The NIM Inertial Mass Measurement Project

An inertial mass measurement project, which is expected to precisely measure the Planck constant, $h$, for possible comparisons with known gravitational mass measurement projects, e.g., the watt balance and the Avogadro project, is being carried out at the National Institute of Metrology, China. The principle, apparatus, and experimental investigations of the inertial mass measurement are presented. The prototype of the experiment and the Planck constant with relative uncertainty of several parts in $10^{4}$ have been achieved for principle testing.Comment: 9pages, 12 figures, accepted for publication in IEEE Transactions on Instrumentation and Measuremen

Resolution of the paradox of the diamagnetic effect on the Kibble Coil

Employing very simple electro-mechanical principles known from classical physics, the Kibble balance establishes a very precise and absolute link between quantum electrical standards and macroscopic mass or force measurements. The success of the Kibble balance, in both determining fundamental constants (h, NA, e) and realizing a quasi-quantum mass in the 2019 newly revised International System of Units, relies on the perfection of Maxwell’s equations and the symmetry they describe between Lorentz’s force and Faraday’s induction, a principle and a symmetry stunningly demonstrated in the weighing and velocity modes of Kibble balances to within 1×10−8, with nothing but imperfect wires and magnets. However, recent advances in the understanding of the current effect in Kibble balances reveal a troubling paradox. A diamagnetic effect, a force that does not cancel between mass-on and mass-off measurement, is challenging balance maker’s assumptions of symmetry at levels that are almost two orders of magnitude larger than the reported uncertainties. The diamagnetic effect, if it exists, shows up in weighing mode without a readily apparent reciprocal effect in the velocity mode, begging questions about systematic errors at the very foundation of the new measurement system. The hypothetical force is caused by the coil current changing the magnetic field, producing an unaccounted force that is systematically modulated with the weighing current. Here we show that this diamagnetic force exists, but the additional force does not change the equivalence between weighing and velocity measurements. We reveal the unexpected way that symmetry is preserved and show that for typical materials and geometries the total relative effect on the measurement is ≈1×10−9

Hydrogen reliquefiers for lunar storage systems

Reliquifier application to eliminate propellant boil off losses in space and lunar storage system

Annual report of the selectmen, treasurer, town clerk, and tax collector of the town of Warner, New Hampshire, together with the reports of the Warner village fire district, vital statistics, etc.

This is an annual report containing vital statistics for a town/city in the state of New Hampshire

Annual report of the selectmen, treasurer, town clerk, and tax collector of the town of Warner, New Hampshire, together with the reports of the Warner village fire district, vital statistics, etc.

This is an annual report containing vital statistics for a town/city in the state of New Hampshire

Annual report of the selectmen, treasurer, town clerk, and tax collector of the town of Warner, New Hampshire, together with the reports of the Warner village fire district, vital statistics, etc.

This is an annual report containing vital statistics for a town/city in the state of New Hampshire

Annual report of the selectmen and other town officers of Charlestown, New Hampshire for the year ending Feb. 15, 1913.

This is an annual report containing vital statistics for a town/city in the state of New Hampshire