In this paper, a parametric study of the airbrush deposition technique was investigated for the deposition biomolecular thin films. The airbrush parameters under investigation were intake valve opening, carrier gas pressure, distance between the airbrush and substrate, concentration of solution, vapor pressure of solvent, and hydrophobic/hydrophilic substrate surface. This study was assessed through the characterization of dried droplet residues of Bovine Serum Albumin (BSA) and of complete films of BSA by means of scanning electron microscopy (SEM) and atomic force microscopy (AFM). It was determined that droplet size was mainly affected by carrier gas pressure and vapor pressure. The parameters intake valve opening, distance between the airbrush and substrate, and concentration of solution control the rate of spray, or solution flux, onto the substrate. Solution flux was determined to have the greatest impact on film roughness. This allowed for flexibility in the airbrush deposition technique to produce films with various substrate wetting rates. Low flux films were produced when the droplets dried on the substrate surface before the next droplet arrived. High flux films were generated when droplets on the surface arrive before subsequent droplets are given time to dry. Finally, as an extension of the results of these experiments, a practical application of the airbrush deposition technique was conducted using appropriate deposition parameters. An E. coli wave guide biosensor was produced on a glass substrate. A sandwich immunoassay was used to confirm E. coli capture.

<p>Road conditions affect fuel efficiency and vehicle fatigue when driving heavy trucks. Information about traveled road conditions enable optimization of chassis configuration when driving, and logging of vehicle stress. Previous work on this topic focus mainly on tuning of active suspension parameters in the car industry. One conceivable application for heavy trucks is implementation of active chassis level control based on road conditions, with possible improvements in driving economy as result. Another is logging of usage conditions which helps explain vehicle faults caused by abnormal wear. This work examines the possibilities to use already on vehicle sensors for road roughness estimation. It also investigates what requirements existing signals must fulfill to ensure reliable estimates. Two methods for road roughness estimation are proposed using rear axle level sensor and a simple linear suspension system model.</p>

The thyroid gland is positioned directly below the larynx in the anterior portion of the neck (Kumrow & Dahlen, 2002). The nerves and arteries of the thyroid and larynx are intertwined thus damage to one structure could easily affect the other structure. Thyroid dysfunction may also affect the histology of the larynx thus changing vocal quality (Stemple, 2010). This study measured vocal quality of patients with thyroid disease using the Consensus Auditory Perceptual Evaluation of Voice (CAPE-V). Voice samples from 16 subjects with thyroid disease were compared to an age-matched group of 18 control subjects with no reported history of thyroid dysfunction. An experienced voice clinician rated each sample on the six parameters of the CAPE-V: overall severity, roughness, breathiness, strain, pitch and loudness. Statistical analysis of the results revealed a significant difference between the thyroid disease group and the control group for overall severity of vocal quality and vocal roughness. These results further strengthen the connection between thyroid disease and vocal dysfunction. Further research is warranted to explore the specific thyroid diagnoses that relate to vocal dysfunction, as well as to strengthen the findings on a larger population of participants. / Lori Lombard, Ph.D., CCC-SLP David Stein, Ph. D., CCC-SLP Jill Brady, Ph.D., CCC-SLP

The enthalpy (sensible and latent heat) exchange processes within the surface layers at an air-water interface have been examined in 15-m wind-wave tunnel at the University of Miami. Measurements yielded 72 mean values of fluxes and bulk variables in the wind speed (referred to 10 m) range form 0.6 to 39 m/s, covering a full range of aerodynamic conditions from smooth to fully rough. Meteorological variables and bulk enthalpy transfer coefficients, measured at 0.2-m height, were adjusted to neutral stratification and 10-m height following the Monin-Obukhov similarity approach. The ratio of the bulk coefficients of enthalpy and momentum was estimated to evaluate Emanuel's (1995) hypothesis. Indirect "Calorimetric" measurements gave reliable estimates of enthalpy flux from the air-water interface, but the moisture gained in the lower air from evaporation of spray over the rough water remained uncertain, stressing the need for flux measurements along with simultaneous spray data to quantify spray's contribution to the turbulent air-water enthalpy fluxes.

Laminar turbulent transition is known for a long time as a critical phenomenon influencing the thermal load encountered by hypersonic vehicle during their planetary re-entry trajectory. Despite the efforts made by several research laboratories all over the world, the prediction of transition remains inaccurate, leading to oversized thermal protection system and dramatic limitations of hypersonic vehicles performances. One of the reasons explaining the difficulties encountered in predicting transition is the wide variety of parameters playing a role in the phenomenon. Among these parameters, surface roughness is known to play a major role and has been investigated in the present thesis. A wide bibliographic review describing the main parameters affecting transition and their coupling is proposed. The most popular roughness-induced transition predictions correlations are presented, insisting on the lack of physics included in these methods and the difficulties encountered in performing ground hypersonic transition experiments representative of real flight characteristics. This bibliographic review shows the importance of a better understanding of the physical phenomenon and of a wider experimental database, including real flight data, for the development of accurate prediction methods. Based on the above conclusions, a hypersonic experimental test campaign is realized for the characterization of the flow field structure in the vicinity and in the wake of 3D roughness elements. This fundamental flat plate study is associated with numerical simulations for supporting the interpretation of experimental results and thus a better understanding of transition physics. Finally, a model is proposed in agreement with the wind tunnel observations and the bibliographic survey. The second principal axis of the present study is the development of a hypersonic in-flight roughness-induced transition experiment in the frame of the European EXPERT program. These flight data, together with various wind tunnel measurements are very important for the development of a wide experimental database supporting the elaboration of future transition prediction methods.

The present thesis is based on three studies that research different aspects of fine texture perception. The goal is to better understand the mechanisms involved in haptic perception of textures below 200 µm, also known as microtextures. Study I was conducted to establish a friction measurement model and relating the friction measurements to perceived coarseness of fine textures. A set of printing papers was used as stimulus material. In Study II an expanded set, including the set of Study I, was used as stimuli in a multidimensional scaling (MDS) experiment of haptic fine texture perception. Through scaling of perceptual attributes and similarities, a three dimensional space was found to best describe the data and the dimensions were interpreted as rough-smooth, thick-thin and distinct-indistinct. In Study III a series of model surfaces were manufactured with a systematically varied sinusoidal pattern, spanning from 300 nm to 80 µm. As in Study II, a similarity experiment was conducted and a two dimensional space was chosen, the dimensions of which were explained well through friction and the wavelength. Together these three studies form a better picture of fine texture perception. The dimensionality found with paper stimuli was very similar to the corresponding spaces for marcrotextures of everyday materials, even though a different perceptual system is used for fine texture perception. Regardless if the information is coded through the spatial or the vibratory sense, the perception does not seem to differ in dimensionality. Further, the largest among the microtextures seem to have been perceived as carrying spatial information. On the systematically varied, rigid, textures, the MDS space did not come out in a similar fashion to those of everyday materials but instead similar to the physical properties that characterizes the change in the textures. It was further found that the participants in Study III successfully discriminated textures with an amplitude of 13 nm from the unwrinkled surfaces. From these studies the main conclusions are (a) haptically measured friction and surface roughness are important contributors to fine texture perception, (b) even at microscales, spatial information is retrieved haptically, probably through vibrations, and (c) persons can haptically discriminate textures at a nanoscale.

Controlling and predicting rupture and dewetting of quiescent thin water films, hundreds of microns thick, was studied experimentally. Wax, polycarbonate, steel and aluminium surfaces were immersed in water; the water level was lowered to form thin films above the surfaces. Spontaneous film rupture only occurred on wax, a low-energy surface. Films ruptured at the edges of the other—high-energy—surfaces. Increased surface roughness decreased chances of rupture and dewetting in the film. Introducing large wax or steel protrusions (on the order of millimetres) on smooth surfaces showed films rupturing above the protrusions and adhering to them; further thinning caused rupture and dewetting away from the protrusions. Entrapped air bubbles, injected through the surface and into the film, ruptured as they breached the film surface to form stable holes in the film if it was sufficiently thin. Entrapped air was the best means of rupturing films on all surfaces.

Controlling and predicting rupture and dewetting of quiescent thin water films, hundreds of microns thick, was studied experimentally. Wax, polycarbonate, steel and aluminium surfaces were immersed in water; the water level was lowered to form thin films above the surfaces. Spontaneous film rupture only occurred on wax, a low-energy surface. Films ruptured at the edges of the other—high-energy—surfaces. Increased surface roughness decreased chances of rupture and dewetting in the film. Introducing large wax or steel protrusions (on the order of millimetres) on smooth surfaces showed films rupturing above the protrusions and adhering to them; further thinning caused rupture and dewetting away from the protrusions. Entrapped air bubbles, injected through the surface and into the film, ruptured as they breached the film surface to form stable holes in the film if it was sufficiently thin. Entrapped air was the best means of rupturing films on all surfaces.

This report details a physical modeling study to investigate the flow characteristics of circular corrugated structural plate (CSP) culverts with 10% embedment and projecting end inlets using a 0.62 m diameter corrugated metal pipe under a range of flows (0.064 m3/s to 0.254 m3/s) and slopes (0%, 0.5% and 1.0%). An automated sampling system was used to record detailed velocity measurements at cross-sections along the length of the model. The velocity data was then used to develop isovel plots and observations were made regarding the effect of water depth, average velocity, boundary roughness and inlet configuration on the velocity structure. Other key aspects examined include the distribution of shear velocity and equivalent sand roughness, Manning’s roughness, an evaluation of composite roughness calculation methods, secondary currents, area-velocity relationships, the effect of embedment on maximum discharge and a simulation of model results using HECRAS. Recommendations are presented to focus future research. / October 2007

The widespread use of low friction PVD coatings on machine elements is limited by the high costs associated with fulfilling the demands on the surface quality of both the supporting substrate and the counter surface. In this work, an attempt is made at lowering these demands, by adding a sacrificial carbon overcoat to a TaC/aC low friction coating. Both coatings were deposited by planar magnetron DC sputtering, as separate steps in a single PVD-process. Coatings were deposited on substrates of two different surface roughnesses, in order to test the ability of this coating system to function on rougher substrates. Reciprocating ball on disc tests was performed, using balls with two different surface roughnesses. The worn surfaces were investigated using 3-D profilometry and SEM. The ability of the different overcoats to initially reduce the roughness of both the coated surface and the counter surface and to produce stable, low-friction conditions was examined for the different initial roughnesses. The implications for design of efficient run-in coatings for various systems are discussed.