bluuebunny/crossref_metadata_2025 huggingface dataset:
Transmission Control Protocol for Mobile Ad Hoc Network
Authors: Bisoy Sukant Kishoro , Pattnaik Prasant Kumar
Published: October 2015

The Transmission Control Protocol (TCP) is a reliable protocol of transport layer which delivers data over unreliable networks. It was designed in the context of wired networks. Due to popularity of wireless communication it is made to extend TCP protocol to wireless environments where wired and wireless network can work smoothly. Although TCP work in wireless and wired-cum-wireless network, the performance is not up to the mark. In literature lot of protocols has been proposed to adopt TCP in wireless mobile ad hoc network. In this, we present an overall view on this issue and detailed discussion of the major factors involved. In addition, we survey the main proposals which aim at adapting TCP to mobile and static Ad hoc environments. Specifically, we show how TCP can be affected by mobility and its interaction with routing protocol in static and dynamic wireless ad hoc network.
Higher Education-Workforce Relationship and Higher Education Job Satisfaction
Authors: Haghshenas Maryam , Sadeghzadeh Abouzar , Nassiriyar Mojtaba , Shahbazi Roghayeh
Published: October 2015

This chapter discusses three major subjects. The major part consists of the relationships between higher education and the job market. Challenges, benefits, advantages and disadvantages of various higher education-workforce schemes to close the gap between courses and degrees offered by higher education institutions and employer demands are explained along with examples such as the current programs offered in the USA and by the National Health Service in the UK. Job satisfaction in higher education is then discussed including examples from around the world. Factors that cause job satisfaction and dissatisfaction are explained from various leading researches and conclusions from relevant researchers are presented. The difference that gender makes in the workplace is also a subject inducing many researches. Higher education influence on marital status is briefly discussed also with the aid of various researches as the closing paragraphs of this chapter. Finally, the conclusion is presented taking into account the main subjects discussed throughout the chapter.
Ontology Based Intelligent System for Online Employer Demand Analysis
Authors: Terblanche Chamonix , Wongthongtham Pornpit , Villazon-Terrazas Boris Marcelo
Published: October 2015

Identifying employer demand is crucial for a nation to ensure it develops accurate and reliable education, workforce development and immigration policies. Skills shortages globally pose a real and urgent need for proper investigation and workforce development planning into the future. Analysing workforce development and employer demand needs through online job market allows much deeper and wider research into skill shortages. Current methods do not provide the level of depth required to address such important economic implications. In this chapter, the authors present an intelligent system aiming to gather and analyse current employer demand information from online job advertisements. An Employer Demand Ontology has been developed and to further the ontology functionality, the Employer Demand Identification Tool has been developed as a semi-automated means to gather and analyse current employer demand information on a regular basis.
Cloud Computing in Higher Education
Authors: Chen Chin Kang , Almunawar Mohammad Nabil
Published: October 2015

This shift involves the movement of applications, documents and other stored content from desktop-based to web-based through the utility known as the ‘cloud'. The cloud links thousands of computers and servers together where users are not limited to one device but are able to access their documents and other contents through any computer device, provided it has the ability to connect to the Internet. This allows for better storage capacity, lower costs, scalability and on-demand access. Higher education institutions are opting to reap the same benefits of cloud computing. Students, academics, administrators, and other users will be able to access computing resources through university applications, e-mail, databases and other cloud hosting services. This book chapter provides a general understanding of cloud computing systems and what benefits and challenges of cloud computing in higher education. It is followed by the trends of cloud computing usage and considerations needed for adopting cloud computing. The chapter will end with recommendations needed for adopting cloud computing.
The Need for Formal Compatibility Analysis in Web Service Choreography via an E-Commerce Application
Authors: Benabdelhafid Maya Souilah , Boufaida Mahmoud
Published: October 2015

The formal analysis of Web service compatibility is an important task that is not supported by current composition languages, due to their lack of well-defined formal semantics. This paper addresses the raised issues by providing a survey of service composition with focus on formal compatibility analysis and proposing an e-commerce application that integrates formal methods in Web service choreographies. These methods, including Colored Petri Nets (CPNs) and Timed CPNs, are used at design-time for analyzing service compatibility that will be monitored at run-time. This paper forms an important step towards reliable choreographies since by analyzing at design-time problems could be detected early in the development cycle before starting the implementation. It discusses the monitoring of the compatibility evolution at run-time. The effectiveness of our work is validated using CPN Tools.
Cognitive Trust Model for B2B E-Market
Authors: Kumar Bimal Aklesh , Mohite Priya
Published: October 2015

In recent years, B2B E-Market has received widespread amount of research attention in the field of electronic commerce. As majority of companies are investing huge amount of money to build the infrastructure for e-collaboration. Selecting suitable trading partners in an e-market still remains a huge challenge, as the selection of supplier depends not only on cost but on other factors such as reputation, satisfaction and trust. Trust is regarded as one of the most important factors for success and to ensure customers repeat trading. One of the major challenges faced by both research and industry is to measure trustworthiness of a supplier in an e-market place. This paper proposes a cognition based model to measure trustworthiness of a supplier. The proposed model with its implementation using multi-agent systems is described in detail. Finally empirical evaluation is carried out to validate the system and future direction for research in this area.
Possibilities of Feedforward Multilayer Neural Network Classifier as a Detector of Pest Birds in Vineyards
Authors: Doležel Petr , Mariška Martin , Taufer Ivan
Published: October 2015

In this paper, the application of artificial neural network clasifier to resolve pest birds in agricultural areas as a part of a comprehensive system of protection against vermin is demonstrated. Firstly, the idea of the whole system is outlined. Then, the method of recognition is described, the process of artificial neural network design is illustrated and the classifier is validated using data gathered in the fields. Eventually, the results are compared to similar works.
Alternatives for Real Time Positioning Control System in Mechatronic System with Pneumatic Artificial Muscles
Authors: Rimár Miroslav , Šmeringai Peter , Fedák Marcel , Kuna Štefan
Published: October 2015

This paper explains the design of real-time control system for control of drives containing the artificial muscles. Described is the design of hardware and software devices, as well as design of their involvement in the experimental device. In this paper are referred experimental measurements on the device, aimed at monitoring the change in observed characteristics caused by position changes in artificial muscles during their operation.
Interpretation of States Structures in the Control of Development of Ecosystems
Authors: Bíla Jiří , Novák Martin
Published: October 2015

This paper continues in the topic of qualitative modeling that were applied for Small Water Cycle violation in ecosystem of Trebon region, South Bohemia. The situation when is impossible to form a semantic content of a sign formation in higher level ofsign modelis a typical case of “bottom-up emergence”. The paper proposes new method how to avoid this principal obstacle. The method is illustrated in the simple state model of a climate change in an ecosystem.
Studying of Optical Fiber Strain Using Speckle Pattern Correlation
Authors: Farid Niveen , Hussein Hatem , El-Bahrawi Mohamed
Published: October 2015

The present work discusses the optical fiber strain induced by the thermal and the mechanical effects. Two different optical fibers of different core diameters were used in the study. The thermal effect was induced by temperature control system in order to raise optical fibers temperatures to controlled values. The mechanical stress was induced on the optical fibers by a micro mechanical stage. The sensitivity of the optical fibers to both effects was studied by speckle pattern correlation in which the speckles are recorded at each disturbance and analyzed. By tracing the recorded speckles , x and y displacements could be measured and the strain could be determined in two dimensions. Power attenuation in each fiber was studied in each case as well. Both speckle correlation and power attenuation techniques used in the study showed similar indication on the sensitivity of the optical fibers to the external disturbers.
Evaluating the Quality of Compression in Very High Resolution Satellite Images Using Different Compression Methods
Authors: Sanjith S. , Ganeshan R.
Published: October 2015

The rapid growth of remote sensing technology has a great advantage in producing high resolution images which are huge in data volume. Due to the huge volume it is tedious to store and transmit the data. In order to overcome this, a good compression algorithm should be used to compress the data before storing are transmitting. In this paper we have chosen seven different very high resolution satellite images namely Worldview 3, Worldview 2, GeoEye-1, Worldview 1, Pleiades, Quick Bird and IKONOS they are compressed using three different compression methods JPEG, SPIHT and JPEG2000. The Mean square Error, Signal to noise Ratio and Peak Signal to Noise Ratio are calculated to evaluate the quality of the compression methods in very high resolution satellite images.
MD Simulations of Nanomachining Monocrystalline Silicon
Authors: Qu Guo Kun
Published: October 2015

Molecular dynamics (MD) simulations of nanomachining of monocrystalline silicon were performed with the aid of Tersoff potential. The effects of machining conditions on the nature of heat distribution and corresponding phase transformation during nanomachining were investigated. It is clearly demonstrated that heat distribution shows a roughly concentric shape around the shear zone. A steep temperature gradient is observed in diamond tool and the highest temperature lies in chip. Stress distribution presents dual annular shapes, the highest compressive stress and tensile stress lay in shear zone and machined surface, respectively. Phase transformation mainly occurred in chips, shear zone and machined surface. Additionally, atoms in the machined surface are transformed from diamond cubic structure (Si-I) to β-tin structure (Si-II) and bct5-Si.
Optimization Design of Diamond Circular Saw-Blade with Discontinuous Cutting and Uneven Distribution for Cutting Thin-Walled Tubes
Authors: Gu Li Zhi
Published: October 2015

To solve the problem of low efficient, big noise and vibration during cutting of the high strength high temperature thin-walled steel tubes, explore and research a new kind of blade with special ingredients for the working band, unique design for the overall blade structure, and process optimization. The investigations are done to obtain the basic cutting performance through the elaborate and literal formula, to ensure the blade to work smoothly, heat dissipation fast, and noise reduction considerable by using discontinuous and uneven distribution of working band and setting cooling--heat dissipation gaps and heat dissipation holes. Ten steps of saw blade manufacturing process are created——alloying of copper, tin and rare metals - water atomization - special ball milling - ingredients and mixture - whole sintering - gap laser cutting for cooling and heat dissipation-laser cooling hole-thermal gap and heat dissipation hole - calibration and stress relief - quality inspection. Eventually the actual saw blade performances are got: high efficiency, smooth cutting, low noise and long service life. Experimental study and production practice show that this kind of cutting piece has obvious advantages relative to the resin, which is a effective tool for cutting high strength high temperature thin-walled steel pipe.
Material Plastic Side Flow and White Layer in Hardened Steel GCr15 Precision Turning
Authors: Chen Guang Jun , Zhou Xiao Qin , He Bai Ting , Ya Meng , Ba Zhe Hao , Liu Xian Li
Published: October 2015

Turning instead of grinding of the hardened steel is an environmentally cleaner production technology and green fabrication technique. Using the negative rake angle basic shape blades of Mountain of Sweden Sandvik Coromant PCBN7015 cut hardened bearing steel GCr15 and observe fine surface under microscopic condition.. Microscopic observation showed that there was side stream between hard turning two knife marks forming carinata. Side stream level aggravate on the fine surface with the enlargement of Tool Nose radius. The White layer of hard turning fine surface is divided into three areas. White-bright zone is made up of Cryptocrystalline martensite, Dark gray zone is made up of tempered martensite, Grayish zone is made up of the original martensite. This research will enrich theory of hard turning.
Electrochemical Characteristics of the Amorphous-Nanocrystal Ni–Mo Cathodes in Sodium Hydroxide Solution
Authors: Li Ning , Huang Jian Meng , Chen Wei Zeng , Wang Bin
Published: October 2015

The amorphous-nanocrystal Ni-Mo deposits were obtained by electrodeposition in alkaline nickel carbonate solution. X-ray diffraction (XRD), scanning electron microscopy (SEM) and modern technologies were used to describe the content, microstructure and morphology of the deposits. The electrochemical characteristics of Ni-Mo deposits were electrolyzed in 33°C, 7 mol/L NaOH electrolytic solutions. The results showed that when I was 100 mA·cm−2, the hydrogen evolution potential of Ni-Mo21.76 was lower than amorphous Ni-Mo26.36 and 250mV lower than the nanocrystal Ni cathode. And the Ni-Mo deposits with more amorphous phase content would be in lower hydrogen evolution overpotential, a higher exchange current density, and a better electrolytic stability. These due to the amorphous combined with nanocrystal, lager contact surface and binding energy of Ni-Mo structure.
Experimental Research on Selective Laser Sintering of Bamboo Flour/Polyamide Hot-Melt Adhensive Blend
Authors: Zhao De Jin , Guo Yan Ling , Song Wen Long , Hui Zhang , Yu Zhi Xiang
Published: October 2015

Bamboo flour is a kind of a cheap reproducible natural plant powder. The polyamide hot melt adhesive (polyamide) is good bamboo adhesives. The bamboo flour/polyamide blend is prepared through mechanical mixing method. The powder bed preheating temperature of the laser sintering processing and the processing parameters of bamboo flour/polyamide blend are determined through the differential scanning calorimetry method (DSC method) and single layer sintering experiment. The mechanical testing parts are successfully fabricated by selective laser sintering using the bamboo flour/polyamide blend of 25/75 (wt/wt). In this series of experiments, the average tensile strength, flexural strength and impact strength of 5.9Mpa、11.5Mpa and 4.5KJ/m2 are obtained when the laser power is 11W, scan spacing is 0.1mm, the thickness of a layer is 0.1mm and scanning speed is 2000mm/s. The tensile strength and flexural strength of the SLS specimens are improved through wax infiltrating process, while the average impact strength of the wax-infiltrated specimens decreases compared with the SLS specimens processed under the same set of parameters. Bamboo flour/polyamide composite powder is new laser sintering with good forming property and low cost.
Micro-Treatment Mechanism Study on Ionic Soil Stabilizer Improving Clay
Authors: Luo Xiao Hua , Qiu Xin , Wang Yu Jie , Wu Jin Hong , Xiao Shang Lin
Published: October 2015

In order to study the treatment mechanism of the ionic liquid soil stabilizer, a series tests were performed for a typical soil, the red-brown clay. The basic physical parameters of typical soil were conducted by variety of tests, including particle size analysis, crucial water content coefficient, loss on ignition, organic matter content, etc. Furthermore, the treatment mechanism of the ionic soil stabilizer was analyzed, involving PH, conductivity, plasma emission spectra, scanning electron microscopy, X-ray diffraction and BET test. The results indicate: Firstly, the ionic soil stabilizer is a sulfonated oleoresin with the features of water soluble, high conductivity and strongly acidic, which exchanged with cations adsorbed on the surface of clay particles to reduce the thickness of hydrated film and the electric double layer thickness. Secondly, it reduced the mutual repulsion energy between soil particles and made the flaky particles of clay minerals contact closely. Finally, it made the particles of clay be close to each other and gradually formed larger particles. Hence, the clay became denser. Therefore, the research provided a theoretical foundation and practical basis for the wide application of the ionic soil stabilizer in China's highway construction.
The Electrothermal Heating Tube Membrane Resistance Test Method Research
Authors: Zhu Xi Lin , Li Gang
Published: October 2015

This thesis uses a kind of detection method: The two ends of the measurement period from two electrodes, and the probe spacing can be adjusted. Two measuring end head into the interior with electric heat pipe membrane contact ,used the voltage dividing circuit,relations indirect detection of electric resistance film ends with the two measuring pitch. Then the measured data analysis, obtains the relationship between the two electrode spacing and the electrothermal membrane resistance. Make this thought method may not be used to measure the electric heating film resistance, become a simple and practical method for measuring the electric heating film resistance. Using this method, the measured data can be analyzed, indirectly electrothermal film heating pipe internal resistance value and the two measurement of the end head distance is linear change. The linear relationship between the use of electrothermal film heating tube internal electric heating film resistance, the resistance can be estimated from the distance between the two electrodes, get the change range of heating tube power.
Development of the Jet Flow Testing System and the Influence of the Hydraulic Oil on the Jet Flow Quality
Authors: Bao Chen Xing
Published: October 2015

The electro-hydraulic servo valve consists of many small hole parts such as nozzles, which are most important parts in a servo valve. The hydraulic oil flows into the nozzle and jets out from another side, the jet flow quality affects the performance of the valve. In order to study how the hydraulic oil influences the jet flow quality, a test system of the jet flow quality is developed.
HLP Type Hydraulic Oil in Meso-Scale Hole Measuring
Authors: Zhang Xiang , Wang Guang Lin , Shao Dong Xiang , Hong Yang , Sun Li
Published: October 2015

HLP type hydraulic oil has wide application in aerospace field. This paper discusses HLP type hydraulic oil’s performance. Then a new meso-scale hole measurement method is proposed base on HLP type hydraulic oil’ characteristic. Several groups of measurement experiments with different measuring parameter are done. The experiment results show that using HLP type hydraulic oil in meso-scale hole is suitable and effective.
Free Modal Analysis for the Pinion of Logarithmic Spiral Bevel Gear with 20CrMnTi
Authors: Gu Li Zhi , Xiang Tie Ming , Li Peng , Xu Jian Min
Published: October 2015

In order to obtain the pinion's natural frequencies and mode shapes of a new kind of spiral bevel gear (SBG) which is logarithmic spiral bevel gear (LSBG) in the unconstrained state for the purpose of dynamic characteristics study, select the low carbon alloy steel 20CrMnTi (China specification) with good mechanical properties, which the carbon content is 0.17%-0.23%, the elastic modulus E=2.06675×1011Pa, the Poisson's ratio is 0.25, and the density is 7.85×103kg/m3, the finite element model of LSBG pinion which consist of 35100 nodes, 19889 Solid187 tetrahedron FEM elements is established by using free meshing method based on LSBG pinion's physical model in this paper. Solve the modal parameters of the first 6 orders, draw the main vibration mode shape according to the first 6 orders natural frequencies respectively. The first 6 orders critical revolution speeds are calculated by the first 6 orders corresponding natural frequencies, and the LSBG pinion allowable work revolution speeds are 117074.16 revolutions per minute. The free modal analysis of the conventional SBG pinion with the same parameters is done for comparison with LSBG pinion. The results show the LSBG pinion's nature frequency and the critical revolution speed are both lower than that of conventional SBG. The conclusions reflect the vibration response characteristics of LSBG pinion, and provide theoretical basis for dynamic response, structure design and optimization of LSBG pinion.
Simulation and Experimental Research on Rubber Waveform Generator
Authors: Gao Ting , Liu Qu Ping , Ma Ji Xiang , Guo Hong Li
Published: October 2015

Based on MSC. DYTRAN, the platform of virtual artillery experiment was developed to carry out the research on rubber waveform generator design using uniform experimental design. Through comparing with the firing data the design scheme of waveform generator and impact simulation experiment was made ,which meets the requirements of the technical indicators.The design scheme of waveform was used in a certain type of artillery impact simulation experiment. The rationality of the design scheme and the validity of the simulation experiment was proved by the result of artillery impact simulation experiment.
Research on CNC of FSW with Serial-Parallel Structure Based on 3-PRS Mechanism
Authors: Wei Yong Geng , Wang Zhong Xian , Li Qiang , Shi Yong
Published: October 2015

With the increase of welding thickness, Friction stir welding equipment (FSW) with traditional milling machine structure could not meet the requirements of stiffness which to support the huge axis load. Therefore, a FSW with serial-parallel mechanism based on 3-PRS platform was proposed. In order to complete real-time control and the actual and virtual axis control of the equipment, the positive solution and inverse solution (based on Newton-Euler method) of the FSW are analyzed. Then, based on the PA system, the open CNC of the equipment is designed, and the inverse kinematics and the numerical positive kinematics based on Newton-Euler method are embedded into the interpolation of NC system. According to the demand of the equipment, human-machiner interface (HMI) is developed to display the positions of actual and virtual axis for the equipment, and compiler and interpolation are designed. At the same time, online real-time 3D motion simulation is designed, space pose of spindle and whole for the equipment are deduced. In the paper, design method of CNC based on the serial-parallel mechanism is provided.
Structure Optimization of the Aluminum Alloy Frames of Flight Simulator
Authors: Liu Jun , Gui Pu Guo , Wang Jian Mei , Yu Yang , Zhong Zheng Hu
Published: October 2015

Frames are the main components of the flight motion simulator, which are the support for each shaft system, at the same time the rotating load for the external shaft, so the stiffness and dynamic characteristics of the frames in a large extent determines the final accuracy and dynamic performance of the flight motion simulator. For the cast aluminum alloy ZL114A frames of a 3-DOF flight motion simulator, using finite element analysis method, the dynamic characteristics are calculated and analyzed, and then the each order resonance frequency and mode of vibration are obtained. By using of the modal synthesis method and optimization algorithms, the structural dynamics of frames are designed optimally, so as to further reducing the moment of inertia, and improving the stiffness and dynamic characteristics of frames. This method has provided important reference for the reasonable design of the frame structure, and definitively established the foundation to further study the triaxial coupling dynamic characteristics and system mechanical optimization for the flight motion simulator.
The Construction of Dimensionless Nonlinear Dynamic Model and the Research on Chaotic Features of Vibration Cutting Based on Dynamic Fracture Mechanics
Authors: Li Peng , Gu Li Zhi
Published: October 2015

In this paper, the author constructs a dimensionless nonlinear dynamic model of Vibration cutting system described by nonlinear differential equations. The model is established on the relationship between cutting force and cutting speed and the relationship of cutting depth to the cutting resistance and the time. It is the nonlinear dynamic friction model of vibration cutting considering tool-chip friction. Based on the model and the method of chaotic identification, Lyapunov Exponent, the further research on the vibration cutting produce behavior and its classification are conducted.
Comparative Study on the Effect that Coir Fibers Have on the Dynamic or Quasi-Static Elastic Moduli of Glass Fiber Laminates Obtained by the Vacuum Bag Technique
Authors: Villalón Mario , Vega Hugo , Montoya Nahary , Rubio Byron , Hernandez Julio , Mendoza Omar , Salas-Zuñiga Roberto , Reyes-Zamora Ulises , Radillo Rodolfo , Reyes-Araiza José Luis , Manzano-Ramirez Alejandro
Published: October 2015

The use of natural fibers has a great interest due to their damping properties, low density and moderate strength. The effect of incorporating chopped natural fibers, as disperse reinforced phase, on the dynamic or quasi-static elastic modulus of glass fiber laminates is presented. Squares of 32 cm2 plain wave glass fiber prepreg with epoxy resin were used in a stacking sequence [0]4. Short length chopped (1-3 mm) natural coir fiber was placed in between of each glass fiber prepreg sheet (4) and laminates were prepared by the vacuum bag technique. The volume fraction of natural fiber was 30% (mass fraction of 10%) and samples of 254 mm length and 25.4 mm width were cut and tested at vibration conditions in a cantilever beam arrangement. The vibration frequency was measured by an accelerometer ADXL335 at z-axis, perpendicular to the sample test plane and the elastic modulus was estimated with the cantilever model. The results showed that the samples with coir fiber showed an increase in the dynamic elastic modulus value of 150 to 171% with regard to that one of glass fiber samples without fiber. Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials (ASTM D3039) was also used to further characterize the thin samples (≈0.75 mm) with an Instron machine 8800, 25kN. The tensile properties obtained are lower for coir fiber samples than the ones without.
Application of Enzymes for Stabilization of Soils in Paving
Authors: Malko José Adriano Cardoso , Brazetti Rubens , Casagrande Michéle D.T. , de Albuquerque e Silva Ben Hur
Published: October 2015

In recent years, there was a great offer of patented additives (enzymes) to the road market as solution to soil stabilization. However, they are many times rejected because there are no theoretical foundation to prove such uses, and also because researches themselves don’t see research opportunities. Anyway, these products has been marketed, and frequently municipalities and states waste resources by choosing for a solution that is not yet well studied. This study aims to present a methodology to solve the problems that affects the use of additives in laboratory, because his use in conventional tests do not shown efficient for these purposes. For this, it was used a portable traffic simulator, easy handling and common in pavement laboratories. It is a standardized equipment, used to assess the effect of compression and the strain characteristics of asphaltic coating layers. It was developed a set with several accessories to mold samples in the shape of tablets (380 x 50 x 10 mm), may be easily adapted to the equipment selected as simulator. The soils used for the production of the tested tablets were lateritic soils from Rio de Janeiro–RJ, and the enzymatic products were imported. A rigorous care was followed in the production of each tablet to ensure equality and, after, compare results each other. These tablets were molded and tested in order to obtain a series of experimental results, comparing the soil treated with enzymes with the soil without any kind of treatment. The study concludes, in principle, that the equipment used and the developed accessories are appropriate for this purpose and that the use of enzymes showed effective for some applications, but lacks more studies, including with the use of other types of soil to prove such effectiveness.
Treatments on CDW Recycled Aggregates Surface Using Silane-Based Water Repellent
Authors: Franco Santos Winnie , Quattrone Marco , Angulo Sergio Cirelli
Published: October 2015

This study aims to investigate the properties of CDW recycled aggregates using silane-based water repellent agent in three different types of treatments: (a) immersion; (b) sprinkling; and (c) dripping; in order to improve the reduces quality of the material due to the high porosity. Wettability and water absorption were determined by apparent contact angle measurements, water absorption after 24h of saturation (standard method) and recording the variation of submerged mass during 24 hs. All treatment allowed reducing the water absorption and its kinetic. The contact angle measurements confirmed the effectiveness of the treatment: the surface resulted always hydrophobic. Comparing the treatments, immersion gave the best result in terms of absolute results and in terms of variability of measurements.
Connection between a Column and its Foundation for Guadua Angustifolia Structures under Lateral Loads
Authors: Andrade Pardo Sofía , Báez Fabián Lamus , Torres Castellanos Nancy
Published: October 2015

In Colombia, as in other developing regions, social housing shortage related problems has led local authorities to propose low cost housing projects that allow its quickly and easy construction. Among the requirements of this type of construction are solicitations for vertical and lateral loads caused by wind or earthquake forces, as well as the sustainable use of natural resources Considering this, the use of Guadua angustifolia Kunth (Guadua a.) as a structural material has awaken a great interest, considering its renewability, high-speed growth, ecological benefits and because is easily obtainable all across the country. Due to the lack of additional information, structural joints in this type of materials, are usually pinned, assuming that there is no moment transmission between the different elements, however, some types of connections can partially restrict the rotation in the supports. Additionally, the degree of constrain that any support can provide to the column is a variable that has not been studied enough, despite being essential for modeling and structural design.In this work a connection between a column of Guadua a. and its foundation was studied. The influence of each component on the connection behavior under horizontal loads was assessed, testing seven different configurations. Monotonic and dynamic testing of connections as well as the characterization of the materials used in its construction were included in the experimental schedule. It was determined that the presence of mortar grouting together with the use of longitudinal bolts slightly increases the connection strength as drastically reduce its ductility. The use of transversal bolts is the best alternative to obtain a strong, stiff and ductile connection, especially when are combined with the use of hoops.
Evaluation of Dehydration Temperature on Properties of Recycled Gypsum Plaster
Authors: Moraes Pereira Valdir , Camarini Gladis
Published: October 2015

Gypsum plaster is a material used as internal covering of walls in Brazilian constructions. However, this material has short setting times and generates a great quantity of material loss. The low energy necessary to dehydrate the waste material for utilization becomes recycling methods viable, since the recycled products have the same properties of the commercial material. This paper aims to evaluate the behavior of recycled gypsum plaster calcined at 100 °C, 150 °C and 200 °C. It was also studied the use an admixture (superplasticizer). Physical and mechanical properties were evaluated. The results showed that the dehydration temperature influences in both fresh and hardened gypsum properties. The temperature of 200 °C reported better values of initial and final setting times and compressive strength. Calcination at 150 °C showed higher values of hardness. The admixture utilization modified the initial and final setting times.
Preparation of Polypropylene Composites with High Levels of Coir Short Fiber for Use in Products by Injection
Authors: Passatore Claudio Roberto , Lopes Leão Alcides , dos Santos Rosa Derval
Published: October 2015

The main objective of this investigation was to study the properties of composites of polypropylene (PP) containing different proportions (20, 40 and 60% wt%) of coir short fiber (natural vegetable fiber) without treatment of fibers, for use in products by injection with applications in the automotive industries, construction and other segments. Samples were prepared in a only stage using a high intensity thermokinetic mixer (K-Mixer). Additives were used in the mass fraction of 3 wt% compatibilizer (PP-g-MA), 2.2 wt% processing additive and 0.12 wt% thermal antioxidant. The composites were characterized by tensile test according to ASTM D638-10. The surface properties of the polymeric matrix with additives were studied by determining the contact angle (CA) in a sessile drop tensiometer and the carbonyl index (CI) by Fourier-transform infrared spectroscopy (FTIR). Thermal properties of the PP and the composition were evaluated by thermogravimetric test, and the interface of the fiber and the matrix in the composites were evaluated using images from scanning electron microscopy (SEM). The CA analysis showed that the PP matrix with additives has become less hydrophobic and the FTIR and the CI that there was a better stabilization of the PP with additives. There was an increase in thermal stability of the composites for all fiber content, which was up to 15 °C above PP for coir fiber composites. In the Young's modulus values showed that the inclusion of fibers reinforced the polymeric matrix and increased the stiffness of the composites, especially in composites containing 60% (wt%) in which the values were ~1.7 times greater than the polypropylene. Images of micrographs showed the interaction of the fiber in the matrix and that despite the hydrophilic character of the fibers and hydrophobic character of the PP, the composites showed non-homogeneous interfaces. These findings confirm the feasibility of using high level of coir fiber in polypropylene composites even without pretreatment of the fibers and the preparation of samples by injection.
Use of Tire Rubber Residue in Reinforced Concrete Pipes
Authors: Trentin Thiago F.S. , Moraes João C.B. , Melges José Luiz Pinheiro , Akasaki Jorge Luís , Fugii Ana P. , Tashima Mauro M. , Camacho Jefferson S.
Published: October 2015

The concrete material has many advantages as high durability, low permeability, weather resistance and high compressive strength. These qualities have led its application to the rainwater collection since the pipes are usually buried, subject to compressive forces and exposed to the action of water. However, the concrete has some limitations, as, for example, low resistance to tensile stress, high self-weight, ease of cracking and brittle behavior in rupture. Thus, many materials are being studied in order to be used as a new concrete component seeking to minimize its disadvantages. One of them is the tire rubber residue. This residue is a fibrous material that takes a long time to decompose and increases the amount of trash in landfills; but, it may give a greater deformation capacity and also a more effective distribution of stresses to the concrete. Furthermore, the tire rubber residue can provide an increase in energy absorption and a decrease in the propagation of cracks in the hardened state. However several studies mention that the inclusion of the waste rubber into the concrete causes a decrease in mechanical strength to compression, a decrease in the workability of the mixtures and an increased content of entrained air. Therefore, an analysis of the structural behavior of four (4) reinforced concrete pipes was made: two (2) of them was molded without tire rubber residue and the other two (2), with a quantity of residue equal to 20 kg per cubic meter of concrete. All the pipes had a nominal diameter of 600 mm and an effective length of 1500 mm; they were subject to the crushing test standardized by the Brazilian Association of Technical Standards - NBR 8890 (ABNT, 2007) which is similar to the European standard NBN-EM 1616. The diametric displacements at the hub and at the spigot were monitored by the use of two dial gauge indicators. The applied force by a hydraulic jack was measured using a cell load. Finally, tests of water absorption using pieces of the tested pipes were performed, based on the recommendations of the NBR 8890 (ABNT, 2007).
Improvement of Collapsible Soil Behavior of a Lateritic Soil Using Rice Husk Ash
Authors: Fagundes Luiza P. , Yacoub Jhaber D. , Lima Andrey C. , Nakatsuchi Flávia R. , Lollo José A. , Akasaki Jorge L. , Tashima Mauro M.
Published: October 2015

Great areas of Brazil present lateritic soils, such as the northeast and the south. Some of these soils have, as main characteristic, instable structures that can present considerable volumetric deformation in the presence of water. This behavior, also named collapse, is responsible for several problems on the building construction such as cracks and fractures that can damage the safety of structures. The aim of this paper is to assess the possibility of improvement of collapsible behavior of a lateritic soil using rice husk ash (RHA). A previous characterization of soil and RHA was performed in order to assess the combined effect of soil/RHA. The results are so promising, showing a new alternative to reduce the collapsible behavior of soils using an environmental friendly technology.
Building Design and Construction Process Influence in Construction Waste Generation
Authors: Angulo Sergio Cirelli , Gulo Thais , Quattrone Marco
Published: October 2015

The amount of construction waste (CW) at building sites is highly variable, for instance the CW generation index ranges between 50-300 dm3 per square meters of gross floor area. Today there is still a lack of knowledge about variables (building design, construction process, construction technologies, etc.) affecting the CW generation. The objective of this paper is to analyse the influence of multi-storey building design and some construction processes on the CW generation indexes. The CW generation was analysed for two groups of buildings with two different construction processes; one with plumbing and electric services installed inside the masonry element and the other with plumbing and electric services installed onto the masonry element and covered with water-resistant drywall system (reducing the construction waste generation). The gross floor area directly affects the amount of executed construction works in a building site. Since the most important works (concrete, masonry and cladding) for CW generation is related to gross floor area, gross floor of buildings is also directly related to CW generation. For buildings with gross area varying from 20,000 to 80,000 m2, there is a reduction of approximately 18% of construction waste only changing the plumbing and electric services installation system, from embedded in the masonry element to installed onto the masonry element and covered with water-resistant drywall system.
Possibilities of Reusing Sugar Cane Straw Ash in the Production of Alternative Binders
Authors: de Moraes João Cláudio Bassan , de Araújo Queiroz Daniela Cintra , Akasaki Jorge L. , Melges José Luiz Pinheiro , Borrachero M.V. , Payá J. , Tashima Mauro M.
Published: October 2015

Sugar cane production is increasing in Brazil due the demand in manufacturing sugar and alcohol. During production process, several wastes are generated, such as sugar cane straw. After a burning process of this waste material, sugar cane straw ash (SCSA) is obtained, and may be used in the production of alternative binders. The aim of this paper is to assess the possibility of reuse SCSA as supplementary cementitious material in blended Portland cement mortars and as raw material in the production of alkali-activated binders. Blended Portland cement mortars were prepared using 0%, 20% and 30% of SCSA in replacement of Portland cement. For alkali-activated mortars, the activating solution is based on sodium hydroxide (NaOH) solution and different Slag/SCSA proportions in mass were assessed: 100/0, 75/25 and 50/50. Mechanical strength of mortars cured at room temperature was tested for 7 and 28 curing days. The results confirm that enhanced mechanical properties can be obtained for both alternative binders using SCSA on its composition.
Study of Pozzolanic Properties of Two Sugarcane Bagasse Ash Samples from Honduras
Authors: Bonilla Mercedes , Borrachero M.V. , Monzó J.M. , Akasaki Jorge Luís , Ma-Tay Daniel , Payá Jordi
Published: October 2015

It is well known that the combustion of agricultural waste such as rice husk, bamboo leaf and bagasse among others, depending on the combustion process, may produce powders with pozzolanic properties. Two samples of sugarcane bagasse ash (SCBA) from Honduras were studied (from Ingenio Santa Matilde, close to the city of San Pedro Sula, and from Ingenio Los Mangos, close to the city of Choluteca). The samples were physico-chemically characterized and pozzolanic reactivity was checked. Both samples of ash have a chemical composition comprising mainly oxides of silicon, iron and aluminum and have similar values of the loss on ignition. Both ashes showed high ability for reacting towards hydrated lime. Moreover, the evolution of the mechanical compressive strength of mortar specimens incorporating these ashes (25% replacement of Portland cement by SCBA) was also studied. Compressive behavior revealed that for this dosage, the cementing efficiency of SCBA is similar to Portland cement.The results suggested that ashes from San Pedro Sula and Choluteca have very good pozzolanic properties. The cement and concrete industries in Honduras have a huge chance for reusing this type of waste in high quality construction materials. Keywords: pozzolan, sugarcane bagasse ash, agricultural waste, mechanical strength.
One-Year Follow up of Auditory Performance in Post-Lingually Deafened Adults Implanted with the Neurelec Digisonic® Sp/saphyr® Neo Cochlear Implant System
Authors: Borger Déborah , Lina-Granade Geneviève , Verneyre Stéphanie , Thai-Van Hung , Saaï Sonia , Hoen Michel , Gnansia Dan , Truy Eric
Published: October 2015

This study aimed to quantify outcomes in a group of patients who were implanted with an Oticon Medical Neurelec (Vallauris, France) cochlear implant system, the Digisonic® SP/Saphyr® Neo. Ten participants took part in this preliminary study. Their speech perception capacities were evaluated at 3, 6, and 12-months after cochlear implant activation and compared to pre-implantation scores and to scores observed with former versions of the sound processor. Compared to former versions of the sound processor, patients using the Saphyr® Neo processor obtained better speech perception scores for sentences in silence at each tests session (3 months: 79%, 6 months: 82% and 12 months: 94%) compared to Digisonic® users (respectively: 58%, 69% and 75%) and Convex sound processor users (resp. 39%, 59% and 51%). These observations confirm that the technological improvements made in the Saphyr® Neo sound processor coupled with the Digisonic® implant, provided quantifiable benefits in speech perception in Quiet compared to former versions of the processor Convex and Digisonic® SP.
Roflumilast succeeds where traditional therapy fails: a case report
Authors: Guarnieri Gabriella
Published: October 2015

The case of a 72-year-old man with a long history of chronic obstructive pulmonary disease (COPD, patient D according to Guidelines GOLD 2013) in a subject professionally exposed to welding fumes is presented. Diagnosis was based on symptoms and spirometry and confirmed by chest X-ray examination. Since 1997 the patient has been under different therapies, including high-dose inhaled corticosteroids and bronchodilators, with poor clinical control and frequent exacerbations. Roflumilast 500 μg once daily was started in January 2012 and patient’s respiratory symptoms, number of exacerbations and spirometry values have gradually improved since then. Roflumilast was an effective treatment in this case of difficult to treat severe COPD.
Tiotropium: a new therapeutic option in asthma
Authors: Novelli F. , Costa F. , Latorre M. , Malagrinò L. , Celi A. , Vagaggini B. , Paggiaro P.
Published: October 2015

Tiotropium: a new therapeutic option in asthma. F. Novelli, F. Costa, M. Latorre, L. Malagrinò, A. Celi, B. Vagaggini, P. Paggiaro. Although bronchial hyperresponsiveness to cholinergic agents is a main feature of asthma, the role of anticholinergic drugs in chronic asthma management has been largely underestimated. Several single-dose studies comparing acute bronchodilation induced by ipratropium bromide with salbutamol have shown that salbutamol is more effective than ipratropium in treating asthma. Recently, tiotropium has been studied in asthma, when added to low-medium dose inhaled corticosteroids (ICS) in unselected moderate asthmatics or in patients with uncontrolled asthma, or with COPD and history of asthma. Later, studies on patients with Arg/Arg beta2-receptor polymorphism demonstrated a similar efficacy of tiotropium in comparison with salmeterol, when both were added to ICS. More recently, pivotal long-term studies have been performed on severe asthmatics uncontrolled under ICS/LABA combination, showing the efficacy of tiotropium in improving lung function and in increasing the time until the first severe asthma exacerbation. These data support the use of tiotropium on top of ICS/LABA combination in moderate-severe asthmatic patients. New studies are going to be published on the use of tiotropium in mild and moderate asthmatics, when added to low or medium dose ICS, in comparison with ICS alone or with ICS/LABA combination. These data might extend the indication for using tiotropium in asthma. Therefore, tiotropium represents now a valid therapeutic option, in addition to the current therapy available for severe asthmatics, and in alternative to LABA in selected asthma populations. The specific asthma phenotype which may be appropriate for tiotropium treatment should still be defined.