This paper investigates the possibility of developing a nonintrusive, low-cost, flow-rate measurement technique. The technique is based on signal noise from an accelerometer attached to the surface of the pipe. The signal noise is defined as the standard deviation of the frequency-averaged time-series signal. Experimental results are presented that indicate a nearly quadratic relationship over the test region between the signal noise and flow rate in the pipe. It is also shown that the signal noise–flow rate relationship is dependent on the pipe material and diameter.

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Fine particles may migrate in the preexisting pores of an internally unstable soil matrix caused by water flow. This migration changes the fine particle distribution and content at different zones and can affect the mechanical properties of these soils. Due to the different roles that fine particles can play in the force chains of an internally unstable soil, the available geometrical assessment methods do not predict post-erosion behavior of the soil. The fine particles may sit loose in the voids, provide lateral support for the primary soil matrix, or participate directly in stress transfer. This will depend on the fine content, particle size distribution, constriction size, relative density, stress path, and particle shape. However, to evaluate the post-erosion behavior accurately, computational modelling or experimental investigation needs to be conducted. A modified triaxial apparatus connected to a water supply system and collection tank was developed to investigate the post-erosion behavior of an internally unstable cohesionless soil under different loading patterns in undrained conditions. This system allowed all test phases to be completed, including erosion inside the triaxial chamber to remove any possible impact of specimen disturbance. The results suggest that the undrained shear strength of the eroded specimen increased at small vertical strains (0-4 %) under monotonic and cyclic loadings, whereas the initial modulus of elasticity remained unchanged. Also, the eroded specimen showed much higher resistance against cyclic loadings, whereas the non-eroded specimen was liquefied during less than five cycles of loading. This improvement was due to a better interlock between coarse particles due to erosion of fine particles. The hardening strain behavior of the noneroded specimen changed to limited flow deformation due to a decrease in the fine content. The flow deformation of the eroded specimen at medium strain may be due to the local increase in lubrication effect of fine particles in the eroded specimen.

Flow-induced pipe vibration caused by fully developed pipe flow has been observed but not fully investigated when turbulent flow prevails. This article presents experimental results that indicate a strong correlation between the volume flow rate and a measure of the pipe vibration. In this work, the standard deviation of the frequency-averaged time-series signal, measured using an accelerometer attached to the pipe, is used as the measure of pipe vibration. A numerical, fluid-structure interaction ͑FSI͒ model used to investigate the relationship between pipe wall vibration and the physical characteristics of turbulent flow is also presented. This numerical FSI approach, unlike commercial FSI software packages, which are based on Reynolds averaged Navier-Stokes flow models, is based on large eddy simulation ͑LES͒ flow models that compute the instantaneous pressure fluctuations in turbulent flow. The results from the numerical LES models also indicate a strong correlation between pipe vibration and flow rate. In general, the numerical simulations show that the standard deviation of the pipe wall vibration is proportional to the pressure fluctuations at the wall induced by the flow turbulence. This research, indicates that the pressure fluctuations on the pipe wall have a near quadratic relationship with the flow rate. Furthermore, the experimental results and the numerical modeling show that there is a definite relationship between the acceleration of the pipe ͑pipe vibration͒ and the flow rate. These last two concepts open possible avenues for the development of a non-intrusive flow sensor.

Vial-based lyophilization for biopharmaceuticals has been an indispensable cornerstone process for over 50 years. However, the process is not without significant challenges. Capital costs to realize a lyophilized drug product facility, for example, are very high. Similarly, heat and mass transfer limitations inherent in lyophilization result in drying cycle on the order of several days while putting practical constraints on available formulation space, such as solute mass percentage or fill volume in a vial. Through collaboration with an external partner, we are exploring microwave vacuum drying (MVD) as a faster drying process to vial lyophilization wherein the heat transfer process occurs by microwave radiation instead of pure conduction from the vial. Drying using this radiative process demonstrates greater than 80% reduction in drying time over traditional freeze-drying times while maintaining product activity and stability. Such reduction in freeze-drying process times from days to several hours is a welcome change as it enables flexible manufacturing by being able to better react to changes either in terms of product volume for on-demand manufacturing scenarios or facilities for production (e.g., scale-out over scale-up). Additionally, by utilizing first-principle modeling coupled with experimental verification, a mechanism for faster drying times associated with MVD is proposed in this article. This research, to the best of our knowledge, forms the very first report of utilizing microwave vacuum drying for vaccines while utilizing the power of simplified models to understand drying principles associated with MVD.