bluuebunny/crossref_metadata_2025 huggingface dataset:
Deformation Analysis and Fracture Mechanism of Steel Casing in Oil Wells
Authors: Zhu Qing Jie , Chen Jing
Published: December 2013

Steel casing damage in oil wells is the primary hazards of oil production in China. There are two main reasons for the steel casing damage, one is the displacement loads on the external interface which primary come from rock creep, and another reason is temperature load on the internal surface which comes from steam injection. In this article, rock creep under fluid-solid interaction is calculated, and the displacement loads on external interface of steel casing is worked out. Then, steel casing deformation and crack propagation with temperature load is investigated. Underground rocks can be treated as porous media and rock creep is controlled by fluid-solid interaction for porous media. The method of fluid-solid interaction for finite element analysis is the calculation of two-way fluid-solid coupling for porous media; it means fully coupling between the solid and fluid solution variables. This method is analyzed and the displacement load is worked out as an example application. Finite element model is constructed; deformation and crack propagation of steel casing under multiple actions of outer loads and inner temperature load are calculated. Finally, fracture mechanism of steel casing in oil wells is analyzed, and some advice is proposed.
The Force Analysis of Landing Stage and Transportation Terminal of Large Module with SPMT Trolley
Authors: She Yue Xia
Published: December 2013

Nickel ore project is the first main part construct project of modular and integrate large smelter. This project includes fifteen modules and its total weight is nearly forty thousand ton and the biggest module is five thousand ton. Use trolley to lade the nickel ore module. Use interim landing stage and shipboard method to land the nickel ore module because of the depth of water. Calculating the three operating modes in the lading process, design the landing stage construct. Thereby lay the foundation to lade the module safely and smoothly.
About Some Misunderstandings in the Modern Theory of the Sound Isolation and Discrete Models of Sound Transmission
Authors: Zakharov Arkadi
Published: December 2013

The present paper is a short critical review of the modern theory of the sound isolation by single-layered protections. It is shown that dependence of insulation upon angle of sound incidence is untenable. The author disproves existence possibility of «spatial frequency resonance» at wave coincidence and of « loss coefficient of a design» defining the abatement of the sound isolation on resonances.The substantiation of application of discrete models of sound transmission through a plate, in which the equations of laws of conservation of momentum and kinetic energy are used, is explained. On the basis of discrete models is offered a practical way of calculation of the sound isolation, not conceding accuracy to modern standard methods, but distinguishing itself in a greater universality and simplicity.
Finite Element Modeling of External Inversion and Comparison of Results with Existed Experimental and Theoretical Results
Authors: Abbasi Kaveh , Hamedani Ali Shirazi
Published: December 2013

The objective of this paper is to simulate inversion process and prediction of proper parameter to perform process successfully. This research present an investigation of the external inversion of tubes by using available commercial numerical codes. The numerical investigation is verified and assessed by means of existing analytical and experimental results. The numerical results have been compared with existing empirical and analytical results, so the ability of numerical codes to predict the required force to perform the inversion process of the tubes has been examined. The theoretical results correlate well with those obtained through experiments. Finally by use of numerical results and their validation using existing experimental results, a method is available in order to help to predict geometry and loading conditions under which the process is conducted successful.
Studies on Process Parameters for Aluminum Extrusion of Slide Rails
Authors: Shao Shun Yu , Wang Wen Yen , Chen Yi An
Published: December 2013

Slide rails are usually fabricated by roll forming and are used in kitchenware and cabinets mostly. However the product weight of slide rails is increased because larger dimensions are required to bear larger load when they are used in dies and warehouses. International suppliers start to develop Aluminum slide rails to decrease the product weight in recent years.
The manufacturing and functional feasibility of Aluminum slide rail were discussed in this study. The Aluminum slide rail was designed according to ready-made slide rail, and the aluminum alloy was selected with required mechanical properties. The suitable extrusion die was designed and direct extrusion parameters of extrusion ratio, extrusion temperature, extrusion speed and extrusion load are also considered. The extrusion process of aluminum alloy was simulated by CAE software to check the mold and process design. The extrusion part of aluminum slide rail was carried out by extruder to verify the simulation results.
A Finite Element Analysis of Cold-Formed Z-Purlins Supported by Sandwich Panels
Authors: Tusnina Olga
Published: December 2013

Nowadays buildings based on lightweight steel skeletons are widespread in civil and industrial engineering. The trapezoidal sheet or roof sandwich panels fastened to thin-walled cold-formed purlins can be used as the building envelopes. In this paper the questions of numerical analysis of thin-walled Z-purlins in the coverings made of sandwich panels are studied. Numerical analyses are performed in the program MSC.NASTRAN. A full scale model of the roof with purlins and sandwich panels is considered. Numerical analyses are based on the laboratory experiments. Results of described analyses are compared with the results of tests. These researches are done to investigate a behavior of the roof system consisted of Z-purlins and sandwich panels and to develop a correct finite element model for the design of cold-formed purlins supported by sandwich panels.
Novel Thermoplastic Materials from Wastes of the Leather Industry
Authors: Puccini Monica , Seggiani Maurizia , Castiello Domenico , Calvanese Gianluigi , Vitolo Sandra
Published: December 2013

Hydrolyzed collagen from leather industry is a natural polymer easily available at low cost and its use is not in competition with food industries or other main applications because it is a waste material and a by-product of the tanning process. In this work, polyethylene-collagen hydrolizate blends, at ratios of 100/0, 90/10 and 80/20, were processed using a blow film line equipped with a single screw extruder. Film blowing is a shaping technique used extensively to produce most plastics films and bags for packaging applications. The effect of processing parameters on the physical properties of blown films was investigated. The extruded films were characterized through mechanical testing, scanning electron microscopy, and thermal analysis. The manufactured films showed satisfactory mechanical and thermal properties, thus polyethylene-collagen hydrolizate blends appears as promising candidate for the production of innovative material suitable for production of thermoplastic items for applications in packaging and agricultural segments.
Early Degradation of Resurfacing Prostheses
Authors: Cirstoiu Catalin , Popescu Dan , Ene Razvan , Cîrstoiu Monica
Published: December 2013

The resurfacing arthroplasty is a new method, superior techniques used in hip arthroplasty, through the immediate post-operative recovery and distance, followed by a complete reversal of limb function and a minimum rate of postoperative complications. Performance of this prosthesis is evident in well selected cases (young patients with physical activity) after a surgical indication correctly formulated. 39 patients with aseptic necrosis of the femoral head prosthesis underwent surgery with total hip resurfacing type in Clinical Orthopaedics-Traumatology, University Hospital Bucharest between 2005-2009.
The diagnosis was established by X-ray and MRI examination. Sex ratio was: 22 men and 17 women. Age groups: 11 patients 20-30 years, 30-40 years 16 patients, 12 patients over 40 years... Approach was developed by postero-lateral joint capsule being maintained to preserve femoral vasculature. Recovery was fast in a short amount of time patients. All patients were reviewed clinically and radiographically at 4 weeks, 6 weeks, 3 months, 6 months, and 12 months, then annually.
There were 5 cases of revision after resurfacing arthroplasty type of causes independent of design and composition of these prostheses. Revision surgeries of these prostheses have gone easier than in the case of conventional prostheses. Most times it is enough just replacing the stem, keeping torque meta-metal large head with all its benefits. The importance of this type of arthroplasty is that: are aimed at young people, preserves bone capital, maintain femoral vasculature, rapid, resumption of intense physical activity, complete recovery of movement in the hip joint, lack of formidable complications in hip arthroplasty dislocation represented.
Applications of Activated Carbon Sorbents Based on Greek Walnut
Authors: Azat S. , Busquets Rosa , Pavlenko V.V. , Kerimkulova A.R. , Whitby Raymond L.D. , Mansurov Z.A.
Published: December 2013

This article presents the results of the synthesis of carbon nanomaterials: Nanoscale materials obtained by carbonization of waste agricultural products (apricot kernel, Greek walnut (GW), rice husk). The results of physico-chemical characteristics of the obtained nanomaterials. Physico-chemical parameters of the synthesis of carbonized sorbents based on plant raw material are investigated along with the properties of these sorbents. The data of FTIR, ESR spectroscopy & BET-method, as well as electron microscopy are reported. It is stated that carbonized sorbents possess high specific surface area and porosity. Carboxylic, carbonyl, hydroxyl groups are detected on the surface of the synthesized sorbents. Separate fusicoccine and similar biostimulators effectively; remove LPS-endotoxines from blood plasma selectively. They may be used as carriers to introduce probiotics into intestine thanks to formation of stable colonies on their developed surface. A method of preparation of honeycomb monoliths from carbonized rice husk with developed mesoporous structure via modification of the porous structure by silica leaching has been developed.
The Impact of Ion Exchange on Nature of Polyacrylic Acid and Nonionic Polymer Complex Formation
Authors: Suleimenov Ibragim , Mun Grigoriy , Panchenko Sergei , Obukhova Polina
Published: December 2013

This paper provides substantiation for division of interpolymer complexes, that are stabilized by hydrogen bonds formed between polyacrylic acid and non-ionic polymer into strong-and low-complexing couples, and elucidates the nature of observed differneces. It is shown, that the formation of complex in presence of low molecular salt depends not only on the energy and number of hydrogen bonds, but on the degree of swelling of polyacid coil too. It is established, that the effect of low-molecular salt on the degree of swelling of the polyacid coil is not unambiguous. The size of the coil is increased by the salt adding at relatively low concentrations as a result of local ion exchange.
Ripple Carry Adder Using Two XOR Gates in QCA
Authors: Suresh Kandula , Ghosh Bahniman
Published: December 2013

Quantum-dot Cellular Automata (QCA) is a very recent technology which can be used for developing new digital circuits which use very less power [1-2]. This paper mainly aims at using XOR gates to implementation of adder circuit in lesser number of cells and with a higher density.
Optimization Design of Auxiliary Grooves on Rotor of Permanent Magnet Synchronous Motor for Electric Vehicles
Authors: Wang Shu Wang , Tian Xu , Sun Chun Zhe , Ma Xiang Hong
Published: December 2013

In order to reduce the influence of the harmonics of the air-gap magnetic field on PMSM performance, in this paper, the method which is to add auxiliary grooves in the rotor surface is proposed to optimize the air-gap magnetic field of PMSM and reduce the iron loss, torque ripple and noise-vibration caused by the harmonics. During the process, the orthogonal experimental method and the time-stepping FEM were used to optimize the structure of the grooves. Analyzed and compared the test-data and the calculated data,it shows that this method can largely improve motors performance.
Hydrophilic Interpolymer Associates as a Satellite Product of Reactions of Formation of Interpolymer Complexes
Authors: Suleimenov Ibragim , Shaltykova Dina , Sedlakova Zdenka , Mun Grigoriy , Semenyakin Nikolay , Kaldybekov Daulet , Obukhova Polina
Published: December 2013

It is shown, that reaction between polyacrylic acid and polyvinyl caprolactam leads to formation of wide range of different products. Besides classic interpolymer complexes and physically cross-linked hydrogels, the intermediates are formed. Those intermediates, particularly, include hydrophilic interpolymer associates, i.e. semistable polymer networks existing in dynamical mode, which is characterized by continuous process of formation/destroying of hydrogen bonds. Other intermediate products are relatively stable fragments of the polymer networks or associates stabilized by hydrogen bonds.
Applied Model of Magnetization of a Granulated Material
Authors: Sandulyak Anna , Sandulyak Alexander , Oreshkin Dmitry V. , Popova Marina
Published: December 2013

Results of researches (of magnetic permeability) of elementary effective magnetic channel in porous (granulated) material are given. Such results permit to calculate a relative intensity of field between the grains.
Determination of the Optimal Locations for Injection Molding Gates with Higher Order Response Surface Approximations
Authors: Chen Kun Nan , Ueng Wen Der
Published: December 2013

This paper proposed a gate location optimization scheme to minimize the maximum injection pressure in plastic injection molding. The method utilized a series of higher order response surface approximations (RSA) to model the maximum injection pressure distribution with respect to gate locations, and the global minimum of these response surface models were subsequently sought by a global optimization method based on a multi-start sequential quadratic programming technique. The design points for RSA were evaluated by the finite element method. After a sequence of repetitions of RSA and optimization, the converged minimizer would represent the optimal gate location. A rectangular plate with two segments of different thicknesses was selected to demonstrate the effectiveness of the procedure. The variation of the thicknesses causes the optimal gate location to deviate from the center and induce multiple valleys in the maximum injection pressure distribution, which is ideal for the application of the higher order RSA and a global searching technique.
The Effects of Application Site and Time of Vibration Stimulation: Changes in Gait Pattern and Muscle Activity
Authors: So Ha Ju , Kim Seong Hyun , Kim Dong Wook
Published: December 2013

This study was conducted to investigate changes in gait pattern that appear after somatosensory stimulation evoked by applying mechanical vibration to the ankle. The gait pattern was observed in a real time using a footswitch mounted on the soles of the feet in order to increase the effectiveness of vibration stimulation. Based on the observed gait pattern, the application site and time of vibration stimulation were determined. The changes in the gait pattern that appear after the application of vibration stimulation were analyzed by comparing the percentage of the gait cycle and the activation of the lower extremity muscles. This study was conducted on young adults, and the result showed that the gait cycle was changed according to the application site of vibrating stimulation, and that the vibration stimulation with intensity less than the threshold, induced a similar effect as shown in vibration stimulation with threshold intensity. The result of this study shows that vibration stimulation could be effectively utilized for gait correction and rehabilitation. It can be also used as basic data for inferring the correlation of the characteristics of vibration stimulation with gait variability.
Potential of Solar Farm Development at UTM Campus for Generating Green Energy
Authors: Mohammad Shahrul Nizam , Zakaria Rozana , Omar Wahid , Abd Majid Muhd Zaimi , Saleh Abd Latif , Mustaffar Mushairry , Mohamad Zin Rosli , Jainudin Noor Azland
Published: December 2013

Energy is an important element in human life. Previous study discovered that buildings consumed more than 40% of global energy mainly electricity and emit 1/3 of global greenhouse gas through combustion of fossil fuels for generating electricity. Nowadays, global warming come to be a major issue facing the world and it leads to a better awareness about renewable energies as alternatives in generating electricity. In certain countries, solar farm has been adopted as an alternative in producing electricity. UTM spent millions of money every year for electricity bills and UTM could consider solar farm as an energy option in generating green electricity due to suitable climate and huge land bank. Governments incentives and decreasing PV panel price are opportunities to be appreciated for UTM to implement solar farm. However, high initial investment is needed to construct the solar farm. Additionally, decision will be based on financial benefits of the solar farm development. The aim of this study is to identify potential of solar farm implementation in generating green electricity. Data will be acquired via literature review, questionnaire survey, record review, and expert interview. Calculations on payback period and net present value were made based on interview data to identify potential of investment for solar farm. The study outlines the suitability factors for UTM to implement solar farm, at the same time financial benefits of solar farm implementation is portrayed.
Development of an Automatic Optical Inspection System and its Application to Defect Examination
Authors: Jean Jong Hann , Chen Chia Hong , Huang Tyng Bin , Tsai Sheng Hong
Published: December 2013

In this paper, we have designed and integrated an automatic optical inspection system, emphasizing on software implementation of the image processing, measurement and analysis utilities. As for the hardware equipments, we design an LED illumination unit and the custom-tailored machinery. By comparing the support functions of several main import brands of the optical inspection machine, we propose an optical inspecting procedure. By using the Windows-based user interface, we implement nine inspecting software tools, namely, the average gray level tool, the thresholding tool, the positioning tool, the edge detection tool, the binary large object (BLOB) tool, the template building tool, the smart matching tool, the inspection sequence tool, and the platform operation tool. All these tools can be used in an inspection with single operation and can also be arranged in a proper sequence of operations to fulfill a complicated inspection procedure. We use several part sample images with defects provided by the supplier to verify our fulfilled system.
Accelerometry-Based Motion Pattern Analysis for Physical Activity Recognition and Activity Level Assessment
Authors: Liu Kai Chun , Liu Chung Tse , Chen Chao Wei , Lin Chih Ching , Chan Chia Tai
Published: December 2013

Physical inactivity is becoming a major public health concern and lead to a variety of chronic diseases. Since adequate moderate or vigorous activity can reduce the incidence of chronic diseases, noncommunicable disease and obesity. The evidence is supporting the importance of physical activity on health and well-being. However, many people nowadays live without adequate physical activity, and do not aware whether their daily activity is enough or not. The activity recognition and activity level can be used to survey the effectiveness and achievement of goals aimed at increasing physical activity. Physical activity monitoring has become a more proactive healthcare service that should build on the real-time reminding offered by healthcare solutions. Therefore, physical activity monitoring and activity level assessment are critical to maintain adequate physical activity and improve health. In this work, we present a motion patterns analysis for physical activity recognition and activity level assessment by using a wearable sensor. The proposed mechanism uses triaxial accelerometer as a sensing device. The sensor node is mounted in the right front waist, sensing and transmitting sensing data to server. The time series of raw data will be preprocessed through the aggregation technique of jumping window. The raw data will be divided into small segments and separated to gravity signal and body acceleration by filter. Through feature extraction and proposed classifier, motion pattern analysis is achieved. The classifier consists of activity recognition and activity level assessment algorithms. The results have demonstrated that the proposed methods can achieve 94.7%, 87.0% accuracy of activity recognition and activity level estimation respectively.
Implementation and Experiments of TDOA Monitoring Techniques for Broadcasting Interferences
Authors: Chang Yao Tang , Lin Yi Chang
Published: December 2013

Since the rapid developing of economy in Taiwan in recently years, a large numbers of constructions have made the changes on theterrain surrounding of the radio monitoring stations rapidly. Hence, the accuracy performance of the radio monitoring station configured by signal angle of arrival (AOA) location technology has been seriously degraded. In this paper, the simulated result of 20km ~ 30km coverage area is evaluated. Furthermore, the implementation and experiments supported by the radio frequency interference have been governed by authority of national communication commissions (NCC) in Taiwan. The results show that the locating accuracy at circle error probability (CEP) 50% is less than 950 m distance under multi-path effect in metropolitan area. Hence, the solution of integrated the AOA/TDOA technologies can be applied and the interference transmitter characterized with low transmitted power, burst and weak signal and metropolitan interference is easy identified, analyzed (located) and prevented.
Valuable Architectural Refurbishment of Prefabricated Houses as a Part of their Complex Renovation
Authors: Minarovičová Katarína , Menďan Rastislav
Published: December 2013

The aim of this paper is architectural refurbishment of panel houses in terms of current requirements for living. Gradual evolution of technical standards and life style changes in recent years has resulted in inadequate layouts and outdated structures as external walls, roofs, openings and building services. Our prefabs have no other choice due to service life of structures related to safe operation. They need static system disorders removal, building envelope thermal insulation, openings replacing, heating and plumbing system updating according to required energy efficiency and economically efficient operation, hygiene and comfort housing. The paper analyses layouts of various systems and their possible modifications in order to meet current construction and technical requirements and demands for comfort living. The contribution presents alternative layouts and structural designs of selected panel houses.
Condensation of Water Vapor in the Functional Gap of Wooden Window
Authors: Palková Adela , Palko Milan
Published: December 2013

The moisture penetration through building envelopes. Condensation or ice coating in the gap is the main problem of wooden windows. Thus, destructive processes on the wood surface finish causing the moisture penetration into the wood occur. The surface condensation is sufficiently covered by the requirements in currently valid standards. The condensate generation in the gap is not described neither limited by the standards nor regulations. The frequent problem occurrence in practice is to be dealt with and solved. The experimental and computing investigation was carried out using four types of 682, 682T, 783, 923 euro-profiles. For computing investigation the ANSYS program was applied.
Diffuse Characteristics of Window Frame Gasket System
Authors: Kamenický Ľuboš , Palko Milan , Puškár Anton
Published: December 2013

Window frame is under constant development from the material and design standpoint. Alongside, serious issues exist and are examined with focus on scientific measurements. First and foremost is condensation and icing in functional gap of wooden frame. Root causes have been analyzed, key factors affecting humid characteristics of gap in between sash and frame have been described. Theoretical analysis is based on experimental measurement performed in research labs in Slovakia and EU. This article deals with future steps leading to resolution of this problem, primarily focusing on gasket system. Especially important features of gasket system are those which affect diffuse characteristics. There is an assumption that by optimization of diffuse characteristics condensation can be reduced significantly. Reader of this article can find below the very own methodology aimed to precisely measure diffuse characteristics of gasket system.
Double-Skin Façade in Flotran CFD
Authors: Palko Milan
Published: December 2013

The Aerodynamic simulation with CFD (Computational Fluid Dynamics). Double skin façade as a new segment of modern facades. The fluid flow problem is defined by the laws of conservation of mass, momentum, and energy. Geometrical parameters of element FLUID 141. Aerodynamic mode of double skin façade. Simulation model for inlet and outlet channel of double skin façade. To estimate aerodynamic entrances for inlet and outlet channel of the intermediate space for double skin facades. Aerodynamic and geometrical boundary conditions of the model. Simplified modelling of net for insect with support of real constant.
Timber Buildings Height and Number of Floors in Slovakia
Authors: Olbřímek Juraj , Jankovič Dušan , Leitnerová Soňa
Published: December 2013

Timber buildings in Slovakia have a long history but also interesting future. One of the limitations that inhibit wide usage in Slovakia is the control of the height. This paper analyzes building height according to valid codes and enactments.
Opening Constructions in a Relation to Fire Safety of Building
Authors: Mikolai Imrich
Published: December 2013

The contribution shows to some changes in requests assessing to doors from fire safety of building point of view. The contribution specifies new requests to doors in escape road, new requests to their equipment and also to their fitting. The contribution tells about requests to doors which stopping penetration of smoke in fire compartments. Requests follow mainly from current legislative regulations valid in the Slovak republic.
Air Exchange across Staircase Windows in Protected Escape Route in Time of Fire
Authors: Reháková Martina , Mikolai Imrich
Published: December 2013

The article is focused on the analysis of air exchange by natural ventilation in the staircase area with elevator in the middle as a protected escape route. The article contains three variants of air exchange rate calculation that are based on the effect of the temperature difference and the effect of wind action. The result of these calculations is the verification if the staircase windows provide sufficient air exchange in the protected escape route to ensure the required level of protection for evacuees.
Occurrences of Standard Skies and Luminuos Turbidity Factor in Bratislava
Authors: Fabian Miroslav , Darula Stanislav
Published: December 2013

Levels of daylighting in nature continually changing and their daily courses are different day to day. Effectiveness of daylight utilisation in buildings depends on exterior luminous conditions resulting from sunny and sunless situations. Generally, prevailing interiors are illuminated by diffuse skylight during year but sunny orientated rooms can be often exposed by direct sunlight. To describe these conditions the occurrence of sky luminance patterns and light attenuation properties of atmosphere expressed e.g. by luminous turbidity factor are needed. This paper presents the comparison and evaluation of occurrences of ISO/CIE General Standard Sky and luminous turbidity factor in two distant years on the base of measured instantaneous global and diffuse horizontal illuminance, global and diffuse horizontal irradiance and zenith luminance taken during 1995 a 2002 at ICA SAS in Bratislava. The different occurrences of luminous situations described by general standard sky types were found. Results of the luminous turbidity factor calculation show that various atmospheric pollutions during sunny situations can be expected.
The Impact of the Dynamic Facade Elements on the Energy Balance of the Reference Building in Winter
Authors: Nagy Zsolt , Moravčík Andrej , Palko Milan
Published: December 2013

Buildings have a significant impact on a long-term energy consumption, therefore it is necessary to focus our effort towards the improvement of energy efficiency of buildings. Alternative solutions that can significantly reduce the amount of energy needed to operate buildings are being sought. In this paper we want to highlight the potential of the building envelope which can dynamically change the properties of structure openings based on the type of the building operation and change of climatic conditions. It is important that modern facades are perceived not only in terms of architecture but also in terms of functionality. We focused on the comparison of the impact of dynamic facades on reducing heat loss through the structure openings on the reference building. We assigned the facade features that improve thermal insulation properties of opening structures. We assessed the impact of dynamic facades on specific heat consumption needed for heating. It has been shown that dynamic facade elements are useful not only in terms of sun protection but also have an impact on the reduction of specific heat consumption. The right design of operation of a dynamic facade with proper thermal insulation elements can provide a quality indoor environment where thermal stability is ensured in winter as in summer.
Long Time Testing of Temperature Parameters in Selected Windows
Authors: Ďurica Pavol , Ďuriníková Mária , Rybárik Ján , Štaffenová Daniela
Published: December 2013

The article presents the partial knowledge of the area of building physics. The goal is to evaluate the measured data of the temperatures of three window constructions from different material and glass systems. The measurements are made at different places of window friezes and glazing and they run continuously throughout the year. These windows are suitable for low-energy buildings.
Optimization of Process Parameters of Diffusing Bonding of Titanium with Titanium and Titanium with Copper
Authors: Chandrappa Kasigavi , Hemanth Joel
Published: December 2013

The diffusion bonding of Ti to Ti, Ti-Cu alloy at different temperatures ranging from 673 K to 923 K under an applied stress of 100 MPa for 1 h was studied. The observation of the microstructure reveals that sound joints between the Ti-Ti and dissimilar titanium/Copper metals sheet were successfully joined by diffusion bonding process. Ti-Cu alloy without any pores or cracks can be achieved through diffusion bonding at temperatures over 873 K under the applied stress of 100 MPa for 1 h. The bond is composed of the zones, and its width increases with the increase of bonding temperature. The Micro hardness at the interface of joints bonded under different conditions was evaluated through Micro hardness testing and the fracture mode was analyzed by SEM observation.
A Comparison among Polynomial Model, Reduced Polynomial Model and Ogden Model for Polyurethane Foam
Authors: Ju Ming Lei , Jmal Hamdi , Dupuis Raphaël , Aubry Evelyne
Published: December 2013

Polyurethane foam is widely used in numerous applications. The quasi-static mechanical behaviour of polyurethane foam shows a nonlinear elasticity and a viscoelasticity in large compression deformation. In this paper, the uniaxial compression / decompression tests in three different strain rates are performed. The purpose of this paper is to propose three visco-hyperelastic models and to identify the parameters based on the experimental results. A difference-stress proper identification method is used to obtain the model parameters. The results show that the three models can predict the mechanical behaviour of polyurethane foam very well. Finally, the three models are compared according to the model results.
Enhanced Efficiency of Au-Deposited BiFeO3 Nanoparticles Based Dye-Sensitized Solar Cells
Authors: Verma Narendra Kumar , Kaur Imanpreet , Kaur Kamaldeep , Lotey Gurmeet Singh
Published: December 2013

BiFeO3 nanoparticles have been synthesized by sol-gel method. The deposition of Au on the surface of BiFeO3 has been done using photo-deposition method. X-ray diffraction confirms that the synthesized nanoparticles are possessing rhombohedral structure with R3c space group. The average particles size of the synthesized nanoparticles found to be 26 nm. Synthesized nanoparticles possess band gap 2.28 eV, in the visible region. The dye-sensitized solar cells (DSSCs) have been fabricated using synthesized nanoparticles. The effect of Au-deposition on photovoltaic performance of DSSCs has been investigated. The different performance parameters of fabricated DSSCs viz. open-circuit voltage (VOC), short circuit current-density (JSC) and fill factor (FF) found to be 0.75 V, 6.5 mA/cm2, 0.62, respectively. The high energy-conversion efficiency 2.99%, has been achieved in Au-deposited BiFeO3 based DSSCs.
Thickness Dependence of Structural and Optical Properties of Al/ZnO Films Prepared by DC Magnetron Sputtering
Authors: Ghorannevis Zohreh , Milani Marzieh Asadi , Habibi Maryam , Ghoranneviss Mahmood
Published: December 2013

In this paper, AZO thin films of different thicknesses were deposited on glass substrates as transparent conducting (TCO) films by changing the deposition time using a DC magnetron sputtering method. The effect of film thicknesses on the structural and optical properties of AZO films was investigated using X-ray diffractometer (XRD) and spectrophotometer, respectively. Results show that increasing the film thickness results in decreasing the optical transmittance. The optimum properties were obtained for a film with 500 nm thickness and 90 min deposition time, which exhibited a transmittance of 95%.
Hydroxyapatite Deposition onto Ti-6Al-4V Surface in Powder Mixed Electrical Discharge Machining
Authors: Ekmekci Nihal , Ekmekci Bülent
Published: December 2013

Hydroxyapatite (HA) is bioactive and biocompatible bioceramics that is commonly used as a filler to replace amputated bone or as a coating to promote bone ingrowth into prosthetic implants. The need to overcome biocompatibility problems and improve the bone bonding ability enforced the researchers to develop suitable coating techniques. Feasibility of Powder Mixed Electrical Discharge Machining of Ti-6Al-4V alloy with HA additives in water dielectric liquid is studied as an alternative coating technique. Machined samples are analyzed by means of optical, scanning electron microscopy and energy dispersive spectroscopy. The experimental results have revealed that it is possible to deposit HA powders onto the work material surface by using the process. The morphology of the deposited material signified the dependency with respect to the operational parameters such as pulse on duration and current. Moderate pulse currents together with low pulse on duration were found to be the plausible choices for HA coating applications.
Analysis of Strain Hardening Behaviour of Cast Aluminium Alloy 354 Subjected to Artificial Ageing at Various Temperatures
Authors: Eswar Aditya , Gupta Arnav , Babu G. Dinesh , Muktinutalapati Nageswara Rao
Published: December 2013

Automotive industry makes wide scale use of cast aluminium alloy 354 in the production of crucial components, such as compressor wheels for turbochargers. The compressor wheels undergo T61 heat treatment, involving artificial ageing at 188°C. This study focuses on the possible improvement of the mechanical behaviour of the components by subjecting them to modified heat treatments involving usage of lower artificial ageing temperatures (160, 171 and 177°C). A comparative analysis of tensile properties and strain hardening behaviour has been carried out with different artificial ageing temperatures. Results showed that the heat treatment routinely employed by the industry (aged at 188°C) leads to overageing, thereby resulting in relatively inferior mechanical properties and lower strain hardening rates as compared to the samples heat treated at lower artificial ageing temperatures. It is concluded that lowering of the artificial ageing temperature can lead to a superior state of components with respect to mechanical behaviour.
Epoxy Emulsion Modified Engineered Cementitious Composite for Enhanced Pipeline Coating
Authors: Wu Ying , Sun Qian Yao , Xu Chun Ming
Published: December 2013

A new class of Epoxy Emulsion modified Engineered Cementitious Composite (EM-ECC) has been developed for enhanced pipeline protection. The performance of typical ECC materials, such as flexural strength, anti-corrosion and early strength, has been improved by the addition of epoxy emulsion and rapid hardening cement. Our results indicated that the flexural strength of as-made EM-ECC increases with the increase of the EM/cement ratio after curing for 28 days. The retention rate of flexural strength of specimens remains analogical after immersed in water, 5 wt% Na2SO4 and 5 wt% NaCl solutions, respectively. The flexural strength reached ca. 16 MPa at 60 wt% replacement rate of rapid hardening cement after curing for 3 days. This new class of EM-ECC will shed light to the design of new applications for the oil and gas industry.
Strength and Microstructural Performance of Nano-SiO2 Gel (NSG) Infused Alkaline Activated Ground Blast Furnace Slag-Ultrafine Palm Oil Fuel Ash (AAGU) Based Mortar
Authors: Yusuf Moruf Olalekan , Megat Johari Megat Azmi , Ahmad Zainal Arifin , Maslehuddin Mohammed
Published: December 2013

The aim of this paper is to study the performance of infused nanoSiO2 gel (NSG) on the developed alkaline activated binary blending of ground blast furnace slag (GBFS) and ultrafine palm oil fuel ash (UPOFA) based mortar (AAGU) using the constant mass of combined activators (10 M NaOHaq+Na2SiO3aq (Ms = SiO2/Na2O=3.3)). The methods include using the 3-day compressive strength results and microstructural characterization (SEM+EDX and FTIR). The finding revealed that the compressive strength of the mortar increased with NSG and the maximum strength achieved was 57.3 MPa signifying 21% strength gain compared to NSG-free sample. The NSG also played the role of microcracks and pore fillings, increased the product homogeneity and reduced its amorphousity due to silicate re-organization but has no effects on Si-Al substitution.
Effect of Capping Agent on Physicochemical Properties of Zinc Substituted Nanoscale Hydroxyapatite
Authors: Kapoor Seema , Batra Uma , Kohli Suchita
Published: December 2013

Nanoscale zinc substituted hydroxyapatite has been synthesized by solgel technique at 70 C using an aqueous solution of calcium nitrate tetrahydrate (CNT), zinc nitrate tetrahydrate (ZNT) and potassium dihydrogen phosphate (KDP) as starting materials with or without a capping agent, triethanolamine (TEA). The synthesized nanopowders were calcined at two temperatures 800 C and 1000 C for 1 hr. The morphology and size of nanopowders were characterized by transmission electron microscopy. The BET surface area was evaluated from N2 adsorption isotherms. Structural analysis and thermal behavior were investigated by means of Fourier transform infrared spectroscopy, x-ray diffraction and thermogravimetry. The results of TEM confirmed that TEA is effective in reducing average crystallite size from 15 nm in case of zinc substituted hydroxyapatite without TEA (ZnHA) to 9 nm in case of zinc substituted hydroxyapatite with TEA (ZnHA-TEA). FTIR spectra showed the presence of weaker HPO4 bands and stronger O-H bands in case of ZnHA as compared to ZnHA-TEA, which indicated that the formation of the latter is delayed due to TEA assistance. TGA study revealed that ZnHA is thermally more stable as compared to ZnHA-TEA. These results show that the introduction of capping agent effectively restricts the particle growth during precipitation as well as on calcination.
Castor Oil Based Polyurethane Nanocomposites with Cellulose Nanocrystallites Fillers
Authors: Kaushik Anupama , Garg Alka
Published: December 2013

In this study the castor oil based polyurethane (PU) nanocomposites were prepared by dispersing the cellulose nanocrystallites (CNC) isolated from cotton linters. CNC was dispersed in PU matrix using ultrasonicator coupled with high shear homogenizer. The filler loading was varied from 0-10% of the total weight of the mixture. The PU/CNC nanocomposites were characterized by SEM, XRD, FTIR, mechanical and barrier properties. SEM confirmed homogeneous dispersion of CNCs in polyurethane matrix with small agglomerates at certain places. Improvement in mechanical properties was observed as compared to neat PU. Diffusivity and permeability of the nanocomposites was reduced at higher loadings of CNC.
Enhancing Biogas Production from Sugarcane Bagasse Using Steam Explosion in According With Acetic Acid Pretreatment
Authors: Srisang Netchanok , Chavalparit Orathai
Published: December 2013

Dilute acetic acid was used to pretreat sugarcane bagasse with 180°C steam explosion prior to anaerobic digestion. The Central Composite Design (CCD) was employed to recognize the optimum condition of pre-treatment sugarcane bagasse for biogas production. The individual variable effects of acetic acid concentration and reaction time on enhancing biogas production were investigated using response surface methodology (RSM). Data obtained from RSM analysis on biogas production were depending on analysis of variance (ANOVA). After optimization, the optimum pre-treatment condition was at 1.0% acetic, 17.45 min reaction time, while the maximum biogas production (434.47 L/kgVS) was 91.88% higher than the control (226.42 L/kgVS). Hence the optimum pre-treatment conditions for maximum biogas production were obtained by RSM analysis. It can be concluded that dilute acetic acid and steam explosion techniques can be used to achieve higher biogas.
Effect of Building Management System on Energy Saving
Authors: Kamali Saeed , Khakzar Golrokh , Abdali Hajiabadi Soolmaz
Published: December 2013

Without any doubt, one of the most worldwide challenging and controversial issues in the current century is the energy problem. In most countries, the increase of energy consumption, especially in building, has made energy saving and efficiency strategies important target for energy policies. In general, there are many ways to save energy. The most common method of economizing is within culturalization. For such purpose, building energy management system (BEMS) is considered as the latest idea of energy. Having a dynamic environment, smart buildings are affordable by the integration of four main elements: systems, structure, service, management, and the relationship between them. Intelligent buildings provide these benefits through intelligent control systems. In this paper, while introducing the energy management in buildings, it studies their applications and also their effects on management and optimization of energy consumption. The office building in San Francisco, USA with 66,943 ft2 area is considered as a case study for this research. Energy consumption is reduced 50 percent by implementing BMS in this building.
Creep Behavior of Catheter Reinforced with Braids: Analytical Simulation of Uniaxial Tension under Two-Stage Step Stress
Authors: Kato Yasuyuki
Published: December 2013

This paper describes the creep deformation behavior of catheter which is made of soft nylon resin and is reinforced with thin stainless wires called braid. In this research, the creep deformation behavior of uniaxial tension generated under two-stage step stress is examined as the most fundamental case that the principal axis of stress is fixed in a space. And the mechanical model, which is composed of a Voigt unit and a single spring element, is proposed for representing the creep deformation behavior. Then, the numerical simulation is carried out, and the validity of this model is verified by comparing the analytical results with the experimental results under two-stage step stress.
Preparation and Characterization of Activated Carbons Based on Lignocellulosic Residues
Authors: Alves Cibele C.O. , Rocha Pablo D. , Franca Adriana S. , Oliveira Leandro S.
Published: December 2013

This paper presents a comparative evaluation of three lignocellulosic residues (corn cobs, spent coffee grounds and Raphanus sativus press cake) as precursor materials in the production of activated carbons (ACs). Results indicate that the precursor material has a significant effect in both physical and chemical aspects of the adsorbent as well as on the adsorption mechanisms. Highest and lowest values of iodine number and density were observed for ACs based on press cake and corn cobs, respectively. Regardless of the observed differences in surface chemical make-up and adsorption mechanisms, all employed materials were deemed adequate for adsorbent production, since the prepared ACs presented adsorption capacities similar or even higher than those of commercial ACs and other residue-based adsorbents.
Experimental and Numerical Study of Plain-Woven Aramid Fabric
Authors: Flores-Johnson E.A. , Carrillo J.G. , Gamboa R.A. , Shen L.
Published: December 2013

In this paper, the tensile properties of plain-woven aramid fabric style 724 (Kevlar® 129 fibre, 1000 denier, 24×24 yarns per inch) and the tensile properties of individual aramid yarn extracted from the fabric are presented. It was found that this fabric is balanced with less than 5% difference in strength between the warp and weft directions. The mechanical properties of the individual yarns were found to be lower than those reported for Kevlar® 129 fibre, which is explained by the fact that the yarns were damaged during the extraction process or weaving process.
A 3D finite-element model of the tensile testing of plain-woven fabric was built at the mesoscale in Abaqus/Explicit by modelling individual crimped yarns and taking into account friction. Material properties and yarn geometry for the model were obtained from experimental observations. An orthotropic elastic model with failure criterion based on the yield stress was used. Numerical results were analysed and compared with experimental results. It was found that the numerical model can reproduce the physical experimental observations, the yield strength and the failure strain.