scholarly journals Reducing Fluctuations in Slow-Extraction Beam Spill Using Transit-Time-Dependent Tune Modulation

2020 ◽  
Vol 13 (4) ◽  
Author(s):  
R. Singh ◽  
P. Forck ◽  
S. Sorge
2020 ◽  
Vol 497 (3) ◽  
pp. 3911-3924
Author(s):  
A F Lanza

ABSTRACT We introduce a model for the orbital period modulation in systems with close-by giant planets based on a spin–orbit coupling that transfers angular momentum from the orbit to the rotation of the planet and vice versa. The coupling is produced by a permanent non-axisymmetric gravitational quadrupole moment assumed to be present in the solid core of the planet. We investigate two regimes of internal planetary rotation, that is, when the planet rotates rigidly and when the rotation of its deep interior is time-dependent as a consequence of a vacillating or intermittent convection in its outer shell. The model is applied to a sample of very hot Jupiters predicting maximum transit-time deviations from a constant-period ephemeris of approximately 50 s in the case of rigid rotation. The transit time variations of WASP-12, currently the only system showing evidence of a non-constant period, cannot be explained by assuming rigid rotation, but can be modelled in the time-dependent internal rotation regime, thus providing an alternative to their interpretation in terms of a tidal decay of the planet orbit.


2014 ◽  
Vol 50 (3) ◽  
pp. 535-541 ◽  
Author(s):  
Meijuan Zou ◽  
Caixia Wang ◽  
Xuezhu Zhang ◽  
Tao Xu ◽  
Jiarong Han ◽  
...  

Our research has focused on the main design features and release performances of time-dependent colon-specific (TDCS) delivery tablets, which relies on the relative constancy that is observed in the small intestinal transit time of dosage forms. But inflammatory bowel disease(IBD)can affect the transit time, and usually results in watery stool. Compared to the TDCS and wax-matrix TDCS tablet, a promising time-dependent colon-specific delivery system was investigated. In our study, a suppository-base-matrix coated tablet was evaluated. Water soluble suppository-base helps the expansion of tablet, facilitates uniform film dissolution and achives high osmotic pressure. Combining the expansion of carboxymethyl starch sodium (CMS-Na) and the moisture absorption of NaCl, the coated TDCS tablet obtained a burst and targeted drug delivery system. A very good correlation between in vitro drug release and in vivo outcome was observed. This TDCS coated tablet provides a promising strategy to control drug release to the desired lower gastrointestinal region.


1977 ◽  
Vol 55 (3) ◽  
pp. 478-481 ◽  
Author(s):  
R. R. Mildenberger ◽  
A. L'Abbate ◽  
D. T. Zborowska-Sluis ◽  
G. A. Klassen

A significant relationship was observed between myocardial oxygen extraction and the extravascular mean time transit time. This relationship implies that oxygen extraction by the myocardium is a time-dependent process, and emphasizes the critical link between blood flow and myocardial oxygen consumption.


1989 ◽  
Vol 65 (10) ◽  
pp. 3781-3785 ◽  
Author(s):  
M. K. El‐Adawi ◽  
S. A. Shalaby ◽  
E. F. Elshehawey ◽  
T. El‐Dessouki

2012 ◽  
Vol 6 (1) ◽  
pp. 13 ◽  
Author(s):  
Thomas Maiwald ◽  
Julie Blumberg ◽  
Andreas Raue ◽  
Stefan Hengl ◽  
Marcel Schilling ◽  
...  

2018 ◽  
Vol 115 (6) ◽  
pp. 1150-1155 ◽  
Author(s):  
Holger Metzler ◽  
Markus Müller ◽  
Carlos A. Sierra

Many processes in nature are modeled using compartmental systems (reservoir/pool/box systems). Usually, they are expressed as a set of first-order differential equations describing the transfer of matter across a network of compartments. The concepts of age of matter in compartments and the time required for particles to transit the system are important diagnostics of these models with applications to a wide range of scientific questions. Until now, explicit formulas for transit-time and age distributions of nonlinear time-dependent compartmental systems were not available. We compute densities for these types of systems under the assumption of well-mixed compartments. Assuming that a solution of the nonlinear system is available at least numerically, we show how to construct a linear time-dependent system with the same solution trajectory. We demonstrate how to exploit this solution to compute transit-time and age distributions in dependence on given start values and initial age distributions. Furthermore, we derive equations for the time evolution of quantiles and moments of the age distributions. Our results generalize available density formulas for the linear time-independent case and mean-age formulas for the linear time-dependent case. As an example, we apply our formulas to a nonlinear and a linear version of a simple global carbon cycle model driven by a time-dependent input signal which represents fossil fuel additions. We derive time-dependent age distributions for all compartments and calculate the time it takes to remove fossil carbon in a business-as-usual scenario.


2018 ◽  
Vol 65 (1) ◽  
pp. 553-560
Author(s):  
Vimal Samsingh Ramalingam ◽  
Malathi Kanagasabai ◽  
Esther Florence Sundarsingh

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