Vibratory Behavior of Rolling Element Bearings: a Lagrangian Approach

Vibratory behavior of a rolling element bearing on a horizontal rotor is studied in this work. This Thesis analyzes the dynamics of a typical roller bearing as a result of internal excitations. These internal excitations stem from the geometric deviations of the interacting surfaces from their ideal geometry. Such deviations in turn are the results of either manufacturing limitations or normal wear of the bearing surfaces. Lagrangian approach is implemented to derive the dynamic equations of motion. Matlab is used to solve the equation of motion of governing the vibrations of the system. Parametric studies are conducted to provide results for several excitation levels. The study shows, that for a surface waviness of 0.00001 (mm), the roller\u27s radial displacement is about 1.5*10-6 (mm) under a linear analysis for a shaft speed of 2000rpm. Consideration of non-linear analysis predicted 2*10-15 (mm) for the roller radial displacement in response to the same surface condition. For shaft speeds of 2400 rpm, 3000 rpm, and 4000 rpm, the roller radial displacements for linear analysis are 8.5*10-7, 8*10-7, and 6*10-7 (mm) respectively. And for nonlinear analysis are 8*10-15, 2*10-16, 6*10-16 respectivel

Vibratory Behavior of Rolling Element Bearings: a Lagrangian Approach

Vibratory behavior of a rolling element bearing on a horizontal rotor is studied in this work. This Thesis analyzes the dynamics of a typical roller bearing as a result of internal excitations. These internal excitations stem from the geometric deviations of the interacting surfaces from their ideal geometry. Such deviations in turn are the results of either manufacturing limitations or normal wear of the bearing surfaces. Lagrangian approach is implemented to derive the dynamic equations of motion. Matlab is used to solve the equation of motion of governing the vibrations of the system. Parametric studies are conducted to provide results for several excitation levels. The study shows, that for a surface waviness of 0.00001 (mm), the roller\u27s radial displacement is about 1.5*10-6 (mm) under a linear analysis for a shaft speed of 2000rpm. Consideration of non-linear analysis predicted 2*10-15 (mm) for the roller radial displacement in response to the same surface condition. For shaft speeds of 2400 rpm, 3000 rpm, and 4000 rpm, the roller radial displacements for linear analysis are 8.5*10-7, 8*10-7, and 6*10-7 (mm) respectively. And for nonlinear analysis are 8*10-15, 2*10-16, 6*10-16 respectivel

Nanoencapsulated Drug-Carrying System for Photodynamic Antimicrobial Chemotherapy (PACT)

The purpose of this study is to develop nanoparticulate drug-carrying systems that are capable of directly delivering photodynamic antimicrobial agents to treat patients with chronic wounds. Chronic wounds are considered as a pandemic health problem. Approximately 1% to 2% of the population in developing countries has experienced a chronic wound during their lifetime. In the United State States, according to the American Academy of Dermatology, the expense of treating chronic wounds constitutes over half of the total cost for all skin diseases, which exceeds $10 billion annually. For the last decade extensive basic science and clinical research in chronic wounds have suggested that pathogenic biofilm is the primary hindrance to the wound healing.Biofilms are highly organized, poly-species bacterial communities living within a protective extracellular matrix that they produce. They are difficult to detect and highly resistant to the host immune system or to antimicrobial elimination.Studies have shown that they can be up to 500 times more resistant to antibiotics than planktonic (unattached, freely living) cells. Owing to bacterial species within biofilms being exceptionally resistant to many traditional therapies, Photodynamic Antimicrobial Chemotherapy (PACT) can provide an effective alternative for chronic wound treatment. The principle of PACT is derived from traditional photodynamic therapy, which is a technique that uses the combination of light and nontoxic drugs (photosensitizers) to destroy specific targeted cells. After the inactive, nontoxic drug is applied topically or injected, it can only be activated by irradiation with a certain wavelength of light. The light switches on the drug; once the drugs are activated they can produce highly reactive intermediates to destroy the targeted cells without damaging the surrounding healthy tissues. Once the irradiation is removed, the photosensitive drug will return to its stable, non-harmful state. The main advantage of PACT would be that it is very unlikely for bacteria to develop resistance to reactive oxygen species However, the main limitation of this technique would be the uptake kinetics of the photosensitizers in microorganisms. Therefore, the main objective of this study is to find a nanoencapsulated drug-carrying system that can easily penetrate into the polymicrobial species habitat within biofilms

SunSat Design Competition 2013-2014 First Place Winner – Team Rajiv Gandhi University: HelioAstra

HelioAstra is a creative design and visualization of an advanced Space Solar Power system. Its concept is validated by a credible science and engineering approach and an innovative business plan. The space and ground receiving segments are made up of high efficiency Fresnel lens concentrator quantum dot solar cells. The solar array in space is sized at 933 m2. It delivers 1 MW (1000 kW) of perennial, clean and eco-friendly solar electric power at the bus-bars on the ground. A solid state laser system containing Neodymium doped Yttrium Aluminium garnet (Nd: Y3Al5O12) will accurately and efficiently transmit power. A ground receiving station with 70m diameter rectifying antenna will collect the power delivered in the form of a laser signal and energize the Sea Water Reverse Osmosis (SWRO) Desalination plant located in the Bay of Bengal near the Indian costal metropolitan city of Vishakhapatnam in the state of Andhra Pradesh. Two Ku band transponders with uplink signal - of intelligent design – will continuously track the HelioAstra SunSat and respond as per Motion Control Facility (MCF) instructions. Being placed in Geostationary orbit helps the satellite maintain a fixed beam footprint on the earth’s surface around the clock. An innovative marketing strategy will enable value addition by a factor of 80 times based on the sale of solar electric power delivered from the HelioAstra solar power spacecraft and sale of 1.734 million litres/day (MLD) of fresh water produced by an SWRO desalination plant. The HelioAstra SSP System Efficiency Chain and the integrated HelioAstra–Aqua (SSP-SWRO) overall System, Mission Efficiency and Performance Chains are presented using open-source published values of component efficiencies. The cost of space segment and ground segment (including ground power receiver and salt water reverse osmosis plant) and annual revenue flow are estimated based on a sensitivity analysis on Excel spread sheet. Revenue value-addition by use of SWRO for production and sale of fresh water and use of the advanced Falcon 9 (Reusable) space launch vehicle are required to enable acceptable system specific costs within a mission-investment payback period of 7 years. Advisors: Mr. Joseph Bland, Air Cmde R Gopalaswami [Retd], Dr. MYS Prasad, Sri Somana Vishwanatham Click here to view the Team video: Team HelioAstra - 2014 International SunSat Design Competition Visualizatio

Scale-Invariant Random Spatial Networks

Real-world road networks have an approximate scale-invariance property; can one devise mathematical models of random networks whose distributions are {\em exactly} invariant under Euclidean scaling? This requires working in the continuum plane. We introduce an axiomatization of a class of processes we call {\em scale-invariant random spatial networks}, whose primitives are routes between each pair of points in the plane. We prove that one concrete model, based on minimum-time routes in a binary hierarchy of roads with different speed limits, satisfies the axioms, and note informally that two other constructions (based on Poisson line processes and on dynamic proximity graphs) are expected also to satisfy the axioms. We initiate study of structure theory and summary statistics for general processes in this class.Comment: 56 page

The Baylis-Hillman reaction: a novel source of attraction, opportunities, and challenges in synthetic chemistry

The Baylis-Hillman reaction is a successful, useful, and atom-economical carbon-carbon bond forming reaction, which has grown from an obscure level to the level of high synthetic popularity due to its operational simplicity and also due to the enormous applications of the Baylis-Hillman adducts in organic synthesis. In this tutorial review, we briefly describe the way this reaction has grown to its present heights and the opportunities, attractions, and challenges the reaction offers with respect to its asymmetric and intramolecular versions, and mechanistic aspects

Photochromic Performance of PLD grown MoO3Thin Films

Molybdenum trioxide (MoO3) thin films are made by Pulsed Laser Deposition (PLD) technique onto cleaned glass substrates at an oxygen partial pressure (PO2) of 100 m Torr by varying substrate temperature (Ts). The present study describes the variation in the growth of films and photochromic properties with respect to substrate temperature. XRD studies confirm unique α - orthorhombic layered structure for grown films and the intensity of prominent peaks increases with substrate temperature. SEM images discloses that the film surface constitutes uniformly spherical grains at lower substrate temperature (Ts = 100 ℃) and turns to needle like structure as substrate temperature reaches to 200 and 300 ℃. The films deposited at 400 ℃ gives nano-crystalline structure which shows stable and high photochromic efficiency. The studies also reveal that the presence of impurities or ions on the surface of the film and effects on the photochromic performance

Scale Invariance in Road Networks

We study the topological and geographic structure of the national road networks of the United States, England and Denmark. By transforming these networks into their dual representation, where roads are vertices and an edge connects two vertices if the corresponding roads ever intersect, we show that they exhibit both topological and geographic scale invariance. That is, we show that for sufficiently large geographic areas, the dual degree distribution follows a power law with exponent 2.2 < alpha < 2.4, and that journeys, regardless of their length, have a largely identical structure. To explain these properties, we introduce and analyze a simple fractal model of road placement that reproduces the observed structure, and suggests a testable connection between the scaling exponent alpha and the fractal dimensions governing the placement of roads and intersections.Comment: 6 pages, 10 figures; revision incorporates more rigorous statistical analyses; matches journal versio