184 research outputs found
2022 IEEE Long Island Systems, Applications and Technology Conference (LISAT 2022)
No full textUma Balaji (with Patrick Evans, Ryan Avery, Maxwell Malcy, and Maverick Ruiz) is a contributing author, Multipurpose Solar Charging Station.https://digitalcommons.fairfield.edu/engineering-books/1079/thumbnail.jp
Fundamental Study into the Mechanics of Material Removal in Rock Cutting
No full textThe objective of this work was to understand the mechanics of material removal during rock cutting. The exact nature of the failure of the rock material at the tool tip was investigated using a single cutting tooth test rig coupled with high speed photography, for various rock-like specimens. Linear cutting tests were performed using a tungsten carbide tipped orthogonal cutting tool with three different rake angles on low and high strength simulated rocks. Statistical analysis together with high speed video analysis were supported by numerical simulation, performed using a commercially available code called ELFEN; a hybrid finite-discrete element software package
Proceedings of the International Conference on Computers Communication and Devices, (ICCCD, 2000)
No full textUma Balaji is a contributing author, Computer aided design of e-plane diplexer.
Book description:
Papers presented at the International Conference on Computers Communication and Devices, (ICCCD, 2000), Indian Institute of Technology, Kharagpur, Dec 2000.https://digitalcommons.fairfield.edu/engineering-books/1035/thumbnail.jp
Submerged mandibular carious deciduous second molar along with an impacted second premolar associated with an atypical inflammatory follicular cyst: A rare case report
No full textThe author presents a case of submerged carious deciduous molar along with an inflammatory atypical follicular cyst associated with an impacted mandibular second premolar in the right mandible identified through clinical and routine radiological examination including cone beam computed tomography and histopathology. The involvement of submerged deciduous molar with dental caries by itself a rare occurrence and an impacted permanent premolar tooth associated with an infected follicular cyst is still more a rare event
Fibre use in concrete - including novel fibres that use the poison ratio to a positive effect for bond strength.
No full textFibres have been used in construction materials for thousands of years. Fibre reinforcement of building materials is not new, indeed the use of straw to reinforce bricks dates back to Egyptian times, also horse hair was commonly used to reinforce lime/sand plaster until the 1950s and asbestos has been used for around 100 years as a cement reinforcement.
It is worth noting in some countries, natural fibres are often used in concrete manufacture, such as flax, wood, palm, jute, bamboo, etc. these natural products have the advantage of having low environmental impact and low environmental manufacturing costs.
“One mechanical property of great practical significance is fibre reinforced concrete’s ability to absorb energy”, this is a key characteristic when analysing the durability of concrete with fibre additions, when considering dynamic or impact loading.
Fibres are categorized into Type 1 and Type 2 synthetic fibres, and straight steel fibres of various shapes. Fibres under development are steel fibres that will provide reinforcement in the x,y and z axes, closed loop steel fibres, positive poission ratio fibres that grip under load. The aforementioned fibre types will be presented and discussed
Experimental investigation and numerical simulation of chip formation mechanisms in cutting rock-like materials
Full text linkIn this study, the effects of tool geometry such as rake angle, and cutting parameters such as depth of cut on the cutting forces were studied and correlated with the built-up edge during the material removal process of a rock-like workpiece. Cutting or scratch tests were performed on low and high strength simulated rock-like materials using a tungsten carbide tipped orthogonal drag tool with three different rake angles (0°, 10° and 20°) in a custom-made machining set-up incorporating a high-speed video camera. Force data were measured by a tri-axial dynamometer and a compatible data acquisition system, and specific cutting energy was calculated to assess the material removal performance. Experiments showed that a cutting tool with a 20° rake angle produced an efficient cut. The high-speed video at the cutting edge were analysed to comprehend the formation and growth of the built-up edge. Novel insight was gained by characterising the shape and was observed that the constantly evolving shape was unique to each rake angle used, this creates an apparent rake angle. By varying the rake angle and cutting parameter, the measured cutting force and thrust force showed that the material strength, cutting tool geometry and depth of cut played important roles in removing materials. Higher cutting efficiency was indicated by lower specific cutting energy at higher depth of cut for all cutting conditions. The formation of the crushed zone in relation to the cutting force revealed that the cutting force increased with the size of the crushed zone having two types of chip formation modes: shearing and fracturing. Numerical simulations were performed using a commercially available tool called ELFEN, a hybrid finite-discrete element software package. The simulations correlated well with experimental investigation. The simulations also showed the formation of crushed zone and crack growth as observed experimentally through the use of high-speed video and also shed light on the state of stress state at the cutting edge
Innovative Techniques in Instruction Technology, E-learning, E-assessment, and Education
Full text linkUma Balaji is a contributing author, Demonstrations of Transmission Line Effects.
Book description:
Innovative Techniques in Instruction Technology, E-Learning, E-Assessment and Education is a collection of world-class paper articles addressing the following topics:
E-Learning including development of courses and systems for technical and liberal studies programs; online laboratories; intelligent testing using fuzzy logic; evaluation of on line courses in comparison to traditional courses; mediation in virtual environments; and methods for speaker verification.
Instruction Technology including internet textbooks; pedagogy-oriented markup languages; graphic design possibilities; open source classroom management software; automatic email response systems; tablet-pcs; personalization using web mining technology; intelligent digital chalkboards; virtual room concepts for cooperative scientific work; and network technologies, management, and architecture.
Science and Engineering Research Assessment Methods including assessment of K-12 and university level programs; adaptive assessments; auto assessments; assessment of virtual environments and e-learning.
Engineering and Technical Education including cap stone and case study course design; virtual laboratories; bioinformatics; robotics; metallurgy; building information modeling; statistical mechanics; thermodynamics; information technology; occupational stress and stress prevention; web enhanced courses; and promoting engineering careers.
Pedagogy including benchmarking; group-learning; active learning; teaching of multiple subjects together; ontology; and knowledge representation.
Issues in K-12 Education including 3D virtual learning environment for children; e-learning tools for children; game playing and systems thinking; and tools to learn how to write foreign languages.https://digitalcommons.fairfield.edu/engineering-books/1034/thumbnail.jp
Investigation into rock mechanics using finite element method
No full textResearch into metal cutting is an established area, whereas the behaviour of rock during cutting is somewhat more complex and not well understood. This makes the field of Rock Mechanics - in particular the use of Finite Element Analysis [FEA] in studying the behaviour of the rock under cutting conditions where many parameters are involved - a challenging area to explore. Here experimental results are needed to justify and verify the results from FEA modelling. Based on the Brazilian Test this paper analyses three types of rocks namely - limestone, sandstone and shale, which belong to the sedimentary rock category with sandstone having greater strength than limestone and shale. The Finite Element-Discrete Element coupled method (FEM-DEM) used in the proposed modelling enables the facture process of the rock to be studied closely in relation to the cutting force component causing the start of fracture and the behaviour of the propagating crack during this process. These results should prove to be useful in analysing the fundamental behaviour of the rock material at the extreme cutting edge of the tool
Predicting the diffusivity of CO2 in substituted amines
No full textThe experimental determination of the diffusivity of carbon dioxide (CO2) in an amine solvent is difficult as the CO2 diffuses and reacts simultaneously when absorbed into an amine solvent. As the knowledge of the diffusivity and solubility of CO2 is essential to design the absorption units based on amine solvents, the nitrous oxide (N2O) analogy is used in practice to estimate them. It consists of evaluating those physical properties by substituting the reacting CO2 with an inert gas of a similar structure, N2O. The diffusion of CO2 in amine solvents is investigated using molecular dynamics (MD) simulation. Unlike experiments, MD simulation allows a direct measurement of the CO2 diffusivity. In MD simulations, the reaction between CO2 and the amine can be switched off. The Fick diffusion coeffcients are derived from the Maxwell-Stefan diffusivities and the thermodynamic factors. Different amine solvents like monoethanolamine, diethanolamine, methyl-diethanolamine and ethylamine are investigated. The N2O analogy in the monoethanolamine-water solution has been validated.EThChemical EngineeringApplied Science
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