NBR Powder Modified Phenolic Resin Composite: Influence of Graphite on Tribological and Thermal Properties

The incorporation of graphite as a solid lubricant in the formulation of brake friction material is well-recognized practice. However, achieving the desired level of performances using graphite is still a significant challenge, due to difficulty in dispersion and loading of graphite in composite materials. The present investigation was aimed at identifying the effect of graphite loading on the tribological and thermal properties of a composite made from phenolic resin modified with powdered acrylonitrile butadiene rubber (NBR). Five composites were prepared with different proportions of graphite (0–40 phr) to the phenolic resin. Thermogravimetric analysis (TGA) and thermal conductivity measurements were carried out to demonstrate the thermal stability and thermal conductivity behaviors. Both the thermal stability and thermal conductivity were found to increase with an increase in graphite content. On the other hand, the tribological properties were found to be optimum at a definite loading of graphite (30 phr). The change in surface morphology of these composites was studied before and after the friction test and correlated with the tribological properties. This investigation provides guidelines for achieving a high-performance composite using graphite for brake friction materials.     

Influence of energy induced from processing parameters on the mechanical properties of friction stir welded lap joint of aluminum to coated steel sheet

Friction stir welding has been attempted to evaluate joint strength of lap joint between aluminum sheet (AA6063) and zinc-coated steel (HIF-GA) sheet under different combination of rotational speed and traverse speed. The shear strength decreases significantly when rotational speed increases from 700 to 1,500 rpm at a traverse speed of 30 mm/min. At traverse speed of 50 mm/min, increasing rotational speed from 700 to 1,500 rpm, shear strength remains more or less the same. However, at a traverse speed of 100 mm/min, the shear strength increases significantly with increasing rotational speed from 700 to 1,500 rpm. Essentially, higher fracture load of the lap joint is obtained within a certain range of energy. The results have been correlated with the microstructural characteristics at the bond interface using energy dispersive X-ray spectroscopy, electron probe micro analyzer, and X-ray diffraction. The results show that characteristics of intermetallic compound formed at the interface derived from energy input takes predominating role towards lap joint of Al and coated steel. Furthermore, force and torque responses influenced by the processing parameters can be utilized as weld quality check.     

Electronic and Structural Engineering of Atomically Dispersed Isolated Single-Atom and Alloy Architectures

Precise configurations of isolated metal atoms in nitrogen-doped carbon materials with 2D single or multilayers and 3D nanoarchitectures are gaining attention owing to their good stability and activity at high current densities. Atomic metal–N_x moieties, which utilize maximum atoms to attain high intrinsic activity and novel electronic architecture of support materials, facilitate strong interaction between the central metal atom and support matrix. However, resource consumption is considerably high due to the inferior atomic utilization of active sites. Therefore, energy-efficient electrochemical processes are needed to develop advanced isolated single-atom architecture, which would provide high atom-utilization and good durability. Herein, the concepts of atomically dispersed metal sites in single-atom and alloy architectures and their electronic features associated with structural evolution are discussed. Opportunities and challenges associated with the use of isolated single-atoms in 2D materials are discussed based on their unique electronic defects, low-valence central metals, mechanical flexibility, and maximum access to metal sites. This insightful revisit into the engineering of single-atom and alloy architectures would provide a profound understanding of electronic modulations and regulation of geometric characteristics, and unravels potential directions for electrochemical energy conversion, charge storage, and sensing processes.     

A new deep model for family and non-family photo identification

Multimedia Tools and Applications - Human trafficking is a global issue of the world and the problems related to human trafficking remain unsolved. This paper presents a new method for the...     

Development of Graphene Oxide Nanosheets as Potential Biomaterials in Cancer Therapeutics: An In-Vitro Study Against Breast Cancer Cell Line

Journal of Inorganic and Organometallic Polymers and Materials - Recent advances in nanotechnology and nano biomaterials have attracted considerable attention in the field of cancer therapy. The...     

A content based image information retrieval and video thumbnail extraction framework using SOM

Searching an image or a video in a huge volume of graphical data is a tedious time-consuming process. If this search is performed using the conventional element matching technique, the complexity of the search will render the system useless. To overcome this problem, the current paper proposes a Content-Based Image Retrieval (CBIR) and a Content-Based Video Retrieval (CBVR) technique using clustering algorithms based on neural networks. Neural networks have proved to be quite powerful for dimensionality reduction due to their parallel computations. Retrieval of images in a large database on the basis of the content of the query image has been proved fast and efficient through practical results. Two images of the same object, but taken from different camera angles or have rotational and scaling transforms is also matched effectively. In medical domain, CBIR has proved to be a boon to the doctors. The tumor, cancer etc can be easily deducted comparing the images with normal to the images with diseases. Java and Weka have been used for implementation. The thumbnails extracted from the video facilitates the video search in a large videos database. The unsupervised nature of Self Organizing Maps (SOM) has made the software all the more robust.