Civil and Structural Engineering

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00 Rui Carneiro Barros1 , Alessandro Baratta2 , Ottavia Corbi3 , Ileana Corbi4 , Manuel César

00 Rui Carneiro Barros1 , Alessandro Baratta2 , Ottavia Corbi3 , Ileana Corbi4 , Manuel César

This paper provides an overview on the latest research and development (R&D) activities carried out under the project entitled Comparison of Vibration Control in Civil Engineering Using Passive and Active Dampers (COVICOCEPAD) which was executed within the framework of the Eurocores project, as a part of the sixth European program. The general interest of the paper relies upon the variety of presented highlights relevant to structural control research streams currently under development in a number of European universities, addressing the use of tuned liquid dampers (TLD), base isolation devices, magneto-rheological (MR) dampers and a hybrid technique using both devices together. The paper also provides details of a few new testing equipments which are in use of the relevant laboratories. Finally, research projects in the field of structural control at the involved research institutes are reviewed.
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EXPERIMENTAL INVESTIGATIONS OF MODAL PARAMETERS OF LAMINATED COMPOSITES (GRAPHITE & KEVLAR) USING FFT ANALYZER

EXPERIMENTAL INVESTIGATIONS OF MODAL PARAMETERS OF LAMINATED COMPOSITES (GRAPHITE & KEVLAR) USING FFT ANALYZER

The laminated composite beams are basic structural components used in a variety of Fiber reinforced composites are finding engineering structures such as airplane wings, helicopter blades and turbine blades as well as many others in the aerospace, mechanical, and civil industries. An important element in the dynamic analysis of composite beams is the computation of their natural frequencies and mode shapes. This is important because composite beam structures often operate in complex environmental conditions and are frequently exposed to a variety of dynamic excitations. In this paper, a combined finite element and experimental approach is used to characterize the vibration behavior of composite laminates. Specimens are made using the hand-lay- up process. Graphite and Kevlar fibers are used as reinforcement in the form of bidirectional fabric and general purpose Epoxy resin as matrix for the composite material of beams. Experimental dynamic tests are carried out using specimens with different fiber orientations. From the results, the influence of fiber orientations on the flexural natural frequencies is investigated. Also, these experiments are used to validate the results obtained from the finite element software ANSYS.
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Design of fibrous structures for civil engineering applications

Design of fibrous structures for civil engineering applications

hydrophobic reinforcing fibres. Refers also studies made that confirming composite reinforced with woven structure presents an increased flexural strength and toughness even if the woven is made with low modulus hydrophobic fibres. However, these studies did not deal with fabric bond characteristics. A few years later, Peled and Bentur [45] have realized a study regarding to the fabric structure efficiency in textile reinforced cement composites and concluded that, in cement composites the woven fabric geometry may have a marked effect on the composites properties. Enhanced bonding of a fabric structure was found to occur when a non-linear geometry is induced in individual yarns by the fabric structure and the woven transversal yarns influence cement composite. According to them at one extreme, fabric geometry, may enhance bonding resulting in a strain hardening behaviour of low modulus yarn composites, at the other extreme it may reduce drastically the efficiency of a high performance bundled yarn that is very effective for reinforcement when it is not part of a fabric. Besides, the perpendicular yarns treated as “non-structural” with the objective of providing a mechanism to hold the longitudinal yarns in place during the production of the composite may have significant and opposing influences in the cement composite: in woven fabric structures they enhance bonding and therefore an increase in their density (up to an optimum value) is beneficial.
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Use of Petri Nets to Manage Civil Engineering Infrastructures

Use of Petri Nets to Manage Civil Engineering Infrastructures

Inspections aim to evaluate the condition state of an infrastructure, through the identification and classification of defects and anomalies that affect its performance, taking into account its intensity and extension. The inspection record has a fundamental role for monitoring the condition state of the infrastructure and to determine an optimized maintenance plan, allowing prioritizing the maintenance and/or rehabilitation actions for the infrastructures with higher deterioration levels. Maintenance action records are essential for the manager to be informed about the nature of all maintenance actions that were carried out and the costs of the conservation works of each infrastructure (Ryall, 2010). The condition rating adopted to describe the condition state of the existing infrastructure is not a direct measure of structural safety but rather of the severity of observable defects and is usually based on a discrete scale based on objective and uniform criteria. The scale of condition ratings is not universal and usually each management system develops its own rating scale (Elbehairy, 2007). For example, Table 2.2 shows the condition rating used by the National Bridge Inventory (NBI) as a guide to evaluate bridge elements. However, this lack of consistency across assets and managers is a significant handicap of current IMS, as it increases the complexity of the inspection process, the probability of errors and limits the ability to use information from other networks to improve modelling.
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Application of Nanocomposite Coatings with Different Structural Physical and Chemical Characteristics in Tissue Engineering

Application of Nanocomposite Coatings with Different Structural Physical and Chemical Characteristics in Tissue Engineering

The amount of transcripts of the studied targets was compared on the base of relative quantitative es- timation of amplification products. In brief, there were prepared consecutive ten-fold dilutions of initial cDNA preparation from each the sample studied. To every dilution there was added a reactive mixture and the amplification was performed. The less target conse- quences were in initial preparation, the earlier (i.e. at smaller dilutions) amplifications stopped. The dilution logarithm (lg) cDNA served as the index of expression rate of the investigated genes. The results were levelled in respect to the expression rate of beta actin gene (housekeeping gene) (NM_007393.3). Reactive mixture with no cDNA was a negative control.
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J. Aerosp. Technol. Manag.  vol.4 número4

J. Aerosp. Technol. Manag. vol.4 número4

 7KHG\QDPLFHTXDWLRQVIRUWKHFRQVWUDLQHGV\VWHPDQG WKHFRPSXWDWLRQDOSURFHGXUHVDUHVXPPDUL]HGLQWKLVVHFWLRQ For the deployable spatial structure, the dependent Cartesian coordinates are used as generalized ones for the dynamic HTXDWLRQ7KHPDVVDQGYHORFLW\RIWKHVWUXWVDUHUHGXFHGWR two revolute joints at the two ends, and the kinetic energy of WKHV\VWHPLVGH¿QHGDV(T

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A Comparative Study of Penetration Resistance Apparatus on Concrete

A Comparative Study of Penetration Resistance Apparatus on Concrete

International Community for Composites Engineering and. College of Engineering, University of New Orleans[r]

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Hazards caused by natural and anthropogenic changes of catchment area in karst

Hazards caused by natural and anthropogenic changes of catchment area in karst

Abstract. Determination of the catchment area is the starting point in most hydrological analyses. It serves as a basis for many hydrological and water resources management calcu- lations. The catchment boundaries and areas in karst regions are often fragmented and not accurately known. They can change over time due to natural and anthropogenic causes. Natural and man-made processes cause changes of catch- ment area on different time and space scales. Human in- tervention, especially construction of dams and reservoirs, as well as interbasin water transfer through long tunnels and pipelines can introduce instantaneous, definite and hazardous change. This paper presents seven examples of natural and anthropogenic factors which influenced changes of catch- ment area in the Dinaric karst: 1) Closing of the Obod Es- tavelle in the Fatniˇceko polje; 2) Operation of the Zakuˇcac hydroelectric power plant on the Cetina River; 3) Problems caused by Salakovac Reservoir; 4) Catastrophic flooding in the Cetinje Polje; 5) Regulation and canalization of the Trebiˇsnjica River; 6) Building of the underground hydroelec- tric power plant Ombla; 7) An earthquake in Southern Croa- tia and Western Herzegovina.
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Image Processing for Displacement Measurements

Image Processing for Displacement Measurements

The paper of (Ranganadham, Gorpuni, and Panda 2009) proposed a methodology based on a PSO algorithm to calculate the bi-directional motion in a video sequence. In a video sequence there is a higher number of static blocks with small or no movement. Their algorithm predicted these movements before starting the motion estimation procedure which allows accelerating the algorithm and saving memory. The matching errors were based on the sum of absolute difference between the block in the current frame and the block at the same location in the reference frame. They are then compared to a predetermined threshold. If the matching error is smaller than a certain value they assume that the block has no movement. They put four particles in a cross shape with size one, and four particles in a cross shape with size two, and then they rotated it by angle π/2. With the shape having particles in 8 directions they tried to balance the global exploration and local refined search in order to create a larger search space as well as higher matching accuracy. The authors claimed that this technique is superior to the existing bi-directional motion compensation methods.
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PRACTICAL APPLICATION OF NEW TECHNOLOGIES IN THE COURSE OF CONSTRUCTION 
OF MODERN BUILDINGS AND STRUCTURES (AS EXPEMPLIFIED BY MOSCOW-CITY INTERNATIONAL BUSINESS CENTRE)

PRACTICAL APPLICATION OF NEW TECHNOLOGIES IN THE COURSE OF CONSTRUCTION OF MODERN BUILDINGS AND STRUCTURES (AS EXPEMPLIFIED BY MOSCOW-CITY INTERNATIONAL BUSINESS CENTRE)

The application of advanced design techniques has proven their efficiency. Advanced metho- dology of design has reduced the time and cost of design due to repetitive use of the information accumulated in the course of design development, timely information support throughout the whole project development period, and the quality and timeliness of decision-making in terms of technolo- gy-related issues. The new design methodology was, to some extent, implemented by means of as- surance of the standard functionality of construction-related systems and organizational actions, and through the customization of the system to assure the implementation of both the new functions and the methodology-related solutions.
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Chlorella sp. coagulation-­‐flocculation by inducing a modification on the pH broth medium

Chlorella sp. coagulation-­‐flocculation by inducing a modification on the pH broth medium

Harvesting   algae   from   the   culture   medium   is   a   major   area   of   R&D   as   it   is   one   of   the   greater   obstacles   for   marketing   microalgal   oil   for   biodiesel   production   at   competitive   costs   when   compared   to   vegetable   oils.   Former   investigations   of   large   scale   algae   harvesting   especially   examine   the   removal   of   freshwater   algal   populations   from   wastewater   treatment   processes   using   metal   salts   like   ferric   chloride   or   aluminum   sulfate   were   used.   These   are   effective   coagulation-­‐flocculation   agents,   but,   besides   of   being   expensive,   their   application   can   be   unacceptable   if   the   oil   will   be   used   for   biodiesel   production   and   the   biomass   for   animal   feeding,   since   the   contamination   of   such   products   with   metals   will   occur.   Indeed,   methods   based   on   autoflocculation,   biofloculation   or   even   new   technologies   like   electrolytic   flotation   are   promising   and   could   be   of   very   low   cost.   However,   for   the   moment   they   require   very   specific  situations  and  provide  significant  operating  limitations.  Chlorella  characteristics  shown   to   impact   on   aggregation   and   flocculation   like   size,   surface   functional   groups   and   surface   charge   were   analyzed.   Effectiveness   of   microalgae   flocculation   by   pH   manipulation   and   ionic   strength   effects   were   investigated   using   the   Jar-­‐test   procedure.     A   relationship   between   cell   surface  at  different  incubation  stages  and  negative  zeta  potential  for  a  wide  range  of  pH  was   checked  and  it  was  found  that  algae  removal  was  not  significantly  affected  by  ionic  strength.    
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Acceptability appraisal of swarf of natural stone and cullet for granite ceramic production ОЦЕНКА ПРИГОДНОСТИ ОТХОДОВ ОБРАБОТКИ ПРИРОДНОГО КАМНЯ И СТЕКЛОБОЯ ДЛЯ ПОЛУЧЕНИЯ ГРАНИТОКЕРАМИКИ

Acceptability appraisal of swarf of natural stone and cullet for granite ceramic production ОЦЕНКА ПРИГОДНОСТИ ОТХОДОВ ОБРАБОТКИ ПРИРОДНОГО КАМНЯ И СТЕКЛОБОЯ ДЛЯ ПОЛУЧЕНИЯ ГРАНИТОКЕРАМИКИ

The analysis of granite ceramic technologies, effective facade ceramic material having good decorative and strength characteristics, and high service durability in a variety of climatic conditions, is carried. Re- search data on the selection and acceptability appraisal of raw materials: granite powder, cul- let, clay — are given. The system tailored com- position granite powder — cullet — clay at a joint grouting temperature of 1050 C: granite powder — 40 %, cullet — 40 %, clay — 20 % (by weight) is found.
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Structural Engineering of the Vacuum Arc ZrN/CrN Multilayer Coatings

Structural Engineering of the Vacuum Arc ZrN/CrN Multilayer Coatings

For multilayer system ZrN/CrN with a large difference in the atomic weights and radiation-induced defect formation of metal components, analyzed the influence of the layer thickness (in[r]

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Análise numérica não-linear de elementos de concreto estrutural considerando a variação de aderência

Análise numérica não-linear de elementos de concreto estrutural considerando a variação de aderência

GOTO, Y. Cracks formed in concrete around deformed tension bars; ACI Journal, Proc.. A new reinforcing steel model with bond-slip; Journal Structural Engineering and Mechanics, Vol. - C[r]

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Subject headings from the ASCE's Civil Engineering Database

Subject headings from the ASCE's Civil Engineering Database

prismatic samples, and MIP determinations for the mortar layer on brick and the plaster 418. on the outdoor protected experimental wall are given in Table 6[r]

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Analysis of Methodologies for Vulnerability and Risk Assement on Coastal Areas

Analysis of Methodologies for Vulnerability and Risk Assement on Coastal Areas

The location of a particular asset facing the coastline, will determine the degree of vulnerability that presents. In fact, the closer a particular asset or infrastructure is the coastline, more vulnerable will be. This parameter is not considered in most of the studies carried out, because the majority of these studies adopts a linear and simplistic approach in relation to the coastal area, assuming a single value of vulnerability index for the entire interior land that corresponds to a specific maritime front, disregarding any variation of topographic and geologic characteristics towards inland (Coelho, 2005). Is a parameter with a subjective character as it does not reflect the right vulnerability of a given infrastructure or asset. A far away building located in a low sandy coast and without protection present a given level of vulnerability, however a close one and in a high rocky coast could not be vulnerable. A vulnerability classification regarding the distance to the shoreline is then presented in Table 2.4. It is consider low vulnerability when distances of assets are higher than 1000 m.
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Análise comparativa do comportamento cíclico de nós viga-pilar com armadura lisa e nervurada.

Análise comparativa do comportamento cíclico de nós viga-pilar com armadura lisa e nervurada.

Damage reports after recent earthquakes proves that slippage between steel reinforcing bars and the surrounding concrete is one the common causes of damage and collapse of existing RC building structures. The bond-slip mechanism assumes particular importance in RC building structures built until the 70’s, with plain reinforcing bars, previously to the enforcement of modern seismic codes. This type of structures is usually FKDUDFWHUL]HGE\SRRUUHLQIRUFHPHQWGHWDLOLQJSRRUERQGSURSHUWLHVDQGLQDGHTXDWHFRQFUHWHFRQ¿QHPHQW,Q5&EXLOGLQJVVXEMHFWHGWRF\FOLF ORDGVDVWKHLQGXFHGE\HDUWKTXDNHVKLJKVWUHVVFRQFHQWUDWLRQRFFXUVDWWKHEHDPFROXPQMRLQWVPDNLQJWKLVUHJLRQVSURQHWRWKHRFFXUUHQFH RIVHYHUHGDPDJH%HDPFROXPQMRLQWVDUHSDUWLFXODUO\VHQVLWLYHWRWKHERQGVOLSPHFKDQLVPGXHWRWKHVWUHVVFRQFHQWUDWLRQEXWDOVRGXHWRWKH IDFWWKDWDQFKRUDJHRIEHDPDQGFROXPQORQJLWXGLQDOUHLQIRUFLQJEDUVLVW\SLFDOO\PDGHLQWKHMRLQWYLFLQLW\
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Lat. Am. j. solids struct.  vol.11 número2

Lat. Am. j. solids struct. vol.11 número2

This system describes the uni-modal large-amplitude free vibrations of a slender inextensible cantilever beam carrying an intermediate mass with a rotary inertia. The third and fourth terms in equation (1) represent inertia-type cubic non-linearity arising from the inextensibility assumption. The last term is a static-type cubic nonlinearity associated with the potential energy stored in bend- ing. The modal constants α and β result from the discretization procedure and they have specific values for each mode as described in (Hamdan and Dado, 1997).
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Built Heritage Research and History of Architecture: Light and Acoustic in the Cistercian Monastic Church of S. Bento de Cástris (Portugal)

Built Heritage Research and History of Architecture: Light and Acoustic in the Cistercian Monastic Church of S. Bento de Cástris (Portugal)

Abstract. The research on the Cistercian legacy in Portugal is an innovative multidisciplinary study. Consequently, the results achieved in this research have many different approaches: the former monasteries and their architecture are the main subjects concerning morphology, architectonic rehabilitation but also acoustics, thermal comfort, or natural light. This research, carried out at the Department of Civil Engineering and Architecture of the University of Beira Interior (DECA-UBI), was developed in connection with two other research centres - Lab2PT (Landscape, Heritage and Territory Laboratory) and CIDEHUS (Interdisciplinary Centre for History, Culture and Societies). In 2015, the curriculum of the Integrated Master Degree in Architecture of the University of Beira Interior underwent revision. Consequently, it was needed to allocate more time to the teaching of History of Architecture and the requirement to assign specific syllabus to the Portuguese History of Architecture, which is emphasized by the specific and multidisciplinary research performed linking with other sciences of engineering. The natural light in the Cistercian churches is closely linked not only with the liturgical requirements at the officium but also with the canonical hours based on the "ora et labora" dictated by the Rule of St. Benedict. The Cistercian Monastery of São Bento de Cástris (13 th -19 th centuries), in Évora,
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Math and Engineering Department

Math and Engineering Department

Another example of an inverted pendulum robot it’s Ballbot. The Ballbot is a mobile robot, an attempt to solve the robotic unicycle problem, and is designed to balance itself on its single spherical wheel while travelling around. It is the focus of the Ballbot Research Platform, a project conducted at Carnegie Mellon University, made possible by grants from the National Science Foundation. The robot is being developed by Ralph Hollis and George Kantor, with help from the graduate students Tom Lauwers, Anish Mampetta and Eric Shearer. The purpose of the Ballbot project is to discover how robots may maintain dynamic stability (that is, reliable balance), to enable designs with narrower bases for improved navigability (such as in a crowded room). This is a departure from the current paradigm in robot design, which relies on the static stability provided by having three or more wheels (and a much wider base). The project is titled "Dynamically-Stable Mobile Robots in Human Environments".
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