Transition and Transit Time Distributions for Time Dependent Reactions with Application to Biochemical Networks

1997 ◽  
Vol 101 (45) ◽  
pp. 9410-9419 ◽  
Author(s):  
Federico Moran ◽  
Marcel O. Vlad ◽  
John Ross
Keyword(s):  
Transit Time ◽  
Biochemical Networks ◽  
Time Dependent

scholarly journals Orbital period modulation in hot Jupiter systems

2020 ◽  
Vol 497 (3) ◽  
pp. 3911-3924
Author(s):  
A F Lanza
Keyword(s):  
Transit Time ◽  
Orbital Period ◽  
Rigid Rotation ◽  
Time Dependent ◽  
Solid Core ◽  
Hot Jupiters ◽  
Planetary Rotation ◽  
Deep Interior ◽  
Time Variations ◽  
Constant Period

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.

scholarly journals A suppository-base-matrix tablet for time-dependent colon-specific delivery system

2014 ◽  
Vol 50 (3) ◽  
pp. 535-541 ◽  
Author(s):  
Meijuan Zou ◽  
Caixia Wang ◽  
Xuezhu Zhang ◽  
Tao Xu ◽  
Jiarong Han ◽  
...  
Keyword(s):  
Drug Release ◽  
Transit Time ◽  
Delivery System ◽  
Water Soluble ◽  
Time Dependent ◽  
Matrix Tablet ◽  
Intestinal Transit Time ◽  
Suppository Base ◽  
Coated Tablet ◽  
Base Matrix

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.

The relationship between oxygen extraction and extravascular mean transit time in the canine heart

1977 ◽  
Vol 55 (3) ◽  
pp. 478-481 ◽  
Author(s):  
R. R. Mildenberger ◽  
A. L'Abbate ◽  
D. T. Zborowska-Sluis ◽  
G. A. Klassen
Keyword(s):  
Transit Time ◽  
Myocardial Oxygen Consumption ◽  
Mean Transit Time ◽  
Time Dependent ◽  
Oxygen Extraction ◽  
Canine Heart ◽  
Myocardial Oxygen Extraction ◽  
The Relationship ◽  
Mean Time ◽  
Critical Link

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.

Laser heating and melting of thin films with time‐dependent absorptance. II. An exact solution for time intervals greater than the transit time

1989 ◽  
Vol 65 (10) ◽  
pp. 3781-3785 ◽  
Author(s):  
M. K. El‐Adawi ◽  
S. A. Shalaby ◽  
E. F. Elshehawey ◽  
T. El‐Dessouki
Keyword(s):  
Thin Films ◽  
Exact Solution ◽  
Transit Time ◽  
Laser Heating ◽  
Time Dependent ◽  
Time Intervals

scholarly journals In silico labeling reveals the time-dependent label half-life and transit-time in dynamical systems

2012 ◽  
Vol 6 (1) ◽  
pp. 13 ◽  
Author(s):  
Thomas Maiwald ◽  
Julie Blumberg ◽  
Andreas Raue ◽  
Stefan Hengl ◽  
Marcel Schilling ◽  
...  
Keyword(s):  
Dynamical Systems ◽  
Transit Time ◽  
In Silico ◽  
Half Life ◽  
Time Dependent

scholarly journals Transit-time and age distributions for nonlinear time-dependent compartmental systems

2018 ◽  
Vol 115 (6) ◽  
pp. 1150-1155 ◽  
Author(s):  
Holger Metzler ◽  
Markus Müller ◽  
Carlos A. Sierra
Keyword(s):  
Transit Time ◽  
Linear Time ◽  
Time Dependent ◽  
Carbon Cycle Model ◽  
Model Driven ◽  
Fossil Carbon ◽  
Compartmental Systems ◽  
Wide Range ◽  
Independent Case ◽  
Time Required

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.

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