Training Graduate Students in Utilization of Analytical Instruments in a Failure Analysis Course

Department of Engineering Technology at University of North Texas offers a graduate course on failure analysis (MSET 5150) during spring semesters. Partial requirement for the course is for students to submit a term paper based on their collected data related to a term project. Case studies are given to groups of students to work on actual failed components received from area industries. Results of their findings are presented at the end of the semester in both oral presentation form and written term paper form followed the format of a well-established technical papers. Results of such exercises allows graduate students devote skills in using scientific instruments and practice manuscript preparations for publication. This paper presents examples of a case studies done by groups of students who worked on failure analysis of components failed in an oil and gas industry. Students developed skills in utilization of scanning electron microscope (SEM), Energy Dispersive Spectroscopy (EDS), and Fourier Transform Infrared Spectrophotometry. This exercise has proven highly effective in introducing young engineers to real world problems in oil and gas industry and help them develop skills needed in performing failure analysis and steps involved.Cockrell School of Engineerin

PROPHYLACTIC MEASURES AGAINST COMMUNICABLE DISEASES W.S.R TO COVID-19: AN AYURVEDIC APPROACH

Ayurveda, the ancient treasure of medical knowledge descended to earth with two aims to serve human beings i.e Swsathasya swasthya rakshanam (Promotive and Preventive measure) and Aturasya vikara prashamanam (curative measures). Ayurveda categorized diseases into two Nija (diseases caused by endogenous factors) and Agantuja (diseases caused by exogenous factors). The term Agantuja implied in broad spectrum under which external trauma and organisms such as bacteria, virus, fungi all been incorporated. Ayurveda described communicable diseases and their causes, mode of transmission, prevention as well as cure under Janapadodhwamsa (Epidemics), Aupasargika roga (infectious diseases), Sankramika roga (Communicable diseases). In promotion of health and in prevention of diseases, Ayurveda prescribed prophylactic measures like Dinacharya (daily regimen), Ritucharya (seasonal regimen), Sadvritta (good personal and social conducts), Rasayana (Rejuvenation therapy) etc. In this article an honest attempt has been made to review systematically the prophylactic measures against communicable diseases with special reference to COVID-19 pandemic- a challenging task for medical fraternity all over the world

Room-Temperature One-Pot Synthesis of pH-Responsive Pyridine-Functionalized Carbon Surfaces

Carbon surfaces (glassy carbon, graphite, and boron-doped diamond) were functionalized with layers composed of linked pyridinium and pyridine moieties using simple electrochemical reduction of trifluoroacetylpyridinium. The pyridinium species was generated in situ in solution by the reaction of trifluoroacetic anhydride and pyridine precursors and underwent electrochemical reduction at −1.97 V vs Fc/Fc+, as determined by cyclic voltammetry. The pyridine/pyridinium films were electrodeposited at room temperature, on a timescale of minutes, and were characterized using X-ray photoelectron spectroscopy. The as-prepared films have a net positive charge in aqueous solution at pH 9 and below due to the pyridinium content, confirmed by the electrochemical response of differently charged redox molecules at the functionalized surfaces. The positive charge can be enhanced further through protonation of the neutral pyridine component by controlling the solution pH. Moreover, the nitrogen-acetyl bond can be cleaved through base treatment to purposefully increase the neutral pyridine proportion of the film. This results in a surface that can be “switched” from functionally near neutral to a positive charge by treatment in basic and acidic solutions, respectively, through manipulation of the protonation state of the pyridine. The functionalization process demonstrated here is readily achievable at a fast timescale at room temperature and hence can allow for rapid screening of surface properties. Such functionalized surfaces present a means to test in isolation the specific catalytic performance of pyridinic groups toward key processes such as oxygen and CO2 reduction

Nanodiamond Relaxometry-Based Detection of Free-Radical Species When Produced in Chemical Reactions in Biologically Relevant Conditions

Diamond magnetometry is a quantum sensing method involving detection of magnetic resonances with nanoscale resolution. For instance, T1 relaxation measurements, inspired by equivalent concepts in magnetic resonance imaging (MRI), provide a signal that is equivalent to T1 in conventional MRI but in a nanoscale environment. We use nanodiamonds (between 40 and 120 nm) containing ensembles of specific defects called nitrogen vacancy (NV) centers. To perform a T1 relaxation measurement, we pump the NV center in the ground state (using a laser at 532 nm) and observe how long the NV center can remain in this state. Here, we use this method to provide real-time measurements of free radicals when they are generated in a chemical reaction. Specifically, we focus on the photolysis of H2O2 as well as the so-called Haber-Weiss reaction. Both of these processes are important reactions in biological environments. Unlike other fluorescent probes, diamonds are able to determine spin noise from different species in real time. We also investigate different diamond probes and their ability to sense gadolinium spin labels. Although this study was performed in a clean environment, we take into account the effects of salts and proteins that are present in a biological environment. We conduct our experiments with nanodiamonds, which are compatible with intracellular measurements. We perform measurements between 0 and 10(8) nM, and we are able to reach detection limits down to the nanomolar range and typically find T1 times of a few 100 mu s. This is an important step toward label-free nano-MRI signal quantification in biological environments.</p

Insight into a Fenton-like Reaction Using Nanodiamond Based Relaxometry

Copper has several biological functions, but also some toxicity, as it can act as a catalyst for oxidative damage to tissues. This is especially relevant in the presence of H2O2, a by-product of oxygen metabolism. In this study, the reactions of copper with H2O2 have been investigated with spectroscopic techniques. These results were complemented by a new quantum sensing technique (relaxometry), which allows nanoscale magnetic resonance measurements at room temperature, and at nanomolar concentrations. For this purpose, we used fluorescent nanodiamonds (FNDs) containing ensembles of specific defects called nitrogen-vacancy (NV) centers. More specifically, we performed so-called T1 measurements. We use this method to provide real-time measurements of copper during a Fenton-like reaction. Unlike with other chemical fluorescent probes, we can determine both the increase and decrease in copper formed in real time

Fast, broad-band magnetic resonance spectroscopy with diamond widefield relaxometry

We present an alternative to conventional Electron Paramagnetic Resonance spectroscopy equipment. Avoiding the use of bulky magnets and magnetron equipment, we use the photoluminescence of an ensemble of Nitrogen-Vacancy centers at the surface of a diamond. Monitoring their relaxation time (or T1), we detected their cross-relaxation with the compound of interest. In addition, the EPR spectra is encoded through a localized magnetic field gradient. While 12 minutes was necessary to record each data point of the spectrum with previous individual NV center's technics, we are able to reconstruct a full spectrum at once in 3 seconds, over a range from 3 to 11 gauss. In term of sensitivity, only 0.5 microliter of a hexaaquacopper (II) ion solution with 1 micromole per liter concentration was necessary.Comment: Main text (15 pages, 6 Figures) + Supplementary (6 Pages, 7 Figures

Diamond Color Centers in Diamonds for Chemical and Biochemical Analysis and Visualization

Beyond the sparkle, other properties of diamond havegained increasing attention in the past few decades amongchemists and physicists. Color centers-impurities formed byone or a few foreign atoms or vacancies in the diamondlattice-are one reason for this. While pure diamond istransparent, the presence of color centers causes changes incoloration. Color centers introduce additional electronic statesin the wide band gap of diamond, giving rise to transitions thatabsorb and emit light in the visible spectrum