An experimental investigation was carried out to establish the performance and emission characteristics of a compression ignition engine while using cerium oxide nanoparticles as additive in neat diesel and diesel-biodiesel-ethanol blends. In the first phase of the experiments, stability of neat diesel and diesel-biodiesel-ethanol fuel blends with the addition of cerium oxide nanoparticles are analyzed. After series of experiments, it was found that the blends subjected to high speed blending followed by ultrasonic bath stabilization improves the stability. The phase separation between diesel and ethanol is prevented using vegetable methyl ester (Biodiesel) prepared from the castor oil through transesterification process. In the second phase, performance characteristics are studied using the stable fuel blends in a single cylinder four stroke computerised variable compression ratio engine coupled with an eddy current dynamometer and a data acquisition system. The cerium oxide acts as an oxygen donating catalyst and provides oxygen for the oxidation of CO or absorbs oxygen for the reduction of NOx. The activation energy of cerium oxide act to burn off carbon deposits within the engine cylinder at the wall temperature and prevents the deposition of non-polar compounds on the cylinder wall results reduction in HC emissions. The tests revealed that cerium oxide nanoparticles can be used as additive in diesel and diesel-biodiesel-ethanol blend to improve complete combustion of the fuel and reduce the exhaust emissions significantly.

In this paper mathematical formulations and simulations were carried out for the prediction of through-thickness stress distributions of fibrous composite panels under variable shape impactors. Considerations were given to selective specimens from aerospace industrial environment to obtain the degree of uniformity of stress distributions throughout the out-of-plane geometry. The interlaminar stresses and strains induced in ‘thin’ laminates through application of membrane loads (i.e., in-plane loads) were also considered. Formulation was also developed for Poisson’s ratios. Finite Element Method (FEM) has received a tremendous attention in engineering & industry because of its diversity and flexibility as an analysis tool. The solutions to physical problems can be obtained very effectively and to a high degree of accuracy using FEM software packages. Therefore, the FEM was chosen to perform simulation in commercially available software ABAQUS. In-plane stresses were computed from the model and Trapezium rule was applied to calculate out-of-plane transverse shear stresses. The procedure is simple and efficient to predict 3-D transverse shear stresses from 2-D model. Results were compared with the results from the available literature and found to be in good agreement. Some of the results are shown in the form of tables and graphs.

The interconnected two area systems are modeled and simulated by integration of Fuzzy controller with sliding gain for improved performance specifications like settling time and peak overshoot over the conventional PI controller. The paper investigates the impact of addition of slider gain with fuzzy logic controller for load frequency control of interconnected thermal-thermal and thermal-hydro interconnected power systems. The dynamic responses under small step load increase i.e. 1% (0.01p.u) is obtained with fuzzy logic controller and compared with that of a conventional integral controller, in MATLAB/SIMULINK environment.

An experimental program was carried out to study the effect of water absorption, apparent porosity and sorptivity on durability of fly ash based geopolymer mortar specimens in Sulfuric acid solution. Low calcium Class F fly ash was activated by a mixture of NaOH and Na₂SiO₃ containing 5% to 8% Na₂O with water to fly ash ratio of 0.33. The durability of geopolymer mortar specimens was evaluated on the basis of reduction in compressive strength when exposed in 10% Sulfuric acid solution for 24 weeks. Specimens containing lesser alkali were found to possess higher apparent porosity, water absorption and water sorptivity. After 24 weeks in sulfuric acid solution, specimens still had substantial residual compressive strength ranging from 29.4% to 54.8%. Specimens with higher water absorption, porosity and water sorptivity lost more strength than those with lesser corresponding values. Results obtained in the experimental program indicate that porosity, sorptivity and water absorption of geopolymer mortar specimens influences the durability of geopolymer mortars in sulfuric acid.

Abstract:

The effect of gel breakers on 60lbs/Mgals gravel pack fluid at different temperatures and concentrations was investigated. Tests at temperatures of 190oF, 210oF and 230oF with high temperature (HT) breaker of concentrations 5.0gal/Mgal, 10gal/Mgal and 15gal/Mgal, respectively were also investigated. The study revealed that break time is a function of temperature and concentration, at a higher temperature and concentration, respectively, gel break is faster and vice-versa. Model coefficients were obtained using DATA FIT engineering software and results indicated that Exponential model described best the variation of break time with breaker concentration and temperature. Model which predicts break time at any breaker concentration and Bottom Hole Temperature was developed. A model equation was developed for different temperatures and concentrations. Results calculated from the model equation showed a good agreement with experimental values with less than 10% deviation. This will help predict gel break time at different concentrations and temperatures thereby saving time and rigor associated with actual laboratory pilot test.

Abstract:

The goal of image enhancement technique is to improve a characteristic or quality of an image, such that the resulting image is better than the original image. Histogram equalization (HE) is widely used for contrast enhancement. However, it tends to change the brightness of an image. Preserving the input brightness of the image is required to avoid annoying artifacts in the output image. To overcome this drawback Brightness preserving Bi-histogram equalization (BBHE) has been proposed and analyzed mathematically that it can preserve the original brightness to a certain extends. However, there are still cases that are not handled well by BBHE, as they require higher degree of preservation. The extension of BBHE is Minimum Mean Brightness Error Bi-Histogram Equalization (MMBEBHE). The result of MMBEBHE is bad for the image with a lot details. To overcome these drawbacks, a new method is proposed. In this method, image enhancement is performed by MMBEBHE based on a modified contrast stretching manipulation.  While the image is enhanced, the impulse noises present in the images are also enhanced. To avoid this effect, the enhanced image is passed through a median filter.  The median filter is an effective method for the removal of impulse based noise on images. This is due to the partial averaging effect of the median filter and its biasing of the input stream, rather than straight mathematical averaging.

To estimate a compressive strength from existing concrete structures by core drilling are usually gathered with a diameter specimen of 100mm or three times of maximum coarse aggregate size and examined by uniaxial compressive strength (UCS) test as stated in JIS A1170. To get an alternative solution with smaller specimen, point load test (PLT) has been selected which is a simple test and widely accepted in rock materials research, but relatively new in concrete. The reliability of PLT is examined by extracting a lot of core drilled specimen from ready mixed concrete blocks with maximum coarse aggregate size, Gmax of 20mm in representative of architectural structures and 40mm in representative of civil structures on the range of concrete grade from 16 to 50. The reference of strength is resulted from concrete core diameter of 100 and 125mm with h/d ratio of 2.0, and examined by UCS test with compressive strength of concrete core of f’cc in results. The core specimen diameters are 35 and 50mm with h/d ratio of 1.5 and 2.0, and examined by PLT with point load index of IS in results. The estimation of compressive strength is conducted by making a linear approximation for IS to f’cc for each group of Gmax and h/d. This study also evaluates the reliability of test results for each core specimen and proposes a new geometric correction factor.

Abstract:

Toxic trace metals can be hazardous even at very low concentrations. When they get into water supplies and aqueous environments the health of plants and animals, as well as humans, can be impaired. Toxic trace metals are commonly found in wastewater and removing them efficiently presents a unique challenge. The discharge of heavy metals into aquatic ecosystems has become a matter of concern in India over the last few decades. These pollutants are introduced into the aquatic systems significantly as a result of various industrial operations. Biosorption experiments for Chromium (Cr (VI)), Copper (Cu (II)), Cadmium (Cd (II)) and Nickel (Ni (II)) were investigated in this study using nonliving biomass of different Pseudomonas species. The Langmuir and Freundlich models for the different biosorbent were applied and tested. Maximum Cr (VI) removal reached around 40% and its removal increased with the increase of Cr (VI) influent. Cu (II) removal was at its maximum value in presence of Cr (VI) as a binary metal, which reached 95% of its influent concentration. Concerning to Cd (II) and Ni (II) similar removal ratios were obtained, since it was ranged between 36 to 90% and their maximum removal were obtained in the case of individual Cd (II) and Ni (II).

Abstract:

The Pre-Rake diversity combining technique decreases the complexity, size and cost of the mobile unit while achieving the same inter symbol interference (ISI) mitigation effects of conventional Rake receiver for direct sequence code division multiple access (DS-CDMA) systems. The technique is based on preprocessing of signal at the transmitter relying on knowledge of the channel state information. This a priori information is available in time division duplex (TDD) mode due to channel reciprocity. In frequency division duplex (FDD) mode the channel has to be estimated at mobile unit (MU) for the downlink and fed to base station to predict the channel for downlink time slot. In this paper, we compare the performance of Pre-Rake system with different spreading codes. We will also propose a method for channel prediction in FDD mode and evaluate the system under ideal and predicted channel conditions using generalized orthogonal (GO) and Walsh codes through analytical and computer simulations for DS-CDMA downlink.

Abstract:

A sensor that can detect methoxy group in cation part of imidazolium ionic liquid was developed based on Reichardt's solvatochromic dye. The Reichardt's dye incorporated into three ionic liquids: 1-methyl-3-octyloxymethylimidazolium tetrafluoroborate, 1-methyl-3-hexyloxymethylimidazolium bis(trifluoromethylsulfonyl)imide, and 1-methyl-3-octylimidazolium tetrafluoroborate (without oxymethyl group in the structure), has been study by absorption and steady state fluorescence spectra. The striking solvatochromic effect was observed in ionic liquid includes oxymethyl group in the structure.

Abstract:

This paper presents a comparative analysis of aircraft acoustical performance based on the definition of a noise performance indicator called ENSA (equivalent number of standard aircraft). ENSA methodology is based on the choice of a standard aircraft, then ENSA’s values are obtained by comparing the generic aircraft’s performances with the standard aircraft’s performances. The performance evaluation is performed by analysing for each aircraft the equivalent number of standard aircrafts movements generating a noise level corresponding with one standard aircraft movement. This comparative analysis permits the evaluation of aircraft noise performance by comparing the ENSA values for different aircrafts.

Abstract:

This study is concerned with finite element modelling and simulation of fibrous composite beams contact with rigid indenter. Mathematical formulations consisting of contact law and indentation wrapping have been developed. Fibrous orientated modulii and types quasi-isotropic materials were also presented.  Finite element method software ABAQUS was chosen to perform simulation incorporating dynamic contact in time-domain using implicit dynamics routine. To improve convergence, mapped meshing techniques were employed to mesh the regions of high stress gradient with fine meshes and coarse meshes for the rest. Results from homogeneous beam were compared with the results from quasi-isotropic beams with 8, 12, and 24 plies and found to be in good agreement. The present study has demonstrated computationally model the contribution of fibre orientation effects on resulting damage and response of composite beams while interacting with rigid indenter.