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This study, framed with a socialization lens, discusses the impact of using stories about early contributors in engineering education (via results of the Engineering Education Pioneers Project) as a mechanism to help socialize the first cohort of graduate students in a new engineering education Ph.D. program. Two instructors designed a new course requiring five students to read selected pioneers' stories weekly. Students subsequently wrote weekly reflections about the stories and submitted a final synthesis of their reflections at the end of the semester. Findings presented using a student-led autoethnographic approach include highlights and themes describing the overall impact of the pioneers' stories to facilitate an understanding of the field and develop an identity as an engineering education researcher. Findings also include the instructors' observations of the stories' impact on students' professional formation. Implications for various stakeholders in the engineering education ecosystem are discussed.

Cylinders with an elliptical, oblong, lenticular, sinus, or diamond transveral shape are very interesting geometries for the design of compact heat exchangers. This work investigates the role of the porosity and of the apex angle of diamond-shaped cylinders networks on the pressure losses, at moderate Reynolds numbers, inside microheat regenerators. The design of the geometry under test has been chosen so that the cross section of the flow remains almost constant along the path of the flow between cylinders. Experiments have been performed at 1⩽Re⩽30 and a porosity range 0.40<ε<0.90 for an apex angle of α=33deg. Numerical simulations have been conducted using the same Reynolds and porosity ranges but varying the apex angle 33deg⩽α⩽90deg. Experimental measurements and dimensional analysis have shown that the friction factor can be affected by the porosity. Two-dimensional numerical simulations confirmed that the friction factor increases with the porosity but also with the apex angle. An analysis at the scale of a channel flanked by adjacent cylinders has provided an original correlation able to describe easily the evolution of the Poiseuille number and the collective effects on the drag coefficient as a function of α and ε. Such a diamond-shaped design is found to induce much lower Poiseuille numbers than those expected from conventional stacked spheres, woven wires, and circular cylinders arrays. The findings of this study can help for better understanding the optimization of low pressure drop regenerators and how to reduce associated hydraulic power. [ABSTRACT FROM AUTHOR]

Recent advances in the field of microelectromechanical systems (MEMS) have generated great interest in the substitution of inorganic microcantilevers by organic ones, due to their low cost, high flexibility and a simplified fabrication by means of printing methods. Here, we present the integration of electrostrictive nanocomposites into organic microcantilever resonators specifically designed for mechanical energy harvesting from ambient vibrations. Strain sensitive nanocomposite materials composed of reduced graphene oxide (rGO) dispersed in polydimethylsiloxane (PDMS) are integrated into all-organic MEMS by means of an innovative low-cost and environment friendly process by combining printing techniques and xurography. Static tests of the electrostrictive nanocomposite with 3.7 wt% rGO show good performances with variations of capacitance that exceeds 4% for strain values lower than 0.55% as the microcantilever is bent. The results in dynamic mode suggest that the organic MEMS meet the requirements for vibration energy harvesting. With an applied sinusoidal acceleration (amplitude 0.5 g, frequency 15 Hz) a power density of 6 μW/cm 3 is achieved using a primitive circuit. [ABSTRACT FROM AUTHOR]

Abstract: Vibrating microcantilevers can be used to measure density and viscosity of surrounding fluids. The classical procedure involves experimental acquisition of the deflection spectrum of the beam, but a systematic calibration step is mandatory for obtaining viscosity and density. In the present study, a method is proposed to facilitate these measurements for Newtonian fluids with only one calibration step in the cantilever lifetime. Our approach is based on approximating the deflection spectrum with a secondorder transfer function and determining a simple analytical relationship between viscosity, density and the parameters of the transfer function. Fluid parameters determination results are shown for validation and discussed. [ABSTRACT FROM AUTHOR]

Abstract: Microcantilevers used as (bio)chemical sensors are usually coated with a chemically sensitive layer. The coated devices operate either in a static bending regime or in a dynamic flexural mode. While the coated devices operate generally well in both the static and dynamic mode, they do suffer from certain shortcomings depending on the medium of operation and the application, including lack of selectivity and of reversibility of the sensitive coating and a reduced quality factor due to the surrounding medium. In particular, the performance of microcantilevers excited in their standard out-of-plane dynamic mode drastically decreases in viscous liquid media. Moreover, the responses of coated cantilevers operating in the static bending mode are often difficult to interpret. To resolve those performance issues, unconventional uses of microcantilever are reviewed in this paper, which consist of the use of the dynamic mode without sensitive coating, the use of in-plane (flexural and longitudinal) vibration modes in liquid media, and fully accounting for the viscoelastic effects of the coatings in the static mode of operation. The advantages and drawbacks of these unconventional uses of microcantilevers for chemical sensing in gas and liquid environments are discussed. [ABSTRACT FROM AUTHOR]

Surgical procedures are considered the gold standard treatment of hydatid cysts. We report the first case of percutaneous treatment of a complex hydatid cyst of the liver, using radio frequency as a scolecidal agent in a 28-year-old man. The procedure was performed under real-time ultrasound control and with the patient under general anesthesia. Injection of alcohol was performed at the end of the procedure to induce retraction of the residual cavity. The percutaneous procedure was associated with oral albendazole therapy. Six months after the procedure, the patient was in very good condition. Liver and blood tests were normal and the cyst cavity was reduced. Further studies are required to define the indication of this new therapeutic strategy of hydatid cyst.

Forceps biopsies of biliary stenoses are difficult to direct under fluoroscopy and for this reason may give spurious results. In addition, fluoroscopy does not prevent the electrohydraulic lithotripsy (EHL) probe from damaging the bile duct wall. Retrograde biliary endoscopy with the ultrathin endoscope (UTE) was tested in 12 patients to guide biopsies and in 6 patients to guide EHL. Results of biopsies were confirmed by surgery or the disease course in each of the 12 patients. Only one stone could not be fragmented and removed because the EHL probe could not be properly placed. The diagnosis of biliary stenosis may be markedly enhanced by using a UTE although at the risk of an endoscopic sphincterotomy and subsequent biliary infection. EHL with UTE is difficult and time consuming but further technical development may make it more practical immediately following sphincterotomy.

Eighteen dogs were studied to determine the presence, extent and evolution of tissue lesions related to extracorporeal lithotripsy of the gallbladder under conditions similar to those encountered in clinical practice (electrohydraulic generator, ultrasonographic localization, prone positioning and 2,500 shocks delivered per session). Twelve dogs underwent lithotripsy 14 days after implantation of a 9 to 14 millimeter human stone in the gallbladder. The dogs were sacrificed one, 14 and 28 days after lithotripsy (four dogs at each date). Two dogs underwent implantation of stone but not lithotripsy and were sacrificed 14 days later. The last four dogs received only shock wave therapy and were sacrificed one (two dogs) and 14 (two dogs) days later. All calculi were completely fragmented into pieces less than 5 millimeters. Increases in leukocyte count (11 +/- 3.7 10(9) per liter) and alanine and aspartate aminotransferase levels (206 +/- 139 and 156 +/- 164 international units per deciliter, respectively) were seen after lithotripsy (p less than 0.05), but returned to normal during the next four weeks. Macroscopic hemorrhages were noted only in the dogs having undergone lithotripsy and were exclusively located in the organs lying in the path of the shock wave. Macroscopic hemorrhages were found in all six dogs sacrificed the day after lithotripsy and in two of the six dogs sacrificed 14 days later; one dog of the four sacrificed 28 days after lithotripsy still showed a large hemorrhage in the wall of the gallbladder. Microscopic abnormalities included congestion and hemorrhage of the same organs; although more discrete, congestion and hemorrhage were still present one month after shock wave therapy. Early and localized pulmonary fibrosis at the hypercellular stage was noted in two of the four dogs sacrificed at 28 days. The clinical implications for biliary lithotripsy upon humans include the necessity for intact coagulation parameters, strict avoidance of the bases of the lungs in targeting the stone and performing an ultrasonographic assessment of the wall of the gallbladder before repeating lithotripsy sessions, month apart.