National Institute of Technology, Meghalaya

About: National Institute of Technology, Meghalaya is a education organization based out in Shillong, India. It is known for research contribution in the topics: Control theory & Computer science. The organization has 503 authors who have published 1062 publications receiving 6818 citations. The organization is also known as: NIT Meghalaya & NITM.

Surface Modification of Medical-Grade Ni55.6Ti44.4 alloy via enhanced machining characteristics of Zn Powder Mixed-μ-EDM

Abstract: The surface modification via subtractive manufacturing intends to localize the desired properties on the produced surface during the machining. In the case of miniaturized components, the powder mixed-micro-electric discharge machining (PM-μ-EDM), a potential variant of EDM, can achieve superior microfeatures such as dimensional accuracy and surface integrity, and a noteworthy surface modification on the hard and tough materials such as titanium and nickel alloys. Besides, the increasing demands for microfabricated devices used in tissue engineering and therapeutics delivery encourage their production with improved surface characteristics and biocompatibility. The superelastic nickel‑titanium alloy (Nitinol) has recently emerged as one of the most desirable biomaterials primarily in the vascular and prosthetic applications. However, the microfabrication followed by surface modification of Nitinol by the PM-μ-EDM has been rarely recorded. Hence, this research aimed to modify the Medical-grade Ni55.6Ti44.4 alloy surface with the least machining time and dimensional deviation using zinc PM-μ-EDM. A comparative study between the μ-tool electrodes (copper and brass) and Zn powder particle concentrations (PPCs: 0, 2, 4, 6, 8, and 10 g/l) revealed that the copper μ-tool electrode in association with 6 g/l PPC, could achieve the most improved machinability and modified layer on the Ni55.6Ti44.4 alloy surface. A field emission scanning electron microscope (FESEM) and energy-dispersive X-ray spectroscopy (EDS) investigated the dimensional, morphological, and compositional features of the modified Ni55.6Ti44.4 alloy surface and reported significant improvements. The X-ray diffraction (XRD) analysis of the modified surface detected a remarkable impact of the thermally induced variations on the crystalline phases of Ni55.6Ti44.4 alloy. Further, the lactate dehydrogenase (LDH) and CellTiter-Blue assays determined improved cytocompatibility characteristics and Drop Shape Analyzer (DSA) ascertained the hydrophobicity of the modified Ni55.6Ti44.4 alloy surface.

Off-line signature verification using elementary combinations of directional codes from boundary pixels

Abstract: Verifying the genuineness of official documents, such as bank checks, certificates, contract forms, bonds, etc., remains a challenging task when it comes to accuracy and robustness. Here, the genuineness is related to the degree of match of the signature contained in the documents relating to the original signatures of the authorized person. Signatures of authorized persons are considered known in advance. In this paper, a novel feature set is introduced based on quasi-straightness of boundary pixel runs for signature verification. We extract the quasi-straight line segments using elementary combinations of the directional codes from the signature boundary pixels and subsequently we obtain the feature set from various quasi-straight line classes. The quasi-straight line segments provide a blending of straightness and small curvatures resulting in a robust feature set for the verification of signatures. We have used Support Vector Machine (SVM) for classification and have shown results on standard signature datasets like CEDAR (Center of Excellence for Document Analysis and Recognition) and GPDS-100 (Grupo de Procesado Digital de la Senal). The results establish how the proposed method outperforms the existing state of the art.

Multi-agent Navigation and Coordination Using GA-Fuzzy Approach

Abstract: This paper presents the coordinated navigation problem of multiple wheeled robots. Two motion planners such as PFM and GA-tuned FLC are combined with a coordination strategy block to solve such problems. Performances of the developed approaches are tested through computer simulations. A total hundred numbers of scenarios are taken to show the efficacy of the proposed navigation schemes. GA-tuned FLC has wholly outperformed the PFM in most of the situations. Also, with the increase in some robots, coordination count has increased, and the need for the strategies was prominent. It is experienced that proposed coordination strategy along with the developed motion planners results in a time-optimal and realistic solution to the discussed problem.

A facile iron-catalyzed dual C–C bond cleavage: an approach towards triarylmethanes

Abstract: A facile iron-catalyzed dual C–C bond cleaving reaction involving 1,3-dicarbonyl units along with electron-rich and sterically bulky arenes as efficient carbon-based leaving groups has been developed. The scope of the dual C–C bond breaking reaction was studied in detail using a range of nucleophiles to synthesize symmetrical triarylmethanes in good to excellent yields. We found success in isolating the intermediate of the reaction, formed via the initial Csp3–Csp3 bond cleavage, and subsequently converted the intermediate to the final product via the Csp3–Csp2 bond cleavage. A notable difference in the leaving aptitudes of the two carbon-based leaving groups perceived during the study enabled us to develop an application of the dual C–C bond breaking reaction for the synthesis of unsymmetrical triarylmethanes in a stepwise manner. To improve the synthetic utility, we have also fashioned a one-pot procedure to generate unsymmetrical triarylmethanes via sequential C–C bond breaking reactions. In addition to studying a novel dual C–C bond breaking reaction and providing a hint to the mechanistic pathway, the application molded from the study for the synthesis of symmetrical and especially unsymmetrical triarylmethanes may render value to the present work.

Francis turbine electrohydraulic inlet guide vane control by artificial neural network 2 degree-of-freedom PID controller with actuator fault:

Abstract: Hydropower system has great attention due to the cheapest and simplest renewable power generation, available potential and environmental concern. Francis turbine has wide operating range compare to...