Effect of Silica Content on Mechanical and Microstructure Behaviour of Resistance Spot Welded Advanced Automotive TRIP Steels

Silicon - This research investigates the effect of SiC wt% on mechanical and microstructure behavior of transformation induced plasticity (TRIP) 780 steels by resistance spot welding. The...     

An Efficient Hybrid Optimization for Skin Cancer Detection Using PNN Classifier

The necessity of on-time cancer detection is extremely high in the recent days as it becomes a threat to human life. The skin cancer is considered as one of the dangerous diseases among other types of cancer since it causes severe health impacts on human beings and hence it is highly mandatory to detect the skin cancer in the early stage for providing adequate treatment. Therefore, an effective image processing approach is employed in this present study for the accurate detection of skin cancer. Initially, the dermoscopy images of skin lesions are retrieved and processed by eliminating the noises with the assistance of Gabor filter. Then, the pre-processed dermoscopy image is segmented into multiple regions by implementing cascaded Fuzzy C-Means (FCM) algorithm, which involves in improving the reliability of cancer detection. The A Gabor Response Co-occurrence Matrix (GRCM) is used to extract melanoma parameters in an efficient manner. A hybrid Particle Swarm Optimization (PSO)-Whale Optimization is then utilized for efficiently optimizing the extracted features. Finally, the features are significantly classified with the assistance of Probabilistic Neural Network (PNN) classifier for classifying the stages of skin lesion in an optimal manner. The whole work is stimulated in MATLAB and the attained outcomes have proved that the introduced approach delivers optimal results with maximal accuracy of 97.83%.     

Twisted Crystalline Organic Semiconductor Photodetectors

Optoelectronic properties of anisotropic crystals vary with direction requiring that the orientation of molecular organic semiconductor crystals is controlled in optoelectronic device active layers to achieve optimal performance. Here, a generalizable strategy to introduce periodic variations in the out-of-plane orientations of 5,11-bis(triisopropylsilylethynyl)anthradithiophene (TIPS ADT) crystals is presented. TIPS ADT crystallized from the melt in the presence of 16 wt.% polyethylene (PE) forms banded spherulites of crystalline fibrils that twist in concert about the radial growth direction. These spherulites exhibit band-dependent light absorption, photoluminescence, and Raman scattering depending on the local orientation of crystals. Mueller matrix imaging reveals strong circular extinction (CE), with TIPS ADT banded spherulites exhibiting domains of positive or negative CE signal depending on the crystal twisting sense. Furthermore, orientation-dependent enhancement in charge injection and extraction in films of twisted TIPS ADT crystals compared to films of straight crystals is visualized in local conductive atomic force microscopy maps. This enhancement leads to 3.3- and 6.2-times larger photocurrents and external quantum efficiencies, respectively, in photodetectors comprising twisted crystals than those comprising straight crystals.     

Upconversion of NaYF4: Yb,Er Nanoparticles Co-doped with Zr 4+ for Magnetic Phase Transition and Biomedical Imaging Applications

Tracking of cancer cells and cytotoxicity of normal tissue are the leading problem in cancer treatment. The magnetic and fluorescent multifunctional particles evolve as an emerging alternative for future target recognition. The ferromagnetic materials potentially treat the defects in the gene. Hence, ferromagnetic materials are the best for the treatment of cancer using gene therapy. Here, β-NaYF₄: Yb, Er compounds doped with 10%, 20% and 30% Zirconium (Zr) are prepared through hydrothermal technique. Citrate itself is a highly biocompatible surface ligand that labels the imaging probe. The X-ray diffraction analysis is evident for transforming hexagonal to cubic phase via Zr doping in NaYF₄: Yb, Er compounds. The electron microscopic images identify the hexagonal plates. This compound can emit visible light in response to infrared (IR) light irradiation. Especially β-NaYF₄: Yb, Er, and 10% of Zr, Yb, Er tridoped NaYF₄ compounds show enhanced red emission exploited in bioimaging applications. Insignificantly, 30% of Zr, Yb, Er tridoped NaYF₄ concentration exhibit hexagonal and dominating cubic (α) phase, could decrease red emissions intensity and magnetisation value. This Zr material reveals peculiar magnetic properties, especially ferromagnetism at a lower magnetic field and produces paramagnetism at a higher magnetic field. Here, 10–20% Zr, Yb, Er tridoped NaYF₄ concentrations exhibit better magnetic properties. The resultant compound is viable for the VERO cells.

     

Study of an Explosive-Driven Metal Plate

Equation of motion of an incompressible metal plate, accelerated by a plane detonation wave, has been solved for a general value of adiabatic exponent ß of detonation products to investigate its effect on terminal velocity of the plate. It has been found that the plate velocity increases with decreasing value of ß. The magnitude of this effect has been found sufficient to determine adiabatic exponent of detonation products from the measurement of flyer plate velocities at different C/M ratios. Velocities of metal plates, hurled by contact explosion of high density explosives, have also been measured with oscillographic technique by using an experimental setup which is insensitive to air shocks. The plate velocities measured by such an experimental setup have been found in good agreement with theoretical ones.