bluuebunny/crossref_metadata_2025 huggingface dataset:
La blasfemia del rey Sabio: vicisitudes de una leyenda (nuevas hipótesis respecto a la datación y la posición relativa del texto portugués)
Authors: De Barros Dias Isabel
Published: November 2015

Este artículo cuestiona algunas ideas existentes sobre la leyenda de la blasfemia de Alfonso X, en particular lo relativo a su presencia en la crónica portuguesa de 1344, redactada por Pedro Afonso de Barcelos, biznieto del rey Sabio. La puesta en valor de un dato menos considerado, la ausencia de este relato en el manuscrito truncado que transmite la primera redacción de la obra del conde portugués, estimula el planteamiento de una nueva hipótesis, basada en reflexiones no solo textuales, sino también contextuales (tanto de índole personal como política).
El castillo perdido del conde Rodrigo González
Authors: Ehrlich Michael
Published: November 2015

Este artículo sugiere que un castillo llamado Toron, construido el año 1137 por el conde Rodrigo González de Lara, y que fue luego otorgado a la orden del Temple, estaba en Summil, donde todavía permanecen las ruinas de un castillo de los cruzados (a unos 25 km de Ascalon, en el sudoeste de Israel). Esta opinión se contrapone a la tesis general que sostiene que el castillo construido por el conde estuvo situado en Latrun, a medio camino entre Tel-Aviv y Jerusalén. Una identificación basada en la similitud de nombres y en la común opinión que Latrun era un castillo templario. En este estudio se demuestra que la ubicación geográfica de Summil encaja con la del castillo del conde, mientras que Latrun no lo hace; que Toron fue un nombre habitual en el reino cruzado y que, por otra parte, no es cierto que Latrun fuera un castillo templario. Se sugiere también que cerca del castillo de Summil existía un pueblo llamado casale Sancti Salvatoris, analizándose asimismo la política de fortificación y colonización llevada a cabo por los cruzados durante el siglo XII.
La geometria del còdex 80 (s. XII) de la catedral de Tortosa
Authors: Lluís i Ginovart Josep , Baiges i Jardí Ignasi J. , Alanyà i Roig Josep
Published: November 2015

[ct] La geometria del còdex 80 de l’Arxiu Capitular de Tortosa ha estat tradicionalment atribuïda, com un text únic, a Gerbert d’Orlhac (c. 940-1003). Una nova lectura del text ens permet assegurar que es tracta d’un text de caràcter miscel·lani de geometria, compost per tres textos independents: una part pertany a la Geometria Incerti Auctoris apòcrifa de Gerbert d’Orlhac; una altra, al fragment De Nuptiis Philologiae et Mercurii de Marcià Capella (fl . 430) Ergasticis Schematibus, del llibre VII de la Geometria; i, finalment, s’hi llegeix una glossa als Elementa d’Euclides (c. 325-c. 265 aC.) d’Al-Ḥajjāj ibn Yūsuf ibn Maṭar (786-833). La interpretació de les proposicions de la geometria dóna el coneixement de la mesura indirecta de llocs als quals no es pot accedir amb l’instrumental medieval, és a dir, amb astrolabi, miralls, bastons i escaires.
Poder y centros de representación: castros y castillos en la Toscana y Tierra de Campos (siglos X-XII)
Authors: Pérez Rodríguez María
Published: November 2015

Desde que Pierre Toubert publicara su estudio sobre el Lazio, el incastellamento se convirtió en un importante punto de partida a la hora de explicar el feudalismo en buena parte del mundo mediterráneo. Lejos de intentar validar su viabilidad en la Península Ibérica, se ha llevado a cabo un estudio sobre el papel ejercido por las fortificaciones y la naturaleza de los vínculos entre monarquía y aristocracias en la región de la Toscana y la ribera del Cea, en Tierra de Campos. El objetivo principal es observar las semejanzas y diferencias existentes entre ambas zonas y su incidencia en el desarrollo del feudalismo.
Nuevos táxones animales descritos en la península Ibérica y Macaronesia desde 1994 (XIX)
Authors: Fernández J.
Published: November 2015

No disponible
Experimental Analysis of MR Fluid by Magneto-Rheological (MR) Damper
Authors: Thirupathi P. , Janaki Ramulu Perumalla , Venukumar S. , Saikiran Reddy Peddabavi , Krishna Reddy B. , Battacharya Sirish
Published: November 2015

Magneto-rheological fluids belong to a group of non-Newtonian fluids, and represent a group of purely-viscous fluids with the controllability of their properties by means of a magnetic field. In the present work, MR damper setup has designed and fabricated. MR fluid is prepared by mixing the lubricating oil, distilled water and iron particles of size 500 meshes in the standard proportions. During the experimentation, arrangement is made for load which falls on the piston head of MR damper to determine the damping effect. For every reputation, time and displacement of piston in the MR fluid is noted. Based on these parameters, velocity of the piston and rate of acceleration with respect to time and acceleration with respect to displacement is determined. Damping effect is calculated by using acceleration with respect to time and displacement respectively.
Multi Objective Design Optimization of Helical Gear Pair Using Adaptive Parameter Harmony Search Algorithm
Authors: Sabarinath P. , Thansekhar M.R. , Jeganathan R. , Saravanan R.
Published: November 2015

Mechanical design engineers design products by selecting the best possible materials and geometries that satisfies the specific operational requirements of the design. It involves lot of creativity and aesthetics to make better designs. A gear design makes the designer to compromise many design variables so as to arrive the best performance of a gear set. The best possible way for multi variable, Multiobjective gear design is to try design optimization. For many complex engineering optimization problems multi objective design optimization methods are used to simplify the design problem. In this paper, multiobjective design of helical gear pair transmission with objective functions namely volume of the small and large helical gear and opposite number of overlap ratio is taken into account. The design variables considered are normal module, helix angle, gear width coefficient and teeth number of small helical gear. A recent meta-heuristic algorithm namely parameter adaptive harmony search algorithm is applied to solve this problem using the weighted sum approach. It is evident from the results that the proposed approach is performing better than other algorithms.
Structural Response and Remaining Life of Damaged Composites
Authors: Singh Dalbir , Ganesan C. , Rajaraman A.
Published: November 2015

Composites are being used in variety of applications ranging from defense and aircraft structures, where usage is profuse, to vehicle structures and even for repair and rehabilitation. Most of these composites are made of different laminates glued together with matrix for binding and now-a-days fibers of different types are embedded in a composite matrix. The characterizations of material properties of composites are mostly experimental with analytical modeling used to simulate the system behavior. But many times, the composites develop damage or distress in the form of cracking while they are in service and this adds a different dimension as one has to evaluate the response with the damage so that its performance during its remaining life is satisfactory. This is the objective of the present study where a hybrid approach using experimental results on damaged specimens and then analytical finite element are used to evaluate response. This will considerably help in remaining life assessment-RLA- for composites with damage so that design effectiveness with damage could be assessed. This investigation has been carried out on a typical composite with carbon fiber reinforcements, manufactured by IPCL Baroda (India) with trade name INDCARF-30. Experimental studies were conducted on undamaged and damaged specimens to simulate normal continuous loading and discontinuous loading-and-unloading states in actual systems. Based on the experimental results, material characterization inputs are taken and analytical studies were carried out using ANSYS to assess the response under linear and nonlinear material behavior to find the stiffness decay. Using stiffness decay RLA was computed and curves are given to bring the influence of type of damage and load at which damage had occurred.
Improving the Mechanical Properties of the Propeller Shaft by Using Composite Materials
Authors: Ramesh Babu N. , Sangeeth Kumar E.
Published: November 2015

This work deals with the replacement of conventional two-piece steel drive shaft with a single-piece high strength composite drive shaft for an automotive application. The structural design parameters were optimized with the help of modelling software with the objective of minimizing the weight of composite drive shaft. The design optimization also showed significant potential improvement in the performance of propeller shaft. The modelling and analysis of the drive shaft [1] assembly was done using CATIA[2]/ANSYS software. Glass fiber reinforced polymer with silicon carbide is used in fabricating the propeller shaft. Finally, the analysis results were compared with conventional steel drive shaft.
Minimizing Makespan in Job Shop Scheduling Problem Using Genetic Algorithm
Authors: Athi Muthiah , Rajkumar R. , Muthukumar B.
Published: November 2015

- Scheduling is an important tool for manufacturing and engineering, where it can have a major impact on the productivity of a process. In manufacturing, the purpose of scheduling is to minimize the production time and costs. Production scheduling aims to maximize the efficiency of the operation and reduce costs. We keep all of our machines well-maintained to prevent any problems, but there is on way to completely prevent down-time. With redundant machines we have the security of knowing that we are not going to be in trouble meeting our deadlines if a machine has any unexpected down-times. Finally we can work to get our batch sizes as small as is reasonably possible while also reducing the setup time of each batch. This allows us to eliminate a sizable portion of each part waiting while the rest of the parts in the batch are being machined.
Wear Behaviour of Polyurethane Coated Aerospace Aluminium Alloy (7075)
Authors: Vijayakumar T. , Senthilvelan T. , Venkatakrishnan R.
Published: November 2015

This paper envisages to predict the life of an aircraft coating using high strength precipitation hardening 7000 series aluminum alloys, such as 7075 which is used extensively in aerospace industry. Aerospace aluminum alloy 7075 has been researched upon especially for aircraft materials. The intention of protective coating is to save the aerospace aluminium alloy 7075 metal surface from weatherability and, at the same time, to obtain the required degree of cosmetic finish for the object. One was epoxy polyamide as primer layer and other was the polyurethane as top-coat layer of coating through conventional spray type on aluminum alloy 7075 substrates. Epoxy polyamide is useful binders for aircraft primers. Top-coats have also been prepared, but polyurethane is still the choice for aircraft coating. This coating system is typically comprised, of a primer layer and a topcoat layer. The ability of the polyurethane coating is to prevent corrosion, weatherability depends on its anti-corrosive pigments and its adhesion to the substrate. All these factors are widely variable with the geographic location and season such as temperature, wind, oxygen and atmospheric pollutants. The effect of structural and process variable on wear resistance of polyurethane coating was analyzed to determine the maximum wear rate using DOE software optimum samples were prepare according to best level of each factor and its morphology was examined by scanning electron microscope (SEM).
Microwave Characterization of Ecosand for Electromagnetic Interference (EMI) Shielded Construction
Authors: Naveenaa S. , Sruthi S. , Sabarish Narayanan B.
Published: November 2015

Experimental study on microwave attenuation of ecosand is presented. Ecosand is a by-product of cement industry, and presents good alternative for natural river sand. Ecosand is a composite mixture, primarily containing silica and alumina. Microwave characterization provides good value enhancement for ecosand, encouraging its utilization in construction of EMI shielded buildings including safety vaults, server chambers and critical defense installations. Wave guide based studies on virgin ecosand and ecosand fly ash mixtures are conducted. Varying proportions of ecosand - flyash mixtures are considered. Reflected and transmitted power levels are measured. The preliminary results provide satisfactory EMI characteristics for a 60-40 ecosand-fly ash mixture. Further experiments on shielding effectiveness measurement of cement mortar composite, incorporating ecosand-fly ash mixture can provide effective conclusions on the microwave attenuation characteristics, and its subsequent utilization for EMI tolerant constructions.
Effect of Cutting Parameters on Feed Force in Machining AISI 1018 Steel
Authors: Sumesh C.S. , Sriram K.
Published: November 2015

In this present work, influence of cutting parameters on feed force is studied and optimized using Taguchi approach. AISI 1018 steel alloy is selected and machined using tungsten carbide tool. Eighty-One specimens were thus turned and cutting force was measured using lathe tool dynamometer. L27 orthogonal array in Taguchi approach selected for optimization. From ANOVA, the results showed that out of the parameters selected feed rate has major effect on feed force. In addition, the combination of cutting speed and feed rate has major effect on feed force
Experimental Investigation and Analysis of Machining Parameters in Drilling of Fly Ash Filled Carbon Fibre Reinforced Composites
Authors: Rajmohan T. , Sridhar Srinivasan , Ganesh Vedula , Sathiamitthran R.
Published: November 2015

The carbon fibre reinforced composites are one such class of materials finding widespread application owing to their superior mechanical and chemical properties. The addition of fillers has further increased their application spectrum. The present paper focuses on the multiple performances analysis in machining characteristics of drilling carbon fibre reinforced Composites produced through compression moulding route. Experiments are conducted on a radial drilling machine using L16orthogonal array. Drilling test is carried out using coated HSS drill of 6 and 10 mm diameter. The effect of drill diameter, wt % of fly ash,spindle speed and the feed rate has been investigated on the thrust force and delamination. After conducting experiment, mathematical models have been developed to fit the output responses using Response surface methodology and drilling parameters have been optimized using Desirability based approach. This methodology deals with the development of modelling equations for each response.The relative significance of the various parameters has been found using ANOVA.
Experimental Investigation of Soyabean Oil Based Cutting Fluid during Turning of Hardened AISI 4340 Steel with Minimal Fluid Application
Authors: Raj Anil , Wins K. Leo Dev , George Kiran Easow , Varadarajan A.S.
Published: November 2015

Turning of hardened steel is normally carried out with copious supply of cutting fluid to improve the cutting performance. Most of the cutting fluids in regular use are petroleum based emulsions which create several environmental problems. In this context, pure dry turning is a logical alternative as it is free from the problems associated with the cutting fluid. The achievable tool life and part finish are often affected while machining under completely dry condition. Under such situation, the concept of minimal cutting fluid application (MCFA) presents itself as a possible solution. In this study an effort was made to study the effect of soya bean oil based cutting fluid on cutting performance with minimal cutting fluid application during turning of hardened AISI4340 steel. An 18 run experiment was designed using Taguchi technique to study the effect of fluid application parameters on cutting temperature and surface roughness. Improvement in cutting performance was observed in terms of reduction in cutting temperature and improvement in surface finish (Ra) when water in oil emulsion of soya bean oil was used as the cutting fluid.
Effect of Equal Channel Angular Pressing on Microstructure and Mechanical Properties of As-Cast Al-B4C Composite
Authors: Saravanan Karunanaithi , Senthil Kumar Mariappan , Venkatachalam Perumal , Raghavan Rajaram
Published: November 2015

In this experiment, comparison analysis of mechanical properties, porosity and grain size of Pure Al (powder), 95%AL + 5% B4C (With sand casting method) and 95%AL + 5% B4C (With ECAP method) are determined. The ECAP method value is much greater than the sand casting method,because of metal matrix composite microstructure refinement during the pressing operation. Because of material porosity value decreases, powder particle consolidation, the closure of porosity, grain refinement and improve in dislocation occurs as ECAP method gives the results of Mechanical properties as like tensile strength 105.8Mpa, Hardness 94HV, density 888.88kg/m3values increase. At the same time, porosity and grain size value will be reduced because of individual power consolidation happening during ECAP methods like as 1.63% and 8μm. In this metal matrix composite is applied to aeronautical and automobile industry
Finite Element Analysis and Experimental Investigation of Drilling of Titanium Alloy (Ti6Al4V)
Authors: Senthilkumar M. , Prabukarthi A. , Prakash U.B.S. , Krishnaraj V. , Balaji K.
Published: November 2015

Drilling is a widely used machining process for various components pertaining to industries such as aerospace, automobile etc. Ti6Al4V is very often used for high stressed components like aircraft structure because of its excellent strength to weight ratio. Tool geometry plays a vital role in effective drilling. It is very difficult to develop a modified geometry in order to achieve better hole quality and improved tool life and validating its outcome experimentally is very expensive. The current paper presents the concept of drilling simulation process using commercial finite element software, Abaqus/Explicit. Five major drill bit geometry such as point angle, helix angle, clearance diameter, and web thickness were varied The proposed simulation model for drilling process was based on Eulierian formulation with explicit interaction. The results of simulation were compared with that of experimental drilling. The simulated result has a good correlation with the experimental result. The change in reference point to chisel tip in the simulation yielded better results as compared to when the reference point is taken at top surface of the tool.
Parameteric Optimization of Surface Roughness in End Milling of Aluminium Rock Dust Composite
Authors: K SOORYA PRAKASH , Sudhagar S. , Sakthivel M. , Gopal P.M.
Published: November 2015

Recent developments in the composite materials with high performance increase its range of application most widely but the major disadvantage of these novel materials is machining. The selection of proper process parameters plays an important role in distinguishing machining quality. This work mainly concentrates on the selection of process parameter for minimizing the surface roughness in end milling operation for the newly developed aluminium rock dust metal matrix composite. Taguchi method is used to design and accordingly L27 orthogonal array with five factors viz particle size, weight percentage, cutting speed, feed and depth of cut each at three levels is employed. The experiments were performed in a CNC vertical machining center and corresponding surface roughness values are measured. From the collected data, ANOVA is performed and observations reveal that feed rate influence more on surface roughness followed by particle size, depth of cut, weight percentage and cutting speed.
Process Optimization of Electric Discharge Machining Using Response Surface Methodology
Authors: Kumar Rajinder , Grover Neel Kanth , Singh Amandeep
Published: November 2015

Electric Discharge Machining (EDM) is one of the most commonly used non-traditional machining processes. Complex geometries can be easily manufactured using EDM. Material removal is achieved by producing continuous spark occurring between well shaped tool electrode and work piece. EDM does not involve direct contact of tool and work piece. Machining process involves a number of input variables like, current, voltage, pulse on/off which in turn affect the machining efficiency of EDM. These process parameters must be optimized to attain high material removal rate and low tool wear rate. The present paper presents theoptimization of tool wear rate of copper and brass electrode on machining of EN-47 using Response Surface Methodology (RSM).
Effect of Friction Stir Welding Process Parameters on Temperature Profile and Tensile Strength of Dissimilar Aluminum Alloys
Authors: Gupta Saurabh Kumar , Pandey K.N. , Kumar Rajneesh
Published: November 2015

The aim of this research is to study the effect of Friction Stir Welding (FSW) process parameters such as tool rotational speed and welding speed on temperature distribution and tensile strength of dissimilar AA5083-O and AA6063-T6 joint welded by FSW. Peak temperature at retreating side was observed lower as compared to advancing side for each experiment. Peak temperature decreases with decreasing the tool rotational speed but vice versa with welding speed. ANOVA indicated that the temperature profile was strongly dependent on the tool rotation speed than the welding speed and it also showed that welding speed is the main process parameter that has highest effect on tensile strength of welded joint.
Influence of Stick-Slip Effect on Gas Metal Arc Welding
Authors: Ashidh Kalathingal , Santha Kumari A , Sumesh A. , Rajasekaran N
Published: November 2015

A key factor in the performance of Gas Metal Arc welding (GMAW) is the feedability of the filler wire. Variations in the wire feed speed (WFS) are caused by adverse conditions during welding. These include damaging effects such as “stick-slip” motion of the welding wire, premature wear of the contact tube and, in general, the conduit cable usage during welding. Experiments were conducted to study these issues. The welding parameters such as arc current and voltage were captured by using data logger and the stick-slip effect was analyzed. It was observed that arc waveforms were found to have significant influence because of the stick-slip effect. The corresponding fusion characteristics of the weldments were studied. The voltage change was suggested to specific conduit cable configuration.
Optimization of Process Parameters in Hot Forging of Medium Carbon Micro-Alloyed Steel
Authors: Talukdar Pinaki , Ohdar Raj Kumar , Singh Balbir , Equbal Md Israr
Published: November 2015

In this paper, a combination of taguchi method and grey taguchi method has been studied for optimization of the hot forging of medium carbon micro-alloyed (MC–MA) steel. The influence of forging parameters viz. forging temperature, percentage reduction and cooling rate are investigated for the responses tensile strength and impact strength after forging operation. In order to optimize the responses simultaneously, Grey Relational Analysis (GRA) is employed along with Taguchi method. Through GRA, grey relational grade is used as a performance index to determine the optimal setting of process parameters for above mentioned responses simultaneously. Analysis of variance (ANOVA) is employed to determine significant parameters. The results indicated that the cooling rate has a remarkable effect on the tensile strength and impact strength at room temperature. Optimization of the parameters simultaneously leading to a higher tensile strength and impact strength and it is also verified through a confirmation experiment for validation of these results.
Fabrication and Mechanical Properties of Hybrid Natural Composite
Authors: Venkatakrishnan R. , Senthilvelan T. , Vijayakumar T.
Published: November 2015

In recent years, natural composite materials have replaced many conventional ones, such as metals and synthetic resin composites in many applications. This is due to the advantage of hybrid natural composite over the conventional materials. The natural composites are made up of both reinforcement and matrix materials which are obtained by the natural resources. Natural fibers reinforcement are strong, light weight, renewable, cheap, completely or partially recyclable, and biodegradable. In this work sisal and banana fibers have been used as the main reinforcing materials to increase the effectiveness of natural fibers. Cashew nut shell liquid (CNSL) resin is a natural resin that can be obtained from cashew nut. CNSL is essentially a mixture of phenol extracted from the shell of the cashew nut and is a good natural alternative to chemically derived phenol.
Determination of the Effect of Nickel Content on Hardness, Optimum Aging Temperature and Aging Time for Spinodal Bronze Alloys Cast in Metal Mould
Authors: Shankar Karthik V. , Sellamuthu R.
Published: November 2015

An investigation was conducted to find the optimum aging temperature and aging time for Cu-Sn-Ni spinodal bronze alloys with varying nickel wt% cast in metal mould. The specimens were subjected to solutionisation and were aged at 250°C, 300°C, 350°C, 400°C and 450°C to induce spinodal decomposition. The microstructural observation reveals that the dendritic structure of the as-cast alloy was completely eliminated after solutionisation and grain boundary precipitates were formed with increase in aging time. The peak hardness and the peak aging time increases with increase in nickel content. This implies that nickel contributes to spinodal decomposition process.
Influence of MoS2 on Microstructure and Mechanical Behaviours of Al6061-Al2O3 Hybrid Composite
Authors: Maivizhi Selvi S. , Saravana Kumar A. , Isaac Daniel Raj G. , Keerthana N. , Madhanagopal G.D. , Nikhilesh G.
Published: November 2015

In this investigation, the influence of MoS2 on the mechanical properties of Al6061-Al2O3hybrid composites was studied. The composites of Al6061 alloy, AA 6061-6% Al2O3 and Al6061-6% Al2O3-2% MoS2 were manufactured using Stir casting method. These samples were examinedusing optical microscope for the dispersion of reinforcement (Al2O3 ) and solid lubricant (MoS2).The micro structure revealed that there were even distribution of the additives in the Al6061 matrix.The presence of these particles improved the mechanical properties of the composites. For these compositions flexural strength was found using 3 point bending test and impact strength was found using Charpy test. It was observed that the hardness, toughness and flexural strength values increases with the addition of Al2O3 and decreases with the addition of MoS2 to the second composition.
Preparation and Characterization of Hybrid Aluminum Matrix Composites Reinforced with MWCNT Using Powder Metallurgy Process
Authors: Dhandapani S , Rajmohan T. , Palanikumar K. , Mugunthan Charan
Published: November 2015

Metal Matrix Nano Composites (MMNC) consist of a metal matrix reinforced with nano-particles featuring physical and mechanical properties very different from those of the matrix. Especially carbon Nano tubes (CNT) can improve the matrix material in terms of wear resistance, damping properties and mechanical strength. The present investigation deals with the synthesis and characterization of aluminium matrix reinforced with micro B4C particles, and Multi Wall Carbon nano Tubes (MWCNT) were prepared by powder metallurgy route. Powder mixture containing fixed weight (%) of B4C and different wt% of MWCNT as reinforcement constituents that are uniaxial cold pressed and later green compacts are sintered in continues electric furnace. Microstructure and Mechanical properties such as micro hardness and density are examined. Micro structure of samples has been investigated using scanning electron microscope (SEM) .The results indicated that the increase in wt % of MWCNT improves the bonding and mechanical properties.
Influence of WC Particulate Reinforcement on the Mechanical Properties and Sliding Wear of Al6061 Alloys
Authors: Veeresh Kumar G.B. , Pramod R.
Published: November 2015

The research community has acknowledged the superiority of composite material properties in comparison to conventional materials. Aluminum Metal Matrix Composites (MMCs) sought over other conventional materials in the fields of automotive, sports, aerospace and marine applications due to their admirable improved properties. These materials are of much interest to the researchers from few decades. In this paper, the investigational results of the sliding and mechanical properties of Al6061–WC metal matrix composites are presented. The Al6061 composites containing 0–3 wt% WC were dispersed in the base matrix in steps of 1 and fabricated by powder metallurgy technique. The experimental results revealed that with an increase in WC content there was an increase in the density of the composites and these values are in sync with the theoretical values determined by the rule of mixtures. The tensile strength and hardness of the Al6061–WC composites are directly related to weight percentage of WC and an increase was observed with a decrease in ductility was observed.Wear properties increased, compared to as-cast Al6061 with an increase in WC content in the matrix.
Numerical Investigation of Forced Convection Heat Transfer from Offset Square Cylinders Placed in a Three Dimensional Confined Channel
Authors: Maheandera Prabu Paulraj , Sivasubramanian Mahadevan , Kanna P. Rajesh , Uthayakumar M. , Padmanaban K.P.
Published: November 2015

Abstract-Flow over two offset square cylinders in a confined channel is simulated for different Reynoldsnumber to reveal the forced convection heat transfer from the heated square cylinders to the ambientfluid. The bottom of the cylinder is maintained at constant temperature. The distance between thecylinder in normal direction as well as transverse direction are fixed as 2d and the blockage ratio is fixedas 0.167. Heat transfer from the cylinders to the ambient fluid as well as conducted within solid wallthrough conjugate interface boundary investigated in connection with Reynolds number are reportedfor both steady and periodic flow. Simulation is carried out for Reynolds number varies from 10 to100 for the fluid as air with Prandtl number as 0.71. The isotherm contours, local Nusselt number andaverage Nusselt number are reported for various Reynolds number. The stagnation zone results higherNusselt number than remaining walls and rear wall results lowest Nusselt number. The downstreamcylinder results higher Nusselt number than the upstream cylinder. The top and bottom surfaceNusselt number from upstream and downstream cylinder are not analogous to single cylinder placed ina channel.
Mathematical Model Development to Predict Wear Rate of Al6061/TiCp Composites under Lubricant
Authors: Ragupathy K. , Velmurugan C. , Rajesh S. , Ebenezer Jacob Dhas D.S.
Published: November 2015

Aluminium matrix composites are mostly used in aerospace and automobile industries due to their improved properties such as hardness, strength, wear resistance combined with considerable weight savings over unreinforced alloys. This paper reports the lubricated wear behavior of Al6061composites reinforced with titanium carbide particles fabricated by stir casting route. The experiments were conducted using central composite rotatable design method. The wear test was performed on the pin on disc machine where aluminium composite pins were rubbed against EN31 steel discs in the presence lubricant. A mathematical model has been developed by response surface methodology. The validity of the developed model was checked by Analysis of variance method. The experimental results revealed that the addition of lubricant at the contact surface reduced wear rate of the composite.
Biodiesel Production from Dairy Scum Oil by Using Heterogeneous Catalyst and its Performance Test on CI Engine
Authors: Omkaresh B.R. , Arun S.B. , Suresh R. , Yathish K.V.
Published: November 2015

Now a days increasing in prices and depletion of fossil fuels, creates very necessary to find out an alternative fuel (biodiesel) from renewable natural resources. This paper deals with the transesterification of animal fat (dairy scum oil) to obtain Fatty Acid Methyl Ester (FAME) or biodiesel in presence of calcium oxide catalyst at 65°C. The properties of produced biodiesels and their blend for different ratios (B10, B20, B30 and B100) are comparable with properties of diesel and ASTM biodiesel standards. Tests have been conducted on CI engine for different blends of biodiesel with standard diesel, at an engine speed of 1500 rpm, fixed compression ratio 17.5, fixed injection pressure of 200bar and varying brake power. The performance parameters includes brake thermal efficiency, brake specific fuel consumption, Exhaust gas temperature and emissions parameters as Carbon monoxide (CO), Carbon dioxide (CO2), Hydrocarbon (HC) and Oxides of nitrogen (NOx) varying against Brake Power (BP).
A Conversion and Tribology Investigation on Used Ayurvedic Oil
Authors: Balakumar Ranganathan , Sriram G. , Arumugam S. , Abhijith Koushal V. , Sai Surya Venkatesh Villa
Published: November 2015

Biofuel plays a major role in IC engine nowadays. Used Ayurvedic Oil (UAO) is one among the alternative fuels utilized. The preliminary property studies were carried out and the UAO had undergone simple Transesterification process to be converted to Used Ayurvedic Oil Methyl Ester (UAOME). The Fourier Transform Infrared (FTIR) spectroscopy analysis confirmed the UAO to UAOME conversion. The Trobological investigation on UAOME is also conducted using Four Ball Wear Tester. The results showed that lower wear scar was observed in UAOME comparatively with diesel. From the results it is clear that the UAO can be a novel partial substitute for diesel fuel.
A Comparison of Porous Structures on the Performance of a Slider Bearing with Surface Roughness in Couple Stress Fluid Film Lubrication
Authors: Rao P.S. , Agarwal Santosh
Published: November 2015

This paper presents the theoretical study and analyzes the comparison of porous structures on the performance of a couple stress fluid based on rough slider bearing. The globular sphere model of Kozeny-Carman and Irmay’s capillary fissures model have been subjected to investigations. A more general form of surface roughness is mathematically modeled by a stochastic random variable with non-zero mean, variance and skewness. The stochastically averaged Reynolds type equation has been solved under suitable boundary conditions to obtain the pressure distribution in turn which gives the expression for the load carrying capacity, frictional force and coefficient of friction. The results are illustrated by graphical representations which show that the introduction of combined porous structure with couple stress fluid results in an enhanced load carrying capacity more in the case of Kozeny-Carman model as compared to Irmay’s model.
Automobile Gearbox Fault Diagnosis Using Naive Bayes and Decision Tree Algorithm
Authors: Sreenath P.G. , Praveen Kumare Gopalakrishnan , Pravin Sundar , Vikram K.N. , Saimurugan M.
Published: November 2015

Gearbox plays a vital role in various fields in the industries. Failure of any component in the gearbox will lead to machine downtime. Vibration monitoring is the technique used for condition based maintenance of gearbox. This paper discusses the use of machine learning techniques for automating the fault diagnosis of automobile gearbox. Our experimental study monitors the vibration signals of actual automobile gearbox with simulated fault conditions in the gear and bearing. Statistical features are extracted and classified for identifying the faults using decision tree and Naïve bayes technique. Comparison of the techniques for determining the classification accuracy is discussed.
Optimization of Electroless Ni-P-Nano-TiO2 Coating Parameters Using Taguchi Method for Corrosion Performance
Authors: Tamilarasan T.R. , Sathish Kumar R. , Rajendran R. , Rajagopal G.
Published: November 2015

This article considers an experimental study of Taguchi’s parameters design to maximize the corrosion resistance of electroless Ni-P-nano-TiO2 on low carbon steel substrate. The experiments were carried out based on Taguchi’s L9 orthogonal array considering four coating parameters of three levels each namely, Bath Temperature, pH of bath, Bath Loading, and concentration of TiO2. Scanning Electron Microscope (SEM) equipped with Energy Dispersive X-ray Spectroscopy (EDS) facilitated the study of the surface morphology and the chemical composition of the coatings. Corrosion performance of the deposits was evaluated by Tafel polarization technique in 3.5 wt. % of NaCl solution. The observation shows that pH level has more significant influence on the corrosion behavior of the composite deposit. The experimental study revealed that the optimum conditions are A3B3C2D1 (Temperature of 88° C, pH of 6, bath loading of 0.5 dm2/l, and TiO2 concentration of 2 g/l).
Design and Analysis of Commercial Automotive Vehicle Brake Pedal
Authors: Ganesh Ghadage , Unmesh Pawar , Kadam Satish S.
Published: November 2015

Over the years, designers have been developing various brake pedals in a bid to eliminate the operator’s risk of pressing the wrong pedal and to reduce his or her braking reaction time. One of the effective methods for reducing weight of trucks brake pedal is to change the design structure of it. The brake pedal is designed and analysed using Ansys 14.0. Different materials are used for the effective design of brake pedal with weight reduction of pedal and improved grip between foot and the pedal. The FEA results obtained and discussed herein confer optimum, cost effective design solution, easy to manufacture, and exhibits better grip.
Space-time scan statistics of 2007-2013 dengue incidence in Cimahi city, Indonesia
Authors: Dhewantara Pandji Wibawa , Ruliansyah Andri , Fuadiyah M. Ezza Azmi , Astuti Endang Puji , Widawati Mutiara
Published: November 2015

Four dengue serotypes threatened more than 200 million people and has spread to over 400 districts in Indonesia. Furthermore, 26 districts in most densely populated province, West Java, have been declared as hyperendemic areas. Cimahi is an endemic city with the highest population (14,969 people per square kilometer). Evidence on distribution pattern of dengue cases is required to discover the spread of dengue cases in Cimahi. A study has been conducted to detect clusters of dengue incidence during 2007-2013. A temporal spatial analysis was performed using SaTScan™ software incorporated confirmed dengue monthly data from the Municipality Health Office and population data from a local Bureau of Statistics. A retrospective space-time analysis with a Poisson distribution model and monthly precision was performed. Our results revealed a significant most likely cluster (p<0.001) throughout period of study. The most likely cluster was detected in the centre of the city and moved to the northern region of Cimahi. Cimahi, Karangmekar, and Cibabat village were most likely cluster in 2007-2010 (p <0.001; RR = 2.16-2.98; pop at risk 12% total population); Citeureup were detected as the most likely cluster in 2011-2013 (p <0.001; RR 5.77), respectively. Temporaly, clusters were detected in the first quarter of each year each. In conclusion, a dynamic spread of dengue initiated from the centre to its surrounding areas during the period 2007-2013. Our study suggests the use of GIS to strengthen case detection and surveillance. An in-depth investigation to relevant risk factors in high-risk areas in Cimahi city is encouraged.
E-cigarettes, smokers and health policies
Authors: Nardini S. , Pacifici R.
Published: November 2015

Not available
Environmental challenges posed by veld fires in fragile regions: The case of the Bulilima and Mangwe districts in southern Zimbabwe
Authors: Dube Ernest
Published: November 2015

This original research confronted challenges to environmental management and sustainability posed by veld fires in the Bulilima and Mangwe Districts of Matabeleland in the South Province in southern Zimbabwe. Veld fires have affected the fauna and flora, polluted air and water, and destroyed livelihoods. The study aimed at establishing challenges to environmental sustainability posed by veld fires, identifying the type of environment upon which veld fires have impacted, analysing legal issues and other interventions surrounding the control of veld fires and suggesting new control measures for veld fires. A qualitative research design and quota sampling were used. The study involved 30 participants. Data was collected through a questionnaire, an interview guide and participant observation. Challenges to environmental management and sustainability posed by veld fires include property damage, reduced soil fertility, destruction of vegetation, air and water pollution and destruction of wildlife. Most veld fires are a result of human actions that emanate from the disposal of cigarettes, the burning of vegetation when preparing fields, the use of fire by hunters, smoking out bees and the making of fires by motorists along highways. The government should consider reviewing the current environmental statues. Fireguards should be wide enough to lessen veld-fire impact. Lastly, veld-fire campaigns and rehearsals should be run on a regular basis. It is hoped that this work would make a significant contribution through improving the current thinking about environmental management and sustainability, thereby benefiting policy makers, practitioners and stakeholders.
Теорема об относительном индексе для $K$-гомологий
Authors: Nazaikinskii Vladimir Evgen'evich
Published: November 2015

Для классов $K$-гомологий доказан аналог теорем об относительном индексе типа теоремы Громова-Лоусона.
Effect of Collagen Matrix Saturation on the Surface Free Energy of Dentin using Different Agents
Authors: Cavalcanti Yuri Wanderley , de Almeida Leopoldina de Fátima Dantas , Souza Samilly Evangelista , Sampaio Aline Araújo , da Silva Wander José , Cur Altair A Del Bel , Hebling Josimeri
Published: November 2015

Introduction

The surface free energy of conditioned-dentin is one of the factors that interfere with monomeric infiltration of the interfibrillar spaces. Saturation of the tooth matrix with different substances may modulate this energy and, consequently, the wettability of the dentin.

Aim

To evaluate the influence of different substances used to saturate conditioned-dentin on surface free energy (SFE) of this substrate.

Materials and methods

Dentin blocks (4 × 7 × 1 mm, n = 6/ group), obtained from the roots of bovine incisors, were etched using phosphoric acid for 15 seconds, rinsed and gently dried. The surfaces were treated for 60 seconds with: ultra-purified water (H2O-control); ethanol (EtOH), acetone (ACT), chlorhexidine (CHX), ethylenediaminetetraacetic acid (EDTA); or sodium hypochlorite (NaOCl). The tooth surfaces were once again dried with absorbent paper and prepared for SFE evaluation using three standards: water, formamide and bromonaphthalene. Analysis of variance (ANOVA) and Dunnet's tests (α = 0.05) were applied to the data.

Results

Ethylenediaminetetraacetic acid was the only substance that caused a change to the contact angle for the standards water and formamide, while only EtOH influenced the angles formed between formamide and the dentin surface. None of the substances exerted a significant effect for bromonaphthalene. In comparison to the control, only EDTA and NaOCl altered both polar components of the SFE. Total SFE was increased by saturation of the collagen matrix by EDTA and reduced when NaOCl was used.

Conclusion

Saturation of the collagen matrix by EDTA and EtOH changed the surface free energy of the dentin. In addition, the use of NaOCl negatively interfered with the properties evaluated.

Clinical significance

The increase of surface free energy and wettability of the dentin surface would allow higher penetration of the the adhesive system, which would be of importance to the clinical success of resin-dentin union.

How to cite this article

de Almeida LFD, Souza SE, Sampaio AA, Cavalcanti YW, da Silva WJ, Cur AADB, Hebling J. Effect of Collagen Matrix Saturation on the Surface Free Energy of Dentin using Different Agents. J Contemp Dent Pract 2015;16(7):531-536.
Randomized Controlled Trial comparing Dressing and No Dressing of Surgical Wound after Cleft Lip Repair
Authors: Gbolahan Olalere Omoyosola , Ogunmuyiwa Stella Amiede , Osinaike Babatunde Babasola
Published: November 2015

Background

Cover wound dressings are regarded as important postoperative care following surgical intervention. Opinions differ on whether the cleft lip repair wound should be routinely covered by dressings or not. Therefore, a well designed randomized controlled trial is required to determine if routine cover dressing offers a better outcome.

Aim

The aim of this study was to compare the outcome of wound and cosmetic appearance of cleft lip repair in a randomized controlled trial between cover wound and no wound dressing groups.

Materials and methods

Forty consecutive patients requiring cleft lip repair were randomized prospectively to receive the traditional wound dressing cover (n = 20) or had the wound left exposed without any dressing cover (n = 20), after the completion of cleft wound closure. The main outcome measures were wound infection and dehiscence rates in the two groups, in addition to the scar cosmetic outcomes.

Result

The two groups were comparable in terms of age and sex. The incidence of wound infection was 0% (0/20) in cover dressing group as compared to 5% (1/20) in no cover dressing group (p = 0.31). No statistical significant differences in the wound dehiscence rate between the wounds that received dressing (15%) and those with no dressing (20%) were observed. The mean diameter of scar at the 5th to 8th week review appointments was almost similar between the group with dressing (3.29 ± 1.26 mm) and no dressing (3.62 ± 1.28 mm). The patient reported outcome in relation to the cosmetic appearance of the scar after repair was similar in the two groups.

Conclusion

There was no difference in the main outcome measures between the group that had cover dressing and those with exposed wound after cleft lip repair surgery. This study demonstrates that dressing of cleft repair wound may be unnecessary.

How to cite this article

Gbolahan OO, Ogunmuyiwa SA, Osinaike BB, Alabi A. Randomized Controlled Trial comparing Dressing and No Dressing of Surgical Wound after Cleft Lip Repair. J Contemp Dent Pract 2015;16(7):554-558.
Biomarkers of Orthodontic Tooth Movement in Gingival Crevicular Fluid: A Systematic Review
Authors: Alhadlaq Adel M
Published: November 2015

Background

The analysis of gingival crevicular fluid (GCF) may be an acceptable way to examine the ongoing biochemical processes associated with bone turnover during orthodontic tooth movement. If it is possible to biologically monitor and predict the outcome of orthodontic forces, then the management of appliances could be based on individual tissue responses, and the effectiveness of the treatment could be improved.

Methodology

A literature search was carried out in major databases, such as medline, EMBASE, cochrane library, web of science, google scholar and scopus for relevant studies. Publications in English between 2000 and 2014 which estimated GCF markers as indicators of orthodontic tooth movement were included.

Results

The list of biomarkers available to date was compiled and presented in table format. Each biomarker is discussed separately based on the available evidence.

Conclusion

Several sensitive GCF markers are available to detect the biomechanical changes occurring during orthodontic tooth movement. Further focused research might help to analyze the sensitivity and reliability of these indicators, which in turn can lead to the development of chairside tests to assess the outcome of orthodontic therapy.

How to cite this article

Alhadlaq AM. Biomarkers of Orthodontic Tooth Movement in Gingival Crevicular Fluid: A Systematic Review. J Contemp Dent Pract 2015;16(7):578-587.