The scope of the present paper is to understand the effects of crystalline admixture on the selfhealing capacity of the cementitious composites. Previous studies were examined and a conclusion was drawn to the effect ...The scope of the present paper is to understand the effects of crystalline admixture on the selfhealing capacity of the cementitious composites. Previous studies were examined and a conclusion was drawn to the effect that different additives to crystalline admixture tend to improve self-healing of concrete for larger cracks. It is recommended that initial treatment with chemical admixture can stimulate and heal further cracks and it has the better repeatability trend in mixing with the concretes and mechanical recovery is possible even under repetitive preloading. Effective self-healing with chemical admixtures even under open-air exposure, leads to study the importance of a service ability design parameter including the maximum allowable crack width by repeatability analysis as a function of the exposure with the concept of sealable crack width.展开更多
In this investigation,the effect of friction stir welding(FSW)parameters such as tool material rotational speed,and welding speed on the mechanical properties of tensile strength,hardness and impact energy of magnesiu...In this investigation,the effect of friction stir welding(FSW)parameters such as tool material rotational speed,and welding speed on the mechanical properties of tensile strength,hardness and impact energy of magnesium alloy AZ31B was studied.The experiments were carried out as per Taguchi parametric design concepts and an L9 orthogonal array was used to study the influence of various combinations of process parameters.Statistical optimization technique,ANOVA,was used to determine the optimum levels and to find the significance of each process parameter.The results indicate that rotational speed(RS)and traverse speed(TS)are the most significant factors,followed by tool material(TM),in deciding the mechanical properties of friction stir processed magnesium alloy.In addition,mathematical models were developed to establish relationship between different process variables and mechanical properties.展开更多
Recently,the application of Wireless Sensor Networks(WSNs)has been increasing rapidly.It requires privacy preserving data aggregation protocols to secure the data from compromises.Preserving privacy of the sensor data...Recently,the application of Wireless Sensor Networks(WSNs)has been increasing rapidly.It requires privacy preserving data aggregation protocols to secure the data from compromises.Preserving privacy of the sensor data is a challenging task.This paper presents a non-linear regression-based data aggregation protocol for preserving privacy of the sensor data.The proposed protocol uses non-linear regression functions to represent the sensor data collected from the sensor nodes.Instead of sending the complete data to the cluster head,the sensor nodes only send the coefficients of the non-linear function.This will reduce the communication overhead of the network.The data aggregation is performed on the masked coefficients and the sink node is able to retrieve the approximated results over the aggregated data.The analysis of experiment results shows that the proposed protocol is able to minimize communication overhead,enhance data aggregation accuracy,and preserve data privacy.展开更多
The land ward displacement of the shoreline caused by the forces of waves and currents is termed as Coastal Erosion. The Coastal areas have become more prone and vulnerable to natural and human made hazards which lead...The land ward displacement of the shoreline caused by the forces of waves and currents is termed as Coastal Erosion. The Coastal areas have become more prone and vulnerable to natural and human made hazards which lead to Coastal Erosion. The Shoreline retreat is recognized as a burgeoning threat because of global climate change and other anthropogenic activities that alter the natural processes of sustaining beaches and coasts. Coastal Erosion mainly occurs when wind, waves and long shore currents move sand from shore and deposit it somewhere else. The sand can be moved to another beach, to the deeper ocean bottom, into an ocean trench or onto the landside of a dune. The removal of the sand from the sand sharing system results in permanent changes in beach shape and structure. The impact of the event is not seen immediately as in the case of Tsunami or Storm Surge but it is equally important when we consider loss of property. It generally takes months or years to note the impact of Erosion;therefore, this is generally classified as a “Long Term Coastal Hazard”. The present paper attempts to describe a Review on Coastal Erosion Process, Parameters’ affecting, and methodologies are adopted to identify the erosion and recommend a solution.展开更多
The aim of present study is to analyze the influence of volume percentage(vol.%) of nano-sized particles(TiB_2: average size is 35 nm) on microstructure, mechanical and tribological behavior of 6061-T6 Al alloy surfac...The aim of present study is to analyze the influence of volume percentage(vol.%) of nano-sized particles(TiB_2: average size is 35 nm) on microstructure, mechanical and tribological behavior of 6061-T6 Al alloy surface nano composite prepared via Friction stir process(FSP). The microstructure of the fabricated surface nanocomposites is examined using optical microscopy(OM) and scanning electron microscope(SEM) for distribution of TiB_2 nano reinforcement particles, thickness of nano composite layer formed on the Aluminum alloy substrate and fracture features. The depth of surface nano composite layer is measured as 3683.82 m m along the cross section of stir zone of nano composite perpendicular to FSP. It was observed that increase in volume percentage of TiB_2 particles, the microhardness is increased up to132 Hv and it is greater than as-received Al alloy's microhardness(104 Hv). It is also observed that at 4volume percentage higher tensile properties exhibited as compared with the 2 and 8 vol. %. It is found that high wear resistance exhibited at 4 volume percentage as-compared with the 2 and 8 vol. %. The observed wear and mechanical properties are interrelated with microstructure, fractography and worn morphology.展开更多
A novel compact Swastika shaped patch antenna is designed in the present work,which can be used for Multiple Input Multiple Output(MIMO) systems.The proposed two element MIMO system resonates at a triband of 3.3 GHz,5...A novel compact Swastika shaped patch antenna is designed in the present work,which can be used for Multiple Input Multiple Output(MIMO) systems.The proposed two element MIMO system resonates at a triband of 3.3 GHz,5.8 GHz,and 7.1 GHz with an improved impedance bandwidth of 37% and a reduced mutual coupling of-33 dB.These results are better compared to a normal E shaped patch antenna designed with same size and thickness,achieved without using any additional decoupling methods.A 2×2 MIMO system employing the Swastika shaped patch antennas is analyzed using computational electromagnetic ray tracing software for an indoor environment.The results show an improvement in the capacity compared to a 2×2 MIMO system developed with dipole antennas.The proposed antenna is a good choice for MIMO systems operating for several Ultra WideBand(UWB) applications.展开更多
The grid DEM(digital elevation model) generation can be from any of a number of sources:for instance,analogue to digital conversion of contour maps followed by application of the TIN model,or direct elevation point mo...The grid DEM(digital elevation model) generation can be from any of a number of sources:for instance,analogue to digital conversion of contour maps followed by application of the TIN model,or direct elevation point modelling via digital photogrammetry applied to airborne images or satellite images.Currently,apart from the deployment of point-clouds from LiDAR data acquisition,the generally favoured approach refers to applications of digital photogrammetry.One of the most important steps in such deployment is the stereo matching process for conjugation point(pixel) establishment:very difficult in modelling any homogenous areas like water cover or forest canopied areas due to the lack of distinct spatial features.As a result,application of automated procedures is sure to generate erroneous elevation values.In this paper,we present and apply a method for improving the quality of stereo DEMs generated via utilization of an entropy texture filter.The filter was applied for extraction of homogenous areas before stereo matching so that a statistical texture filter could then be applied for removing anomalous evaluation values prior to interpolation and accuracy assessment via deployment of a spatial correlation technique.For exemplification,we used a stereo pair of ASTER 1B images.展开更多
<span style="font-family:Verdana;">A series of colossal magneto resistance (CMR) materials with compositional formula Pr<sub><span style="font-family:Verdana;">0.5</sub><...<span style="font-family:Verdana;">A series of colossal magneto resistance (CMR) materials with compositional formula Pr<sub><span style="font-family:Verdana;">0.5</sub><span style="font-family:Verdana;">Sr<sub><span style="font-family:Verdana;">0.5</sub><span style="font-family:Verdana;">Mn<sub><span style="font-family:Verdana;">1-x</sub><span style="font-family:Verdana;">Cr<sub><span style="font-family:Verdana;">x</sub><span style="font-family:Verdana;">O<sub><span style="font-family:Verdana;">3</sub><span style="font-family:Verdana;"> (x = 0, 0.1, 0.2, 0.3, 0.4) were prepared by sol-gel technique using pure metal nitrates as the starting materials. These samples were characterized structurally by X-ray diffraction, FTIR and SEM. All the <span style="font-family:Verdana;">samples exhibit orthorhombic structure without any detectable impurities.<span style="font-family:Verdana;"> The bulk den<span style="font-family:;" "=""><span style="font-family:Verdana;">sities for all the compositions were measured from the pellets. The Young’s and Rigidity moduli, Poisson’s ratio and Debye temperature of all the compositions were calculated with the experimentally measured ultra<span style="font-family:Verdana;">sonic longitudinal and shear velocities at room temperature using pulse<span style="font-family:Verdana;"> transmission technique. As the materials are porous, zero porous elastic moduli have also been calculated using a well-known Hasselmann and Fulrath model. <span style="font-family:Verdana;">The observed variation of elastic moduli with varying chromium doping<span style="font-family:Verdana;"> concentration has been studied qualitatively.展开更多
Atmospheric aerosols being an important component of the atmosphere play an important role in global and regional climate change. Aerosols can affect air quality, climate change and human health and have a significant...Atmospheric aerosols being an important component of the atmosphere play an important role in global and regional climate change. Aerosols can affect air quality, climate change and human health and have a significant effect on the solar energy budget. To study their quantitative effect is a challenging task due to their high spatial and temporal variability. This parameter represents one of the extinction coefficients of solar radiation and rate of suspended particles in the atmosphere. Ocean Colour Remote Sensing provides information about the four major geophysical parameters like chlorophyll and total suspended sediment concentration, vertical diffuse attenuation co-efficient and the aerosol optical thickness measured at 865 nm. Aerosol optical depth can be expressed as function of wavelength through Angstrom’s equation ?, where “α” and “β” are known as Angstrom parameters. The Angstrom exponent, “α” is related to the size distribution of the aerosol particles and “β” represents the amount of aerosols present in the atmosphere. In this present study, an attempt is made to study the impact of these two parameters by changing values from 0 to 0.05 for “α” and from 0.0 to 0.6 for “β” in SeaDAS processing for estimating the aerosol optical depth. From this study, it is clear that for most of the applications either in the coastal or open ocean waters, alpha value varies from 0.0 to 0.3 over the north Indian Ocean. However, this has been further evaluated by various combinations for retrieving the AOD using OCM-2 data.展开更多
It is often very difficult for the patient to tell the difference between angina symptoms and heart attack symptoms, so it is very important to recognize the signs of heart attack and immedi-ately seek medical attenti...It is often very difficult for the patient to tell the difference between angina symptoms and heart attack symptoms, so it is very important to recognize the signs of heart attack and immedi-ately seek medical attention. A practical case of this type of remote consultation is examined in this paper. To deal with the huge amount of electrocardiogram (ECG) data for analysis, storage and transmission;an efficient ECG compression technique is needed to reduce the amount of data as much as possible while pre-serving the clinical significant signal for cardiac diagnosis. Here the ECG signal is analyzed for various parameters such as heart rate, QRS-width, etc. Then the various parameters and the compressed signal can be transmitted with less channel capacity. Comparison of various ECG compression techniques like TURNING POINT, AZTEC, CORTES, FFT and DCT it was found that DCT is the best suitable compression technique with compression ratio of about 100:1. In addition, different techniques are available for implementation of hardware components for signal pickup the virtual im-plementation with labview is also used for analysis of various cardiac parameters and to identify the abnormalities like Tachycardia, Bradycardia, AV Block, etc. Both hardware and virtual implementation are also detailed in this context.展开更多
A stability-indicating UPLC method has been developed and validated for the determination of related substances of Posaconazole with its four related substances (Hydroxytriazole, Tosylated compound, Deshydroxy posacon...A stability-indicating UPLC method has been developed and validated for the determination of related substances of Posaconazole with its four related substances (Hydroxytriazole, Tosylated compound, Deshydroxy posaconazole and Benzylated posaconazole) in the drug substance. Forthwith simple UPLC chromatographic separations were achieved on a Waters Acquity BEH shield C18 (100 mm length, 2.1 mm internal diameter and 1.7 μm particle size) with a mobile phase containing 0.1% Orthophosphoric acid (i.e. 1 mL in 1000 mL water) in gradient combination with acetonitrile (ACN) at a flow rate of 0.5 mL/min and the eluent were monitored at 210 nm. As a result, the resolution of Posaconazole from any of impurities was found to be greater than 2.0. The test solution and spiked solutions were found to be stable in the diluent for 48 h. For the purpose method to be stability indicating, forced degradation studies were conducted and the method resolved the drug from its known impurities, stated above, and from additional impurities generated when POS subjected to forced degradation;the mass balance was found close to 100%. Regression analyses indicate correlation coefficient value greater than 0.999 for Posaconazole and its known impurities. The LOD for Posaconazole and the known impurities was at a level below 0.05%. The method has shown good, consistent recoveries for known impurities (89% - 106%). To summarise, the method was found to be accurate, precise, linear, specific, sensitive, rugged, robust, and stability-indicating.展开更多
Nano-crystalline Cr<sub>x</sub>CoFe<sub>2–x</sub>O<sub>4</sub> (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) ferrites were synthesized by sol-gel method. The X-ray diffraction patterns of all t...Nano-crystalline Cr<sub>x</sub>CoFe<sub>2–x</sub>O<sub>4</sub> (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) ferrites were synthesized by sol-gel method. The X-ray diffraction patterns of all the samples provide information about the existence of single phase spinel structure. The SEM and TEM micrographs show the uniform particle distribution and SAED pattern represents the polycrystalline nature of the resultant ferrite nano-particles. High purity of the sample is confirmed by energy dispersive X-ray analysis. The FTIR spectra show two strong absorption bands in the range of 600 - 400 cm<sup>–1</sup>, which confirm the presence of M-O stretching band in ferrites. The magnetic properties of the synthesized samples were investigated by using vibrating sample magnetometer at room temperature. According to VSM reports the main magnetic parameters like saturation magnetization (M<sub>s</sub>), coercivity (H<sub>c</sub>) were found to decrease with the substitution of Cr<sup>3+</sup> content. Possible mechanisms which are responsible for the results are scrutinized minutely in this paper.展开更多
Mechanical as well as durability properties are pivotal for any type of concrete which gets adversely affected due to cracks that may form due to loading beyond its capacity.Concrete has the intrinsic property to heal...Mechanical as well as durability properties are pivotal for any type of concrete which gets adversely affected due to cracks that may form due to loading beyond its capacity.Concrete has the intrinsic property to heal itself to some extent but not fully as the passive form of autogenous healing plays an inferior role for a complete repair of a cementitious material.The self-healing capabilities can be enhanced by adding chemical admixtures,polymers,and bacteria strains induced calcium carbonate precipitation,etc.In this paper,the advancements in the development and performance of self-healing concrete using chemical admixtures,polymers,and bacteria strains are reviewed.This systematic review includes the available experimental tests and methodologies investigating self-healing efficiency over the last decade.Further,this review focussed on self-healing materials,the ideology,and opinions of those in the construction field on the direction of self-healing concrete for future applications.It is yet not possible to predict the most appropriate technique,however,a generalized opinion about the effectiveness of the different approaches has been illustrated.展开更多
A variety of new materials in the field of concrete technology have been developed during the past three decades with the ongoing demand of construction industry to meet the functional, strength, economical and durabi...A variety of new materials in the field of concrete technology have been developed during the past three decades with the ongoing demand of construction industry to meet the functional, strength, economical and durability requirements. Though reinforced concrete has high strength and is most widely used construction material it suffers from disadvantages like corrosion of steel, susceptibility to chemical and environmental attack. In order to overcome the above deficiencies of reinforced concrete new materials （special concrete composites） have been developed over the past three decades. Glass Fibre Reinforced Polymer （GFRP） is one such material with wide range of applications. Based on the preliminary investigations on GFRP bars, an optimum fiber/resin ratio of 7：3 was arrived. The tensile strength of GFRP bars is comparable to that of the mild steel as per the tests carried out, but the modulus of elasticity is about 25-30 percentage of that of steel bars. This paper deals with the experimental investigations carried out on small slab panels supported on all four edges with effective spans of 0.9 m ~ 0.45 m, which is a part of large research problem undertaken with different ratios of 10ng span to short span with different support conditions. The test results are compared with similar slab panels reinforced with conventional mild steel bars.展开更多
Due to the higher reliability and small ground space requirement, compressed GIS （gas insulated substation） has found extensive applications in urban areas and developing countries. The major parts of GIS is the gas...Due to the higher reliability and small ground space requirement, compressed GIS （gas insulated substation） has found extensive applications in urban areas and developing countries. The major parts of GIS is the gas insulated busducts, circuit breakers, isolators, etc.. The voltage withstand capability of SF6 （sulphur hexafluoride） busduct is strongly dependent on field perturbations such as those caused by conductor surface imperfections and by conducting particle contaminants which arise due to manufacturing process, mechanical vibrations, moving parts of system etc.. Contamination can create insulation problems at operating fields. An optimized design of GIS by varying the inner and outer diameter to 89 mm and 241 mm is considered for analysis and compared with a single phase enclosure with outer diameter as 152 mm and inner conductor diameter of 55 mm with aluminum and copper particles of size 10 mm in length and 0.25 mm in radius present on the enclosure. The results have been compared on the extent of particle movement for the same condition of the gas and particle geometry. Monte Carlo simulation is also carried out for determining the motion of particles in axial and radial directions. The random solid angle is changed from 1 to 0.5 degrees to take into account more smooth end profile of the particle. The simulation results have been presented and analyzed.展开更多
Experimental tests have been carried out to evaluate the performance,emission and combustion characteristics of a diesel engine using neat sea lemon oil and its blends of 25%,50%,&75%and standard diesel fuel separ...Experimental tests have been carried out to evaluate the performance,emission and combustion characteristics of a diesel engine using neat sea lemon oil and its blends of 25%,50%,&75%and standard diesel fuel separately.The common problems posed when using vegetable oil in a compression ignition engine are poor atomization,carbon deposits,ring sticking etc.This is because of the high viscosity and low volatility of vegetable oil.When blended with diesel,sea lemon oil presented lower viscosity,improved volatility,better combustion and less carbon deposit.It was found that there was reduction in NO for neat sea lemon oil and its diesel blends along with marginal increase in smoke,HC and CO emissions compared to that of standard diesel.Brake thermal efficiency was slightly lower for neat sea lemon oil and its diesel blends.From the combustion analysis,it was found that sea lemon oil-diesel blends performed better than neat sea lemon oil.展开更多
In a deregulated power system uncertainty exists and lack of sufficient damping can lead to Low FrequencyOscillations (LFO). The problem can be addressed using robust Power System Stabilizers (PSS). In this paper, ano...In a deregulated power system uncertainty exists and lack of sufficient damping can lead to Low FrequencyOscillations (LFO). The problem can be addressed using robust Power System Stabilizers (PSS). In this paper, anoptimal procedure to design a robust PID-PSS using interval arithmetic for the Single Machine Infinite Bus (SMIB)power system is proposed. The interval modelling captures the wide variations of operating conditions in boundsof system coefficients. In the proposed design procedure, simple and new closed loop stability conditions for anSMIB interval system are developed and are used to design an optimum PID-PSS for improving the performance ofan SMIB system. The optimum PID-PSS is attained by tuning the parameters using the FMINCON tool provided inMATLAB. The robustness of the proposed PID-PSS design is validated and compared to other notable methods inthe literature when the system is subjected to different uncertainties. The simulation results and performance errorvalues show the effectiveness of the proposed robust PID-PSS controller.展开更多
Passive image forgery detection methods that identify forgeries without prior knowledge have become a key research focus.In copy-move forgery,the assailant intends to hide a portion of an image by pasting other portio...Passive image forgery detection methods that identify forgeries without prior knowledge have become a key research focus.In copy-move forgery,the assailant intends to hide a portion of an image by pasting other portions of the same image.The detection of such manipulations in images has great demand in legal evidence,forensic investigation,and many other fields.The paper aims to present copy-move forgery detection algorithms with the help of advanced feature descriptors,such as local ternary pattern,local phase quantization,local Gabor binary pattern histogram sequence,Weber local descriptor,and local monotonic pattern,and classifiers such as optimized support vector machine and optimized NBC.The proposed algorithms can classify an image efficiently as either copy-move forged or authenticated,even if the test image is subjected to attacks such as JPEG compression,scaling,rotation,and brightness variation.CoMoFoD,CASIA,and MICC datasets and a combination of CoMoFoD and CASIA datasets images are used to quantify the performance of the proposed algorithms.The proposed algorithms are more efficient than state-of-the-art algorithms even though the suspected image is post-processed.展开更多
The advancement in technologies made the entire manufacturing system,to be operated with more efficient,flexible,user friendly,more productive and cost effective.One such a system to be focused for advancement is plas...The advancement in technologies made the entire manufacturing system,to be operated with more efficient,flexible,user friendly,more productive and cost effective.One such a system to be focused for advancement is plasma cutting system,which has wider industrial applications.There are many researches pursuing at various area of plasma cutting technology,still the automated and optimized parameters value selection is challenging.The work is aimed to eliminate the manual mode of feeding the input parameters for cutting operation.At present,cutting parameters are fed by referring the past cut data information or with the assistance of experienced employers.The cutting process parameters selections will have direct impact on the quality of the material being cut,and life of the consumables.This paper is intended to automate the process parameters selection by developing the mathematical model with existing cutting process parameters database.In this,three different approaches,multiple regression,multiple polynomial regression and AI technique,are selected and analyzed with the mathematical relations developed between the different cutting process parameters.The accuracy and reliability of those methods are detailed.The advantage and disadvantage of those methods for optimal setting conditions are discussed.The appropriate method that can be preferred for automated and optimal settings are elucidated.Finally,the selected technique is checked for accuracy and reliability for the existing cut data.展开更多
In the present paper,we present some important properties of N-transform,which is the Laplace transform for the nabla derivative on the time scale of integers(Bohner and Peterson in Dynamic equations on time scales,Bi...In the present paper,we present some important properties of N-transform,which is the Laplace transform for the nabla derivative on the time scale of integers(Bohner and Peterson in Dynamic equations on time scales,Birkhauser,Boston,2001;Advances in dynamic equations on time scales,Birkhauser,Boston,2002).We obtain the N-transform of nabla fractional sums and differences and then apply this transform to solve some nabla fractional difference equations with initial value problems.Finally,usingN-transforms,we prove that discrete Mittag-Leffler function is the eigen function of Caputo type nabla fractional difference operator∇α.展开更多
文摘The scope of the present paper is to understand the effects of crystalline admixture on the selfhealing capacity of the cementitious composites. Previous studies were examined and a conclusion was drawn to the effect that different additives to crystalline admixture tend to improve self-healing of concrete for larger cracks. It is recommended that initial treatment with chemical admixture can stimulate and heal further cracks and it has the better repeatability trend in mixing with the concretes and mechanical recovery is possible even under repetitive preloading. Effective self-healing with chemical admixtures even under open-air exposure, leads to study the importance of a service ability design parameter including the maximum allowable crack width by repeatability analysis as a function of the exposure with the concept of sealable crack width.
文摘In this investigation,the effect of friction stir welding(FSW)parameters such as tool material rotational speed,and welding speed on the mechanical properties of tensile strength,hardness and impact energy of magnesium alloy AZ31B was studied.The experiments were carried out as per Taguchi parametric design concepts and an L9 orthogonal array was used to study the influence of various combinations of process parameters.Statistical optimization technique,ANOVA,was used to determine the optimum levels and to find the significance of each process parameter.The results indicate that rotational speed(RS)and traverse speed(TS)are the most significant factors,followed by tool material(TM),in deciding the mechanical properties of friction stir processed magnesium alloy.In addition,mathematical models were developed to establish relationship between different process variables and mechanical properties.
文摘Recently,the application of Wireless Sensor Networks(WSNs)has been increasing rapidly.It requires privacy preserving data aggregation protocols to secure the data from compromises.Preserving privacy of the sensor data is a challenging task.This paper presents a non-linear regression-based data aggregation protocol for preserving privacy of the sensor data.The proposed protocol uses non-linear regression functions to represent the sensor data collected from the sensor nodes.Instead of sending the complete data to the cluster head,the sensor nodes only send the coefficients of the non-linear function.This will reduce the communication overhead of the network.The data aggregation is performed on the masked coefficients and the sink node is able to retrieve the approximated results over the aggregated data.The analysis of experiment results shows that the proposed protocol is able to minimize communication overhead,enhance data aggregation accuracy,and preserve data privacy.
文摘The land ward displacement of the shoreline caused by the forces of waves and currents is termed as Coastal Erosion. The Coastal areas have become more prone and vulnerable to natural and human made hazards which lead to Coastal Erosion. The Shoreline retreat is recognized as a burgeoning threat because of global climate change and other anthropogenic activities that alter the natural processes of sustaining beaches and coasts. Coastal Erosion mainly occurs when wind, waves and long shore currents move sand from shore and deposit it somewhere else. The sand can be moved to another beach, to the deeper ocean bottom, into an ocean trench or onto the landside of a dune. The removal of the sand from the sand sharing system results in permanent changes in beach shape and structure. The impact of the event is not seen immediately as in the case of Tsunami or Storm Surge but it is equally important when we consider loss of property. It generally takes months or years to note the impact of Erosion;therefore, this is generally classified as a “Long Term Coastal Hazard”. The present paper attempts to describe a Review on Coastal Erosion Process, Parameters’ affecting, and methodologies are adopted to identify the erosion and recommend a solution.
文摘The aim of present study is to analyze the influence of volume percentage(vol.%) of nano-sized particles(TiB_2: average size is 35 nm) on microstructure, mechanical and tribological behavior of 6061-T6 Al alloy surface nano composite prepared via Friction stir process(FSP). The microstructure of the fabricated surface nanocomposites is examined using optical microscopy(OM) and scanning electron microscope(SEM) for distribution of TiB_2 nano reinforcement particles, thickness of nano composite layer formed on the Aluminum alloy substrate and fracture features. The depth of surface nano composite layer is measured as 3683.82 m m along the cross section of stir zone of nano composite perpendicular to FSP. It was observed that increase in volume percentage of TiB_2 particles, the microhardness is increased up to132 Hv and it is greater than as-received Al alloy's microhardness(104 Hv). It is also observed that at 4volume percentage higher tensile properties exhibited as compared with the 2 and 8 vol. %. It is found that high wear resistance exhibited at 4 volume percentage as-compared with the 2 and 8 vol. %. The observed wear and mechanical properties are interrelated with microstructure, fractography and worn morphology.
文摘A novel compact Swastika shaped patch antenna is designed in the present work,which can be used for Multiple Input Multiple Output(MIMO) systems.The proposed two element MIMO system resonates at a triband of 3.3 GHz,5.8 GHz,and 7.1 GHz with an improved impedance bandwidth of 37% and a reduced mutual coupling of-33 dB.These results are better compared to a normal E shaped patch antenna designed with same size and thickness,achieved without using any additional decoupling methods.A 2×2 MIMO system employing the Swastika shaped patch antennas is analyzed using computational electromagnetic ray tracing software for an indoor environment.The results show an improvement in the capacity compared to a 2×2 MIMO system developed with dipole antennas.The proposed antenna is a good choice for MIMO systems operating for several Ultra WideBand(UWB) applications.
基金Supported by the Ministry of Human Resource Development (MHRD),India (for Distinguished Institute Fellow)
文摘The grid DEM(digital elevation model) generation can be from any of a number of sources:for instance,analogue to digital conversion of contour maps followed by application of the TIN model,or direct elevation point modelling via digital photogrammetry applied to airborne images or satellite images.Currently,apart from the deployment of point-clouds from LiDAR data acquisition,the generally favoured approach refers to applications of digital photogrammetry.One of the most important steps in such deployment is the stereo matching process for conjugation point(pixel) establishment:very difficult in modelling any homogenous areas like water cover or forest canopied areas due to the lack of distinct spatial features.As a result,application of automated procedures is sure to generate erroneous elevation values.In this paper,we present and apply a method for improving the quality of stereo DEMs generated via utilization of an entropy texture filter.The filter was applied for extraction of homogenous areas before stereo matching so that a statistical texture filter could then be applied for removing anomalous evaluation values prior to interpolation and accuracy assessment via deployment of a spatial correlation technique.For exemplification,we used a stereo pair of ASTER 1B images.
文摘<span style="font-family:Verdana;">A series of colossal magneto resistance (CMR) materials with compositional formula Pr<sub><span style="font-family:Verdana;">0.5</sub><span style="font-family:Verdana;">Sr<sub><span style="font-family:Verdana;">0.5</sub><span style="font-family:Verdana;">Mn<sub><span style="font-family:Verdana;">1-x</sub><span style="font-family:Verdana;">Cr<sub><span style="font-family:Verdana;">x</sub><span style="font-family:Verdana;">O<sub><span style="font-family:Verdana;">3</sub><span style="font-family:Verdana;"> (x = 0, 0.1, 0.2, 0.3, 0.4) were prepared by sol-gel technique using pure metal nitrates as the starting materials. These samples were characterized structurally by X-ray diffraction, FTIR and SEM. All the <span style="font-family:Verdana;">samples exhibit orthorhombic structure without any detectable impurities.<span style="font-family:Verdana;"> The bulk den<span style="font-family:;" "=""><span style="font-family:Verdana;">sities for all the compositions were measured from the pellets. The Young’s and Rigidity moduli, Poisson’s ratio and Debye temperature of all the compositions were calculated with the experimentally measured ultra<span style="font-family:Verdana;">sonic longitudinal and shear velocities at room temperature using pulse<span style="font-family:Verdana;"> transmission technique. As the materials are porous, zero porous elastic moduli have also been calculated using a well-known Hasselmann and Fulrath model. <span style="font-family:Verdana;">The observed variation of elastic moduli with varying chromium doping<span style="font-family:Verdana;"> concentration has been studied qualitatively.
文摘Atmospheric aerosols being an important component of the atmosphere play an important role in global and regional climate change. Aerosols can affect air quality, climate change and human health and have a significant effect on the solar energy budget. To study their quantitative effect is a challenging task due to their high spatial and temporal variability. This parameter represents one of the extinction coefficients of solar radiation and rate of suspended particles in the atmosphere. Ocean Colour Remote Sensing provides information about the four major geophysical parameters like chlorophyll and total suspended sediment concentration, vertical diffuse attenuation co-efficient and the aerosol optical thickness measured at 865 nm. Aerosol optical depth can be expressed as function of wavelength through Angstrom’s equation ?, where “α” and “β” are known as Angstrom parameters. The Angstrom exponent, “α” is related to the size distribution of the aerosol particles and “β” represents the amount of aerosols present in the atmosphere. In this present study, an attempt is made to study the impact of these two parameters by changing values from 0 to 0.05 for “α” and from 0.0 to 0.6 for “β” in SeaDAS processing for estimating the aerosol optical depth. From this study, it is clear that for most of the applications either in the coastal or open ocean waters, alpha value varies from 0.0 to 0.3 over the north Indian Ocean. However, this has been further evaluated by various combinations for retrieving the AOD using OCM-2 data.
文摘It is often very difficult for the patient to tell the difference between angina symptoms and heart attack symptoms, so it is very important to recognize the signs of heart attack and immedi-ately seek medical attention. A practical case of this type of remote consultation is examined in this paper. To deal with the huge amount of electrocardiogram (ECG) data for analysis, storage and transmission;an efficient ECG compression technique is needed to reduce the amount of data as much as possible while pre-serving the clinical significant signal for cardiac diagnosis. Here the ECG signal is analyzed for various parameters such as heart rate, QRS-width, etc. Then the various parameters and the compressed signal can be transmitted with less channel capacity. Comparison of various ECG compression techniques like TURNING POINT, AZTEC, CORTES, FFT and DCT it was found that DCT is the best suitable compression technique with compression ratio of about 100:1. In addition, different techniques are available for implementation of hardware components for signal pickup the virtual im-plementation with labview is also used for analysis of various cardiac parameters and to identify the abnormalities like Tachycardia, Bradycardia, AV Block, etc. Both hardware and virtual implementation are also detailed in this context.
文摘A stability-indicating UPLC method has been developed and validated for the determination of related substances of Posaconazole with its four related substances (Hydroxytriazole, Tosylated compound, Deshydroxy posaconazole and Benzylated posaconazole) in the drug substance. Forthwith simple UPLC chromatographic separations were achieved on a Waters Acquity BEH shield C18 (100 mm length, 2.1 mm internal diameter and 1.7 μm particle size) with a mobile phase containing 0.1% Orthophosphoric acid (i.e. 1 mL in 1000 mL water) in gradient combination with acetonitrile (ACN) at a flow rate of 0.5 mL/min and the eluent were monitored at 210 nm. As a result, the resolution of Posaconazole from any of impurities was found to be greater than 2.0. The test solution and spiked solutions were found to be stable in the diluent for 48 h. For the purpose method to be stability indicating, forced degradation studies were conducted and the method resolved the drug from its known impurities, stated above, and from additional impurities generated when POS subjected to forced degradation;the mass balance was found close to 100%. Regression analyses indicate correlation coefficient value greater than 0.999 for Posaconazole and its known impurities. The LOD for Posaconazole and the known impurities was at a level below 0.05%. The method has shown good, consistent recoveries for known impurities (89% - 106%). To summarise, the method was found to be accurate, precise, linear, specific, sensitive, rugged, robust, and stability-indicating.
文摘Nano-crystalline Cr<sub>x</sub>CoFe<sub>2–x</sub>O<sub>4</sub> (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) ferrites were synthesized by sol-gel method. The X-ray diffraction patterns of all the samples provide information about the existence of single phase spinel structure. The SEM and TEM micrographs show the uniform particle distribution and SAED pattern represents the polycrystalline nature of the resultant ferrite nano-particles. High purity of the sample is confirmed by energy dispersive X-ray analysis. The FTIR spectra show two strong absorption bands in the range of 600 - 400 cm<sup>–1</sup>, which confirm the presence of M-O stretching band in ferrites. The magnetic properties of the synthesized samples were investigated by using vibrating sample magnetometer at room temperature. According to VSM reports the main magnetic parameters like saturation magnetization (M<sub>s</sub>), coercivity (H<sub>c</sub>) were found to decrease with the substitution of Cr<sup>3+</sup> content. Possible mechanisms which are responsible for the results are scrutinized minutely in this paper.
文摘Mechanical as well as durability properties are pivotal for any type of concrete which gets adversely affected due to cracks that may form due to loading beyond its capacity.Concrete has the intrinsic property to heal itself to some extent but not fully as the passive form of autogenous healing plays an inferior role for a complete repair of a cementitious material.The self-healing capabilities can be enhanced by adding chemical admixtures,polymers,and bacteria strains induced calcium carbonate precipitation,etc.In this paper,the advancements in the development and performance of self-healing concrete using chemical admixtures,polymers,and bacteria strains are reviewed.This systematic review includes the available experimental tests and methodologies investigating self-healing efficiency over the last decade.Further,this review focussed on self-healing materials,the ideology,and opinions of those in the construction field on the direction of self-healing concrete for future applications.It is yet not possible to predict the most appropriate technique,however,a generalized opinion about the effectiveness of the different approaches has been illustrated.
文摘A variety of new materials in the field of concrete technology have been developed during the past three decades with the ongoing demand of construction industry to meet the functional, strength, economical and durability requirements. Though reinforced concrete has high strength and is most widely used construction material it suffers from disadvantages like corrosion of steel, susceptibility to chemical and environmental attack. In order to overcome the above deficiencies of reinforced concrete new materials （special concrete composites） have been developed over the past three decades. Glass Fibre Reinforced Polymer （GFRP） is one such material with wide range of applications. Based on the preliminary investigations on GFRP bars, an optimum fiber/resin ratio of 7：3 was arrived. The tensile strength of GFRP bars is comparable to that of the mild steel as per the tests carried out, but the modulus of elasticity is about 25-30 percentage of that of steel bars. This paper deals with the experimental investigations carried out on small slab panels supported on all four edges with effective spans of 0.9 m ~ 0.45 m, which is a part of large research problem undertaken with different ratios of 10ng span to short span with different support conditions. The test results are compared with similar slab panels reinforced with conventional mild steel bars.
文摘Due to the higher reliability and small ground space requirement, compressed GIS （gas insulated substation） has found extensive applications in urban areas and developing countries. The major parts of GIS is the gas insulated busducts, circuit breakers, isolators, etc.. The voltage withstand capability of SF6 （sulphur hexafluoride） busduct is strongly dependent on field perturbations such as those caused by conductor surface imperfections and by conducting particle contaminants which arise due to manufacturing process, mechanical vibrations, moving parts of system etc.. Contamination can create insulation problems at operating fields. An optimized design of GIS by varying the inner and outer diameter to 89 mm and 241 mm is considered for analysis and compared with a single phase enclosure with outer diameter as 152 mm and inner conductor diameter of 55 mm with aluminum and copper particles of size 10 mm in length and 0.25 mm in radius present on the enclosure. The results have been compared on the extent of particle movement for the same condition of the gas and particle geometry. Monte Carlo simulation is also carried out for determining the motion of particles in axial and radial directions. The random solid angle is changed from 1 to 0.5 degrees to take into account more smooth end profile of the particle. The simulation results have been presented and analyzed.
文摘Experimental tests have been carried out to evaluate the performance,emission and combustion characteristics of a diesel engine using neat sea lemon oil and its blends of 25%,50%,&75%and standard diesel fuel separately.The common problems posed when using vegetable oil in a compression ignition engine are poor atomization,carbon deposits,ring sticking etc.This is because of the high viscosity and low volatility of vegetable oil.When blended with diesel,sea lemon oil presented lower viscosity,improved volatility,better combustion and less carbon deposit.It was found that there was reduction in NO for neat sea lemon oil and its diesel blends along with marginal increase in smoke,HC and CO emissions compared to that of standard diesel.Brake thermal efficiency was slightly lower for neat sea lemon oil and its diesel blends.From the combustion analysis,it was found that sea lemon oil-diesel blends performed better than neat sea lemon oil.
文摘In a deregulated power system uncertainty exists and lack of sufficient damping can lead to Low FrequencyOscillations (LFO). The problem can be addressed using robust Power System Stabilizers (PSS). In this paper, anoptimal procedure to design a robust PID-PSS using interval arithmetic for the Single Machine Infinite Bus (SMIB)power system is proposed. The interval modelling captures the wide variations of operating conditions in boundsof system coefficients. In the proposed design procedure, simple and new closed loop stability conditions for anSMIB interval system are developed and are used to design an optimum PID-PSS for improving the performance ofan SMIB system. The optimum PID-PSS is attained by tuning the parameters using the FMINCON tool provided inMATLAB. The robustness of the proposed PID-PSS design is validated and compared to other notable methods inthe literature when the system is subjected to different uncertainties. The simulation results and performance errorvalues show the effectiveness of the proposed robust PID-PSS controller.
文摘Passive image forgery detection methods that identify forgeries without prior knowledge have become a key research focus.In copy-move forgery,the assailant intends to hide a portion of an image by pasting other portions of the same image.The detection of such manipulations in images has great demand in legal evidence,forensic investigation,and many other fields.The paper aims to present copy-move forgery detection algorithms with the help of advanced feature descriptors,such as local ternary pattern,local phase quantization,local Gabor binary pattern histogram sequence,Weber local descriptor,and local monotonic pattern,and classifiers such as optimized support vector machine and optimized NBC.The proposed algorithms can classify an image efficiently as either copy-move forged or authenticated,even if the test image is subjected to attacks such as JPEG compression,scaling,rotation,and brightness variation.CoMoFoD,CASIA,and MICC datasets and a combination of CoMoFoD and CASIA datasets images are used to quantify the performance of the proposed algorithms.The proposed algorithms are more efficient than state-of-the-art algorithms even though the suspected image is post-processed.
文摘The advancement in technologies made the entire manufacturing system,to be operated with more efficient,flexible,user friendly,more productive and cost effective.One such a system to be focused for advancement is plasma cutting system,which has wider industrial applications.There are many researches pursuing at various area of plasma cutting technology,still the automated and optimized parameters value selection is challenging.The work is aimed to eliminate the manual mode of feeding the input parameters for cutting operation.At present,cutting parameters are fed by referring the past cut data information or with the assistance of experienced employers.The cutting process parameters selections will have direct impact on the quality of the material being cut,and life of the consumables.This paper is intended to automate the process parameters selection by developing the mathematical model with existing cutting process parameters database.In this,three different approaches,multiple regression,multiple polynomial regression and AI technique,are selected and analyzed with the mathematical relations developed between the different cutting process parameters.The accuracy and reliability of those methods are detailed.The advantage and disadvantage of those methods for optimal setting conditions are discussed.The appropriate method that can be preferred for automated and optimal settings are elucidated.Finally,the selected technique is checked for accuracy and reliability for the existing cut data.
文摘In the present paper,we present some important properties of N-transform,which is the Laplace transform for the nabla derivative on the time scale of integers(Bohner and Peterson in Dynamic equations on time scales,Birkhauser,Boston,2001;Advances in dynamic equations on time scales,Birkhauser,Boston,2002).We obtain the N-transform of nabla fractional sums and differences and then apply this transform to solve some nabla fractional difference equations with initial value problems.Finally,usingN-transforms,we prove that discrete Mittag-Leffler function is the eigen function of Caputo type nabla fractional difference operator∇α.
