5,199 research outputs found
Passive fetal monitoring sensor
An ambulatory, passive sensor for use in a fetal monitoring system is discussed. The invention is comprised of a piezoelectric polymer film, combined with a metallic mounting plate fastened to a belt, and electrically connected to a signal processing unit by means of a shielded cable. The purpose of the sensor is to receive pressure pulses emitted by a fetus inside an expectant mother. Additionally, the monitor will filter out pressure pulses arising from other sources, such as the maternal heart
World heritage site management: a case study of sacred sites and pilgrimage routes in the Kii mountain range, Japan
This research examines three themes: heritage management and conservation activities, local communities and tourism development in Kii World Heritage Site (WHS) after WHS designation. Kii is a cultural WHS having links with Japanese religions and consisting of shrines, temples and pilgrimage routes. This study inductively and qualitatively examines these three themes. Overall, the current status of Kii WHS is satisfactory. Local people, tourists/visitors and experts are all actively involved in heritage management and conservation activities. WHS listing seems to have enhanced local identity, increased local people’s pride in their culture and place of residence, and triggered a revitalisation of local culture. Moreover, tourism’s negative impacts appear to be minimal, despite an increase in the number of visitors since UNESCO inscription. There are a few issues to be improved, which derive mainly from a lack of understanding of WHS status or conflicts between heritage management/tourism and religious practices. A more holistic approach, such as establishing a forum consisting of all key stakeholders, would be useful for the further success of Kii WHS as a religious and sacred site, place to live and tourist destination
Histotripsy Erosion of Model Urinary Calculi
Background and Purpose: Histotripsy is a pulsed focused ultrasound technology in which initiation and control of acoustic cavitation allow for precise mechanical fractionation of tissues. The present study examines the feasibility of using histotripsy for erosion of urinary calculi. Materials and Methods: Histotripsy treatment was delivered from a 750-kHz transducer in the form of 5-cycle acoustic pulses at a 1-kHz pulse repetition frequency. Model stones were sonicated for 5 minutes at peak negative pressures (p-) of 10, 15, 19, 22, and 24-MPa. Resulting fragment sizes and comminution rates were assessed and compared with those achieved with a piezoelectric lithotripter (Wolf Piezolith 3000) operated at 2-Hz pulse repetition frequency and power level 17 (p- = 14-MPa). Results: Histotripsy eroded the surface of stones producing fine (<100--m) particulate debris in contrast to the progressive and incomplete subdivision of stones achieved with piezoelectric lithotripsy. The histotripsy erosion rate increased with increasing peak negative pressure from 10 to 19-MPa and then saturated, yielding an average rate of 87.9+/-12.8 mg/min at maximum treatment intensity. Piezoelectric lithotripsy achieved an average treatment rate of 110.7+/-27.4 mg/min. Conclusions: Histotripsy comminution of urinary calculi is a surface erosion phenomenon that is mechanistically distinct from conventional shockwave lithotripsy (SWL), producing only fine debris as opposed to coarse fragments. These characteristics suggest that histotripsy offers a potential adjunct to traditional SWL procedures, and synergistic interplay of the two modalities may lead to possible increases in both rate and degree of stone fragmentation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90440/1/end-2E2010-2E0407.pd
Preparation for Hollow Cathode Testing for the Advanced Electric Propulsion System at NASA Glenn Research Center
NASA Glenn Research Center is performing activities to support the unique needs of hollow cathode development and testing for the Advanced Electric Propulsion System (AEPS). Three existing vacuum facilities have been outfitted as cathode test facilities, and each will serve a different role in upcoming testing. Vacuum Facility 67 is being developed to serve as a long-duration test facility for the Engineering Development Unit cathode, which is to be delivered by the AEPS contractor. It will feature a thruster-like magnetic field simulator and cold-cycle capability via a liquid nitrogen-cooled cold plate. Vacuum Facility 17 is being developed as a test facility for short- to medium-duration experiments in order to provide auxiliary support for the long-duration testing. It will feature a magnetic field simulator but not cold-cycling. Finally, Vacuum Facility 1 will be a high-pumping speed cathode development environment, and will feature an array of plasma and temperature diagnostics. In addition to the facility preparation work, a new cathode, referred to as the Mark II, has been designed. The Mark II is an evolution of the Technology Demonstration Unit cathodes that better evokes the geometry, fabrication, and construction of the forthcoming Engineering Development Unit. This cathode serves as a transition between the Technology Demonstration Unit cathodes used during early thruster development and the forthcoming Engineering Development Unit cathodes. It will be used as a means of verifying the new test facilities prior to arrival of Engineering Development Unit hardware. Details of the Mark II design and key features are presented, as well as details of future work to be performed
Characterization of Propellant Flow and Bias Required to Initiate an Arc Discharge in a Heaterless Hollow Cathode
Heaterless hollow cathodes provide an opportunity to reduce complexity and improve reliability in electric propulsion systems. While removal of the heater has little effect on steady-state operation of a hollow cathode, it has a considerable effect on the ignition process. To successfully integrate a heaterless hollow cathode into a spaceflight electric propulsion system, it will be necessary to establish definitive requirements for the propellant feed and electrical subsystems so that ignition of a plasma discharge can be achieved reliably. The aim of this research was to form a better understanding of these requirements by performing an investigation of the propellant flow and voltage conditions required for the ignition of a plasma arc discharge. This aim was achieved by performing discharge initiation experiments using both a specially designed experimental apparatus and a functional heaterless hollow cathode assembly. It was demonstrated that there is a distinct difference in the voltage required to initiate a plasma discharge between two common electric propulsion propellants, xenon and krypton, which suggests that the developmental testing of heaterless hollow cathodes needs to be performed with the appropriate propellant gas species. Heaterless hollow cathode ignition experiments showed that the keeper orifice diameter has a strong effect on the voltage required to ignite a plasma discharge at a given propellant mass flow rate, while the effect of keeper-cathode separation distance was only strong at flow rates below 25 sccm (Xe)
Developing a framework for the analysis of power through depotentia
Stakeholder participation in tourism policy-making is usually perceived as providing a means of empowerment. However participatory processes drawing upon stakeholders from traditionally empowered backgrounds may provide the means of removing empowerment from stakeholders. Such an outcome would be in contradiction to the claims that participatory processes improve both inclusivity and sustainability. In order to form an understanding of the sources through which empowerment may be removed, an analytical perspective has been developed deriving from Lukes�s views of power dating from 1974. This perspective considers the concept of depotentia as the removal of �power to� without speculating upon the underlying intent and also provides for the multidimensionality of power to be examined within a single study. The application of this analytical perspective has been tested upon findings of the government-commissioned report of the Countryside and Community Research Unit in 2005. The survey and report investigated the progress of Local Access Forums in England created in response to the Countryside and Rights of Way Act 2000. Consideration of the data from this perspective permits the classification of individual sources of depotentia which can each be addressed and potentially enable stakeholder groups to reverse loss of empowerment where it has occurred
Energy transitions and uncertainty: creating low carbon investment opportunities in the UK electricity sector
This paper examines how actors in the UK electricity sector are attempting to deliver investment in low carbon generation. Low carbon technologies, because of their relative immaturity, capital intensity and low operational costs, do not readily fit with existing electricity markets and investment templates which were designed for fossil fuel based energy. We analyse key electricity market and infrastructure policies in the UK and highlight how these are aimed at making low carbon technologies ‘investable’ by reducing uncertainty, managing investment risks and repositioning actors within the electricity socio-technical ‘regime’. We argue that our study can inform contemporary debates on the politics and governance of sustainability transitions by empirically investigating the agency of incumbent regime actors in the face of uncertainty and by offering critical insights on the role of markets and finance in shaping socio-technical change
Recommended from our members
De novo assembly of the cattle reference genome with single-molecule sequencing.
BackgroundMajor advances in selection progress for cattle have been made following the introduction of genomic tools over the past 10-12 years. These tools depend upon the Bos taurus reference genome (UMD3.1.1), which was created using now-outdated technologies and is hindered by a variety of deficiencies and inaccuracies.ResultsWe present the new reference genome for cattle, ARS-UCD1.2, based on the same animal as the original to facilitate transfer and interpretation of results obtained from the earlier version, but applying a combination of modern technologies in a de novo assembly to increase continuity, accuracy, and completeness. The assembly includes 2.7 Gb and is >250× more continuous than the original assembly, with contig N50 >25 Mb and L50 of 32. We also greatly expanded supporting RNA-based data for annotation that identifies 30,396 total genes (21,039 protein coding). The new reference assembly is accessible in annotated form for public use.ConclusionsWe demonstrate that improved continuity of assembled sequence warrants the adoption of ARS-UCD1.2 as the new cattle reference genome and that increased assembly accuracy will benefit future research on this species
- …
