64 research outputs found
Emerging catalytic applications of transition metal oxide nanomaterials under microwave and conventional heating
No full textHeterogeneous transition metal oxide catalysts have advantages over homogeneous catalysts, such as easy separations and efficient recycling and minimization of metal traces in the products. Transition metal oxide nanomaterials with different properties such as shapes and particle size were synthesized by hydrothermal, solvothermal, solvent-free and by energy efficient microwave heating methods and characterized using X-Ray and microscopic techniques. The synthesized catalysts were tested for tandem reactions to form quinoxalines, oxidations of hydrocarbons to form alcohols, aldehydes and ketones, epoxidation, epoxide ring opening, and N-aryl coupling reactions. The kinetics and energy consumption associated with these reactions were compared for both microwave and conventionally heated reactions. Further, Synchrotron radiation-based time-resolved XRD experiments under a wide variety of temperature and pressure conditions were conducted to study the reactions under working conditions. EXAFS and XANES data collections were performed to determine inter-atomic distances and oxidation states of the catalysts
Sensor Failure Detection and Fault Management Scheme for Pressure Probes Using Kalman Filtering Technique.
No full textDetermination of distribution coefficient of geomaterials and immobilizing agents
No full textLes caracteristiques de sorption et de desorption des geomateriaux (sols et roches) et des agents immobilisants gerent la destinee et le transport de contaminant(s) reactif(s) dans les geomateriaux, ainsi que l'efficacite des methodes d'immobilisation et de rehabilitation des geomateriaux contamines. Pour cette raison, il est necessaire d'etablir les caracteristiques de sorption et de desorption de ces materiaux. Generalement, des essais par lots sont effectues et les coefficients de distribution sont obtenus a partir des isothermes de Freudlinch, lineaires et de Langmuir. Cependant, l'efficacite relative de ces isothermes doit etre evaluee afin de bien selectionner le coefficient de distribution pour un systeme contaminant geomateriau - agent immobilisant. Pour ce faire, des essais par lots conventionnels ont ete realises sur differents geomateriaux et agents immobilisants dans le but d'etablir leurs caracteristiques de sorption et de desorption. Par contre, les essais par lots ne representent pas l'interaction re[]elle entre le contaminant, le geomateriau et l'agent immobilisant et sont plutot difficiles et longs. Dans ces circonstances, une methode alternative possible est de correler les caracteristiques de sorption et de desorption de ces materiaux avec la conductivite electrique de leurs solutions. L'utilisation de ce concept pour modeliser des cas reels d'interaction contaminant geomateriau - agent immobilisant a ete bien demontree dans cette etude
Development of Feature Recognition Algorithm for Automated Identification of Duplicate Geometries in CAD Models
No full textThis research presents a feature recognition algorithm for the automated identification of duplicate geometries in the CAD assembly. The duplicate geometry is one of the seven indicators of the lazy parts mass reduction method. The lazy parts method is a light weight engineering method that is used for analyzing parts with the mass reduction potential. The duplicate geometry is defined as any geometries lying equal to or within the threshold distance with the user-defined orientation between them and have the percentage similarity that is equal to or greater than the threshold value. The feature recognition system developed in this research for the identification of duplicate geometries is also extended to retrieve the weighted bipartite graph of part connections for the assembly time estimation. The weighted bipartite graph is used as input for the part connectivity based assembly time estimation method. The SolidWorks API software development kit is used in this research to develop a feature recognition system in SolidWorks CAD software package using C++ programming language. The feature recognition system built in the SolidWorks CAD software uses a combination of topology and geometric data for the evaluation of duplicate geometry. The measurement of distances between the sampling points strategy is used for the duplicate geometry feature recognition. The feature recognition algorithm has three phases of evaluation: first, is the evaluation for threshold distance condition of parts in the CAD assembly. Second, the part pairs that have satisfied the threshold distance condition are evaluated for the orientation condition. The threshold distance and orientation are the necessary but not the sufficient conditions for duplicate geometries. In the third phase, the geometries that have satisfied orientation condition are evaluated for the percentage similarity condition. The geometries that satisfy the percentage similarity condition are highlighted in order to help designers review the results of the duplicate geometry analysis. The test cases are used to validate the algorithm against the requirements list. The test cases are designed to check the performance of the algorithm for the evaluation of the threshold distance, orientation, and percentage similarity condition. The results indicate that the duplicate geometry algorithm is able to successfully conduct all the three phases of evaluation. The algorithm is independent of the geometric type and is able to analyze planar, cylindrical, conical, spherical, freeform, and toroidal shapes. The number of sampling points generated on the faces of parts for the orientation and percentage similarity evaluation has the significant effect on the analysis time. The worst case complexity of the algorithm is the big O (nC2x m12 x m22x p4), where n = the number of parts in the assembly m1 = the number of faces in the parts that meet the threshold distance condition m2 = the number of faces that meet the orientation condition p = the number of sampling points on the face The duplicate geometry feature recognition approach is used to demonstrate the applicability in the extraction of assembly relations for the part connectivity based assembly time estimation method. The algorithm is also able to extract part connectivity information for the patterns. Further research is required to automate the identification of other laziness indicators in order to make the lazy parts method a completely automated tool. With regards to the complete automation of part connectivity based assembly time estimation method, the duplicate geometry feature recognition system needs integration with the algorithm for the computation of bipartite graph of part connections for the prediction of assembly time
Detection of Runway and Obstacles using Electro-optical and Infrared Sensors before Landing
No full text
Synthesis and structure characterization of two cadmium coordination polymers based on μ<sub>2</sub>-bridging bidentate hydrazine ligand
No full text905-909Synthesis, single crystal structures, spectral and thermal characteristics of two cadmium coordination polymers, viz., [Cd(NO3)2(N2H4)2] (1) [Cd(C3H2O4)(N2H4)] (where C3H2O4 is malonate) (2) are reported. The μ2-bridging bidentate binding mode of the crystallographically unique hydrazine ligands in (1) leads to a one-dimensional polymeric structure extending along c axis. The central Cd(II) in (2) exhibits hepta-coordination and is bonded to a unique malonate anion which exhibits a μ3-bridging pentadentate coordination, extending the structure along the a axis. The bridging bidentate binding of the crystallographically independent hydrazine ligand extends along b axis resulting in a 2-D structure
- …
