The influence of the singlet radical-pair decay rate on RYDMR and SNP spectra, and the mean RP lifetime

1990 ◽  
Vol 175 (5) ◽  
pp. 467-471 ◽  
Author(s):  
I.V. Koptyug ◽  
N.N. Lukzen ◽  
E.G. Bagryanskaya ◽  
A.B. Doctorov
Keyword(s):  
Decay Rate ◽  
Radical Pair ◽  
The Mean

SET-VALUED PERFORMANCE APPROXIMATIONS FOR THE QUEUE GIVEN PARTIAL INFORMATION

2020 ◽  
pp. 1-23
Author(s):  
Yan Chen ◽  
Ward Whitt
Keyword(s):  
Steady State ◽  
Decay Rate ◽  
Waiting Time ◽  
Partial Information ◽  
Upper And Lower Bounds ◽  
Interarrival Time ◽  
Limited Information ◽  
Wide Range ◽  
The Mean ◽  
Third Moment

In order to understand queueing performance given only partial information about the model, we propose determining intervals of likely values of performance measures given that limited information. We illustrate this approach for the mean steady-state waiting time in the $GI/GI/K$ queue. We start by specifying the first two moments of the interarrival-time and service-time distributions, and then consider additional information about these underlying distributions, in particular, a third moment and a Laplace transform value. As a theoretical basis, we apply extremal models yielding tight upper and lower bounds on the asymptotic decay rate of the steady-state waiting-time tail probability. We illustrate by constructing the theoretically justified intervals of values for the decay rate and the associated heuristically determined interval of values for the mean waiting times. Without extra information, the extremal models involve two-point distributions, which yield a wide range for the mean. Adding constraints on the third moment and a transform value produces three-point extremal distributions, which significantly reduce the range, producing practical levels of accuracy.

A Theoretical Investigation on the Structure of Fan Wakes

1978 ◽  
Vol 100 (1) ◽  
pp. 113-119 ◽  
Author(s):  
R. Raj ◽  
J. L. Lumley
Keyword(s):  
Decay Rate ◽  
Theoretical Investigation ◽  
Axial Velocity ◽  
Analytical Study ◽  
Turbulence Structure ◽  
Relative Order ◽  
Turbulent Characteristics ◽  
Order Of Magnitude ◽  
The Mean ◽  
Insight Into

An analytical study is presented of the mean and turbulent characteristics of axial turbulent wakes behind a rotating fan. Simplified solutions are presented governing the mean radial and axial velocity profiles and their decay rate. An estimate is made of the relative order of magnitude of various turbulence quantities. The effect of rotation on the turbulence structure is described. Sufficient physical interpretations and explanations are presented for insight into and formulation of the problem.

scholarly journals Comparable viral decay with initial dolutegravir plus lamivudine versus dolutegravir-based triple therapy

2019 ◽  
Vol 74 (8) ◽  
pp. 2365-2369 ◽  
Author(s):  
Jason Gillman ◽  
Patrick Janulis ◽  
Roy Gulick ◽  
Carole L Wallis ◽  
Baiba Berzins ◽  
...  
Keyword(s):  
Drug Therapy ◽  
Decay Rate ◽  
Triple Therapy ◽  
Therapy Group ◽  
Dual Therapy ◽  
Baseline Viral Load ◽  
Linear Mixed Effect Model ◽  
Mixed Effect ◽  
The Mean ◽  
The Impact

Abstract Objectives To expand understanding of the virological potency of initial dolutegravir plus lamivudine dual therapy (dolutegravir/lamivudine), we compared the viral decay seen in the pilot ACTG A5353 study with the decay observed with dolutegravir plus two NRTIs in the SPRING-1 and SINGLE studies, while also exploring the impact of baseline viral load (VL). Methods Change in VL from baseline was calculated for timepoints shared by A5353 (n = 120, including 37 participants with pretreatment VL >100000 copies/mL), SPRING-1 (n = 51) and SINGLE (n = 417). The 95% CIs of change from baseline were determined for each observed week, using the mean log10-transformed VL, and compared between the dolutegravir/lamivudine and triple therapy groups using the Wilcoxon Rank Sum test for non-inferiority (δ = 0.5). To assess the impact of baseline VL on viral decay, we examined a bi-exponential non-linear mixed-effect model. Results The mean VL change from baseline to week 24 was −2.9 log10 copies/mL for dolutegravir/lamivudine versus −3.0 log10 copies/mL for dolutegravir-based three-drug therapy (P < 0.001). In the decay model, baseline VL >100000 copies/mL was associated with a slower initial decay rate (d1). A faster initial decay rate was seen with dolutegravir/lamivudine, which was partially offset when baseline VL was >100000 copies/mL as indicated by a significant interaction between baseline VL and drug therapy group. The secondary decay rate (d2) was not significantly different from zero, with no significant associations. Conclusions Viral decay with dolutegravir/lamivudine was comparable to viral decay with dolutegravir-based triple therapy, even in individuals with higher pretreatment VL (>100000 copies/mL).

Velocity and particle-flux characteristics of turbulent particle-laden jets

1989 ◽  
Vol 426 (1870) ◽  
pp. 31-78 ◽  
Keyword(s):  
Decay Rate ◽  
Gas Phase ◽  
Correlation Coefficient ◽  
Gaseous Phase ◽  
Mass Loading ◽  
Exit Velocity ◽  
Rate Of Spread ◽  
Air Jet ◽  
The Mean ◽  
Centreline Velocity

The velocity and flux of spherical glass beads with nominal diameters of 200, 80 and 40 μm have been obtained by phase-Doppler anemometry in a round unconfined air jet over the first 28 diameters. The jet diameter was 15 mm and the exit velocity was 13 ms -1 giving a Reynolds number of 13 000 and a timescale of 1.15 ms, which increased quadratically with axial distance: the bead inertial time constants were 298, 48 and 12 ms. The purposes of the experiments were to quantify the velocity and flux characteristics of the beads and of the gas phase in the presence of the beads as a function of bead diameter and of the mass loading in the jet nozzle. Due to the large inertia of the 200 μm beads, the mean bead velocity downstream of the exit of the jet was constant and independent of mass loading up to 0.37 and the axial root mean square (r.m.s.) bead velocity decayed by about one-fifth : at the exit of the jet, the axial r.m.s. bead velocity was higher than that of the corresponding clean jet. The mean centreline velocity of the 80 μm beads decayed to about one-half of the bead exit velocity by 28 diameters downstream and was independent of mass loading up to 0.86. The decay rate of the mean gas centreline velocity in the presence of the beads reduced as the loading increased because of momentum transfer from the discrete to the gaseous phase. The axial r.m.s. velocity of the beads was comparable to that of the gas phase and both decreased with increasing loading and the rate of spread of the half width of the jet increased with increasing loading. For the 40 μm beads, the decay rate of the mean centreline velocity of the beads decreased with increasing loading and, in contrast to the 80 μm beads, the rate of spread decreased with increasing loading up to 0.80. The axial r.m.s. velocity of the beads became largest at a position downstream of the nozzle exit, which moved downstream with increasing loading and was larger than the axial r.m.s. velocity of the clean jet, although the beads were not expected to be responsive to the frequencies of the energy-containing eddies. The bead axial r.m.s. velocity was more than twice as large as the radial r.m.s. velocity and the correlation coefficient of the cross correlation was larger than that of the clean jet. The large bead turbulence, anisotropy and strong correlation coefficient are explained by the superposition of bead trajectories from regions of different bead mean velocity and are not because of acquisition of axial turbulent motion from the gaseous phase.

scholarly journals Recovering Decay Rates from Noisy Measurements with Maximum Entropy in the Mean

2009 ◽  
Vol 2009 ◽  
pp. 1-13 ◽  
Author(s):  
Henryk Gzyl ◽  
Enrique Ter Horst
Keyword(s):  
Maximum Likelihood ◽  
Decay Rate ◽  
Maximum Entropy ◽  
Standard Method ◽  
Simulated Data ◽  
Decay Rates ◽  
Parametric Estimation ◽  
Large Level ◽  
The Mean ◽  
Noisy Measurements

We present a new method, based on the method of maximum entropy in the mean, which builds upon the standard method of maximum entropy, to improve the parametric estimation of a decay rate when the measurements are corrupted by large level of noise and, more importantly, when the number of measurements is small. The method is developed in the context on a concrete example: that of estimation of the parameter in an exponential distribution. We show how to obtain an estimator with the noise filtered out, and using simulated data, we compare the performance of our method with the Bayesian and maximum likelihood approaches.

Experimental Study of the Sidewall Effect on Three Dimensional Turbulent Wall Jet

2021 ◽  
Author(s):  
Sarvesh Kumar ◽  
Amitesh Kumar
Keyword(s):  
Experimental Study ◽  
Decay Rate ◽  
Three Dimensional ◽  
Wall Jet ◽  
Mean Velocity ◽  
Self Similar ◽  
The Mean ◽  
Vertical Jet ◽  
H 30 ◽  
Flow Stream

Abstract An experimental study on the effect of sidewalls on the flow characteristics of a three-dimensional turbulent square wall jet is carried out at a Reynolds number of 25,000. The sidewalls are defined as the two parallel plates along the vertical jet centerline. Four different sizes of sidewall enclosure (here after referred to as SWE) are placed at the lateral positions (z) of ±3.5h, ±4h, ±4.5h and ±5h from the vertical jet centerline plane, where h is the height of square jet. The mean characteristics of fluid flow in wall normal (y) and lateral (z) directions at different downstream locations (x/h = 0.2 - 45) are measured using a hotwire anemometer. The velocity measurements are also performed in the z ? y lateral plane at four downstream locations (x/h = 30, 35, 40 and 45). Results indicate that the mean velocity profile in lateral and wall normal directions behaves differently depending on the size of SWEs. The decay rate of mean velocity increases with decrease in size of SWEs after the downstream location (x/h ≥ 20). The decay rate of the maximum mean velocity increases about 5% in 140mm SWE as compared to 200mm SWE. It is noted that spread of the jet in wall normal and lateral directions increases with decrease in size of SWEs after the attachment of the flow stream on the sidewalls. In the present case, the smaller size of SWE (140mm SWE) has 14.3% and 26.2% higher spread rate as compared to larger size of SWE (200mm SWE) in wall-normal and lateral directions, respectively. It is also seen that the self similar profile gets delayed in wall normal direction as compared to lateral direction for all the cases. The wall normal self-similar profile is obtained early with increase in the size of SWEs and it is obtained at x/h = 30, 27, 24 and 20 for 140mm ,160mm,180mm and 200mm SWEs respectively. The flow stream seems to climb the sidewall and this tendency increases with increase in size of SWEs.

Modeling the decay of coarse woody debris in a subalpine Norway spruce forest of the West Carpathians, Poland

2008 ◽  
Vol 38 (3) ◽  
pp. 415-428 ◽  
Author(s):  
Jan Holeksa ◽  
Tomasz Zielonka ◽  
Magdalena Żywiec
Keyword(s):  
Decay Rate ◽  
Norway Spruce ◽  
Residence Time ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
Subalpine Forest ◽  
Residence Times ◽  
Stem Size ◽  
The Mean ◽  
Total Residence Time

Coarse woody debris (CWD) is an important structural element in forests. Its role depends on the species, size, position, and decay rate. This paper reports an attempt to determine the total residence time of CWD across all decay classes and also within successive decay classes. We simulated the process of CWD decomposition for stem size and position (snags versus logs), using matrices of the transition of CWD between decay classes. The study was based on a sample of 2785 Norway spruce snags and logs measured twice over a 10  year period in a Carpathian subalpine forest. The revealed pattern of decomposition depended highly on CWD size. When log numbers were considered, the mean total residence time increased from 71 years for small logs (diameter < 23 cm) to 90 years for medium-sized logs (23–35 cm), and to 113 years for large logs (>35 cm). In terms of volume, the mean total residence times of logs were 47, 49, and 63 years for the three diameter categories. Still shorter were the mean total residence times for log mass: 34, 41, and 41 years for the three diameter categories. The pattern of decomposition depended highly on the CWD attributes taken into consideration. The differences in decay rate between log diameter categories are considerable when the number of logs is taken into account, but they practically vanish when log mass is considered.

On the effects of microbubbles on Taylor–Green vortex flow

2007 ◽  
Vol 572 ◽  
pp. 145-177 ◽  
Author(s):  
ANTONINO FERRANTE ◽  
SAID E. ELGHOBASHI
Keyword(s):  
Decay Rate ◽  
Vortex Core ◽  
Vortex Flow ◽  
Volume Fraction ◽  
Numerical Study ◽  
Fluid Velocity ◽  
The Core ◽  
Vorticity Dynamics ◽  
The Mean ◽  
Two Fluid

The paper describes a numerical study of the effects of microbubbles on the vorticity dynamics in a Taylor–Green vortex flow (TGV) using the two-fluid approach. The results show that bubbles with a volume fraction ∼10−2 enhance the decay rate of the vorticity at the centre of the vortex. Analysis of the vorticity equation of the bubble-laden flow shows that the local positive velocity divergence of the fluid velocity, ∇·U, created in the vortex core by bubble clustering, is responsible for the vorticity decay. At the centre of the vortex, the vorticity ωc(t) decreases nearly linearly with the bubble concentration Cm(t). Similarly, the enstrophy in the core of the vortex, ω2(t), decays nearly linearly with C2(t). The approximate mean-enstrophy equation shows that bubble accumulation in the high-enstrophy core regions produces a positive correlation between ω2 and ∇·U, which enhances the decay rate of the mean enstrophy.

Photo-electric Hβ and uvby photometry

1966 ◽  
Vol 24 ◽  
pp. 170-180
Author(s):  
D. L. Crawford
Keyword(s):  
Narrow Band ◽  
Line Strength ◽  
Interference Filter ◽  
B Stars ◽  
Relative Line ◽  
The Mean ◽  
F Stars ◽  
Two Parameters ◽  
Filter Photometry ◽  
The Continuum

Early in the 1950's Strömgren (1, 2, 3, 4, 5) introduced medium to narrow-band interference filter photometry at the McDonald Observatory. He used six interference filters to obtain two parameters of astrophysical interest. These parameters he calledlandc, for line and continuum hydrogen absorption. The first measured empirically the absorption line strength of Hβby means of a filter of half width 35Å centered on Hβand compared to the mean of two filters situated in the continuum near Hβ. The second index measured empirically the Balmer discontinuity by means of a filter situated below the Balmer discontinuity and two above it. He showed that these two indices could accurately predict the spectral type and luminosity of both B stars and A and F stars. He later derived (6) an indexmfrom the same filters. This index was a measure of the relative line blanketing near 4100Å compared to two filters above 4500Å. These three indices confirmed earlier work by many people, including Lindblad and Becker. References to this earlier work and to the systems discussed today can be found in Strömgren's article inBasic Astronomical Data(7).

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

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