Transient Thermo-Mechanical Stress Analysis of Hot Surface Probe Using Sequentially Coupled CFD-FEA Approach

Energy addition using a hot surface probe is required for reliable ignition of aircraft compression ignition engines running on fuel variations and at altitude conditions. Thus, durability of the hot surface probe is crucial for application in these engines. Thermo-mechanical stress is one of the key parameters that determine durability, which requires an accurate prediction of the transient temperature field based on well-defined boundary conditions representing the dynamic and complex fluid flow inside engines. To meet this requirement, the present study focuses on transient thermo-mechanical stress analysis using a sequentially coupled CFD-FEA approach to understand transient thermo-mechanical responses of the hot surface probe. A 3D transient reacting flow simulation was conducted first using CONVERGE software, the results of which were exported to map thermal and pressure boundary conditions onto a structural finite element mesh. Transient thermo-mechanical stress analysis was performed sequentially using ABAQUS software utilizing the mapped boundary conditions. The results such as transient temperature history, resultant thermo-mechanical stress, displacement, potential failure modes, etc. were critically reviewed, which can provide helpful information for further design improvement.

Multiplexed Affinity Measurements of Extracellular Vesicles Binding Kinetics

Extracellular vesicles (EVs) have attracted significant attention as impactful diagnostic biomarkers, since their properties are closely related to specific clinical conditions. However, designing experiments that involve EVs phenotyping is usually highly challenging and time-consuming, due to laborious optimization steps that require very long or even overnight incubation durations. In this work, we demonstrate label-free, real-time detection, and phenotyping of extracellular vesicles binding to a multiplexed surface. With the ability for label-free kinetic binding measurements using the Interferometric Reflectance Imaging Sensor (IRIS) in a microfluidic chamber, we successfully optimize the capture reaction by tuning various assay conditions (incubation time, flow conditions, surface probe density, and specificity). A single (less than 1 h) experiment allows for characterization of binding affinities of the EVs to multiplexed probes. We demonstrate kinetic characterization of 18 different probe conditions, namely three different antibodies, each spotted at six different concentrations, simultaneously. The affinity characterization is then analyzed through a model that considers the complexity of multivalent binding of large structures to a carpet of probes and therefore introduces a combination of fast and slow association and dissociation parameters. Additionally, our results confirm higher affinity of EVs to aCD81 with respect to aCD9 and aCD63. Single-vesicle imaging measurements corroborate our findings, as well as confirming the EVs nature of the captured particles through fluorescence staining of the EVs membrane and cargo.

Multiplexed Affinity Measurements of Extracellular Vesicles Binding Kinetics

<p>Extracellular vesicles (EVs) have attracted significant attention as impactful diagnostic biomarkers, since their properties are closely related to specific clinical conditions. However, designing experiments that involve EVs phenotyping is usually highly challenging and time-consuming, due to laborious optimization steps that require very long or even overnight incubation durations. In this work, we demonstrate label-free, real-time detection and phenotyping of extracellular vesicles binding to a multiplexed surface. With the ability of label-free kinetic binding measurements using the Interferometric Reflectance Imaging Sensor (IRIS) in a microfluidic chamber, we successfully optimize the capture reaction by tuning various assay conditions (incubation time, flow conditions, surface probe density and specificity). A single (less than 1 hour) experiment allows for characterization of binding affinities of the EVs to multiplexed probes. We demonstrate kinetic characterization of 18 different probe conditions, namely three different antobodies, each spotted at six different concentrations, simultaneously. The affinity characterization is then analyzed through a model which considers the complexity of multivalent binding of large structures to a carpet of probes, and therefore introduces a combination of fast and slow association and dissociation parameters. Additionally, our results confirm higher affinity of EVs to aCD81 with respect to aCD9 and aCD63. Single-vesicle imaging measurements corroborate our findings, as well as confirming the EVs nature of the captured particles through fluorescence staining of the EVs membrane and cargo. </p>

Multiplexed Affinity Measurements of Extracellular Vesicles Binding Kinetics

<p>Extracellular vesicles (EVs) have attracted significant attention as impactful diagnostic biomarkers, since their properties are closely related to specific clinical conditions. However, designing experiments that involve EVs phenotyping is usually highly challenging and time-consuming, due to laborious optimization steps that require very long or even overnight incubation durations. In this work, we demonstrate label-free, real-time detection and phenotyping of extracellular vesicles binding to a multiplexed surface. With the ability of label-free kinetic binding measurements using the Interferometric Reflectance Imaging Sensor (IRIS) in a microfluidic chamber, we successfully optimize the capture reaction by tuning various assay conditions (incubation time, flow conditions, surface probe density and specificity). A single (less than 1 hour) experiment allows for characterization of binding affinities of the EVs to multiplexed probes. We demonstrate kinetic characterization of 18 different probe conditions, namely three different antobodies, each spotted at six different concentrations, simultaneously. The affinity characterization is then analyzed through a model which considers the complexity of multivalent binding of large structures to a carpet of probes, and therefore introduces a combination of fast and slow association and dissociation parameters. Additionally, our results confirm higher affinity of EVs to aCD81 with respect to aCD9 and aCD63. Single-vesicle imaging measurements corroborate our findings, as well as confirming the EVs nature of the captured particles through fluorescence staining of the EVs membrane and cargo. </p>

THE ABILITY TO ASSESS THE DEGREE OF CORROSION DAMAGE BY EDDY CURRENT TESTING

Considers possibility of corrosion damage evaluation using eddy current method implemented with surface probe. Comparative analysis of amplitude-phase and phase suppression methods implementation has been conducted. Finite-element model for calculating probe signal response to defects of different corrosion type was designed. Experimental research has been conducted that allowed to verify the designed model and to confirm results gained with mathematical simulation.

Surface Probe Linker with Tandem Anti-Fouling Properties for Application in Biosensor Technology

This paper describes the anti-fouling capability of the novel monolayer-forming surface linker 3-(3-(trichlorosilylpropyloxy) propanoyl chloride (MEG-Cl). This compound was successfully attached to quartz crystal surfaces which are employed in an electromagnetic piezoelectric acoustic sensor (EMPAS) configuration. The MEG-Cl coated surface was both employed with Ni-NTA for the binding of recombinant proteins and for the tandem property of the avoidance of fouling from serum and milk. The MEG-Cl coated surfaces were found to provide a large degree of anti-fouling on the EMPAS device, and were comparable to previously studied MEG-OH surfaces. Importantly, the monolayer continued to provide anti-fouling capability to the biosensor following extension with Ni-NTA in place. Accordingly, this surface linker provides an attractive system for use in biosensor technology in terms of both its anti-fouling and linking properties.

Unique sequence-dependent properties of trinucleotide repeat monolayers: electrochemical, electrical, and topographic characterization

The sequence-dependent properties of the surface-assembled trinucleotide repeat interface on a gold surface were explored by electrochemical methods and surface probe microscopy.