mass measurement
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Author(s):  
Zachary Bogorad ◽  
Prajwal MohanMurthy ◽  
Joseph A Formaggio

Abstract The Kassiopeia software package was originally developed to simulate electromagnetic fields and charged particle trajectories for neutrino mass measurement experiments. Recent additions to Kassiopeia also allow it to simulate neutral particle trajectories in magnetic fields based on their magnetic moments. Two different methods were implemented: an exact method that can work for arbitrary fields and an adiabatic method that is limited to slowly-varying fields but is much faster for large precession frequencies. Additional interactions to simulate reflection of ultracold neutrons from material walls and to allow spin-flip pulses were also added. These tools were used to simulate neutron precession in a room temperature neutron electric dipole moment experiment and predict the values of the longitudinal and transverse relaxation times as well as the trapping lifetime. All three parameters are found to closely match the experimentally determined values when simulated with both the exact and adiabatic methods, confirming that Kassiopeia is able to accurately simulate neutral particles. This opens the door for future uses of Kassiopeia to prototype the next generation of atomic traps and ultracold neutron experiments.


2022 ◽  
Vol 163 (2) ◽  
pp. 52
Author(s):  
Aldo G. Sepulveda ◽  
Brendan P. Bowler

Abstract HR 8799 is a young A5/F0 star hosting four directly imaged giant planets at wide separations (∼16–78 au), which are undergoing orbital motion and have been continuously monitored with adaptive optics imaging since their discovery over a decade ago. We present a dynamical mass of HR 8799 using 130 epochs of relative astrometry of its planets, which include both published measurements and new medium-band 3.1 μm observations that we acquired with NIRC2 at Keck Observatory. For the purpose of measuring the host-star mass, each orbiting planet is treated as a massless particle and is fit with a Keplerian orbit using Markov chain Monte Carlo. We then use a Bayesian framework to combine each independent total mass measurement into a cumulative dynamical mass using all four planets. The dynamical mass of HR 8799 is 1.47 − 0.17 + 0.12 M ⊙ assuming a uniform stellar mass prior, or 1.46 − 0.15 + 0.11 M ⊙ with a weakly informative prior based on spectroscopy. There is a strong covariance between the planets’ eccentricities and the total system mass; when the constraint is limited to low-eccentricity solutions of e < 0.1, which are motivated by dynamical stability, our mass measurement improves to 1.43 − 0.07 + 0.06 M ⊙. Our dynamical mass and other fundamental measured parameters of HR 8799 together with Modules for Experiments in Stellar Astrophysics Isochrones and Stellar Tracks grids yields a bulk metallicity most consistent with [Fe/H] ∼ −0.25–0.00 dex and an age of 10–23 Myr for the system. This implies hot-start masses of 2.7–4.9 M Jup for HR 8799 b and 4.1–7.0 M Jup for HR 8799 c, d, and e, assuming they formed at the same time as the host star.


2021 ◽  
Vol 10 (36) ◽  
pp. 271-282
Author(s):  
Silvio Leite Monteiro da Silva ◽  
Angelo Herbert Moreira Arcanjo ◽  
Lucas da Rocha Pinto ◽  
Gabriel Pinto Rosa ◽  
Gustavo Henrique De Souza

Highly-diluted medicines are used in clinical practice to treat many pathologies of pigs [1-4]. This therapeutic tool had its potential for valued use due to the global scenario changing on the restriction to limit of antimicrobial residues in the security feeding and production of foods from animal origin for human consume, especially the meat production [5]. Through the evidence of mass measurement, the usage profile of group B treatment shown to work with pigs and give greater weight live gain in group A during the available trial. Future studies should be conducted with larger numbers of animals to confirm the incidence of the unique profile, with replications to assess the complete production cycle, including the relationship ending / sow / year. Finally, other scales and dilutions should be analyzed to adjust for best answer from the best treatment effect profile


Separations ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 245
Author(s):  
Filomena Lelario ◽  
Raffaella Pascale ◽  
Giuliana Bianco ◽  
Laura Scrano ◽  
Sabino Aurelio Bufo

The development and application of advanced analytical methods for a comprehensive analysis of Cannabis sativa L. extracts plays a pivotal role in order to have a reliable evaluation of their chemotype definition to guarantee the efficacy and safety in pharmaceutical use. This paper deals with the qualitative and quantitative determination of cannabidiol (CBD), tetrahydrocannabinol (THC), cannabinol (CBN), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), and cannabigerol (CBG) based on a liquid chromategraphy-mass spectrometry (LC-MS) method using electrospray ionization in positive mode (ESI+), coupled with a hybrid quadrupole linear ion trap (LTQ) and Fourier transform ion cyclotron resonance mass spectrometer (FTICR-MS). For the first time, structural information of phytocannabinoids is available upon precursor ions’ isolation within the FTICR trapping cell and subsequent fragmentation induced by infrared multiphoton dissociation (IRMPD). Such fragmentation and accurate mass measurement of product ions, alongside collision-induced dissociation (CID) within LTQ, was advantageous to propose a reliable fragmentation pattern for each compound. Then, the proposed LC-ESI(+)-LTQ-FTICR MS method was successfully applied to the hemp chemotype definition of three registered Italian accessions of hemp C. sativa plants (Carmagnola C.S., Carmagnola, and Eletta Campana), thus resulting in the Eletta Campana accession being the best one for cannabis product manufacturing.


2021 ◽  
Vol 163 (1) ◽  
pp. 3
Author(s):  
Caleb I. Cañas ◽  
Suvrath Mahadevan ◽  
William D. Cochran ◽  
Chad F. Bender ◽  
Eric D. Feigelson ◽  
...  

Abstract We validate the planetary nature of an ultra-short-period planet orbiting the M dwarf KOI-4777. We use a combination of space-based photometry from Kepler, high-precision, near-infrared Doppler spectroscopy from the Habitable-zone Planet Finder, and adaptive optics imaging to characterize this system. KOI-4777.01 is a Mars-sized exoplanet (R p = 0.51 ± 0.03R ⊕) orbiting the host star every 0.412 days (∼9.9 hr). This is the smallest validated ultra-short period planet known and we see no evidence for additional massive companions using our HPF RVs. We constrain the upper 3σ mass to M p < 0.34 M ⊕ by assuming the planet is less dense than iron. Obtaining a mass measurement for KOI-4777.01 is beyond current instrumental capabilities.


Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2216
Author(s):  
Barouch Giechaskiel ◽  
Anastasios Melas ◽  
Giorgio Martini ◽  
Panagiota Dilara

Vehicle emissions are a significant source of air pollution in cities. Particulate matter (PM) is a pollutant with adverse health effects. Regulations worldwide determine the PM exhaust emissions of vehicles by gravimetric quantification of the mass deposited on a filter over a test cycle. The introduction of particulate filters as vehicle exhaust gas aftertreatment devices led to low PM emissions. A particle number methodology (counting solid particles >23 nm), complementary to the PM mass measurement, was developed by the PMP (Particle Measurement Programme) group of the GRPE (Working Party on Pollution and Energy) of the UNECE (United Nations Economic Commission for Europe) during the first decade of the 21st century. The methodology was then introduced in the EU (European Union) regulations for light-duty (2011), heavy-duty (2013), and non-road mobile machinery (2019). In parallel, during the last 15 years, UN (United Nations) regulations and GTRs (Global Technical Regulations) including this methodology were also developed. To address the on-road emissions, the EU introduced RDE (real-driving emissions) testing with PEMS (portable emissions measurement systems) in 2017. Other countries (e.g., China, India) have also started adopting the number methodology. The PMP group recently improved the current laboratory and on-board methodologies and also extended them to a lower particle size (counting solid particles >10 nm). Due to the rapid evolution of the vehicle exhaust particle number regulations and the lack of a summary in the literature, this paper gives an overview of current and near future regulations. Emphasis is given on the technical specifications and the changes that have taken place over the years.


2021 ◽  
Author(s):  
Arnaud Cassan ◽  
Clément Ranc ◽  
Olivier Absil ◽  
Łukasz Wyrzykowski ◽  
Krzysztof A. Rybicki ◽  
...  
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