High Velocity Oxy Fuel Spraying of Cold Work Tool Steels‐ A Novel Approach to Thick Coatings for Wear Protection Applications

Within this work, HVOF sprayed coatings based on X220CrVMo13‐4 cold work steel were applied to a S235JR construction steel substrate. The investigations focus on the influence of particle size and spray parameters on the coating microstructure, analyzed by means of optical microscope (OM) and scanning electron microscopy (SEM). Additional XRD measurements and micro hardness plots across the interface between substrate material and coating were carried out. Furthermore, the influence of particle size on the detected phases and coating porosity was studied. The results were compared with an X220CrMoV13‐4 reference sample produced by HIP.     

Microstructure and some properties of aluminium alloy AA6061 reinforced in situ formed zirconium diboride particulate stir cast composite

The objective of this work is to fabricate aluminium alloy AA6061 reinforced with ZrB₂ particles (10 wt-%) by the in situ reaction of K₂ZrF₆ and KBF₄ salts with molten aluminium. The microstructure, tensile strength, wear resistance and corrosion rate of the fabricated composite were compared with those of matrix alloy. The in situ formed ZrB₂ particles were uniformly dispersed in the aluminium matrix predominantly concentrated in inter granular regions and refined the microstructure of the matrix alloy. The incorporation of in situ formed ZrB₂ particles into the aluminium matrix improved tensile strength and wear resistance but reduced ductility and corrosion resistance.     

The Effect of Melt Ultrasound Treatment on the Microstructure and Age Hardenability of Al-4 Wt Pct Cu/TiC Composite

Metallurgical and Materials Transactions B - In the present work, Al-4 wt pct Cu/TiC composite was synthesized by the molten salt route that contains submicron-sized TiC particles in the Al-4 wt...     

Unsupervised learning-based clustering approach for smart identification of pathologies and segmentation of tissues in brain magnetic resonance imaging

Human-made/developed algorithms provide automatic identification and segmentation of the tissues, lesions and tumor regions available in brain magnetic resonance scan images, which invocates predicaments such as high computational cost and low accuracy rate. Such hassles are reconciled with the utilization of an unsupervised approach in combination with clustering techniques. Initially, static features are chosen from the input image, which is fed to the self-organizing map (SOM), where the algorithm employs the dimensionality reduction of input images. Consecutively, the reduced SOM prototype of data is clustered by the modified fuzzy K-means (MFKM) algorithm. The MFKM algorithm can be modified in terms of membership variables because it operates with spatial information and converges quickly, and this would be of greater benefit to radiologists as they reduce the wrong predictions and voluminous time that normally occur owing to human involvement. The proposed algorithm provides 98.77% sensitivity and 97.5% specificity, which are better than any other traditional algorithms mentioned in this article.     

Automatic segmentation of gallbladder using bio-inspired algorithm based on a spider web construction model

The Journal of Supercomputing - In medical image processing, an accurate segmentation and classification are very important and this field still needs an effective computer-based algorithm for...     

Enhancing bioavailability and hepatoprotective activity of andrographolide from Andrographis paniculata,a well‐known medicinal food,through its herbosome

BACKGROUND: Andrographis paniculata is a health food used extensively in Southeast Asia, India and China and contains the pharmacologically important phytochemical andrographolide. Although andrographolide has antihepatotoxic activity, its bioavailability from A. paniculata is restricted by its rapid clearance and high plasma protein binding. The aim of this study was to formulate a herbosome of andrographolide with a naturally occurring phospholipid in order to enhance the bioavailability and hepatoprotective activity of andrographolide in rats. RESULTS: Andrographolide herbosome equivalent to 25 and 50 mg kg⁻¹ andrographolide significantly protected the liver of rats, restoring hepatic enzyme activities with respect to carbon tetrachloride‐treated animals (P < 0.05 and P < 0.01 respectively). The rat plasma concentration of andrographolide obtained from the complex equivalent to 25 mg kg⁻¹ andrographolide (C_max = 9.64 µg mL⁻¹) was higher than that obtained from 25 mg kg⁻¹ andrographolide (C_max = 6.79 µg mL⁻¹), and the complex maintained its effective plasma concentration for a longer period of time. CONCLUSION: The results proved that the andrographolide complex produced by this method has better bioavailability and hence improved hepatoprotective activity compared with andrographolide at the same dose. Andrographolide complexation is therefore helpful in solving the problem of rapid clearance and low elimination half‐life associated with andrographolide from A. paniculata. Copyright © 2009 Society of Chemical Industry     

Photocatalytic hydrogen generation by splitting of water from electrospun hybrid nanostructures

MWCNT-TiO₂ hybrid nanostructures are prepared using sol–gel and electrospinning followed by post annealing of as-spun nanofibers at 450 °C per 1 h in air. These hybrid nanostructures composed of MWCNTs varied from 0 to 20% (w/w) and are characterized by SEM, TEM, XRD, and FT-IR analysis. MWCNT-TiO₂ hybrid structures are utilized in commercially available Methylene blue (MB) dye degradation and found that 2% of MWCNT exhibit superior kinetic constant 6.379 × 10⁻³ min⁻¹ extracted. In addition, we demonstrate that the doping of MWCTs within TiO₂ leads to a significant enhancement of the UV–vis light assisted photocatalytic activity is optimized in comparison with higher (5, 10 and 20%) compositions. UV–vis assisted photocatalytic hydrogen is evolved by photoelectrolytic splitting of water by using MWCNT-TiO₂ hybrid nanostructures as electrode.     

Optimization of process parameters to maximize ultimate tensile strength of friction stir welded dissimilar aluminum alloys using response surface methodology

Aluminium alloys generally present low weldability by traditional fusion welding process. Development of the friction stir welding （FSW） has provided an alternative improved way of producing aluminium joints in a faster and reliable manner. The quality of a weld joint is stalwartly influenced by process parameter used during welding. An approach to develop a mathematical model was studied for predicting and optimizing the process parameters of dissimilar aluminum alloy （AA6351 T6-AA5083 Hlll）joints by incorporating the FSW process parameters such as tool pin profile, tool rotational speed welding speed and axial force. The effects of the FSW process parameters on the ultimate tensile strength （UTS） of friction welded dissimilar joints were discussed. Optimization was carried out to maximize the UTS using response surface methodology （RSM） and the identified optimum FSW welding parameters were reported.     

Analysis of Stress Control on 33-kV Non-ceramic Insulators Using Finite-element Method

In this article, analysis of electric field stress and electric potential distributions of a 33-kV composite insulator and factors that affect the electric field are discussed. Accordingly, the article is classified into two parts. In the first part, the designs of three different configurations of non-ceramic (composite) insulator based on their geometry modification in end fittings and water shed are discussed. The electrical performances are analyzed using electric field and electrical potential distribution. In the second part, a reduction of the electric field near the end fittings is done to control the electric field stress intended for long-term performance. For that, the grading material is placed between the core and housing materials by fitting the arcing horn near the end fittings. A 33-kV composite insulator is modeled in two dimensions by the finite-element method to investigate the electric field and electric potential distribution under normal and polluted conditions. The results reveal that an optimum installation of an arcing horn at the high-voltage end in the composite insulator with silicone rubber overlapping the edges of metal end fittings made a significant reduction in electric field stress on 33-kV non-ceramic insulators.