Acoustic energy transmission in cast iron pipelines

In this paper we propose acoustic power transfer as a method for the remote powering of pipeline sensor nodes. A theoretical framework of acoustic power propagation in the ceramic transducers and the metal structures is drawn, based on the Mason equivalent circuit. The effect of mounting on the electrical response of piezoelectric transducers is studied experimentally. Using two identical transducer structures, power transmission of 0.33 mW through a 1 m long, 118 mm diameter cast iron pipe, with 8 mm wall thickness is demonstrated, at 1 V received voltage amplitude. A near-linear relationship between input and output voltage is observed. These results show that it is possible to deliver significant power to sensor nodes through acoustic waves in solid structures. The proposed method may enable the implementation of acoustic - powered wireless sensor nodes for structural and operation monitoring of pipeline infrastructure

F1 rotary motor of ATP synthase is driven by the torsionally-asymmetric drive shaft.

F1F0 ATP synthase (ATPase) either facilitates the synthesis of ATP in a process driven by the proton moving force (pmf), or uses the energy from ATP hydrolysis to pump protons against the concentration gradient across the membrane. ATPase is composed of two rotary motors, F0 and F1, which compete for control of their shared γ -shaft. We present a self-consistent physical model of F1 motor as a simplified two-state Brownian ratchet using the asymmetry of torsional elastic energy of the coiled-coil γ -shaft. This stochastic model unifies the physical concepts of linear and rotary motors, and explains the stepped unidirectional rotary motion. Substituting the model parameters, all independently known from recent experiments, our model quantitatively reproduces the ATPase operation, e.g. the 'no-load' angular velocity is ca. 400 rad/s anticlockwise at 4 mM ATP. Increasing the pmf torque exerted by F0 can slow, stop and overcome the torque generated by F1, switching from ATP hydrolysis to synthesis at a very low value of 'stall torque'. We discuss the motor efficiency, which is very low if calculated from the useful mechanical work it produces - but is quite high when the 'useful outcome' is measured in the number of H(+) pushed against the chemical gradient.The authors have benefited from extensive discussions with J. R. Blundell, C. Prior, and G. Fraser, as well as the conceptual input from J. E. Walker (who has originally suggested that the torsional energy of the γ–shaft might be asymmetric). This work has been funded by the {100 + 100 + 100} program by the Ukrainian Government, and the EPSRC Critical Mass Grant for Cambridge Theoretical Condensed Matter EP/J017639

Clamped closed-loop flux guides for power line inductive harvesting

Inductive harvesting from existing power lines in vehicle, industrial and infrastructure environments offers an opportunity for providing energy autonomy to sensors in a wide range of environments with high sensing interest. Flux funnelling has been shown to improve the power density of such devices by over an order of magnitude. The requirement for retrofitting onto existing power lines leads to a demand for detachable magnetic core interfaces, which introduce gaps and uncertainty to device performance. In this paper, an inductive energy harvesting device design that addresses this challenge is introduced. The design allows the interfaces to be internal to the device housing. Repeatable fixing, with reduced sensitivity to installation practicalities and controllable force is achieved by a screw-pressing mechanism, and the employment of a hard polyoxymethylene housing material. This method is utilized in an inductive power-line prototype, demonstrating power output up to 260 mW from a 40 A RMS, 500 Hz current, emulating aircraft power lines

Power supply based on inductive harvesting from structural currents

Monitoring infrastructure offers functional optimisation, lower maintenance cost, security, stability and data analysis benefits. Sensor nodes require some level of energy autonomy for reliable and cost-effective operation, and energy harvesting methods have been developed in the last two decades for this purpose. Here, a power supply that collects, stores and delivers regulated power from the stray magnetic field of currentcarrying structures is presented. In cm-scale structures the skin effect concentrates current at edges at frequencies even below 1 kHz. A coil-core inductive transducer is designed. A fluxfunnelling soft magnetic core shape is used, multiplying power density by the square of funnelling ratio. A power management circuit combining reactance cancellation, voltage doubling, rectification, super-capacitor storage and switched inductor voltage boosting and regulation is introduced. The power supply is characterised in house and on a full-size industrial setup, demonstrating a power reception density of 0.36 mW/cm3, 0.54 mW/cm3 and 0.73 mW/cm3 from a 25 A RMS structural current at 360 Hz, 500 Hz and 800 Hz respectively, corresponding to the frequency range of aircraft currents. The regulated output is tested under various loads and cold starting is demonstrated. The introduced method may enable power autonomy to wireless sensors deployed in current-carrying infrastructure

Shaped coil-core design for inductive energy collectors

Coil design is important for maximizing power density in inductive energy harvesting as well as in inductive power transfer. In this work, we present a study of coil performance, based on simulated flux distributions corresponding to a real aircraft application case. The use of funnel-shaped soft magnetic cores boosts magnetic flux density by flux concentration and allows the use of a smaller diameter coil. This reduces the transducer mass as well as the coil resistance (R COIL ), thereby increasing the power density. Analysis and simulation shows a fifty-fold power density increase from moderate funneling and another two-fold increase by coil size optimization. Results are compared with experimental measurements presented in [1] which demonstrate a 36μW/g(106μW/cm 3 ) power density from alternating environmental magnetic fields in the 10μT/300 Hz range

Inductive power line harvester with flux guidance for self-powered sensors

Self-powered sensors are expected to enable new large-scale deployment and location access capabilities for sensor systems. Energy harvesting devices have been shown to provide adequate power densities but their dependence on very specific environmental conditions restricts their applicability. Energy harvesting from power line infrastructure offers an architecture for addressing this challenge, because such infrastructure is widely available. In this paper an inductive power line harvester concept is presented, based on a flux concentration approach adapted to a closed-loop core geometry. Flux concentration is studied by simulation, showing a 26% flux increase using a 1:3 geometrical concentration ratio in a closed-loop core. A 20×20×25 mm prototype with a U-shaped soft-core sheet and a 200-turn Cu coil around a 5 mm diameter, 20 mm long soft-core rod is introduced. The total device volume is 9.1 cm 3 . Characterization results on a power line evaluation setup for currents up to 35 A RMS and a 50 Hz – 1 kHz range are presented. Power between 2.2 mW (50 Hz) and 233 mW (1 kHz) is demonstrated on an ohmic load, from a 10 A RMS power line current, employing impedance matching with reactance cancellation. The corresponding power densities are 0.24 mW/cm 3 and 25 mW/cm 3 respectively, per total device volume. This performance is adequate for enabling self-powered wireless sensor networks installed along power distribution lines

Colocalization of GLUT2 glucose transporter, sodium/glucose cotransporter, and gamma-glutamyl transpeptidase in rat kidney with double-peroxidase immunocytochemistry.

Glucose is reabsorbed from the glomerular filtrate in the proximal segment of the renal tubule in two stages. The first stage is uphill transport across the brush border membrane by Na(+)-glucose cotransport and the second stage is downhill transport across the basolateral membrane by facilitated diffusion. Genes for both a renal Na(+)-glucose cotransporter (SGLT1) and a renal facilitated glucose transporter (GLUT2) have been cloned and sequenced. To examine whether SGLT1 and GLUT2 colocalize to the same tubular epithelial cells in rat kidney, double-immunoperoxidase studies with dual chromogens and paraformaldehyde perfusion-fixed frozen sections of rat kidney were performed. Antipeptide antisera were prepared against rat GLUT2 (amino acids 510-522) and rabbit SGLT1 (amino acids 402-420). Proximal tubules were identified immunocytochemically with an antiserum raised against a synthetic peptide corresponding to the 21 amino acids at the COOH-terminal of the heavy chain of rat gamma-glutamyl transpeptidase, which is a proximal tubule-specific enzyme. The anti-GLUT2 antiserum strongly stained the basolateral membrane of 46% of cortical tubules, whereas the SGLT1 antiserum stained the brush border of 56% of the cortical tubules. The gamma-glutamyl transpeptidase antiserum also stained the brush border of 51% of the cortical tubules. GLUT2 and SGLT1 colocalized to 40% of cortical epithelium, but 16% of cortical epithelial cells were immunopositive for brush border SGLT1 and immunonegative for basolateral GLUT2. These gamma-glutamyl transpeptidase staining results suggest that at least 50% of the tubules in the cortex are proximal tubules and that SGLT1 and GLUT2 colocalize to most proximal tubules. The fact that SGLT1 antiserum immunoreacted with tubules unreactive to the GLUT2 antiserum suggests that either the SGLT1 epitope is conserved on a related brush border protein or that there is another GLUT transporter responsible for the exit of sugar from these proximal tubule cells

Tuning Resonant Energy Harvesters Using a Variable Reluctance Link

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Opinion leaders and changes over time: a survey

<p>Abstract</p> <p>Background</p> <p>Opinion leaders represent one way to disseminate new knowledge and influence the practice behaviors of physicians. This study explored the stability of opinion leaders over time, whether opinion leaders were polymorphic (<it>i.e.</it>, influencing multiple practice areas) or monomorphic (<it>i.e.</it>, influencing one practice area), and reach of opinion leaders in their local network.</p> <p>Methods</p> <p>We surveyed surgeons and pathologists in Ontario to identify opinion leaders for colorectal cancer in 2003 and 2005 and to identify opinion leaders for breast cancer in 2005. We explored whether opinion leaders for colorectal cancer identified in 2003 were re-identified in 2005. We examined whether opinion leaders were considered polymorphic (nominated in 2005 as opinion leaders for both colorectal and breast cancer) or monomorphic (nominated in 2005 for only one condition). Social-network mapping was used to identify the number of local colleagues identifying opinion leaders.</p> <p>Results</p> <p>Response rates for surgeons were 41% (2003) and 40% (2005); response rates for pathologists were 42% (2003) and 37% (2005). Four (25%) of the surgical opinion leaders identified in 2003 for colorectal cancer were re-identified in 2005. No pathology opinion leaders for colorectal cancer were identified in both 2003 and 2005. Only 29% of surgical opinion leaders and 17% of pathology opinion leaders identified in the 2005 survey were considered influential for both colorectal cancer and breast cancer. Social-network mapping revealed that only a limited number of general surgeons (12%) or pathologists (7%) were connected to the social networks of identified opinion leaders.</p> <p>Conclusions</p> <p>Opinion leaders identified in this study were not stable over a two-year time period and generally appear to be monomorphic, with clearly demarcated areas of expertise and limited spheres of influence. These findings may limit the practicability of routinely using opinion leaders to influence practice.</p

A phase 1 trial dose-escalation study of tipifarnib on a week-on, week-off schedule in relapsed, refractory or high-risk myeloid leukemia.

Inhibition of farnesyltransferase (FT) activity has been associated with in vitro and in vivo anti-leukemia activity. We report the results of a phase 1 dose-escalation study of tipifarnib, an oral FT inhibitor, in patients with relapsed, refractory or newly diagnosed (if over age 70) acute myelogenous leukemia (AML), on a week-on, week-off schedule. Forty-four patients were enrolled, two patients were newly diagnosed, and the rest were relapsed or refractory to previous treatment, with a median age of 61 (range 33-79). The maximum tolerated dose was determined to be 1200 mg given orally twice daily (b.i.d.) on this schedule. Cycle 1 dose-limiting toxicities were hepatic and renal. There were three complete remissions seen, two at the 1200 mg b.i.d. dose and one at the 1000 mg b.i.d. dose, with minor responses seen at the 1400 mg b.i.d. dose level. Pharmacokinetic studies performed at doses of 1400 mg b.i.d. showed linear behavior with minimal accumulation between days 1-5. Tipifarnib administered on a week-on, week-off schedule shows activity at higher doses, and represents an option for future clinical trials in AML