bluuebunny/crossref_metadata_2025 huggingface dataset:
La lutte contre la radicalisation ou deux formes de la pensée magique
Authors: Ragazzi Francesco
Published: November 2016

Les attentats qui ont touché les villes occidentales au cours des douze dernières années (Madrid, Londres, Oslo, Boston, Toulouse, Bruxelles, Copenhague et maintenant Paris) nous effraient d’autant plus que leurs auteur.e.s ne viennent pas de l’étranger mais sont issu.e.s de nos propres sociétés. À cette peur s’en ajoute une autre pour un nombre croissant de parents, qui craignent que leur fils ou leur fille ne disparaisse un jour pour réapparaître en Syrie où 5000 à 6000 combattants européens ont, d’après les estimations, rejoint les rangs d’un groupe armé. Enfin, la peur d’être rejeté se diffuse au sein des minorités musulmanes confrontées à la suspicion du groupe majoritaire et, de façon croissante, à la stigmatisation et aux discriminations de la part d’institutions telles que les médias, l’école ou la police qui sont censées garantir leur information, leur éducation et leur sécurité. Répondant à ces peurs, les gouvernements européens ont renforcé et durci l’arsenal de la lutte contre le terrorisme : extension de la surveillance, pénalisation d’un nombre croissant d’activités (dont les déplacements vers la Syrie) intégrées dans une définition élargie du terrorisme, renforcement des contrôles aux frontières, instauration de mesures d’exception dans le droit pénal, etc. 1 . La politique antiterroriste ne se réduit cependant pas à ce volet répressif. S’y ajoute un volet préventif, souvent qualifié de « lutte contre la radicalisation », que Francesco Ragazzi interroge ici : quels sont les fondements de cette forme soft d’antiterrorisme qui se déploie depuis une dizaine d’années un peu partout en Europe ? Les mesures mises en œuvre ont-elles produit les effets recherchés ? Leurs effets pervers ne devraient-ils pas conduire à envisager d’autres approches ?
Estudio metalúrgico de las armas ibéricas halladas en el valle de Jutia (Nerpio-Yeste, Albacete). Trabajo, armamento, ritual y comunidades de montaña
Authors: Gener Moret Marc , Romero Perona Damián , González Reyero Susana , García Cardiel Jorge
Published: November 2016

Presentamos un estudio metalúrgico de las armas de época ibérica documentadas en el valle de altura de Jutia (Nerpio-Yeste, Albacete) integrado en el análisis de su contexto arqueológico y en nuestra investigación en curso de las formas de organización de los paisajes de montaña durante la Edad del Hierro. Los resultados obtenidos son especialmente válidos en el caso de un soliferreum, cuyo análisis metalográfico nos permite caracterizar la tecnología del proceso de producción, y en el de una moharra de lanza, cuyo análisis plantea argumentos sobre la compleja vida social y las acciones sociales diversas que potencialmente contienen los objetos depositados en contextos rituales y funerarios.
Los castillos Mayor y Real de la ciudad de Calatayud en el año 1371 a la luz de dos inventarios del Archivo Real
Authors: Cantos Carnicer Álvaro
Published: November 2016

Se analizan aquí dos interesantes inventarios de los objetos existentes en los Castillos Mayor y Real de Calatayud (Aragón) que fueron realizados en 1371. El estudio ha partido de la transcripción del texto original catalán del Archivo de la Corona de Aragón y se ha centrado en los elementos de arnés o armadura, armas e ingenios o máquinas de guerra; se ha indagado sobre el carácter y funcionalidad de cada objeto, así como en la terminología empleada, con aragonesismos patentes; se ha comparado en lo posible con textos coetáneos. El trabajo ha permitido conocer los elementos existentes en los castillos, determinando su especificidad, sus elementos, su estado, así como las carencias, no fácilmente explicables, como el caso de las ballestas. Por el contrario, la minuciosa descripción de las máquinas de guerra resulta verdaderamente excepcional.
El desarrollo de empuñadura de karabela de las espadas y sables: un estudio comparativo
Authors: Toichkin Denis , Moshtagh Khorasani Manouchehr
Published: November 2016

Se describe la empuñadura de karabela como una empuñadura con una guarnición de cruz y un pomo en forma de una cabeza estilizada de un pájaro con más frecuencia similar a un halcón. Se montaba este tipo de empuñadura con largas hojas de sable de caballería. En general se montaba las empuñaduras de karabela con con diferentes tipos de hojas, a menudo con una forma de la hoja curvada de un shamshir persa clásico. Las karabelas más antiguas (de origen turco o basado en modelos turcos) que se conservan en los museos de Polonia, generalmente tienen hojas con un contrafilo llamado yelman. El llamado `sable de halcón` es cercanamente asociado con karabela con su característica principal, una forma característica de un pomo curvo parecido a la cabeza de un halcón y una guarnición de cruz. El principal objetivo del presente artículo es hacer un estudio comparativo sobre las diferentes fuentes sobre los sables y espadas con empuñadura karabela y tratar de establecer un origen de este tipo de empuñadura.
La traílla. Auxiliar mecánico de las grandes excavaciones modernas
Authors: Editorial Equipo
Published: November 2016

El material auxiliar moderno empleado en las grandes excavaciones ha mejorado y aumentado tanto en estos últimos años, que su descripción no puede extenderse a las distintas familias o grupos de máquinas, pues por mucha extensión que se le otorgase, aún resultaría incompleta. La forma más racional de dar a conocer las distintas características más importantes de estas máquinas auxiliares, empleadas en los movimientos de tierras, consiste en la descripción de un tipo específico. En este trabajo nos ceñiremos únicamente al tema traílla, sus características y empleos inmediatos.
Experimental Study on the Effect of Recycled Aggregate and GGBS on Flexural Behaviour of Reinforced Concrete Beam
Authors: Deepa P.R. , Anup Joy
Published: November 2016

Globally, the concrete industry consumes large quantities of natural resources, which are becoming insufficient to meet the increasing demands. Cement and aggregates are major constituents of concrete. Utilisation of waste materials in concrete instead of raw materials reduces environmental pollution. Ground-granulated blast-furnace slag (GGBS) is a by-product of steel industry. It has cementatious property. Recycled aggregates are obtained from demolishing waste. By using recycled concrete aggregate and GGBS in concrete we can reduce environmental problem to some extent. This experimental study evaluate the effective utilisation of GGBS and recycled aggregate in concrete. In this study GGBS is used as partial replacement for cement and recycled aggregate as partial replacement for coarse aggregate.
Finite Element Analysis of Post Tensioned I-Beam with Web Openings
Authors: Jyothis Alex , Vinay Mathews
Published: November 2016

Construction of pre-stressed concrete (PSC) structures is becoming a common practice in various parts of the world, because of its better stability, serviceability, economy, aesthetic appearance and structural efficiency. Post tensioning is a method of reinforcing concrete or other materials with high strength steel strands or bars, typically referred to as tendons. The provision of large openings in pre-stressed concrete beams is necessary to accommodate utility services in residential, commercial, and industrial buildings. A post tensioned I-beam is analyzed by using ANSYS software and the deformation and stress pattern of beam is studied for different parametric conditions by changing the position of opening and different shapes of openings.
A Finite Element Study of Eccentricity in Axial Compression and Transverse Impact Loading on Cold Formed Stiffened Steel Column
Authors: George Johnson , Narayanan N.I.
Published: November 2016

The columns are one of the main load bearing elements that are subjected to impact loads, mainly in the form of projectile impact, vehicle impact, etc. The resulting severe damage to column may leads to failures of the supporting structure that are dangerous in nature. However, the columns in existing buildings are seldom designed for impact due to inadequacies of design guidelines. The knowledge about the behavior of dynamic impact loading on the cold formed steel columns is limited. The simulation of transverse impact loading was done using finite element (FE) method. The parameter considered in the finite element study consists, axial compression and its eccentricity under transverse impact. Results showed that axial load carrying capacity decrease with increase in eccentricity of loading. In this paper, cold formed stiffened steel tube considered for the lateral impact assessment.
Numerical Analysis of Steel Reinforced Concrete Deep Beam with Openings Using ANSYS
Authors: Biju Reshma , Mani Nissy Susan , Kumar Kavya K.
Published: November 2016

In the modern building construction, a good deal of work has been done on openings in reinforced concrete deep beam to accommodate utility pipes and ducts of essential services. However, accommodation of such openings saves considerable amount of materials and offer more versatility. The analysis of reinforced concrete deep beam is a complex problem and there is no code provision exists for the analysis of deep beam with openings. In this paper, the behaviour of deep beam with circular opening is assessed numerically using ANSYS software. A detailed parametric study is also conducted to evaluate the effect of circular opening in deep beam with varying location of opening with fixed shear span by depth ratio and effective span by depth ratio.
Numerical Analysis of Through-Beam Connection between CFST Column and RC Beam
Authors: Anupama P.N. , Anu Mathew , Kumar Kavya K.
Published: November 2016

The concrete filled steel tubular (CFST) columns consist of steel tube in-filled with concrete. The connections are the most important components of a CFST column and reinforced concrete beam structural system, since it combines the beams and the columns. In this paper, a through-beam ring connection for strengthening the joint between CFST column and RC beam is modeled using the finite element software package ANSYS and analysed the axial compressive behavior of the connection system. The numerical model is validated with the results available in the literature to confirm the structural efficiency of the ring beam connection system.
Period Formula for Reinforced Concrete Buildings with Infill Walls
Authors: Banik Arijit , Halder Lipika
Published: November 2016

The calculation of fundamental time period of vibration is a crucial step in seismic design and analysis of the structures to assess global response of the structure. Different international code proposed empirical expressions considering only height for bare frame structures and height and width of the buildings with infill to estimate the fundamental time period. This paper summaries the effect of the following parameters of building height, bay width, number of bays, cracked or un-cracked section of the structural member and support condition at the base on the fundamental time period of reinforced concrete bare frame and buildings with infill. Modal analysis of 360 building models with selected parameters is investigated in this study. A new equation, which is a function of the selected parameters (building height, bay width, number of bays, type of support condition, cracked or un-cracked sections and type of frame chosen for analysis) is also proposed using multiple linear regression analysis for predicting the fundamental period of buildings. The proposed simple model, including the building height, bay width, number of bays, type of support condition, cracked or un-cracked sections and type of frame chosen for analysis, showed better estimate in predicting the fundamental period of buildings compared to the code equations.
Properties of High Strength Fibre Reinforced Concrete Using Ultra Fine Slag
Authors: Lal C. Mohan , Sai Srujan Reddy Vontary
Published: November 2016

High strength concrete has become a design requirement in recent years due to increase in number of infrastructure projects. This paper presents the effect of incorporating Ultra Fine Slag (UFS) and steel fibre to obtain high strength concrete. To achieve target strength of about 80 MPa, it is proposed to the replacement of cement of 10%, 20% and 30% with UFS and incorporating 0.5% and 1.0% fibre in concrete. An experimental investigation is carried out to find the mechanical properties of the concrete. From the test results, it was observed that a compressive strength of 95 MPa was achieved at 30% replacement of cement with UFS and 1.0% fibre content. In addition, there was a significant improvement in split tensile strength and flexural strength of the concrete. This study demonstrates that a high strength concrete can be obtained from partial replacement of cement with UFS and addition of steel fibre.
A Review of Diagrid Systems for Lateral Load Resistance of Structures
Authors: Minu Ann Peter , Sajith A.S. , Praveen Nagarajan
Published: November 2016

Diagrid structures are exterior structures, consisting of diagonal struts and ties in the periphery and an interior core. These diagonal members carry gravity load and lateral load by the axial action of the member. Due to the structural efficiency of diagrids, interior and corner columns can be avoided thereby providing flexibility in the floor plan. The diagrid structures are emerging as popular structural system in many developed countries of the world, but in India it is yet to gain importance. This paper presents a review on the literature of diagrid structures. Studies conducted on diagrid structures to determine the diagrid angle for the efficient design is presented. The stiffness-based methodology adopted for determining preliminary member sizes of steel diagrid structures and the effect of shear lag on high rise buildings with diagrid and its comparison with framed tube structures are discussed. The distribution of the load resisted by interior frame and diagrids is outlined. The parameters used in the comparison of analysis are time period, top storey displacement, inter-storey drift and storey shear. This paper also reviews the studies on the comparison of diagrids with regular configuration and diagrids with varying angles. The analysis and comparison of diagrid and conventional structural system on the basis of consumption of steel, structural weight and displacement are also highlighted. This review covers diagrids with all the materials in practice namely concrete, steel and concrete-filled steel tube(CFST).
Static Analysis of Gravity Dams Considering Foundation-Structure Interaction
Authors: Abraham Margaret , Kuriakose Bennet , Kuruvilla Reni
Published: November 2016

A dam is an artificial barrier constructed across a stream channel to impound water. Analysis of stresses and displacements are inevitable for the structural design and failure analysis of dams. This paper deals with the numerical simulation of structural response of gravity dams, duly considering the foundation-structure interaction. The optimum depth and width of foundation extend to be considered in the numerical model is also studied. A parametric study based on the stiffness of the foundation is also exercised. As an application of the developed model, a case study of Peechi gravity dam is presented. This study proved the importance of consideration of foundation-structure interaction in the structural analysis of dams. The developed numerical model can be further improved for performing seismic analysis of gravity dams, considering the foundation-structure as well as fluid-structure interactions.
Static Analysis of Interlocked Water Tower
Authors: Mohan Akhila S. , Varghese George M.
Published: November 2016

In the areas prone to natural disasters, ability of lifeline systems from catastrophic damages is one of the most important challenges in civil engineering. One of the most important structures is elevated water tanks. Most of the damages observed to these structures under seismic events are due to the improper design and wrong selection of supporting system. This paper investigates the suitability of interlocking system for staging of an elevated water tank of higher capacity. As a preliminary study the performance of concrete interlock panelled tower under static condition is analyzed by considering the standard earth gravity under full and empty conditions. The study concludes that the new system can perform in a similar way as that of the conventional system.
Comparative Study of Steel Beam Column Connection under Cyclic Loading
Authors: Anisha S. , Krishnan Dhanya
Published: November 2016

A structure is an assembly of various elements or components which are fastened together through some type of connections. Steel beam column connection may fail due to large earth quake. Plastic hinge formation is the main failure of a steel beam column connection. There are two methods for improving the steel beam column connection (i) connection reinforcement/strengthening (ii) beam weakening by reducing the cross-sectional area of the beam at a certain distance from the connection. When reducing the cross section area plastic hinge is formed away from column face. The main objective of this study is to compare reduced beam section (RBS) and reduced web section (RWS) pattern and find out the location of plastic hinge. For steel beam column plastic hinge is located near column. When reducing the cross section area the location of plastic hinge will shift from the column. Aim of this project is to locate the position of plastic hinge apart from column face, and also evaluate the stress and deformation.
Experimental Study on Corrosion Behaviour of Concrete Containing Bottom Ash as Partial Replacement of Fine Aggregate
Authors: Priyaa K. Meenu , Srinivasan P. , Gajalakshmi P.
Published: November 2016

Concrete is a material synonymous with strength and longevity and plays a vital role in the construction activity. Scarcity of natural sand and its fast rising cost have paved way for use of bottom ash, a residue being collected from the thermal power stations, as substitute for sand. Recent research shows that the mechanical properties of concrete containing bottom ash as a partial replacement of fine aggregate is suitable for construction. The various parameters involved are different percentage of bottom ash and grades of concrete. This present experimental study is made on chloride induced corrosion using accelerated corrosion test (ACT) and related durability properties such as water absorption & porosity, water sorptivity and rapid chloride penetration test (RCPT). Compressive strength test is performed in order to ascertain the mechanical property of bottom ash concrete. The above tests were conducted on the concrete specimens and the results were found comparable with the control concrete up to 20% replacement of bottom ash. Utilization of bottom ash in concrete becomes more significant in cost-saving and reducing the quantity of landfill, thus providing an economical and ecological way of conservation of natural resources.
Experimental Investigation on the Seismic Performance of a Chinese Traditional Wooden Pagoda
Authors: Wu Ya Jie , Song Xiao Bin , Luo Lie
Published: November 2016

To investigate the seismic performance of the traditional Chinese timber structure, a one-fifth scale model of a seven-story pavilion-style wooden pagoda was tested on a shaking table. An artificial wave and two natural earthquake waves were used. Different excitation intensities ranging from frequent-met level to rare-met level of 7 degree as specified in Chinese code were mainly considered. White noise excitations were applied to obtain the change of the dynamic characteristics of the model. The identification results of dynamic characteristics indicated that the model’s damping ratio was more than 0.1, and the first natural frequency decreased by 17% with the corresponding damping ratio increased by 46% after the earthquake excitations. Typical components which including ludous and sandous were observed with splitting perpendicular- to-wood-grain under rare-met earthquake excitations, but other structural members were not found noticeable damage. The maximum acceleration amplification coefficient of the top point was 2.46, and the maximum displacement was 239 mm. Small residual deformation was detected under the rare-met earthquake excitations. The experiment implied the extraordinary seismic performance of such kind of structures.
Seismic Fragility Analysis for Typical Multi-Span Simply Supported Railway Box Girder Bridges
Authors: Wu Yun Dan , Yao Xiao , Zhou Shi Jun
Published: November 2016

Fragility curves for typical multi-span simply supported concrete box girder bridges in eastern China are presented. A set of bridge samples, of which five uncertain parameters are considered, is established using the Latin hypercube sampling. Nonlinear time history analyses are conducted to capture the structural response quantities. Probabilistic seismic demand models are formulated by quadratic regression analysis for the capacity/demand ratios. Fragility curves of bridge components are developed and the fragility of bridge system is evaluated using the first-order bound method. The results show that the columns and expansion bearings among bridge members are more fragile under earthquake excitation, and the bridge system is more fragile than any bridge component. The typical bridges have more than 50% probability when subjected to PGAs of 0.46, 0.58, 0.82, and 1.0g for four damage states, respectively. The fragility curves can be used for retrofit prioritization for this type of bridges.
Shear Strength of a Cemented Paste Backfill Submitted to High Confining Pressure
Authors: de Araújo Eduardo Eiler  Batista , Simon Dragana , de França Fagner Alexandre Nunes , de Freitas Neto Osvaldo , dos Santos Jr. Olavo Francisco
Published: November 2016

Deep mining operations require special measures in order to keep safe and economic aspects. After mine ore is extracted, voids are created and need to be filled with high-strength, low-cost materials. Cemented Paste Backfill (CPB) has recently become one of the main alternatives in filling stopes. Although numerous papers have mentioned the magnitudes of the strength of this material, its behavior under high confining pressures is still not well understood. Therefore, the purpose of this study is to increase the knowledge regarding the CPB behavior. Triaxial compression tests were performed using a Hoek Cell and Load Frame System under high confining pressures. Samples with two different binder contents were used in order to obtain the CPB strength improvement. Besides the self-weight consolidation curing method, samples were subjected to a different curing method that simulated a zero gravity condition (rotating wheel) in the first curing day to compare their mixture properties. The results suggested that both curing method and binder content have influenced the geomechanical properties of Cemented Paste Backfill. By increasing the curing time, the CPB shear strength has increased slightly, whereas specimens with higher binder content presented a significant increase in shear strength values.
Study on the Influence of Piloti Arrangement on Outdoor Wind Environment in Residential Blocks in Subtropical Climate Zones
Authors: Xi Tian Yu , Ding Jian Hua , Jin Hong
Published: November 2016

To create shadows and enhance ventilation, piloti is commonly used in subtropical climate areas, and the influence of piloti on outdoor environment need to be revealed. Taking the city of Guangzhou China, as an example, by adopting coupled simulation method, this work researched on the influence of piloti on wind environment in residential blocks. Firstly, a series of building cases with piloti in the center of each building was simulated, and the piloti of each case is 0%, 40%, 60%, 80% and 100%. Secondly, another 3 cases with 50 percent piloti ratio were simulated, and the piloti arrangement method is crossed, vertical and horizontal for each case. The results showed that, when piloti is in the center of each building, both of velocity under piloti and out of piloti area showed positive correlation with piloti ratio, and the inflection point is 60 percent and 80 percent independently. The result of another 3 cases was plotted on the figure of piloti centralized cases, and for the velocity out of piloti area, the value of these 3 cases is very close to each other and much lower than the centralized case. For the velocity under piloti area, the vertical piloti arrangement case fits the trend of centralized cases well, and the horizontal and cross piloti arrangement case is much lower than that of centralized cases.
Evaluating the Performance of Eaves to Promote Energy Efficiency of Traditional Dwellings in Suzhou
Authors: Fu Yue , Yang Wei Ju
Published: November 2016

A shading roof can be an effective strategy to decrease the air-conditioning energy consumption as well as to improve the thermal environment inside a house in the place that is hot in summer and cold in winter. In Suzhou, a city in such place, traditional dwellings were constructed with shading roof eaves that have different sizes, allowing them adaptive to local climate. These eaves are worthy of being studied and improved. This study presents a summary of the sizes of the shading roof eaves of traditional Suzhou dwellings. The southward eave that has the greatest effect on indoor thermal environment is taken as the object of the current study, and a traditional Suzhou dwelling is selected as our case for the current study. Several comparative models are built, in which, the southward length of the roof eave is increased by 0.2m, from 0m to 2m. The effects of the length on both heating and cooling energy consumption are simulated by using the software Energyplus. As shown in the quantitative analysis of the simulation results, the structure is energy-efficient when the length is less than 0.6m, and the annual energy consumption reaches its minimum when the length is 0.4m.
Sustainable Update Exploration of Urban Blocks of Old Town
Authors: Wei Xuan
Published: November 2016

This paper presents a case study in the city of Hefei, China that exhibits the principles employed by the current practice of transforming and renovating old city districts. The studied is a district around Town God’s Temple, an important heritage building in Hefei.
Research on the Design Method of a Scale Model of ECC Reinforced Concrete Precast Shear Wall Structure
Authors: Yang Jian , Liang Shu Ting , Zhu Xiao Jun , Wu Dong Yue , Wang Guang Yun
Published: November 2016

Engineered cementitious composite (ECC) is a class of high performance cementitious composites with pseudo strain hardening behavior and excellent crack control. Substitution of concrete with ECC can avoid the cracking and durability problems associated with brittleness of concrete. In this paper, it is aimed to design a scale model of ECC reinforced concrete precast shear wall structure. Referencing the prototype structure which is a precast concrete shear wall structure in Nantong, Jiangsu Province, China, the size similarity constant is taken as 1/2. Consulting the scale similarity conditions, the similarity similar constants representing material characteristics, geometrical features, and load characteristics are calculated using the strength similarity theory. Besides, the reinforcements in the model structure are calculated and analyzed. The diameters of reinforcing steel bars in the model structure are determined by the principle of similar size. Equivalent principle of yield bearing capacity are used when there is no corresponding reinforcement selection. The research results of this paper will provide valuable preferences for design and analysis of ECC reinforced concrete precast shear wall structure.
Mix Design and Performance Verification of Asphalt Mixture to Improve the Service Performance in Inner Mongolia Heavy Asphalt Pavement
Authors: Wang Jing , Yan Jin , Tian Miao Miao , Li Ya Fei
Published: November 2016

With the implementation of the "One Belt, one Road" national strategy, the western region traffic can develop rapidly. This paper aims to improve the service performance in Inner Mongolia cold and heavy-load asphalt pavement through research. The mix design and performance verification of Zhuozi mountain mixture is the main line, in order to get a good fit to the local situation, and draw the key technical indicators of the design.
Research and Analysis on the Wave Transformation and Irregular Wave Breaking Criterion on the Shore
Authors: You Tao , Zhao Li Ping , Xiao Zheng , Huang Lun Chao , Han Xiao Rui
Published: November 2016

Within the surf zone which is the region extending from the seaward boundary of wave breaking to the limit of wave uprush, breaking waves are the dominant hydrodynamics acting as the key role for sediment transport and beach profile change. Breaking waves exhibit various patterns, principally depending on the incident wave steepness and the beach slope. Based on the equations of conservation of mass, momentum and energy, a theoretical model for wave transformation in and outside the surf zone was obtained, which is used to calculate the wave shoaling, wave set-up and set down and wave height distributions in and outside the surf zone. The analysis and comparison were made about the breaking point location and the wave height variation caused by the wave breaking and the bottom friction, and about the wave breaking criterion under regular and irregular breaking waves. Flume experiments relating to the regular and irregular breaking wave height distribution across the surf zone were conducted to verify the theoretical model. The agreement is good between the theoretical and experimental results.
Effects of Connecting Plates on Cold-Formed Steel Wall Plate System
Authors: Adeline Ng Ling Ying , Hii Wei Hui
Published: November 2016

The paper presents experimental investigations on cold-formed steel (CFS) wall plate system. The behavior and the modes of failure of the system under uplift were studied. The parameters tested were the presence of gaps and the thickness of connecting plates. Results showed that samples with and without gaps at the supports experienced the same failure mode. Failure began with the yielding of connecting plates followed by the buckling of C-channel. Similar ultimate capacity was also obtained for samples with and without gaps. When connecting plates of different thicknesses were used to connect the wall-plate, different modes of failure were observed. Instead of yielding in the connecting plates, screw pull-out was observed in the connection before the C-channel buckled. Besides, it was observed that the ultimate capacity of the system was reduced when thicker connecting plates were used. It is not conservative to estimate the capacity of screwed connection according to the design standard and it is proposed that the capacity of the wall plate system is taken as the yield capacity of the connecting plates of the same material properties.
Research Status of Fatigue Damage Mechanism of Reinforced Concrete Beam
Authors: Zhou Hong Yu , Chen Yi Bo , Ci Jun Chang , Yang Cong Kun
Published: November 2016

Based on the fatigue damage mechanism, fatigue life, stiffness degradation, crack width change, bending, shear fatigue properties and other aspects, this paper introduces the research progress of the fatigue properties of ordinary reinforced concrete beams. And the existing reinforced concrete beam flexural, shear fatigue properties of research ideas, methods and results are summarized, providing the basis for further study on the fatigue performance of reinforced concrete beams. At present, the research results show that the fatigue damage of reinforced concrete beam is basically in accordance with the law of the three stages. In the early stage of fatigue, the tensile concrete cracks and exits, and the damage develops rapidly. In the middle of fatigue crack growth, fatigue damage is developed into a more moderate linear growth. In the late stage of fatigue, fatigue fracture occurs in the steel bar, and the bearing capacity of the beam is quickly lost.
Cantilever Force Distribution on Jack-Up Rig
Authors: Tee Kong Fah , Feng Shi Lun , Fan Jun Tao , Li Jing Jing , Bian Chen
Published: November 2016

Cantilever is the most important structure of the jack-up rig. Jack-up usually has three working conditions: drilling condition, storm condition, preloading condition. The fulcrums of the cantilever in the drilling condition are less than the other two. So the distribution of the cantilever force in the storm and preloading conditions becomes extremely complicated with the increase of fulcrums. In order to facilitate the evaluation of jack-up rig strength, a simplified analytical method and a finite element method (FEM) are presented to distribute the cantilever force on a jack-up rig during the storm and preloading conditions. For the simplified analytical method, the fulcrum force is obtained from the distance between the fulcrum and the position of the cantilever resultant force. For the FEM, the cantilever is assumed to be perfect rigid body without any strain. The fulcrum force is calculated according to the balance of the fulcrum forces. Both results of fulcrum force are analyzed and compared. It is shown that they are in good agreement. Thus both methods can be applied in distributing the cantilever force to evaluate the strength of jack-up rig.
Instability Mechanism of Du Yun Pass Tunnel Entrance Weathered Stacking Area Analysis
Authors: Liu Lin , Rong Yao , Zhang Cheng Ke , Mao Meng Yun , Zhang Lu Lin
Published: November 2016

The stability of the tunnel portal section under poor terrain and geological condition has always been the focus of construction safety. The stability problem has become more complex for the erosion accumulation area under the valley. In this paper, firstly the stability of the tunnel portal is classified. Combined with engineering cases, the FEM numerical method is used to simulate the supporting structure and construction process of the tunnel. Based on the distribution of the plastic zone and displacement of surrounding rock, the mechanism of the instability of the tunnel portal is analyzed. Through the optimized construction scheme that arranges pile foundation in tunnel arch foundation, the bearing capacity of foundation has been greatly improved, which has effectively prevented the instability of surrounding rock caused by the slope deformation and foundation settlement. The conclusions that have been drawn in this paper can be used for reference for related projects.
Experimental Study of Dynamic Mechanical Properties of Granite
Authors: Chen Zhen Ming , Li Yue Xiao , Zhang Zheng
Published: November 2016

Based on the SHPB (Split Hopkinson Pressure Bar), the dynamic mechanical properties of the granite in the borehole have been tested separately. The data shows that the impact dynamic strength increases as the precompression stress increases and can reach its maximum when the precompression stress is about 50% of the static tension strength. Meanwhile, the coupled static and dynamic strength increases as well, and it could reach about three times of the static precompression stress and one and half times of the dynamic strength respectively. Also, the failure model of the coupled static and dynamic loading is tension failure, which is the same as the static tension and conventional dynamic loading test.
Behaviors of Xiashu Loess in the Lower Reaches of China’s Yangtze River under Triaxial Compression and the Microscopic Explanations
Authors: Xiao Jun Hua , Zheng Wen Qi
Published: November 2016

To investigate the macroscopic mechanical properties of undisturbed structural Xiashu loess in the lower reaches of China’s Yangtze River under triaxial compression, and obtain the intrinsic explanations for the macroscopic mechanical properties from the microscopic point of view, in laboratory, triaxial compression tests were carried out, microstructure images of sheared samples were collected by scanning electron microscope (SEM), and quantitative parameters of microstructure (mainly about particle or pore size, distribution, and alignment) were extracted by digital image processing technique. Based on the test results, the deviator stress-strain relationships of both undisturbed and remoulded Xiashu loess, the structural strength, and the microstructural evolution mechanism about the formation of shear failure zone of Xiashu loess under triaxial compression were analyzed.
Preparation of Hydroxyapatite Honeycomb through Dissolution-Precipitation Reaction under Hydrothermal Condition
Authors: Kim Y.J. , Cho Sung Baek , Kim Ill Yong , Ohtsuki Chikara
Published: November 2016

Hydroxyapatite (Ca10(PO4)6(OH)2) can be obtained from calcium carbonates through dissolution-precipitation reaction in a phosphate solution under a hydrothermal condition, with keeping its external shape. In this study, we assumed preparation of hydroxyapatite honeycombs from a calcite (CaCO3) honeycomb. Calcite honeycomb was hydrothermally treated in a phosphate solution. After hydrothermal processing for 24 h, calcite transformed partially to hydroxyapatite phase and its external shape was kept. Moreover, specific surface areas of the specimens were increased after the hydrothermal processing. Consequently, this processing is useful to prepare honeycomb structure of hydroxyapatite from calcium carbonates.
Chemical State of Nitrogen in Nitrogen-Doped Hydroxyapatite Ceramics with Enhanced Bioactivity
Authors: Namiki Ryota , Suyama Takuya , Izawa Chihiro , Ikeda-Fukazawa Tomoko , Honda Michiyo , Watanabe Tomoaki , Aizawa Mamoru
Published: November 2016

The chemical state of nitrogen which was induced into crystal structure of hydroxyapatite by nitrogen-doping method (N-doping method) was examined. Determination of lattice constants by powder X-ray diffraction (XRD) showed that the nitrogen species induced by N-doping method substituted the OH- ion in the crystal structure of hydroxyapatite. In addition, Fourier transform infrared spectroscopy (FT-IR) and temperature programmed desorption-mass spectroscopy (TPD-MS) determined that the chemical state of nitrogen induced by N-doping method was N2O.
Synthesis of Ag-Hydroxyapatite
Authors: Mendonça Fonseca Flavia , Costa Andrea Machado , Blazutti Marçal Rubens Lincoln Santana , Navarro da Rocha Daniel , de Campos José Brant , Prado da Silva Marcelo Henrique
Published: November 2016

Silver-bioceramics have a great potential to optimize the bone grafts materials to avoid microorganism infections on patients. The present study synthesized and characterized hydroxyapatite doped with silver (Ag), by an acidic route of precipitation method, and the proposal of the Ag-HA synthesis is to promote the bioactivity and bactericidal ability with less toxicity for organism. The samples were analyzed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analysis. There was a pronounced grain growth after 1100°C HA and AgHA heat treatments for both HA and Ag-HA powders, observed by FEG-SEM analysis. XRD patterns of AgHA sintered at 1100°C showed HA as the main phase, but also a secondary whitlockite phase. However, 100% HA was observed for the Ag-HA samples heat treated at 700°C and 900°C. However, pure HA showed decomposition at 900°C. The acidic route of precipitation method showed to be effective for silver-doped hydroxyapatite production.
Characterization of Piezoelectric and Bioactive NaNbO3 from Metallic Niobium and Niobium Oxide
Authors: Prado da Silva Marcelo Henrique , Navarro da Rocha Daniel , Azevedo Luciana M.S , Louro Luis Henrique Leme , Costa Andrea Machado
Published: November 2016

In this study, stoichiomectric sodium niobate was synthesized by two alkali routes. On the first route, niobium oxide was used as precursor, whereas metallic niobium was the precursor used for NaNbO3 synthesis.
Wear and Corrosion Resistance of Low Temperature Degradation Free ZTA for Artificial Joint
Authors: Ikeda Junji , Murakami Takayuki , Sasaki T. , Shimozono T. , Shouyama Y. , Iwamoto M.
Published: November 2016

Low-temperature-degradation-free (LTD-free) zirconia-toughened alumina (ZTA) has been developed as an alternative to alumina and zirconia. It has been reported that ZTA has more beneficial mechanical characteristics than alumina, because of the stress-induced transformation and the spontaneous transformation of the zirconia phase that occurs for some ZTA in a hydrothermal environment. To achieve high-reliability artificial-joint prostheses, it is necessary to improve both the mechanical characteristics and phase stability of the joint material simultaneously. Thus, in this study, we evaluate the wear characteristics and corrosion resistance of LTD-free ZTA using a hip wear simulator, so as to confirm the long-term stability and reliability of this material in clinical use. The ZTA with advantageous mechanical characteristics used in this study has extremely high wear and corrosion resistance. Therefore, this ZTA could be quite useful as a bearing material in artificial joints for longer-term clinical use. It is also confirmed that the newly developed LTD-free ZTA is extremely stable under sliding conditions. Thus, it can be expected that the initial superior surface characteristics will be maintained through long-term clinical use.
Effect of the Pore Diameters and Amino-Organo Functional Structures on Mesoporous Silicas for DNA Adsorption
Authors: Hikosaka Ryouichi , Nagata Fukue , Tomita Masahiro , Kato Katsuya
Published: November 2016

Deoxyribonucleic acid (DNA) adsorption onto particles has applications in biosensors, separation methods, and gene delivery. Mesoporous silica (MPS), which exhibits a high surface area and large pore volume, is used in these applications because its pore size is easily controlled and its surface functional groups are easily exchanged. In this study, three types of MPSs with different pore sizes (2.4, 5.6, and 11.8 nm) were functionalized with different aminosilane coupling reagents and the effects of the MPS pore size and surface functional groups on DNA adsorption were evaluated. As the pore size of MPS increased, MPSs with diethylenetriamine (–3NH2) adsorbed higher amounts of DNA, whereas MPSs with hexylenediamine groups (–2HNH2) adsorbed lower amounts of DNA. Moreover, the fitting of DNA adsorption equilibrium data to Langmuir and Freundlich isotherm models was investigated.
Spectroscopic Studies of Adsorbed Myoglobin on Zinc Containing Hydroxyapatite
Authors: Costa Andrea Machado , Mavropoulos Elena , Rossi Alexandre Malta , Prado da Silva Marcelo Henrique
Published: November 2016

The knowledge on human tissue is very important to recognize desirable properties of biomaterials. Host cells, extracellular matrix, integrated vessels and interstitial fluids create a complex and dynamic system able to regenerate and respond to environmental stimuli. Myoglobin is a protein with most of α-helices on its secondary structure, and responsible for oxygen binding and release in muscles, by the heme group. This work investigates the Mb adsorption process onto zinc-hydroxyapatite (ZnHA) surface by spectroscopic studies. To do so, ZnHA (0.05 g) was incubated with 4mL of 2mg Mb/mL on phosphate buffer solution pH 6.0 for 24h at 37°C. The FTIR analyses of ZnHA powders before and after protein adsorption provided information concerning the protein content. UV-Vis spectrocopy in the reflectance mode suggested a mixture of MbO2 and Met Mb on lyophilized solid Mb, and the prevalence of MetMb form when Mb was adsorbed on ZnHA sample. The decrease of UV-Vis secondary bands suggests interactions through the Mb heme group and the ZnHA surfaces. Circular Dichroism (CD) spectroscopy indicated the maintenance of the Mb α-helices secondary structure after the adsorption process on ZnHA powders.
An Intrinsic Angiogenesis Approach and Varying Bioceramic Scaffold Architecture Affect Blood Vessel Formation in Bone Tissue Engineering In Vivo
Authors: Adel-Khattab Doaa , Kampsculte Marian , Peleska Barbara , Gildenhaar Renate , Berger Georg , Gomes Cynthia , Linow Ulf , Günster Jens , Houshmand Alireza , Stiller Michael , Abdel Ghaffar Khaled , Gamal Ahmed , El-Mofty Mohammed , Knabe C.
Published: November 2016

Early establishment of angiogenesis is critical for bone tissue engineering. Recently, a technique was introduced, which is based on the idea of using axial vascularization of the host tissues in engineered grafts, namely the “intrinsic angiogenesis chamber” technique, which utilizes an artery and a vein to construct an AV-Bundle. The aim of this study was to evaluate the effect of varying scaffold architecture of calcium alkali orthophosphate scaffolds (CAOP), resulting from two different fabrication procedures, namely 3D printing (RP) or a Schwarzwalder-Somers replica technique (SSM), on angiogenesis in vivo when combining a microvascular technique with bioceramic scaffolds colonized with stem cells for bone tissue engineering. 32 adult female Wistar rats, in which critical size segmental discontinuity defects 6 mm in length were created in the left femur, were divided into 4 groups, group 1 received a RP scaffold colonized with rat stem cells after 7d of dynamic cell culture and an AV-Bundle (AVB), group 2 a SSM scaffold with rat stem cells after 7d of dynamic cell culture and an AVB, group 3 a RP control scaffold (without cells and AVB), group 4 a SSM control scaffold (without cells and AVB). After 3 and 6 months, angiomicro-CT after perfusion with a contrast agent, image reconstruction, histomorphometric and immunohistochemical analysis utilizing antibodies to collagen IV, vWF and CD-31 were performed. At 6 months, a statistically significant higher blood vessel volume%, blood vessel surface/volume, blood vessel thickness, blood vessel density and blood vessel linear density was observed with RP scaffolds with cells and AVB than with the other groups. At 6 mths, RP with cells and AVB displayed the highest expression of collagen IV (score 2.75), CD31 (score 2.75) and vWF (score 2.6), which is indicative of highly dense blood vessels. Both angio-CT and immunohistochemical analysis demonstrated that AVB is an efficient technique for achieving scaffold vascularization in critical size segmental defects after 3 and 6 months of implantation.