The pharmaceutical industry is looking for new technology that is easy to scale up from analytical to process scale and is cheap and reliable to operate. Large scale counter-current chromatography is an emerging technology that could provide this advance, but little was known about the key variables affecting scale-up. This paper investigates two such variables: the rotor radius and the tubing bore. The effect of rotor radius was studied using identical: length, beta-value, helix angle and tubing bore coils for rotors of different radii (50 mm, 110 mm and 300 mm). The effect of bore was researched using identical: length, helix angle and mean beta-value coils on the Maxi-DE centrifuge (R=300 mm). The rotor radius results show that there is very little difference in retention and resolution as rotor radius increases at constant bore. The tubing bore results show that good retention is maintained as bore increases and resolution only decrease slightly, but at the highest bore (17.5 mm) resolution can be maintained at very high flow rates making it possible for process scale centrifuges to be designed with throughputs exceeding 25 kg/day.
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http://dx.doi.org/10.1016/j.chroma.2007.02.084 | DOI Listing |
Eddy current sensors are increasingly being used to measure the dynamic blade tip clearance in turbines due to their robust anti-interference capabilities and non-contact measurement advantages. However, the current research primarily focuses on enhancing the performance of eddy current sensors themselves, with few studies investigating the influence of turbine rotor parameters on the measurements taken by these sensors for dynamic blade tip clearance. Hence, this paper addresses this gap by using COMSOL Multiphysics 6.
View Article and Find Full Text PDFPhys Rev Lett
April 2024
Facility for Rare Isotope Beams, East Lansing, Michigan 48824, USA.
We report the first mass measurement of the proton-halo candidate ^{22}Al performed with the low energy beam ion trap facility's 9.4 T Penning trap mass spectrometer at facility for rare isotope beams. This measurement completes the mass information for the lightest remaining proton-dripline nucleus achievable with Penning traps.
View Article and Find Full Text PDFSensors (Basel)
April 2024
College of Mechanical and Electrical Engineering, Northeast Forestry University, Harbin 150000, China.
This paper presents the design and the non-linearity optimization of a new vertical non-contact angle sensor based on the electromagnetic induction principle. The proposed sensor consists of a stator part (with one solenoidal excitation coil and three sinusoidal receiver coils) and a rotor part (with six rectangular metal sheets). The receiver coil was designed based on the differential principle, which eliminates the effect of the excitation coil on the induced voltage of the receiver coil, and essentially decouples the excitation field from the eddy current field.
View Article and Find Full Text PDFSensors (Basel)
February 2024
School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
Multi-degree-of-freedom piezoelectric motors have the advantages of high torque and resolution, simple structure, and direct drive, which are widely used in robot wrist joints, deep-sea mechanisms, medical equipment, and space mechanisms. To solve the problems of high force/torque coupling degree and ball low stator and rotor bonding strength of the traditional traveling wave type three-degree-of-freedom piezoelectric spherical motor, a new structure of ball-hinged piezoelectric spherical motor is proposed. Through coordinate transformation and force analysis, the driven mathematical model of the spherical motor is given.
View Article and Find Full Text PDFEnviron Sci Technol
March 2024
Department of Civil Engineering, McGill University, Montreal, Quebec H3A 0G4, Canada.
Estimates of the land area occupied by wind energy differ by orders of magnitude due to data scarcity and inconsistent methodology. We developed a method that combines machine learning-based imagery analysis and geographic information systems and examined the land area of 318 wind farms (15,871 turbines) in the U.S.
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