Microneedle (MN)-based technologies are currently one of the most innovative approaches that are being extensively investigated for transdermal delivery of low molecular weight drugs, biotherapeutic agents and vaccines. Extensive research reports, describing the fabrication and applications of different types of MNs, can be readily found in the literature. Effective characterization tools to evaluate the quality and performance of the MNs as well as for determination of the dimensional and kinetic properties of the microchannels created in the skin, are an essential and critical part of MN-based research. This review paper provides a comprehensive account of all such tools and techniques.

Presently, there is no standard testing procedure for piezoelectric actuators. It is then very difficult for a very specific given application to design the most efficient actuator in terms of blocked force, displacement, power consumption, weight, cost, etc. Piezoelectric actuator suppliers would like to have the possibility to fully characterize their actuators to be able to guide their customers on selection of the most suitable actuator based on their utilization. However, this is not an easy goal to reach since performance of a given actuator depends on the specific dynamic conditions under which it is applied. In order to characterize an actuator, it is therefore necessary to recreate similar conditions to those experienced in the real application. Because of the infinite variety of possible applications for piezoelectric actuators, physically recreating those conditions could take an enormous amount of time, means and money. The aim of the research is then to develop the technology required in order to test an actuator under a various range of dynamic load conditions using a single automated test set-up. To do so, a second actuator will be used with a suitable sensing apparatus (impedance head) and an active control system. Using data from the sensing apparatus (force and velocity signals), the active control system will drive the second actuator to recreate any load condition the first actuator would be supposed to experience in a real application. <i>[Vita removed May 14, 2012. Gmc]</i> / Master of Science

Scanning electrochemical microscopy is a method that incorporates an ultramicroelectrode capable of facilitating electrochemical reactions paired with an XYZ positioning system capable of micron-level movements. This study investigates the corrosion behavior of structural transition joint clad material that contains steel, pure aluminum, and an aluminum alloy blast welded into a single joint. This study will characterize the corrosion response of the structural transition joint and identify the galvanic activity measured between its layers. High-temperature coatings in this study are designed to be used effectively up to 1400?F. In this study, we characterized several commercial high-temperature coatings exposed to different levels of heat. General trends of decreasing barrier performance were observed with the exception when these coatings are exposed to their rated temperature limit of 1400?F, at which the barrier increased slightly, indicated by their low-frequency impedance modulus. The cause is a combination of sintering and oxide formation.

We reported the primary structure, tissue distribution, and in vitro functional characterization of a peptide transporter, oPepT1, from ovine intestine. The ovine intestinal oPepT1 cDNA was 2,829 bp long encoding a protein of 707 amino acid residues with an estimated molecular size of 79 kDa, and a pI of 6.57. The cDNA contained a 79-bp 5' untranslated sequence and a 630-bp 3' untranslated sequence. The proposed oPepT1 protein was 77.9, 81.3, and 82.6 percent identical to PepT1 from rabbit, rat, and human, respectively. High stringency northern blot analysis demonstrated that oPepT1 is expressed strongly in the small intestine, at lower levels in the omasum, and at much lower levels in the rumen, but is not expressed in liver and kidney. The presence of the peptide transporter in the forestomach at such levels could provide amino acid nitrogen for the ruminant in a nutritionally significant manner. Transport function of oPepT1 was assessed by expressing oPepT1 in Xenopus oocytes using a two-electrode voltage-clamp technique. Overall, the in vitro transport characteristics of oPepT1 expressed in oocytes were similar to those of PepT1 from other species. The transport process is electrogenic and pH-dependent, but independent of Na+, Cl-, and Ca2+. It displayed a broad substrate specificity that transported neutral and charged dipeptides and tripeptides. All dipeptides and tripeptides examined evoked inward currents in a saturable manner, with an affinity constant (Kt) ranging from 20 mM to .6 mM for dipeptides and .15 to 3.0 mM for tripeptides. No responses were detected from tetrapeptides or free amino acids. Although many of the properties displayed by oPepT1 were similar to those of PepT1 from other species, some differences were noted. First, the isoelectric point of oPepT1 was lower than that of others, but the oPepT1 protein appeared to have the same biological activity as that of others at a physiological pH. Second, more potential phosphorylation sites for protein kinases were present in oPepT1. Third, compared with PepT1 from other species, oPepT1 has more negatively charged amino acids at its C-terminus. / Ph. D.

In recent years super-hydrophobic micro-patterned substrates (SHS) have been successfully used for the suspension of a few biological molecules, allowing the further characterization in a background-free environment by label-free techniques such as Raman spectroscopy, SEM and TEM in one device. This result is due to the combined action of laminar flow and shear stress exerted on the molecules contained in a drop that is spotted on top of the SHS and slowly evaporates. This new method is here proposed for the label-free formation and background-free characterization of amyloid fibers. Amyloids are insoluble aggregates formed by proteins that convert from a misfolded form into highly-organized β-sheet structures that could accumulate in different organs and compromise their normal physiological functions. Known amyloid-related diseases, named amyloidosis, are for instance Alzheimer, Parkinson, and type 2 diabetes. In classical crystallography, the study of the amyloid aggregates structure is often hampered by the laborious and time consuming sample preparation techniques. Therefore the need of a quick reproducible technique, has emerged. The amyloid fibers investigated in this work are derived from a lysozyme protein and a Tau-derived short peptide, both known to be related to two forms of amyloidosis. With this technique we demonstrate that threads of protein fibers are deposited on the substrate helped by the patterning of the SHS and its properties, and by characterizing them with Raman spectroscopy technique we revealed that they are anisotropic structures of amyloid nature. This type of sample preparation technique arises from the effect of the evaporation on the SHS, and opens up new possibilities for the formation of oriented fibers of amyloids and more in general, of proteins, ready for a substrate-free characterization, while classic crystallographic methods could have a limitation.

The midcontinent United States, a region which typically does not experience many earthquakes, has experienced a significant increase in the number of earthquakes over the last decade. This increase in earthquake activity has been linked to wastewater injection, a process in which large volumes of wastewater from oil and gas extraction are injected into deep (2-3 km), high-permeability sedimentary rocks, near low-permeability Precambrian (>540-million-year-old) crystalline ‘basement’ rocks. The contact between these two rock types is referred to as the Precambrian nonconformity. Injection-induced earthquakes occur on or near basement-hosted faults due to an increase in pore fluid pressures, which implies that there may be a hydrological connection between the basement-hosted faults and the injection point. We hypothesize that the Precambrian nonconformity greatly influences this hydrological connection. We investigate the geologic properties of Precambrian nonconformity zone outcrop and core analogs to examine how the geology of the nonconformity zone controls fluid flow. Methods include mapping of geological materials and deformation structures (faults and fractures), mineralogical analysis, and geochemical analysis. These data sets allow us to infer the nature of fluid flow in the past, and make predictions about fluid flow in the future. In addition, this information is used to inform hydrological models, improving the ability to predict earthquakes due to wastewater injection. We identify three main geological scenarios that are likely to be encountered at the nonconformity. These are: 1) basal conglomerate, 2) weathered/altered horizon, and 3) mineralized contacts. These scenarios, or combinations of these scenarios, may be fractured or faulted, resulting in a variety of hydrological implications. The permeability of basal conglomerates and weathered horizons at the contact depends on the textures and minerals that are present. Regolith, clast-supported granitic wash, or poorly cemented conglomeratic horizons, may act as high permeability conduits, whereas a clay-rich grus or granitic wash, or tightly cemented conglomerate, may act as low permeability barriers. Mineralized contacts may act as low permeability barriers due to a reduction of pore space. The mineralized contact shows that the introduction of warm brines by modern injection may result in mineralization or chemical weathering, dynamically affecting permeability over time depending on the mineralogy of the host rock and chemical composition of the injected brine.

Accurate terrain models provide the chassis designer with a powerful tool to make informed design decisions early in the design process. During this stage, engineers are challenged with predicting vehicle loads through modeling and simulation. The accuracy of these simulation results depends not only on the fidelity of the model, but also on the excitation to the model. It is clear that the terrain is the main excitation to the vehicle [1]. The inputs to these models are often based directly on physical measurements (terrain profiles); therefore, the terrain measurements must be as accurate as possible. A collection of novel methods can be developed to aid in the study and application of 3D terrain measurements, which are dense and non-uniform, including efficient gridding, stochastic modeling, and compact characterization. Terrain measurements are not collected with uniform spacing, which is necessary for efficient data storage and simulation. Many techniques are developed to help effectively grid dense terrain point clouds in a curved regular grid (CRG) format, including center and random vehicle paths, sorted gridding methods, and software implementation. In addition, it is beneficial to characterize the terrain as a realization of an underlying stochastic process and to develop a mathematical model of that process. A method is developed to represent a continuous-state Markov chain as a collection of univariate distributions, to be applied to terrain road profiles. The resulting form is extremely customizable and significantly more compact than a discrete-state Markov chain, yet it still provides a viable alternative for stochastically modeling terrain. Many new simulation techniques take advantage of 3D gridded roads along with traditional 2D terrain profiles. A technique is developed to model and synthesize 3D terrain surfaces by applying a variety of 2D stochastic models to the topological components of terrain, which are also decomposed into frequency bandwidths and down-sampled. The quality of the synthetic surface is determined using many statistical tests, and the entire work is implemented into a powerful software suite. Engineers from many disciplines who work with terrain surfaces need to describe the overall physical characteristics compactly and consistently. A method is developed to characterize terrain surfaces with a few coefficients by performing a principal component analysis, via singular value decomposition (SVD), to the parameter sets that define a collection of surface models. / Master of Science

Indiana University-Purdue University Indianapolis (IUPUI) / With passage of time and repeated usage of a system, component values that make up the system parameters change, causing errors in its functional output. In order to ensure the fidelity of the results derived from these systems it is thus very important to keep track of the system parameters while being used. This thesis introduces a method for tracking the existing system parameters while the system was being used using the inherent noise of its signal source. Kalman filter algorithm is used to track the inherent noise response to the system and use that response to estimate the system parameters. In this thesis this continuous characterization scheme has been used on a Universal Invertible Amplifier (UIA). Current biomedical research as well as diagnostic medicine depend a lot on shape profile of bio-electric signals of different sources, for example heart, muscle, nerve, brain etc. making it very important to capture the different event of these signals without the distortion usually introduced by the filtering of the amplifier system. The Universal Invertible Amplifier extracts the original signal in electrodes by inverting the filtered and compressed signal while its gain bandwidth profile allows it to capture from the entire bandwidth of bioelectric signals. For this inversion to be successful the captured compressed and filtered signals needs to be inverted with the actual system parameters that the system had during capturing the signals, not its original parameters. The continuous characterization scheme introduced in this thesis is aimed at knowing the system parameters of the UIA by tracking the response of its source noise and estimating its transfer function from that. Two types of source noises have been tried out in this method, an externally added noise that was digitally generated and a noise that inherently contaminates the signals the system is trying to capture. In our cases, the UIA was used to capture nerve activity from vagus nerve where the signal was contaminated with electrocardiogram signals providing us with a well-defined inherent noise whose response could be tracked with Kalman Filter and used to estimate the transfer function of UIA. The transfer function estimation using the externally added noise did not produce good results but could be improved by means that can be explored as future direction of this project. However continuous characterization using the inherent noise, a bioelectric signal, was successful producing transfer function estimates with minimal error. Thus this thesis was successful to introduce a novel approach for system characterization using bio-signal contamination.

No description available.

No description available.