Bi-level thresholding using PSO, Artificial Bee Colony and MRLDE embedded with Otsu method

Image segmentation is required to be studied in detail some particular features (areas of interest) of a digital image. It forms an important and exigent part of image processing and requires an exhaustive and robust search technique for its implementation. In the present work we have studied the working of MRLDE, a newly proposed variant of differential evolution combined with Otsu method, a well known image segmentation method for bi-level thresholding. The proposed variant, termed as Otsu+MRLDE, is tested on a set of 10 images and the results are compared with Otsu method and some other well known metaheuristics.     

Deciphering Internal and External π-Conjugation in C3-Symmetric Multiple Azobenzene Connected Systems in Self-Assembly

Two tripodal C₃-symmetric photoswitchable molecular systems T1 and T2 are reported that have extended conjugation at external and internal positions using an acryl group. The influence of the extended π-bonds in their absorption properties, thermal relaxation of the photoisomers and their propensities in forming supramolecular self-assemblies have been explored through spectroscopy, and microscopic studies. In particular, the investigations on the self-assembly have been carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM), polarized optical microscopy (POM), X-ray diffraction studies (XRD) and atomic force microscopy (AFM). Remarkably, the position of the acryl group influences the behaviour of the two target molecules in supramolecular assembly, and also in the formation of photoresponsive organic hydrogels or microcrystals.     

Investigation and optimization of the recovery of coal fines using oil agglomeration process: Use of waste oils from different sectors

The high cost of the bridging liquid subdues the implementation and commercialization of oil agglomeration process. To overcome this problem, waste oils from different sectors were used in this present study. The performance of the process was assessed based on the responses like ash rejection and organic matter recovery. The aim of the present study was to investigate the usage of waste oils from different sectors and to optimize and analyze the behavioral pattern showcased by different variables (pulp density, oil dosage, agglomeration time and oil type) using response surface methodology (Box-Behnken design). Experimental investigation shows that the optimum pulp density, oil dosage, agglomeration time and oil type condition obtained as 3%, 15%, 15?min and waste engine oil, respectively. At optimum condition, the % ash rejection and % organic matter recovery obtained as 63.94% and 81.8%, respectively.     

Tuning of Bistability,Thermal Stability of the Metastable States,and Application Prospects in the C3-Symmetric Designs of Multiple Azo(hetero)arenes Systems

Light-responsive molecular systems with multiple photoswitches in C₃-symmetric designs have enormous application potential. The design part of such molecular systems is critical due to its influence in several properties associated with the photoswitches. In order to tune, and in the evaluation of the design–property relationship, we synthesized 18 tripodal systems with variations in the core, linkers, connectivity, and azo(hetero)arene photoswitches. Through extensive spectroscopic and computational studies, we envisaged the factors controlling near-quantitative photoisomerization in both the directions (bistability) and the thermal stability of the metastable states. Furthermore, we also evaluated the impact of designs in obtaining reversible photo-responsive sol-gel phase transitions, solvatochromism, photo- and thermochromism.     

An evaluation of the emission profile for two-wheelers at a traffic junction

Two-wheeler vehicles are an important mode of transportation in developing countries.However,the emissions from two-wheeler vehicles are significant.Urban two-wheeler vehicles with gasoline-fueled engines produce NO,and particulate matter emissions that affect urban air quality.During traffic light stops and programmed stops,for instance,pollutants are emitted and are dangerous to human health.In this experimental study,two-wheeler vehicles with different makes,technologies and engine capacities were tested for exhaust emissions including gravimetric and online measurements at different engine speeds and a no load condition at a si mutated traffic junction.Gravimetric measurements were performed by collecting the particulate mass(at two engine speeds:1500 and 2500 rpm) from a diluted engine-out exhaust on quartz filter paper.Next,these collected particulates were used to determine the presence of metals,as well as the benzene soluble organic fraction(BSOF).The total particulate mass,BSOF and trace elements were slightly higher at a higher engine speed(2500 rpm).Online measurements were performed by sampling the engine exhaust(at four engine speeds:1500.2000,2500,and 3000 rpm)and using online instruments to determine the particle number and size distribution,the particle-bound polyaromatic hydrocarbons(PAHs),the gaseous emissions and the smoke opacity.Engines with higher cubic capacity emitted a higher concentration of nano-particles.The particle-bound PAH concentration increased as the engine speed increased,but this concentration was notably low for the highest engine speed tested(3000 rpm).The regulated gaseous emissions increased as the engine speed increased for all vehicles.     

Emission profiling of diesel and gasoline cars at a city traffic junction

In congested urban roads,cars must stop at intersections because of city traffic lights.As a result,pedestrians and traffic police personnel are exposed to pollutants emanating from the tailpipe of various vehicles at such city traffic junctions.In this study,various gasoline- and diesel-fueled cars complying with different emission standards were tested for their emissions in simulated city traffic junction conditions.The engine exhaust from these cars was subjected to physicochemical characterization at different engine speeds under no-load conditions.These engine conditions were chosen because the cars idle at different engine speeds at a city traffic junction.Gravimetric and real-time measurements were performed for the tailpipe exhaust sampled from these vehicles.Exhaust particles were collected on 47 mm diameter quartz filter papers and subjected to gravimetric analysis for determining the total particulate mass(TPM)and trace metals while the engines were operated at two different engine idling speeds,1500 rpm(representing low idling) and 2500 rpm(representing high idling).At similar engine operating conditions,TPM and trace metals were lower for the exhaust from gasoline engines compared to the exhaust from diesel engines.Real-time measurements were performed for particle-bound poly-aromatic hydrocarbons(PAHs),particle number and size distribution,regulated gaseous emissions and smoke opacity of the exhaust at four different engine speeds,1500,2000,2500,and 3000 rpm.Particle-bound PAHs showed a decreasing trend for the vehicles that complied with stricter vehicular emission standards.Higher particle peak number concentrations were observed for diesel exhausts compared to the results for gasoline exhaust.Regulated gaseous emissions were also compared.     

Infrared and thermal behaviour of thorium(IV) and oxozirconium(IV) complexes of dibenzyl sulphoxide

A series of complexes of thorium(IV) and oxozirconium(IV) with dibenzyl sulphoxide having the general compositions ThX₄·2BzSO (X = Cl, Br, NCS or NO₃), ThI₄·4BzSO, Th(ClO₄)₄·6BzSO, ZrOX₂·2BzSO (X = Cl, Br, I, NCS, NCSe or BPh₄) and ZrO(ClO₄)₂· 6BzSO were synthesised and characterized by elemental analyses, electrolytic conductivity, moleculer weight, IR, and magnetic susceptibility measurements. TG and DTA of the complexes were also studied.     

Modal analysis and dynamic responses of a rotating Cartesian manipulator with generic payload and asymmetric load

Abstract

Here, investigation to explore the effect of generic payload and externally applied asymmetric load on the calculation of modal parameters and dynamic performance of a rotating flexible manipulator under prismatic motion has been established. We thus have developed a dynamic model of a rotating Cartesian manipulator with a payload whose center of gravity doesn’t coincide with the point of attachment, to determine the modal parameters i.e., natural frequency and corresponding mode-shape. These modal parameters are then illustrated graphically upon varying parameters like offset parameters (i.e., offset mass, offset inertia, offset length), mass and stiffness of rotary actuator, and amplitude and frequency of asymmetric load. An investigation into the nonlinear dynamics of the system accounting of geometric nonlinearity has been executed while obtained results have been validated numerically within the permissible error at the assorted critical points in frequency characteristic curves. Current research further investigates the influences of offset parameters, mass and stiffness of the actuator, frequency and amplitude of axial force on the steady state responses for the primary and sub-harmonic resonance conditions to reveal the built-in saddle-node and pitchfork bifurcation due to which the system losses its structural stability. This work enables an insight into the modal characteristics and nonlinear behavior of a rotating-Cartesian manipulator with a generic payload under asymmetric axial force and prismatic motion.     

Arylazo-3,5-dimethylisoxazoles: Azoheteroarene Photoswitches Exhibiting High Z-Isomer Stability,Solid-State Photochromism,and Reversible Light-Induced Phase Transition

Reversibly photoswitchable phenylazo-3,5-dimethylisoxazole and 37 aryl-substituted derivatives were synthesized. Excellent photoswitching ability of these compounds in solution and the solid state was demonstrated. Through kinetics studies by means of NMR spectroscopy, high Z-isomer stability was demonstrated. Interestingly, the majority of the derivatives showed light-induced contrasting color changes in solution and the solid state. Besides, many of the derivatives exhibit partial phase transition upon UV irradiation. The highlight of this class of photoswitches is the reversible light-induced phase transition between solid and liquid phases in the parent compound, which can be used in patterned crystallization. These results show that this new class of azoheteroarene based photoswitches has opportunities to be useful in various domains.