A Waveguide Based Acoustic Microscope with Application to the Evaluation of Bone

A new ultrasonic scanning system has been developed which is capable of accurate velocity measurements with high spatial resolution. This performance is achieved while using relatively low frequencies to minimize the cost of the instrument. A waveguide detector is used in place of the normal focused ultrasonic transducer. The waveguide receiver makes it possible to provide the needed spatial resolution without limitations imposed by the finite aperture of the transducer. An increase in the complexity of the signal processing required and reduced throughput of the instrument results from this approach. However, these disadvantages are amply compensated by the ability to investigate materials with high attenuation and low wave velocities. These measurements are not possible with traditional acoustic microscopes.</p

The effect of material on bipolar membrane fuel cell performance: a review

Bipolar membrane fuel cell (BPMFC) was firstly discovered in 2000 that composed of two-layered ionic conducting membranes. The importance of BPMC development is its ability to humidify the cell when operating at a high current density that eliminates the use of the external humidification system. It is able to self-humidify the cell because of water formation at the intermediate layer from the reaction of hydrogen ion (H+) with hydroxide ion (OH-). Up to now, there is no commercial bipolar membrane (BPM) in water formation configuration for the fuel cell humidifying purpose. Thus, the researcher had come out with a composition of proton exchange membrane with anion exchange membrane by the hotpressing method that allows them to carry the proton and anion simultaneously in a single cell. There are a few of polymeric-based PEM and AEM material had been selected for developing BPM such as Nafion, FumaPEM FAA3, quaternary ammonium polysulfone (QAPSF), and quaternary ammonium poly(phenylene)oxide (QAPPO). This review aims to determine the effect of material selection and design for developing BPM toward its performance in fuel cell based on published works. Besides, the potentialities of polymeric-based material are discussed, pointing out the main positive and negative effect of this BPM for fuel cell applications. As a case study, the use of different types of PEM and AEM material for BPM is particularly stressed, pointing out the main properties for its applications in BPMFC

Experimental investigation of the effect of henna leaf extracts on cuttings transportation in highly deviated and horizontal wells

Henna leaf extracts (HLE) was used to formulate henna water-based mud (HWBM) and its performance on cuttings transport efficiency (CTE) was compared with bentonite water-based mud (BWBM) and fresh water. Tests were conducted in a laboratory-scale flow-loop equipped with a 16-ft-long test section consisting of a concentric annulus outer casing (3.5-in. ID) and a static inner drill-pipe (2.4-in. OD) at hole-angles of 0°, 45°, 60°, 75° and 90° with annular fluid velocities (1.1, 1.54, 1.98 and 2.31 ft/s) using a cuttings size diameter of 1.0 mm. Experimental results showed that HWBM have better rheological and filtration properties before and after thermal aging tests than BWBM. Plastic viscosity (PV) was 7.4 cP for BWBM and 6.5 cP for HWBM. Apparent viscosity (AV) of BWBM was 12.7 cP and 13 cP for HWBM. The yield point (YP) of BWBM was 10.5 lb/100 ft2 and 12.2 lb/100 ft2 for HWBM, while high pressure high temperature (HPHT) filtrates volume of HWBM was increased by 70.4% from 5.4 to 9.2 ml but, that of BWBM was increased by 94.4% from 7.1 to 13.8 ml. After heating, the PV of BWBM and HWBM decreased by 6.76% and 1.54%, respectively. The YP of BWBM and HWBM was reduced by 21% and 4.1%, respectively. 45° was the most challenging hole-angle, which needs attention while preparing drilling mud. The findings reported in this study could open new areas of research, in particular HLE additive to boost the drilling industry

Bovine viral diarrhea virus cyclically impairs long bone trabecular modeling in experimental persistently infected fetuses

Persistent infection (PI) with bovine viral diarrhea virus (BVDV) has been associated with osteopetrosis and other long bone lesions, most commonly characterized as transverse zones of unmodeled metaphyseal trabeculae in fetuses and calves. This study was undertaken to characterize the morphogenesis of fetal long bone lesions. Forty-six BVDV-naïve pregnant Hereford heifers of approximately 18 months of age were inoculated with noncytopathic BVDV type 2 containing media or media alone on day 75 of gestation to produce PI and control fetuses, respectively, which were collected via cesarean section on days 82, 89, 97, 192, and 245 of gestation. Radiographic and histomorphometric abnormalities were first detected on day 192, at which age PI fetal long bone metaphyses contained focal densities (4 of 7 fetuses) and multiple alternating transverse radiodense bands (3 of 7 fetuses). Day 245 fetuses were similarly affected. Histomorphometric analysis of proximal tibial metaphyses from day 192 fetuses revealed transverse zones with increased calcified cartilage core (Cg.V/BV, %) and trabecular bone (BV/TV, %) volumes in regions corresponding to radiodense bands (