275 research outputs found
Potential for improved radiation thermometry measurement uncertainty through implementing a primary scale in an industrial laboratory
A primary temperature scale requires realising a unit in terms of its definition. For high
temperature radiation thermometry in terms of the International Temperature Scale of 1990
this means extrapolating from the signal measured at the freezing temperature of gold, silver
or copper using Planck’s radiation law. The difficulty in doing this means that primary scales
above 1000 °C require specialist equipment and careful characterisation in order to achieve the
extrapolation with sufficient accuracy. As such, maintenance of the scale at high temperatures
is usually only practicable for National Metrology Institutes, and calibration laboratories have
to rely on a scale calibrated against transfer standards. At lower temperatures it is practicable
for an industrial calibration laboratory to have its own primary temperature scale, which
reduces the number of steps between the primary scale and end user. Proposed changes to the
SI that will introduce internationally accepted high temperature reference standards might
make it practicable to have a primary high temperature scale in a calibration laboratory. In
this study such a scale was established by calibrating radiation thermometers directly to high
temperature reference standards. The possible reduction in uncertainty to an end user as a
result of the reduced calibration chain was evaluated
Augmenting forearm crutches with wireless sensors for lower limb rehabilitation
Forearm crutches are frequently used in the rehabilitation of an injury to the lower limb. The recovery rate is improved if the patient correctly applies a certain fraction of their body weight (specified by a clinician) through the axis of the crutch, referred to as partial weight bearing (PWB). Incorrect weight bearing has been shown to result in an extended recovery period or even cause further damage to the limb. There is currently no minimally invasive tool for long-term monitoring of a patient's PWB in a home environment. This paper describes the research and development of an instrumented forearm crutch that has been developed to wirelessly and autonomously monitor a patient's weight bearing over the full period of their recovery, including its potential use in a home environment. A pair of standard forearm crutches are augmented with low-cost off-the-shelf wireless sensor nodes and electronic components to provide indicative measurements of the applied weight, crutch tilt and hand position on the grip. Data are wirelessly transmitted between crutches and to a remote computer (where they are processed and visualized in LabVIEW), and the patient receives biofeedback by means of an audible signal when they put too much or too little weight through the crutch. The initial results obtained highlight the capability of the instrumented crutch to support physiotherapists and patients in monitoring usage
Review of battery powered embedded systems design for mission-critical low-power applications
The applications and uses of embedded systems is increasingly pervasive. Mission and safety critical systems relying on embedded systems pose specific challenges. Embedded systems is a multi-disciplinary domain, involving both hardware and software. Systems need to be designed in a holistic manner so that they are able to provide the desired reliability and minimise unnecessary complexity. The large problem landscape means that there is no one solution that fits all applications of embedded systems. With the primary focus of these mission and safety critical systems being functionality and reliability, there can be conflicts with business needs, and this can introduce pressures to reduce cost at the expense of reliability and functionality. This paper examines the challenges faced by battery powered systems, and then explores at more general problems, and several real-world embedded systems
Investigation of a temperature tolerant InGaP (GaInP) converter layer for a 63Ni betavoltaic cell
A prototype InGaP p+–i–n+ mesa photodiode was studied for its potential as the energy conversion device in a 63Ni betavoltaic cell; its electrical performance was analysed across the temperature range −20 °C to 100 °C. The results show that the InGaP detector when illuminated with a laboratory 63Ni radioisotope beta particle source had a maximum output power of 0.92 pW at −20 °C, this value decreased at higher temperatures. A decrease in the open circuit voltage and in the cell internal conversion ef ciency were also observed when the temperature was increased: at −20 °C, the open circuit voltage and the cell internal conversion ef ciency had values of 0.69 V and 4%, respectively. A short circuit current of 4.5 pA was measured at −20 °C
Boundary-Layer-Ingesting Inlet Flow Control
This paper gives an overview of a research study conducted in support of the small-scale demonstration of an active flow control system for a boundary-layer-ingesting (BLI) inlet. The effectiveness of active flow control in reducing engine inlet circumferential distortion was assessed using a 2.5% scale model of a 35% boundary-layer-ingesting flush-mounted, offset, diffusing inlet. This experiment was conducted in the NASA Langley 0.3-meter Transonic Cryogenic Tunnel at flight Mach numbers with a model inlet specifically designed for this type of testing. High mass flow actuators controlled the flow through distributed control jets providing the active flow control. A vortex generator point design configuration was also tested for comparison purposes and to provide a means to examine a hybrid vortex generator and control jets configuration. Measurements were made of the onset boundary layer, the duct surface static pressures, and the mass flow through the duct and the actuators. The distortion and pressure recovery were determined by 40 total pressure measurements on 8 rake arms each separated by 45 degrees and were located at the aerodynamic interface plane. The test matrix was limited to a maximum free-stream Mach number of 0.85 with scaled mass flows through the inlet for that condition. The data show that the flow control jets alone can reduce circumferential distortion (DPCPavg) from 0.055 to about 0.015 using about 2.5% of inlet mass flow. The vortex generators also reduced the circumferential distortion from 0.055 to 0.010 near the inlet mass flow design point. Lower inlet mass flow settings with the vortex generator configuration produced higher distortion levels that were reduced to acceptable levels using a hybrid vortex generator/control jets configuration that required less than 1% of the inlet mass flow
Evolution of crystalline orientations in the production of ferritic stainless steel
Ferritic stainless steel EN 1.4016 is used in a wide range of applications, the most common ones related to sheet forming. Several problems in the post-processing of these steels relates to their texture and anisotropy. Therefore, it is necessary to know the mechanisms of texture formation in the subsequent stages of metal manufacturing processes. EBSD has been demonstrated as a successful characterisation technique for this purpose.
It is known that during re-crystallisation of Fe-Cr steels, deviations from the desired.-fibre texture promote a decrease of deep drawability. Additionally, a-fibre damages formability. Subsequent cold rolling and annealing can enhance the deep drawing properties of the steel sheet.
In this research, a standard sample and a modified one with optimised settings as regard to chemical composition and manufacturing process, to improve the formability properties, are characterised. To analyse the preferred orientation and the type of main fibre present in the material, ODF and Aztec Reclassify Phase, to calculate the content of martensite, were used
Automatic Detection of User Abilities through the SmartAbility Framework
This paper presents a proposed smartphone application for the unique SmartAbility Framework that
supports interaction with technology for people with reduced physical ability, through focusing on
the actions that they can perform independently. The Framework is a culmination of knowledge
obtained through previously conducted technology feasibility trials and controlled usability
evaluations involving the user community. The Framework is an example of ability-based design that
focuses on the abilities of users instead of their disabilities. The paper includes a summary of
Versions 1 and 2 of the Framework, including the results of a two-phased validation approach,
conducted at the UK Mobility Roadshow and via a focus group of domain experts. A holistic model
developed by adapting the House of Quality (HoQ) matrix of the Quality Function Deployment (QFD)
approach is also described. A systematic literature review of sensor technologies built into smart
devices establishes the capabilities of sensors in the Android and iOS operating systems. The review
defines a set of inclusion and exclusion criteria, as well as search terms used to elicit literature from
online repositories. The key contribution is the mapping of ability-based sensor technologies onto
the Framework, to enable the future implementation of a smartphone application. Through the
exploitation of the SmartAbility application, the Framework will increase technology amongst people
with reduced physical ability and provide a promotional tool for assistive technology manufacturers
The misuses of sustainability: adult education, citizenship and the dead hand of neoliberalism
‘‘Sustainability’’ has a captivating but disingenuous simplicity: its meanings are complex, and have political and policy significance. Exploring the application of the term to adult education, this paper argues that a particular discourse of ‘‘sustainability’’ has become a common-sense, short-circuiting critical analysis and understanding of policy options. This ‘‘business discourse’’ of sustainability, strongly influenced by neoliberal ideas, encourages the presumption that educational programmes and movements which have died out were unsustainable, bound to fail, and even responsible – having failed to adapt – for their own demise. Potentially valuable experience is thus excluded from the educational policy canon. The author uses three cases from 20th-century adult education, namely (1) English liberal adult education; (2) ‘‘mass education’’, also known as community development, in the British colonies; and (3) UNESCO’s Fundamental Education, to challenge this presumption. He demonstrates for each case how a business discourse has implied their ‘‘unsustainability’’, but that the reality was more complex and involved external political intervention
Characterisation of aggregates of cyclodextrin-drug complexes using Taylor Dispersion Analysis
There is a need to understand the nature of aggregation of cyclodextrins (CDs) with guest molecules in increasingly complex formulation systems. To this end an innovative application of Taylor dispersion analysis (TDA) and comparison with dynamic light scattering (DLS) have been carried out to probe the nature of ICT01-2588 (ICT-2588), a novel tumor-targeted vascular disrupting agent, in solvents including a potential buffered formulation containing 10% hydroxypropyl-β-cyclodextrin. The two hydrodynamic sizing techniques give measurement responses are that fundamentally different for aggregated solutions containing the target molecule, and the benefits of using TDA in conjunction with DLS are that systems are characterised through measurement of both mass- and z-average hydrodynamic radii. Whereas DLS measurements primarily resolve the large aggregates of ICT01-2588 in its formulation medium, methodology for TDA is described to determine the size and notably to quantify the proportion of monomers in the presence of large aggregates, and at the same time measure the formulation viscosity. Interestingly TDA and DLS have also distinguished between aggregate profiles formed using HP-β-CD samples from different suppliers. The approach is expected to be widely applicable to this important class of drug formulations where drug solubility is enhanced by cyclodextrin and other excipients
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