The Miniaturized Electron pRoton Telescope, MERiT, is a low‐mass, low‐power, compact instrument using an innovative combination of particle detectors, sensor electronics, and onboard processing. ...MERiT is flying on the Compact Radiation belt Explorer, CeREs, a 3U CubeSat launched into a low earth orbit of 500‐km altitude and inclination of 85° on 16 December 2018. The primary and secondary science goals of CeREs are to investigate electron microbursts and to study solar particles. MERiT comprises a stack of solid state detectors (SSD) behind space facing avalanche photo diodes (APDs) surrounded by W‐Al shielding to reduce side‐penetrating particle background. The APD‐SSD combination enables measurement of electrons from 5 to 200 keV and 1 to 8 MeV; protons from 200–400 keV and 7–100 MeV in differential channels with energy resolution ΔE/E≈30% for both electrons and protons. MERiT measures microbursts with a high time resolution ranging from 4 to 16 ms and solar particles with a cadence of 1 s. MERiT energy channels and cadences are software configurable via algorithms and lookup tables residing on a field‐programmable gate array. The lookup tables can be changed via ground commands. MERiT geometry factor is 31 sq.cm‐sr and optimized to measure microbursts with the instrument viewing the local zenith in orbit. MERiT enables investigation of dynamical processes of radiation belt electron energization and loss, solar electron and proton transport, and their access to the Earth's polar caps. We describe the MERiT sensor design, calibration, operational modes, data products, and science goals.
Obituaries Crum, David G; Nicholas, Nick
New Zealand dental journal,
20/Dec , Letnik:
115, Številka:
4
Journal Article
Recenzirano
Pays tribute to dentists John Stevenson Howie and John Gianni who are recently deceased. Backgrounds their careers and hobbies. Source: National Library of New Zealand Te Puna Matauranga o Aotearoa, ...licensed by the Department of Internal Affairs for re-use under the Creative Commons Attribution 3.0 New Zealand Licence.
Obituary : Lawrence J. Croxson Crum, David G
New Zealand dental journal,
20/Jun , Letnik:
112, Številka:
2
Journal Article
Recenzirano
Pays tribute to dentist Lawrence Croxson who was a tireless campaigner for the improvement of oral health in New Zealand. Details his professional career which included providing advice to the ...Minister of Health and well as being in private practice. Source: National Library of New Zealand Te Puna Matauranga o Aotearoa, licensed by the Department of Internal Affairs for re-use under the Creative Commons Attribution 3.0 New Zealand Licence.
An Escherichia coli catalyst with tyrosine ammonia lyase activity (TAL) has been stabilized for repeated use in batch conversions of high tyrosine solids to p‐hydroxycinnamic acid (pHCA). The TAL ...biocatalyst was stabilized by controlling the reaction pH to 9.8 ± 0.1 and immobilizing the cells within a calcium alginate matrix that was cross‐linked with glutaraldehyde and polyethyleneimine (GA/PEI). We found a GA range where the bead‐encapsulated TAL was not inactivated, and the resulting cross‐linking provided the beads with the mechanical stability necessary for repeated use in consecutive batch reactions with catalyst recycle. The GA/PEI calcium alginate TAL catalyst was used in 41 1‐L batch reactions where 50 g L−1 tyrosine was converted to 39 ± 4 g L−1 pHCA in each batch. The practical usefulness and ease of this process was demonstrated by scaling up the TAL bead immobilization and using the immobilized TAL catalyst in four 125‐L bioconversion reactions to produce over 12 kg of purified pHCA.
B. G. Crum, J. B. Williams and K. A. Nagy
Total body water (TBW) volumes determined from the dilution space of
injected tritiated water have consistently overestimated actual water
volumes ...(determined by desiccation to constant mass) in reptiles and
mammals, but results for birds are controversial. We investigated potential
errors in both the dilution method and the desiccation method in an attempt
to resolve this controversy. Tritiated water dilution yielded an accurate
measurement of water mass in vitro. However, in vivo, this method yielded a
4.6% overestimate of the amount of water (3.1% of live body mass) in chukar
partridges, apparently largely because of loss of tritium from body water
to sites of dissociable hydrogens on body solids. An additional source of
overestimation (approximately 2% of body mass) was loss of tritium to the
solids in blood samples during distillation of blood to obtain pure water
for tritium analysis. Measuring tritium activity in plasma samples avoided
this problem but required measurement of, and correction for, the dry
matter content in plasma. Desiccation to constant mass by lyophilization or
oven-drying also overestimated the amount of water actually in the bodies
of chukar partridges by 1.4% of body mass, because these values included
water adsorbed onto the outside of feathers. When desiccating defeathered
carcasses, oven-drying at 70 degrees C yielded TBW values identical to
those obtained from lyophilization, but TBW was overestimated (0.5% of body
mass) by drying at 100 degrees C due to loss of organic substances as well
as water.
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