Eddy Current System for Material Inspection and Flaw Visualization

Eddy current methods have been successfully used in a variety of non-destructive evaluation applications including detection of cracks, measurements of material thickness, determining metal thinning due to corrosion, measurements of coating thickness, determining electrical conductivity, identification of materials, and detection of corrosion in heat exchanger tubes. This paper describes the development of an eddy current prototype that combines positional and eddy-current data to produce a C-scan of tested material. The preliminary system consists of an eddy current probe, a position tracking mechanism, and basic data visualization capability. Initial test results of the prototype are presented in this paper

Martin Lensch: „Eine kommissarische Verwendung kommt bei Pastor Lensch und seiner ablehnenden Haltung zum heutigen Kurs kaum in Frage“

Martin Siegmund Lensch, Sohn von Johann Heinrich und Anna Sophia Lensch, wurde am 11. April 1869 auf Pellworm geboren. Er war der erste festangestellte Pastor der neuen Gemeinde Neu-Galmsbüll. Ab 1910 wirkte er bis zu seinem Ruhestand 1934 als Pastor in Elmshorn. Lensch war Mitglied der Bekennenden Kirche. Er gehörte zu den wenigen Theologen, die dem NS-Regime ablehnend gegenüberstanden

Ultra High-Performance Concrete As a High Friction Surface Treatment for Pavements and Bridges

High Friction Surface Treatment (HFST) is a proven technology to reduce crashes on roadways by increasing the coefficient of friction between vehicle tires and the pavement. However, it is an expensive solution due to the high cost of the two commonly used constituent materials, calcined bauxite aggregate and epoxy resin binders. This study evaluated the abrasion resistance performance of four alternative HFST aggregates to calcined bauxite using Los Angeles Abrasion and Micro-Deval Abrasion tests, and studied the surface texture utilizing a high-resolution laser scanner and friction utilizing the British Pendulum Test. This study also assessed the performance of non-proprietary Ultra High-Performance Concrete (UHPC) for use as an alternative to epoxy resins in HFST application. In this regard, the flow, setting behavior, bond strength, abrasion resistance, compressive strength and drying shrinkage of the UHPC mixtures were assessed. Additionally, the effects of intermixing calcined bauxite aggregate in UHPC at varying contents on the performance of UHPC were evaluated. Furthermore, this study developed and evaluated various application methodologies for UHPC based HFST surfaces including the use of UHPC with intermixed aggregate where surface retarders were used to expose the aggregate. Other methods included broadcasting the aggregate onto the UHPC binder and embedding under self-weight or with the use of vibration to improve embedment. Effects of aggregate moisture content and UHPC water content were also evaluated. The performance of UHPC based surfaces was evaluated by the British Pendulum Test and the Dynamic Friction Tester for friction, a high-resolution laser scanner for texture, and outflow meter for drainage. Polishing was conducted using a Three Wheel Polishing Device and the effects of polishing on friction and texture across selected surface types were evaluated. The experiments revealed that while two alternative aggregates among the four aggregates were able to provide seemingly good abrasion resistance and initially high levels of friction with adequate texture, under polishing the friction was greatly reduced. Therefore, none of the alternative aggregates tested can be recommended for long term frictional performance, and calcined bauxite remains the premier reliable choice. Evaluation of UHPC mixtures showed that a UHPC mix could provide adequate bond strength, compressive strength and flow for use as an HFST binder. The bond performance of resin binders exceeded that of UHPC, particularly on asphalt substrates. Calcined bauxite to cementitious materials ratio between 1.5 and 2.0 by mass showed the best performance across various properties of UHPC for application in HFST. Vibration was shown to improve aggregate embedment in UHPC mixtures, overcoming the poor embedment observed when broadcasting on UHPC with low water content. Based on the potential effects of aggregate moisture content on the properties of UHPC, it is recommended that only oven-dry aggregate be used in UHPC for HFST application. UHPC based HFSTs with calcined bauxite aggregate were able to produce acceptable levels of friction and texture and maintain the performance under polishing such that they can be categorized as HFST. However, resin-based surfaces with calcined bauxite were superior across testing and provided a more consistent surface. As a proof of concept, UHPC is a viable alternative to epoxy resins for use as an HFST binder with calcined bauxite aggregate. Field scale evaluation is warranted to verify the findings from this lab study

Enhancement of Network Level Macrotexture Measurement Practices through Deterioration Modeling and Comparison of Measurement Devices for Integration into Pavement Management Systems

This research sought to integrate measurement and prediction of surface macrotexture for use in pavement management systems. This was achieved through two experiments, the first modeled the behavior of a binder-rich stone matrix asphalt when subjected to traffic loading using a heavy vehicle simulator to report the effect on pavement macrotexture. The second experiment compared high-speed macrotexture measurement devices on a variety of surfaces and under various operating conditions. The change in macrotexture due to traffic loading showed that as the cumulative load increased, the macrotexture decreased due to bleeding on the pavement's surface. A regression model determined that, on average, the macrotexture's root mean square (RMS) decreased 0.14 mm per million equivalent single axle load applied. A comparison of RMS and mean profile depth (MPD) outputs indicated that RMS was more sensitive to changes in macrotexture due to bleeding. In comparing devices, pairwise device agreement was evaluated using a Limits of Agreement. The results demonstrate good repeatability for each of the devices tested. The agreement analysis showed that not all high-speed devices can be used interchangeably for all pavement surfaces. Data acquisition speed was found to be a factor in macrotexture parameter calculation for two of the devices. The effect of speed was found to be worse on randomly textured surfaces than on transversely textured surfaces.Master of ScienceThis thesis sought to integrate the collection and prediction of a pavement surface property known as macrotexture for use in the management of pavement networks. This was achieved through two experiments, the first of which modeled the behavior of asphalt concrete with a higher than typical asphalt content when subjected to simulated traffic to determine the effect on pavement macrotexture. The second experiment compared five high-speed macrotexture measurement devices on a variety of pavement surface types and under various operating conditions. The change in macrotexture due to traffic loading showed that as the cumulative traffic increased, the macrotexture decreased due to the asphalt coming out on the surface, referred to as bleeding. For the comparison of measurement devices data were processed using current industry standards. The results demonstrate good repeatability for each of the devices tested. The analysis also showed that not all high-speed devices can be used interchangeably for all pavement surface types. Vehicle speed was found to be a factor for two of the devices. The effect of speed was found to vary by surface type. Finally, vehicle acceleration was shown to influence the parameters produced by one of the devices, demonstrating that care should be taken to gather high-quality datasets for the critical pavement characteristic of macrotexture

Yeast 2 Hybrid System to Find Map Kinase (MK-2) Interacting Binding Proteins

The protein MAPKAPK2 (MK2) encodes for Ser/Thr in the protein kinase family, and along with p38 MAP kinase, play a crucial role in many cellular processes including inflammatory responses, nuclear export, gene expression regulation, and cell proliferation. The goal of this C.U.R.E.(course-based undergraduate research experiment) study is to find out more information about the MK2 protein, its function, and possible therapeutics in cancer and medicine research. To achieve this, a Yeast 2 Hybrid (Y2H) assay was utilized to screen for proteins interacting with MK2. The Yeast 2 Hybrid assay involved the insertion of a Gal4 Binding Domain (BD) fused with a bait protein and Gal4 Activation Domain (AD) fused with a prey protein. If the bait and prey proteins interact, GAL4 transcription factor is reconstituted and the reporter genes will be turned on, one of which, the alpha galactosidase, will turn the yeast colonies blue. The autoactivation of Gal4 by the “bait” protein, MK2, was assessed along with the positive and negative controls. The positive control was p53 with a BD and a T-antigen with a AD, these are known interactors and, in the Yeast 2 Hybrid system, did turn the yeast colonies blue. The negative control was Lamin with a BD (pGBKT7-LAM) and a T-antigen with an AD, these plasmids do not interact and no blue colonies were observed. The positive control of the reporter genes exhibited activation, while the negative control exhibited no activation. The experimental findings align with the predicted plates where interactions were expected to occur; similarly, the plates where no interactions were anticipated did align with the predictions. The Yeast 2 Hybrid System further supported the notion that the binding domain cannot activate the reporter genes by itself

Purification and Analysis of the Three isoforms of Mitogen Activated Protein Kinase-Interacting Serine/Threonine-Protein Kinase 1 (MKNK1)

Cellular responses to stimuli are essential to the proper functioning of all organisms. The specific protein interactions that pass along a message that induce cellular changes are numerus and include the extensive p38 MAPK pathway known to be activated by environmental stressors such as inflammatory cytokines, DNA damage, or oxidative stress. Dysregulation and improper responses to these conditions have been linked to various cancers and immune disorders, making members of the pathway highly desirable drug targets. We are focused on Mitogen Activated Protein Kinase-Interacting Serine/Threonine-Protein Kinase 1 (MKNK1) which has three isoforms, long, primary and short; long has never been studied but primary and short are known to be involved in translational regulation (via binding to eIF4G and phosphorylation of eIF4E), though the overall function and role of MKNK 1 is not entirely known. Thus far, we have successfully expressed and purified all isoforms using plasmids that enabled creation of gst-tagged fusion proteins. Further purification via tag removal was conducted to prepare the proteins for metal analysis, predicted in the cysteine containing loop of MKNK1s. Kinase assay was also performed to detect MKNK1 phosphorylation by p38, using a coupled assay with kemptide as the final substrate. Further analysis is underway to explore the functional differences of the isoforms