener. Cross and angle ply shells with different edge conditions have been studied varying the size and position of the cutouts to arrive at a set of inferences of practical engineering significances.
Redesigning of a Canard Control Surface of an Advanced Fighter Aircraft: Effect on Buckling and Aerodynamic Behavior
Authors: Shrivastava Sachin , Mohite P.M.
Published: May 2015

A redesign of canard control-surface of an advanced all-metallic fighter aircraft was carried out by using carbon fibre composite (CFC) for ribs and panels. In this study ply-orientations of CFC structure are optimized using a Genetic-Algorithm (GA) with an objective function to have minimum failure index (FI) according to Tsai-Wu failure criterion. The redesigned CFC structure was sufficiently strong to withstand aerodynamic loads from stress and deflection points of view. Now, in the present work CFC canard structure has been studied for its buckling strength in comparison to existing metallic design. In this study, the existing metallic design was found to be weak in buckling. Upon a detailed investigation, it was revealed that there are reported failures in the vicinity of zones where initial buckling modes are excited as predicted by the finite element based buckling analysis. In view of buckling failures, the redesigned CFC structure is sufficiently reinforced with stringers at specific locations. After providing reinforcements against buckling, the twist and the camber variations of the airfoil are checked and compared with existing structure data. Finally, the modal analysis has been carried out to compare the variation in excitation frequency due to material change. The CFC structure thus redesigned is safe from buckling and aerodynamic aspects as well.
Analytical solution to bending of stiffened and continuous antisymmetric laminates
Authors: Sun Liecheng , Harik Issam E.
Published: May 2015

Analytical Strip Method is presented for the analysis of the bending-extension coupling problem of stiffened and continuous antisymmetric thin laminates. A system of three equations of equilibrium, governing the general response of antisymmetric laminates, is reduced to a single eighth-order partial differential equation (PDE) in terms of a displacement function. The PDE is then solved in a single series form to determine the displacement response of antisymmetric cross-ply and angle-ply laminates. The solution is applicable to rectangular laminates with two opposite edges simply supported and the other edges being free, clamped, simply supported, isotropic beam supports, or point supports.
The Fujiki class and positive degree maps
Authors: Bharali Gautam , Biswas Indranil , Mj Mahan
Published: May 2015

We show that a map between complex-analytic manifolds, at least one ofwhich is in the Fujiki class,
is a biholomorphism under a natural condition on the second cohomologies. We use this to establish that,
with mild restrictions, a certain relation of “domination” introduced by Gromov is in fact a partial order.