Development of tailored preform processing technology for net-shape manufacturing of large monolithic structures

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on January 31, 2008)Vita.Thesis (Ph. D.) University of Missouri-Columbia 2007.The aim of the present research effort involves exploration of a new processing approach, "Tailored Preform Processing (TPP)" technology for net-shape manufacturing of monolithic structures for the transportation industry. The proposed technology combines friction stir welding (FSW) and forming in order to tailor the properties of the preform to meet design requirements and provide net-shape preforms, which can subsequently be turned into finished structural parts through light machining or other standard processes. TPP can provide several advantages including weight reduction, part count reduction, improved damage tolerance, improved material and energy utilization, and cost saving. The research focuses on understanding of the process behavior and the effects of various process parameters on the properties and integrity of the produced structure during different stages of the TPP approach. Objectives of the proposed work also include providing capability for robust process design, prediction and characterization of process-induced damage and properties of the finished structure. These objectives are accomplished through innovative solution to the Tailored Perform Processing problems using the presented experimental and virtual models. Finite Element Method was used to model 3-D friction stir welding and forming processes. Numerical model of friction stir welding was carried out using Fully Coupled-Temperature Displacement Analysis. Forming of the Tailor Welded Blanks was modeled using ABAQUS/Explicit followed by the Springback simulation using ABAQUS/ Standard. FEA models were used to investigate the process behavior and effects of various parameters on the properties and integrity of produced structure. An optimization scheme based on Genetic Algorithm is integrated with the numerical models to provide the optimal process conditions for quality and cost effective production.Includes bibliographical reference

Computational Study of the Stability of Tautomers and equilibrium constants of Cyanuric acid (CA) in Different solvents.

In the present investigation, the tautomeric and equilibrium of Cyanuric acid has been studied using Hartifock (HF) method in the gas phase and different solvents using the PCM model. The relative energies of these tautomers have been calculated at the HF level of theory using 6-311++ G (d,p) basis set. Energetics and relative stabilities of the tautomers were compared and analyzed in both the gaseous and different solvents. The results indicate that the keto tautomer (CA1) is the most stable form in the gas phase and other solvents. The order of stability of isomers was found to be CA1 > CA3> CA11> CA2> CA6> CA10> CA7> CA4> CA5> CA9>CA8. Having the largest dipole moment the CA8 tautomer is expected to have the strongest interaction with polar solvents. The HF method calculated tautomeric equilibrium constants with respect to the most stable tautomer CA1 of Cyanuric acid both in the gas and in different solvents. The  of the equilibrium constants calculated starting from the general outline of interconversion.&nbsp

AWARENESS AND USE OF PUBLIC LIBRARY RESOURCES: A STUDY IN REGIONAL LIBRARY, TIRUPATI

The main purpose of this study was to examine the awareness and usage of library resources by the user in Regional Library of Tirupati. To achieve the objectives of the study, a survey method was conducted using convenient sampling method. Two hundred questionnaires have been distributed to the public library users. Out of two hundred questionnaires, one hundred and seventy usable response sheets were received. This study reveals that majority of the respondents (37.65%) visit library for updating subject knowledge, 32.94% to update their employment information. It is also clear that majority of the library users (83.5%) have ICT knowledge. But they need help for searching relevant information. It is suggested that sufficient budget, skilled manpower, ICT and physical facilities should be improved to fulfill the objectives of the public libraries

Effect of pullulanase debranching and storage temperatures on structural characteristics and digestibility of sweet potato starch

AbstractThe effect of autoclaving (120°C/30min), debranching (2% pullulanase/1h) and storage at 4°C (DS4) or 32°C (DS32) or 60°C (DS60) for 24h on starch fractions, functional, pasting, thermal and structural properties of sweet potato starch was investigated. Results showed that DS4 sample displayed the lower functional properties than other modified starches. Debranching showed a significant increase in the apparent amylose content of native starch from 18.56% to 25%. A higher yield of RS (28.76%) was observed in debranched starch stored at 4°C (DS4) due to the higher degree of retrogradation. All debranched starches showed a substantial decrease in pasting profile and higher gelatinization temperatures than in native starch. B+V X-ray diffraction pattern was observed in debranched starches with increased crystallinity value. The scanning electron micrographs of debranched starches showed rough plate-like surfaces with irregularly shaped structures were observed due to debranching and retrogradation during storage. The study concludes that a combination of autoclaving, debranching and subsequent storage at 4°C is best technique to produce a higher amount of resistant starch in the sweet potato starch

Applications of Current Density Functional Theory (DFT) Methods in Polymer Solar Cells

DFT and time-dependant DFT (TD-DFT) quantum chemical calculations have become helpful for qualitative and quantitative analyses of materials at the molecular level. In this paper, we will attempt to outline successes and opportunities associated with the use of DFT and TD-DFT in OSC research. Density functional theory (DFT) has evolved as a QM method that is both rigorous and efficient enough to be employed in photovoltaic solar cell challenges in the last ten years. DFT is a prominent method for precisely and efficiently calculating molecular systems’ electrical and optical characteristics at a low computational cost. The possible uses of DFT to polymer solar cells were comprehensively examined in this article. First, the foundations of DFT are examined. Following that, the precision of DFT for studying photovoltaic properties particular to polymer solar cell design is highlighted. Next, this chapter looks at how DFT is used in polymer solar cell research and its accuracy. Following that, a discussion of how DFT works and how it can investigate polymer solar cell features will be given

A STUDY ON PERCEPTIONS OF FACULTY MEMBERS ON INFORAMATION SOURCES OF LIBRARIES OF ENGINEERING COLLEGES AFFILIATED TO JNTU-ANANTAPUR, ANDHRA PRADESH, INDIA

Analysis of data collected from a simple random sample of 1130 faculty members belonging to 37 Engineering colleges affiliated to JNTU-Anantapur using a questionnaire, reveals that most of the faculty members are using textbooks (97.3%), and Internet (85.7%) for their teaching activity. Further, most of the faculty members are using e-journals (80.1%) and Internet (79.0%) for their research activity. Most of the faculty members are satisfied with latest editions of books available (79.8%) and with the multiple copies available for prescribed textbooks in their libraries (75.02%). Most of them (77.3%) are consulting periodicals for their teaching and research work. Most of them (78.1%) are satisfied with the present collection of periodicals. Nearly half of them (51.3%) are consulting indexing and abstracting periodicals to know the latest literature for their teaching and research needs. Most of them (77.2%) replied that the latest issues of periodicals are available in their libraries concerned. Majority of the faculty members replied that current issues of periodicals (68.8%) and the back volumes of periodicals (60.5%) are not issued for home reading. Most of them (81.8%) replied that their libraries are subscribing to e-journals. Majority of them (53.7%) replied that their libraries are not subscribing to e-books. A few recommendations have been made by the researchers on the basis of findings

A STUDY ON PERCEPTIONS OF FACULTY MEMBERS ON INFORAMATION SOURCES OF LIBRARIES OF ENGINEERING COLLEGES AFFILIATED TO JNTU-ANANTAPUR, ANDHRA PRADESH, INDIA

Analysis of data collected from a simple random sample of 1130 faculty members belonging to 37 Engineering colleges affiliated to JNTU-Anantapur using a questionnaire, reveals that most of the faculty members are using textbooks (97.3%), and Internet (85.7%) for their teaching activity. Further, most of the faculty members are using e-journals (80.1%) and Internet (79.0%) for their research activity. Most of the faculty members are satisfied with latest editions of books available (79.8%) and with the multiple copies available for prescribed textbooks in their libraries (75.02%). Most of them (77.3%) are consulting periodicals for their teaching and research work. Most of them (78.1%) are satisfied with the present collection of periodicals. Nearly half of them (51.3%) are consulting indexing and abstracting periodicals to know the latest literature for their teaching and research needs. Most of them (77.2%) replied that the latest issues of periodicals are available in their libraries concerned. Majority of the faculty members replied that current issues of periodicals (68.8%) and the back volumes of periodicals (60.5%) are not issued for home reading. Most of them (81.8%) replied that their libraries are subscribing to e-journals. Majority of them (53.7%) replied that their libraries are not subscribing to e-books. A few recommendations have been made by the researchers on the basis of findings

BIOCHEMICAL EVALUATION OF CHRONIC CONSUMPTION OF MONOSODIUM GLUTAMATE ON LIVER OF WISTAR ALBINO RATS

Objective: The objective of this study was to determine if there were any harmful effects of monosodium glutamate (MSG) on the liver of Wistar albino rats chronically at three different doses, namely, low, mid, and high doses equivalent to human consumption doses in developing countries. Methods: The Wistar albino rats (n=24) were divided into four groups, namely control, Low dose MSG (180 mg/kg), Mid dose MSG (360 mg/kg), and High dose MSG (720 mg/kg). At the end of the experimental period (120 days), animal blood was collected retro-orbitally to analyze the liver enzymes such as aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), Total protein, Albumin, and Total Bilirubin in blood serum. Lipid profiles, namely, Triglycerides, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and Total cholesterol were subjected to analysis using blood serum. Results: Significant increase (p<0.05) in AST, ALT, ALP, and total bilirubin in serum of MSG induced low, mid, and high dose groups when compared to control group were recorded. There was a significant increase (p<0.05) in LDL, decrease in HDL, increase in total cholesterol and triglycerides of MSG-induced animal groups. Conclusion: The effects of MSG on serum liver enzymes and lipid profiles in this present animal study were not severely alarming even though the dosage was chronic which opens further discussion on the controversies revolving around MSG

ANALYSIS OF OXIDATIVE STRESS MARKERS IN CHRONIC CONSUMPTION OF MONOSODIUM GLUTAMATE ON LIVER OF WISTAR ALBINO RATS

Objective: The study was intended to explore whether Monosodium glutamate (MSG) induces oxidative stress on the liver of Wistar albino rats when fed chronically at three different doses, namely, low, mid, and high doses identical to human consumption doses in growing countries. Methods: The acclimatized Wistar albino rats (n=24) were randomly selected and grouped into four groups, namely Control, Low dose MSG (180 mg kg), Mid dose MSG (360 mg/kg), and High dose MSG (720 mg/kg). The animals were orally administered MSG for 120 days. After completion of the experimental period (120 days), euthanized animal liver was homogenized to investigate the oxidative stress marker enzymes such as Superoxide Dismutase (SOD), Glutathione Peroxidase (GPx), Catalase (CAT), and Myeloperoxidase (MPO). Results: The MPO showed a significant increase (p<0.05) in liver homogenate of all MSG induced groups when compared to control group. The SOD, CAT, and GPx activity deteriorated (p<0.05) in monosodium induced groups contrasting to the control group. Conclusion: The effects of MSG on oxidative stress markers on liver homogenate in the current study exhibited erratic abnormal changes in oxidative stress markers of monosodium induced groups which contemplate the harmful effects of MSG consumed chronically. The further studies should confirm the genetic basis of oxidative stress damage and transform the safety regulations of MSG consumption throughout the world