90 research outputs found
2010 Seventh International Conference on Information Technology: New Generations
No full textIsaac Macwan (with Hassan Bajwa, Vignesh Veerapandian, and Xinghao Chen) is a contributing author, VHDL Implementation of High-Performance and Dynamically Configures Multi-port Cache Memory, pp. 1212-1216.https://digitalcommons.fairfield.edu/engineering-books/1057/thumbnail.jp
How the planning, engineering and politics of transportation established, preserves and perpetuates the automobile city
No full textThesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning; and, (S.M. in Transportation)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2012.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis. Page [167] blank.Includes bibliographical references (p. 161-166).The last eight decades of urban transportation planning and engineering in the United States have been dominated by the hegemony of the automobile. Auto-oriented planning of the transportation and land use system has had a profound impact on the built environment both in greenfield developments and neighborhoods that predated the auto. The pedestrian quality of cities has been eroded by the automobile, and urban renewal in the United States erased many neighborhoods strongly oriented around walking and transit use. Equally pervasive as the auto itself is the place for the car in the institutional cultures and practices involved in shaping the city. The shortcomings of mobility-oriented transportation planning have been well critiqued, even from the very early days of Interstate building. In recent decades there has been a flurry of interest in articulating sustainable transportation policies to provide multi-modal accessibility and to consider the interactions between transportation, land use, and other policy realms such as health, energy, environment and equity. The current impending crisis of aging and ailing highway structures in the United States presents a momentous opportunity to reassess the need and purpose of such infrastructure, and to rebuild, reconceptualize, or remove it in a matter more consistent with current policy goals and planning processes - rather than the ones in place when initially built. Despite the interest, need and opportunity to reconceptualize aging infrastructure in America to support a more sustainable reshaping of land use and activity patterns, the potential to do so is heavily impaired by a transportation planning process that is still dominated by the tools, methods and assumptions, political biases, procedural failures, and instilled human behaviors of the first highway-building era. The McGrath Highway in Somerville, MA is used as a case study to discuss how persistence of 1950s technical, procedural and political dysfunctions threaten to undermine this opportunity. Short-term actions and strategies to avoid this impending fate are suggested for McGrath Highway with applicability to a wider national context of similar opportunities.by Vignesh Krishnamurthy.S.M.in TransportationM.C.P
Helicobacter pylori in dyspepsia: Phenotypic and genotypic methods of diagnosis
No full textBackground: Helicobacter pylori affects almost half of the world's population and therefore is one of the most frequent and persistent bacterial infections worldwide. H. pylori is associated with chronic gastritis, ulcer disease (gastric and duodenal), mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Several diagnostic methods exist to detect infection and the option of one method or another depends on various genes, such as availability, advantages and disadvantages of each method, monetary value, and the age of patients. Materials and Methods: Patients with complaints of abdominal pain, discomfort, acidity, and loss of appetite were chosen for endoscopy, detailed history was contained, and a physical examination was conducted before endoscopy. Biopsies (antrum + body) were received from each patient and subjected to rapid urease test (RUT), histopathological examination (HPE), polymerase chain reaction (PCR), and culture. Results: Of the total 223 biopsy specimens obtained from dyspeptic patients, 122 (54.7%) were positive for H. pylori for HPE, 109 (48.9%) by RUT, 65 (29.1%) by culture, and 117 (52.5%) by PCR. The specificity and sensitivity were as follows: RUT (99% and 88.5%), phosphoglucosamine mutase PCR assay (100% and 95.9%), and culture (100% and 53.3%), respectively. Conclusion: In this study, we compared the various diagnostic methods used to identify H. pylori infection indicating that, in comparison with histology as gold standard for detection of H. pylori infection, culture and PCR showed 100% specificity whereas RUT and PCR showed 99% and 100% sensitivity, respectively
In-Situ Infrared Spectroscopic Studies of Palladium Thin Films during CO2 Electro-Reduction
No full textAn exponential growth in CO2 concentration over the past few decades has led to an accelerated impact of climate change on planet earth. In a bid to curb these emissions, people across the globe are slowly transitioning towards renewable energy sources with battery technology aiding this growth. Given that battery technology is still in its nascent stage, the “Electrochemical reduction of CO2” could be a viable solution supporting it without decelerating the momentum gained towards renewable development. Although plausible, the direct reduction of CO2 to liquid fuels entails huge energy expenditure thus requiring the implementation of catalysts. Unique in its ability, palladium reversibly reduces CO2 to formic acid making it an interesting candidate for the reduction reaction. In addition to the production of formic acid, palladium is also know to produce carbon monoxide (CO) which completely deactivates the surface preventing further reactions from occurring. Thus the aim of the current study is focused on analysing the electrochemical reduction of CO2 on palladium thin films using surface enhanced infrared absorption spectroscopy to better understand the deactivation mechanisms of CO on the palladium thin film. The smoothness of the as- sputtered 15 nm palladium thin film with a RMS roughness of 0.511 nm and partially coalesced islands were ascertained, thus requiring surface activation to introduce the enhancement mechanism. Experimental analysis of CO2 reduction on the palladium thin film was performed to unearth significant insights through the combination of electrochemical analysis techniques with surface enhanced infrared absorption spectroscopy. Results obtained through implementation of these methodologies provided substantial information not only on the influence of the palladium-hydrogen system on the electrochemical reduction of CO2 but also on the impact of alkali metal cations on the palladium-hydrogen system and the CO2 reduction reaction over the sputtered palladium thin film. CO formation, accumulation and desorption coupled with hydrogen evolution and desorption were some of the few avenues that were enumerated upon during the experimental investigation. The identity of CO chemisorbed on the palladium thin film along with bicarbonate direct/ indirect reduction to form CO was confirmed through the utilization of N2 saturated C13 NaHCO3 solution. In addition to the analysis of the reduction reaction, emphasis on the oxidation of CO was also provided suggesting the formation of dense CO structures with the existence of strong CO dipole – dipole coupling on the palladium surface. Materials Science and Engineerin
Design, Fabrication and Testing of a Micro-Malting Unit
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
Stability of excitons in double quantum well: Through electron and holes transmission probabilities
No full textEffect of non-parabolicity and confinement potential on exciton binding energy in a quantum well
No full textWAAM Martensitic Stainless Steel: Process Optimization & Resulting Weld Geometrical Characterization
No full textWire Arc Additive Manufacturing (WAAM), one of the Additive Manufacturing (AM) deposition methods which employs the basic principles of Gas Metal Arc Welding (GMAW) welding technique was used to show that it is possible to build moulds for ceramic products using AISI 420 stainless steel due to its characteristics such as corrosion resistance, machinability, hardness and dimensional stability. The WAAM process also is efficient in terms of its deposition rate, reduced material wastage and high surface quality.To investigate the feasibility of AM of AISI 420 stainless steel using WAAM, Response Surface Methodology (RSM - a predictive technique) was used to navigate within the input parameter range for process optimization. Bead-on-plate welding experiments were performed with a MIG welding robot on a structural steel (S355J2) as the substrate. In the tested range according to RSM analyses, the optimum weld condition was 261 A (Current), 29 V (Volts) and 0.59 m/min S (Travel Speed) with preheating at 200°C. However, this condition was found to be unsuitable for AM due to its low deposition speed, non - uniform building surface morphology and inter-run porosities when overlapping welds were deposited. Further analyses on the metallurgy of the WAAM AISI 420 stainless steel through Scanning Electron Microscope (SEM) revealed that the weld metal consisted of a martensite matrix and delta-ferrite at the grain boundaries. The Vickers Hardness of the weld metal was 514HV.To achieve WAAM feasibility using AISI 420 stainless steel, modified RSM method was performed by expanding the input parameters and visually inspecting the bead for its shape, size and quality. The experiment adopted was called the Ramping Procedure wherein a single resulting weld bead can represent many input parameter combinations. The optimum condition for the input parameters were identified to be 200 A (Current), 18.5 V (Volts) and 1.00 m/min S (Travel Speed). With the optimal processing conditions, rectangular blocks or walls were modelled and designed in the Autodesk Powermill software and built to evaluate the feasibility of WAAM AISI 420 stainless steel. Samples were built without preheating and no surface defects and cracking were observed. Microstructural and hardness studies were then performed. Results show that the as-welded weld metal consisted of delta-ferrite present in a martensite matrix. The hardness of the weld metal was 623 HV. The WAAM optimization procedure for AISI 420 stainless steel that has not been explored for AM processes due to its high sensitivity to welding thermal cycles that can lead to cracking. In this study, it has been successfully demonstrated that crack free AISI 420 stainless steel can be deposited with WAAM
Life Cycle Assessment (LCA) analysis of thin film Silicon-based HyET solar cells
No full textGiven the rising research of thin film solar cells in recent years, flexible technology has been proven to be more light weight and cost effective. As photovoltaics is increasingly becoming the front runner in sustainable energy production, concerns over the associated impacts of solar modules throughout their life cycle are also increasing. This study quantifies the environmental impacts through LCA analysis for Roll-to-Roll (R2R) production process of thin film flexible silicon-based solar modules manufactured by a Dutch company HyET in The Netherlands.This study considers three product lines over a life cycle demarcated into its manufacturing, encapsulation and installation. The three product lines (cases) are as follows.1. Single junction a-Si with 7% efficiency.2. a-Si/nc-Si tandem cell with 10% efficiency3. a-Si/nc-Si tandem cell with 12% efficiencyThe installation phase considers a rooftop setup of capacity of 2.1 kWp with Balance of System (BoS) components.LCA analysis is carried out on Simapro 9.1.0.11 following the guidelines and the framework of International Organization for Standardization ISO14044. The outcome of LCA analysis is measured in terms of Global Warming Potential (GWP), Primary Energy Demand (PED) and Energy Pay Back Time (EPBT). Ecoinvent 3.5 is used as the primary database for these analyses to select the inventory. GWP is assessed using the CML-IA baseline method while PED is assessed using Cumulative energy demand v1.11 method. Sensitivity analysis is done by changing the location of production and up-scaling capacity. The installation stage is observed to contribute the highest GWP and also has the highest PED on account of BoS components. The LCA analysis has demonstrated similar trends of GWP, PED for all three product lines. EPBT on the other hand, is longer for 10% tandem cell on account of relatively larger module area as compared to 12% tandem cell and also the relatively higher energy consumption as compared to the single junction cell. The choice of substrate material is seen to impact the assessment indicators significantly. Flexible glass is observed to be the optimal choice for large-scale production. The choice of encapsulant material also affects the indicators demonstrably. Sensitivity analysis shows a positive impact on the indicators through up-scaling, while the location is not established as a significant factor sufficiently under considered assumptions.This project describes about the Life Cycle Assessment analysis of thin film Silicon-based HyET solar cells and their comparison to different substrate technologiesElectrical Engineering | Sustainable Energy Technolog
- …
