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Scalable fabrication of supercapacitors by nozzle-free electrospinning
No full textNozzle-free electrospinning was investigated as a facile technique for producing nanoscale materials for supercapacitors. MnO2 nanofibers and their composites with multiwalled carbon nanotubes (MWCNTs) were synthesized in a single step, using polyvinylpyrrolidone (PVP) and Mn(CH3COO)2\ub74H2O as starting materials, followed up by heat treatment in ambient air. Nanofibers of relatively uniform diameter were produced at high rates. The nanofibers exhibited good electrical contact between MnO2 and MWCNT without degradation, which was attributed to the improved stability of MWCNTs in PVP solutions. Electrochemical testing of the composites demonstrated a high capacitance of 1.43 F cm\u20132 at a scan rate of 100 mV s\u20131 in the three-electrode tests. Electrodes and devices produced by nozzle-free electrospinning are promising for practical energy storage applications.Peer reviewed: YesNRC publication: Ye
The ASTC ratings of mid-rise wood constructions using CertainTeed SilentFX\uae QuickCut gypsum board [2nd edition]
No full textThe 2015 edition of the National Building Code of Canada (NBCC) includes significant changes to the acoustic requirements for residential constructions. The 2015 edition defines the acoustic requirements in terms of the Apparent Sound Transmission Class (ASTC) rating which includes contributions from flanking transmission and therefore is a better descriptor of how well the sound insulation of a building will actually protect the inhabitants of the building from unwanted noise than the STC rating which was used in earlier editions of the NBCC. The 2015 NBCC requires an ASTC rating 65 47 for constructions between dwelling units.
The ASTC rating that a construction will achieve depends on the design of the building elements including the gypsum board, the framing and the thermal insulation as well as the design of the junctions between the building elements. Changes to the building elements or the junctions will change the ASTC rating.
Fifty five examples of the calculation of the ASTC rating for typical mid-rise wood constructions (single and triple staggered wood stud walls and floors constructed of I-joists) with 15.9 mm (5/8\u201d) SilentFX\uae QuickCut gypsum board, 15.9 mm CertainTeed Type X gypsum board and CertainTeed Sustainable fiberglass insulation are presented. All of the constructions shown in the examples have an ASTC rating which is greater than 47.
In addition to the examples for mid-rise wood framing, an example using 15.9 mm SilentFX\uae QuickCut gypsum board as a lining on a cross laminated timber (CLT) construction is also presented.2nd edition supersedes 1st edition2e \ue9dition remplace la 1e \ue9ditionOn title page: CertainTeedDans le page de titre: CertainTeedPeer reviewed: NoNRC publication: Ye
Bright single InAsP quantum dots at telecom wavelengths in position-controlled InP nanowires: the role of the photonic waveguide
No full textWe report on the site-selected growth of bright single InAsP quantum dots embedded within InP photonic nanowire waveguides emitting at telecom wavelengths. We demonstrate a dramatic dependence of the emission rate on both the emission wavelength and the nanowire diameter. With an appropriately designed waveguide, tailored to the emission wavelength of the dot, an increase in count rate by nearly two orders of magnitude (0.4kcps to 35kcps) is obtained for quantum dots emitting in the telecom O-band. Using emission-wavelength-optimised waveguides, we demonstrate bright, narrow linewidth emission from single InAsP quantum dots with an unprecedented tuning range from 880nm to 1550nm. These results pave the way towards efficient single photon sources at telecom wavelengths using deterministically grown InAsP/InP nanowire quantum dots.Peer reviewed: NoNRC publication: Ye
On the impact of ICRU report 90 recommendations on kQ factors for high-energy photon beams
No full textPurpose: To assess the impact of the ICRU report 90 recommendations on the beam-quality conversion factor, kQ , used for clinical reference dosimetry of megavoltage linac photon beams. Methods: The absorbed dose to water and the absorbed dose to the air in two ionization chambers representative of those typically used for linac photon reference dosimetry, a graphite- and a plasticwalled chamber, are calculated at the reference depth in a water phantom using Monte Carlo simulations. Depth-dose calculations in water are also performed to investigate changes in beam quality specifiers. The calculations are performed in a cobalt-60 beam and MV photon beams with nominal energy between 6 MV and 25 MV using the EGSnrc simulation toolkit. Inputs to the calculations use stopping-power data for graphite and water from the original ICRU-37 report and the new proposed values from the recently published ICRU-90 report. Calculated kQ factors are compared using the two different recommendations for key dosimetry data and measured kQ factors. Results: Less than about 0.1 % impacts from ICRU-90 recommendations on the beam quality specifiers, the photon component of the percentage depth-dose at 10 cm, %d d (10)x, and the tissuephantom ratio at 20 cm and 10 cm, TPR20 10, are observed. Although using different recommendations for key dosimetric data impact water-to-air stopping-power ratios and ion chamber perturbation corrections by up to 0.6 % and 0.4 %, respectively, we observe little difference (0.14 %) in calculated kQ factors. This is contradictory to the predictions in ICRU-90 that suggest differences up to 0.5%in highenergy photon beams. A slightly better agreement with experimental values is obtained when using ICRU-90 recommendations. Conclusion: Users of the addendum to the TG-51 protocol for reference dosimetry of high-energy photon beams, which recommends Monte Carlo calculated kQ factors, can rest assured that the recommendations of ICRUreport 90 on basic data have little impact on this central dosimetric parameter.Peer reviewed: NoNRC publication: Ye
The development of the advanced cryogenic radiometer facility at NRC
No full textThe National Research Council (NRC) of Canada has established a next generation facility for the primary realization of optical radiant power. The main feature of this facility is a new cryogenic electrical substitution radiometer with a closed-cycle helium cryocooler. A monochromator-based approach allows for detector calibrations at any desired wavelength. A custom-designed motion apparatus includes two transfer standard radiometer mounting ports which has increased our measurement capability by allowing the calibration of two photodetectors in one measurement cycle. Measurement uncertainties have been improved through several upgrades, including newly designed and constructed transimpedance amplifiers for the transfer standard radiometers, and a higher power broadband light source. The most significant improvements in uncertainty arise from the enhanced characteristics of the new cryogenic radiometer including its higher cavity absorptance and reduced non-equivalence effects.Peer reviewed: YesNRC publication: Ye
Human serum albumin stabilizes aqueous silver nanoparticle suspensions and inhibits particle uptake by cells
No full textIncubation of 20 nm silver nanoparticles with human serum albumin (HSA) stabilizes the nanoparticles against aggregation and dissolution and produces particles that can be lyophilized for longterm storage and redispersed in water consistently. Biological studies of this stabilized material showed reduced toxicity and cellular uptake compared to other 20 nm particles.Peer reviewed: YesNRC publication: Ye
Permanent magnets produced by cold spray additive manufacturing
No full textPeer reviewed: YesNRC publication: Ye
