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IN: Part 1, The original 1990 science behind the MUS, the hypothesized closure mechanisms, and the prototype MUS itself were presented. The next phase of MUS development began in 1990 in collaboration with the late Ulf Ulmsten. It had two arms Further development of the prototype MUS. Further anatomical, imaging, urodynamic studies to validate the role of PUL in the closure mechanisms. A second series of prototype MUS operations performed under LA/sedation resulted in a permanently implanted polypropylene sling and the MUS as is known today. The tape was elevated until no urine leaked on coughing. This demonstrated that the artificial PUL neoligament needed to be at a specific length to work. Anatomical, EMG and video ultrasound, and X-ray studies confirmed three directional muscles contracted pubourethral (PUL) and uterosacral (USL) ligaments. The contribution of the horseshoe shaped rhabdosphincter (RS) to continence was directly tested with pressure measurements under live surgery conditions. It was concluded that the RS was responsible for pressure generation but not continence. Continence was a consequence of intraurethral resistance to flow created by the distal and proximal urethral closure mechanisms, both governed ultimately by the Law of Poiseuille. CONCLUSIONS: The key element in curing USI is creation of a competent PUL using the collagenous neoligament surgical principle described in Part 1. This creates a firm insertion point for the three directional muscle forces, restoring their contractile strength and closure.

Due to its meshless nature, the smoothed particle hydrodynamics method (SPH) provides high potential for the simulation of free-surface flows and mixing in complex geometries. We used SPH to analyze the flow inside five typical screw elements of corotating twin-screw extruders, two conveying elements, two kneading elements and a mixing element. Our results show conveying capabilities, pressure generation and power input for various operation states, completely and partially filled. We conducted a detailed mixing analysis based on tracer particles, which yielded the time evolution of the intensity of segregation for different tracers. From that, we determined exponential mixing rates, which describe the relative decrease of the intensity of segregation per screw revolution and characterize the mixing performance in different operation states. This provides valuable input information for simplified models of extruders, which are relevant to industrial applications and can significantly contribute to the efficient design, optimization and scale-up of extruders. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2451–2463, 2017

It was hypothesized that tongue-palate pressure generation might directly facilitate hyoid movement in swallowing through the anatomical connections of the extrinsic tongue muscles. If true, non-invasive measures of tongue-palate pressure timing might serve as a proxy measure of hyoid excursion. The timing relationships between events in the tongue-palate pressure and hyoid movement profiles during water and nectar-thick liquid swallowing in healthy adults were explored. Concurrent intra-oral manometry and submental B-mode midsagittal ultrasound were recorded. It was determined that there is no obligate sequence in the onsets, or offsets, of tongue-palate pressures and hyoid excursion. Timing lags (either of hyoid movement lagging tongue-palate pressures or vice versa) fell within 0.5 s, on average. It is concluded that tongue-palate pressure generation and hyoid movement are separate phenomena in the swallowing sequence and that non-invasive measures of tongue-pressure timing cannot be used reliably as proxy measures of hyoid movement timing.

To provide a viable bridge-to-transplant, bridge-to-recovery, or bridge-to-surgical reconstruction for patients with failing Fontan physiology, we are developing a collapsible, percutaneously inserted, magnetically levitated axial flow blood pump to support the cavopulmonary circulation in adolescent and adult patients. This unique blood pump will augment pressure and thus flow in the inferior vena cava through the lungs and ameliorate the poor hemodynamics associated with the univentricular circulation. Computational fluid dynamics analyses were performed to create the design of the impeller, the protective cage of filaments, and the set of diffuser blades for our axial flow blood pump. These analyses included the generation of pressure-flow characteristics, scalar stress estimations, and blood damage indexes. A quasi-steady analysis of the diffuser rotation was also completed and indicated an optimal diffuser rotational orientation of approximately 12 degrees. The numerical predictions of the pump performance demonstrated a pressure generation of 2-25 mm Hg for 1-7 L/min over 3000-8000 rpm. Scalar stress values were less than 200 Pa, and fluid residence times were found to be within acceptable ranges being less than 0.25 s. The maximum blood damage index was calculated to be 0.068%. These results support the continued design and development of this cavopulmonary assist device, building upon previous numerical work and experimental prototype testing.

The quantity and composition of airway surface liquid (ASL) are essential to host defense. To date, attempts to harvest ASL and measure its composition have yielded conflicting results. We investigated the physical principles underlying two techniques that were proposed for harvesting ASL: filter paper pledgets and polyethylene catheters. We compared the force and pressure generation and the kinematics of capillarity-induced fluid uptake with both techniques. Both have significant limitations for harvesting ASL, generating physiologically significant pressures (filter paper, 60.4 Pa; polyethylene, 14.3 Pa) that could potentially compromise epithelial integrity. Furthermore, filter paper generates a force 85-fold higher than the polyethylene catheter, which is associated with a very high rate of uptake of liquid and a large total amount of liquid relative to ASL thickness. While the PE catheter harvests liquid more gently, it is only effective when ASL surface tension is below 31 mN/m. These limitations likely account for some of the variability in reported ASL composition, and highlight the need for improved methods for harvesting ASL.

The reduction of nitro arenes to anilines under microwave irradiation and heating in a pressure tube proceeds with concomitant loss of bromo, chloro and iodo substituents which stay intact upon stirring at 25° C or reflux without microwave irradiation and pressure generation.

The coefficient of dynamic friction is often the controlling factor for solids conveying, pressure generation, and thermal decomposition of a resin in the feed section of a single-screw plasticating extruder. The coefficients of friction are, however, very poorly understood, and the interpretation of the measurements are complicated by the dissipation of frictional energy at the sliding interface. A new instrument was recently built to help understand dynamic friction, and a numerical technique was developed to estimate the interface temperature. Coefficients of dynamic friction for several polyethylene resins are presented in this paper as a function of the surface temperature, pressure, and velocity. The relationship of the data with respect to the extrusion process is discussed

The coefficient of dynamic friction is often the controlling factor for solids conveying, pressure generation, and thermal decomposition of a resin in the feed section of a single-screw plasticating extruder. The coefficients of friction are, however, very poorly understood, and the interpretation of the measurements are complicated by the dissipation of frictional energy at the sliding interface. A new instrument was recently built to help understand dynamic friction, and a numerical technique was developed to estimate the interface temperature. The coefficients of dynamic friction for a low-density polyethylene resin are presented in this paper as a function of the surface temperature, pressure, and velocity.

Urinary bladder function consists of a filling and storage phase followed by an active coordinated expulsion phase. A large part of our knowledge of bladder function, as well as bladder physiology and pharmacology, comes from a variety of in-vivo and in-vitro experimental animal models. Of the in-vitro methodologies available for the study of bladder smooth muscle, the isolated bladder smooth muscle strip techniques and isolated whole bladder techniques are two of the most popular. In general, the ability to generate pressure in the non-emptying whole bladder model is directly related to phasic contraction of the bladder smooth muscle, and can be equated with the response of isolated strips. Although both techniques generate useful and important information, one must be very careful in making conclusions concerning bladder function based solely on contractile data. We have studied the volume-pressure relationship of the bladders of control rabbits and of those subjected to bladder outlet obstruction (2 week) and unilateral ischemia (2 week). For each bladder, in-vitro cystometry, pressure generation, and the ability of the bladder to empty (in response to both bethanechol and field stimulation) was determined. Although it was clear that outlet obstruction and unilateral ischemia induced marked alterations in bladder compliance, capacity, and the ability to empty, bladder pressure generation was not significantly affected. These studies support the view that contractile studies in and of themselves cannot be used to describe the functional state of the bladder. Only through the application of several techniques including studies on bladder compliance, capacity, and the ability of the bladder to empty can the functional state of the bladder be evaluated.

The generation of pressure in the feed section of an extruder is analyzed. It is concluded that body forces must be considered since they provide the necessary conditions for pressure initiation. Solutions are given which take into account gravity forces in both vertical and horizontal screws together with centrifugal force. Some numerical results are also given which illustrate the practical importance of these effects.

A new type of feeding system by an extruder-feeder was utilized to pump high concentrations of slurries into an advanced biomass liquefaction reactor operating at pressures of up to 25 MPa and temperatures of up to 400°C. The operability of such an extruder-feeder and the design criteria for this type of unit operation are described, and operational data are reported. Three types of extruder-feeders were used, and many different types of feedstocks were tested. The extruder-feeder proved to be effective in the biomass direct liquefaction process and could prove applicable in many other processes where high concentrations of solids are to be pumped, thus reducing drastically the size of the plant and the need for recycle of large amounts of liquid carriers for the solids. Typical experimental data and results of the flow rates and pressure generation for the various extruder-feeders and their operational conditions for several feedstocks are reported. The theoretical models developed for plasticating extruders were found to be acceptable also for the extruder-feeder of biomass feedstock, applying appropriate drag and pressure flow coefficients. On a utilise un nouveau systeme d'alimentation-extrusion pour pomper des concentrations elevees de boues dans un reacteur de liquefaction de biomass perfectionne et fonctionnant a des pressions allant jusqu'a 25 MPa et des temperatures jusqu'a 400°C. On decrit les capacites de fonctionnement de tels systemes ainsi que les criteres de conception s'appliquant a ce type d'operation fondamentale et on presente les donnees de fonctionnement. Trois systemes d'alimentation-extrusion differents ont ete utilises et de tres nombreux produits d'alimentation testes. Le systeme s'est avere efficace dans le procede de liquefaction directe de la biomasse et pourrait ětre applicable dans beaucoup d'autres procedes necessitant le pompage d'importantes concentrations de solides, permettant ainsi de reduire considerablement la taille de l'installation et le besoin de recyclage de quantites importantes de transporters liquides pour les solides. On presente des donnees experimentales typiques et des resultats sur les debits et la generation de pression pour les differents systemes d'alimentation-extrusion et les conditions de fonctionnement sont decrites pour plusieurs produits d'alimentation. On a trouve que les modeles theoriques mis au point les extrudeuses de plastification convenaient egalement au systeme d'alimentation-extrusion de biomasse, en appliquant les coefficients de traǐnee et de circulation forcee appropries.

An analysis is given of the pressure generation mechanism in the tapered channel of a single-screw extruder. It is shown that when increasing the throughput the pressure build-up capacity of the melting zone tends to decrease. As a result, severe pressure drops may occur in the tapered sections. A relationship between the pressure profile and the melting mechanism (solid bed/melt pool configuration) is described in terms of the cross-channel melt circulation.

Current pharyngeal deglutition theory has stressed the role of the pharyngeal constrictors as producing a peristaltic wave responsible for bolus propulsion through the pharynx. This thesis presents data obtained using manofluorography which supports the significance of tongue and laryngeal motion in swallowing. The usage of the term peristalsis to describe the constrictor contraction is challenged. The results of this quantitative study of swallowing in normal subjects, laryngectomized patients, and patients with restricted tongue motion show that tongue driving pressure and the negative pressure developed in the pharyngeal esophageal segment appear more important than the peristaltic-like pressure of the constrictors. Bolus transit is really dependent upon these two pressures. This model for analysis has clinical significance because it permits quantification of the pharyngeal swallowing mechanism.