407 research outputs found
The use of embedded sensors for the monitoring of adhesive joints in marine environments
A copolymer incorporating polyaniline was used as a sensing medium in the construction of a resistance based humidity sensor. Aniline monomer was polymerised in the presence of poly (butyl acrylate / vinyl acetate) and a copolymer containing polyaniline emeraldine salt was obtained. The sensing medium was then developed by redissolving 1-2 w/w% of the resulting polymer residue in dichloromethane to produce a processable polymer blend solution. Some of this polymer residue was also de-doped in a solution of ammonia, and then washed with distilled water until the waste water had a neutral pH. This residue was then redissolved at 1-2 w/w% in dichloromethane to produce a second processable polymer blend this time containing polyaniline emeraldine base. The final sensor design utilised 125μm polyester insulated platinum wire as conducting electrodes that were dip coated in the emeraldine salt copolymer solution and allowed to dry in a desiccator. The sensor was then dip-coated in a protective barrier layer of the emeraldine base copolymer to prevent over-oxidation and/or de-protonation of the emeraldine salt sensing medium under this coating. The sensors had an overall final thickness of less than 150μm and showed high sensitivity to humidity, low resistance, and good reversibility without hysteresis. Sensors were monitored for 2-probe resistance changes when in contact with water. Calibration curves for each sensor were produced to convert the resistance reading to mass uptake of water. Individual sensors were embedded within Aluminium 5083 / Araldite 2015 adhesive joints to monitor mass uptake of water when exposed to marine environments. Correlations between mass uptake of water and joint strength were made. There are various advantages of such a sensor design. Polymer based thin film humidity sensors have the advantage that the high processability of the material allows for simple fabrication of a range of geometries including smaller sensor designs. The ease of processing gives a low cost sensor, whilst the small size and good mechanical properties gives a robust sensor which has the flexibility to be able to be used in applications where dynamic stresses and strains are encountered. Such sensors may find uses in a number of areas including electronic textiles, food/ electronics packaging and corrosion detection
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The Texas Petawatt Laser And Current Experiments
The Texas Petawatt Laser is operational with experimental campaigns executed in both F/40 and F3 target chambers. Recent improvements have resulted in intensities of >2x10(21) W/cm(2) on target. Experimental highlights include, accelerated electron energies of >2 GeV, DD fusion ion temperatures >25 keV and isochorically heated solids to 10-50 eV.Physic
The Bionic Bra: Using electromaterials to sense and modify breast support to enhance active living
Background: Although the most supportive sports bras can control breast motion and associated breast pain, they are frequently deemed uncomfortable to wear and, as a result, many women report exercise bra discomfort. Given that exercise bra discomfort is associated with decreased levels of physical activity, there is a pertinent need to develop innovative solutions to address this problem. Objectives: This research aimed to evaluate the use of electromaterial sensors and artificial muscle technology to create a bra that was capable of detecting increases in breast motion and then responding with increased breast support to enhance active living. Methods: The research involved two phases: (i) evaluating sensors suitable for monitoring and providing feedback on changes in the amplitude and frequency of breast motion, and (ii) evaluating an actuator capable of changing breast support provided by a bra during activity. Results: When assessed in isolation, the developed technologies were capable of sensing breast motion and actuating to provide some additional breast support. Conclusions: The challenge now lies in integrating both technologies into a functional sports bra prototype, and assessing this prototype in a controlled biomechanical analysis to provide a breast support solution that will enable women to enjoy active living in comfort
Proton acceleration by irradiation of isolated spheres with an intense laser pulse
We report on experiments irradiating isolated plastic spheres with a peak laser intensity of 2-3 x 10(20) W cm(-2). With a laser focal spot size of 10 mu m full width half maximum (FWHM) the sphere diameter was varied between 520 nm and 19.3 mu m. Maximum proton energies of similar to 25 MeV are achieved for targets matching the focal spot size of 10 mu m in diameter or being slightly smaller. For smaller spheres the kinetic energy distributions of protons become nonmonotonic, indicating a change in the accelerating mechanism from ambipolar expansion towards a regime dominated by effects caused by Coulomb repulsion of ions. The energy conversion efficiency from laser energy to proton kinetic energy is optimized when the target diameter matches the laser focal spot size with efficiencies reaching the percent level. The change of proton acceleration efficiency with target size can be attributed to the reduced cross-sectional overlap of subfocus targets with the laser. Reported experimental observations are in line with 3D3V particle in cell simulations. They make use of well-defined targets and point out pathways for future applications and experiments.DFG via the Cluster of Excellence Munich-Centre for Advanced Photonics (MAP) Transregio SFB TR18NNSA DE-NA0002008Super-MUC pr48meIvo CermakCGC Instruments in design and realization of the Paul trap systemIMPRS-APSLMUexcellent Junior Research FundDAAD|ToIFEEuropean Union's Horizon research and innovation programme 633053Physic
Evaluation of DFO-HOPO as an octadentate chelator for zirconium-89.
The future of 89Zr-based immuno-PET is reliant upon the development of new chelators with improved stability compared to the currently used deferoxamine (DFO). Herein, we report the evaluation of the octadentate molecule DFO-HOPO (3) as a suitable chelator for 89Zr and a more stable alternative to DFO. The molecule showed good potential for the future development of a DFO-HOPO-based bifunctional chelator (BFC) for the radiolabelling of biomolecules with 89Zr. This work broadens the selection of available chelators for 89Zr in search of improved successors to DFO for clinical 89Zr-immuno-PET
Emerging nuclear collectivity in Te
The emergence of nuclear collectivity near doubly-magic Sn was
explored along the stable, even-even Te isotopes. Preliminary
measurements of the transition strengths
are reported from Coulomb excitation experiments primarily aimed at measuring
the factors of the states. Isotopically enriched Te targets
were excited by 198-205 MeV Ni beams. A comparison of transition
strengths obtained is made to large-scale shell-model calculations with
successes and limitations discussed.Comment: 5 pages, 3 figures, Submitted to Proceedings HIAS 2019, EPJ Web of
Conference
Shape polarization in the tin isotopes near from precision -factor measurements on short-lived isomers
The factors of isomers in semimagic Sn and Sn
(isomeric lifetimes ns and ns, respectively)
were measured by an extension of the Time Differential Perturbed Angular
Distribution technique, which uses \LaBr detectors and the hyperfine fields of
a gadolinium host to achieve precise measurements in a new regime of
short-lived isomers. The results,
and , are significantly lower in
magnitude than those of the isomers in the heavier isotopes and depart
from the value expected for a near pure neutron configuration.
Broken-symmetry density functional theory calculations applied to the sequence
of states reproduce the magnitude and location of this deviation. The
values are affected by shape core polarization; the odd
neutron couples to configurations in the
weakly-deformed effective core, causing a decrease in the -factor
magnitudes.Comment: 8 pages, 7 figures. Accepted in Physics Letters
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