scholarly journals Modeling the relationship between E × B vertical drift and the time rate of change of hmF2 (ΔhmF2/Δt) over the magnetic equator

2008 ◽  
Vol 35 (5) ◽  
Author(s):  
Xinan Yue ◽  
Weixing Wan ◽  
Jiuhou Lei ◽  
Libo Liu
1959 ◽  
Vol 37 (5) ◽  
pp. 614-618 ◽  
Author(s):  
K. L. Chopra ◽  
T. S. Hutchison

The phase propagation in superconducting aluminum has been studied by measuring the time rate of change of ultrasonic attenuation. The time taken for the destruction of the superconducting phase in a cylindrical specimen, by means of a magnetic field, H, greater than the critical field, Hc, is approximately proportional to{H/(H–Hc)} in agreement with eddy-current theory. In the converse case, where the superconducting phase is restored by switching off the magnetic field H (>Hc), the total time taken is nearly independent of the temperature (or Hc) as well as H. The superconducting phase grows at a non-uniform volume rate which is considerably less than the uniform rate of collapse.


Author(s):  
Taat Guswantoro ◽  
Manogari Sianturi ◽  
Nurafni Prapitasari ◽  
Areli Elona

<p class="AbstractEnglish"><strong>Abstract</strong>: In this study hot water was placed in two erlenmeyer scale 100 ml clogged and without plug, each filled with 150 ml hot water and allowed to cool in air. Measurement of water temperature using sensor connected to the interface and recorded using the pasco capstone 14.1. The wind is raised with the fan, to adjust the wind speed by adjusting the fan distance, the speed is measured using an anemometer. The water cooling constant is obtained by a decay exponential regression analysis of temperature vs time. The relationship between water colling coefficient with wind speed is used linear regression. From the research, the water cooling coefficient naturally for clogging erlenmeyer is 3,1 x 10<sup>-4</sup> s<sup>-1</sup> and for erlenmeyer without plug 3.8 x 10<sup>-4</sup> s<sup>-1</sup>, the rate of change of water cooling constant to wind speed is 1 , 4 x 10<sup>-4</sup> m<sup>-1</sup>.</p><p class="KeywordsEngish"> </p><p class="AbstrakIndonesia"><strong>Abstrak: </strong>Pada penelitian ini air panas ditempatkan dalam dua buah erlenmeyer berskala 100 ml bersumbat dan tanpa sumbat, masing-masing diisi air panas dengan volume 150 ml dan dibiarkan mendingin di udara. Pengukuran suhu air dengan menggunakan sensor panas yang dihubungkan ke interface dan dicatat menggunakan program pasco capstone 14.1. Angin dibangkitkan dengan kipas, untuk mengatur kecepatan angin dengan cara mengatur jarak kipas, kecepatan angin diukur menggunakan anemometer. Konstanta pendinginan air diperoleh dengan analisis regresi eksponensial meluruh dari data suhu dan waktu. Hubungan antara koefisien pendinginan air dengan kecepatan angin digunakan regresi linier. Dari penelitian diperoleh koefisien pendinginan air secara alami untuk erlenmeyer tersumbat sebesar 3,1 x 10<sup>-4</sup> s<sup>-1</sup> dan untuk erlenmeyer tanpa sumbat sebesar  3,8 x 10<sup>-4</sup> s<sup>-1</sup>, laju perubahan konstanta pendinginan air terhadap kecepatan angin adalah sebesar 1,4 x 10<sup>-4</sup> m<sup>-1</sup><sub>.</sub></p>


2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Tomoko Imai ◽  
Ayako Sezaki ◽  
Keiko Miyamoto ◽  
Chisato Abe ◽  
Fumiya Kawase ◽  
...  

Abstract Background Traditional Japanese diets are considered to be health and longevity. We created a Traditional Japanese Diet Score (TJDS) and investigated the relationship between the TJDS and healthy life expectancy (HALE) longitudinally using global database. Methods Average food (g/day/capita) and energy supply (kcal/day/capita) by countries were identified by the Food and Agriculture Organization of the United Nations Statistics Division database. The sum of characterizing traditional Japanese foods supply (beneficial food components in Japanese diet; rice, fish, soybeans, vegetables, eggs, seaweeds, food components not use so much in Japanese diet; wheat, milk, and red meat) were divided as tertile (beneficial food components;-1, 0, 1, not use so much food components; 1, 0, -1). HALE values by country were derived from the Global Burden of Disease 2017 database. The longitudinal effects of TJDS on the rate of change in HALE from 1990 to 2013 were evaluated using a generalized mixed-effect model (GLMM), which takes into account the dependence of repeated observations within countries. The interaction between TJDS and survey year was applied to access the effects on HALE. This study covered 137 countries with populations of 1 million or greater. Results Longitudinal analysis controlled for covariates showed that smooth term of the interaction between TJDS and survey year was significant (p &lt; 0.001). The TJDS was negative associated with HALE in 1990, and in 1991, but positive associated after 2002. Conclusions The relationship between the TJDS as a healthy eating style and HALE is getting stronger since the 21st century. Key messages Well-balanced eating habits of traditional Japanese diets is supports healthy life expectancy.


2021 ◽  
Author(s):  
Bernhard Schmid

&lt;p&gt;The work reported here builds upon a previous pilot study by the author on ANN-enhanced flow rating (Schmid, 2020), which explored the use of electrical conductivity (EC) in addition to stage to obtain &amp;#8216;better&amp;#8217;, i.e. more accurate and robust, estimates of streamflow. The inclusion of EC has an advantage, when the relationship of EC versus flow rate is not chemostatic in character. In the majority of cases, EC is, indeed, not chemostatic, but tends to decrease with increasing discharge (so-called dilution behaviour), as reported by e.g. Moatar et al. (2017), Weijs et al. (2013) and Tunqui Neira et al.(2020). This is also in line with this author&amp;#8217;s experience.&lt;/p&gt;&lt;p&gt;The research presented here takes the neural network based approach one major step further and incorporates the temporal rate of change in stage and the direction of change in EC among the input variables (which, thus, comprise stage, EC, change in stage and direction of change in EC). Consequently, there are now 4 input variables in total employed as predictors of flow rate. Information on the temporal changes in both flow rate and EC helps the Artificial Neural Network (ANN) characterize hysteretic behaviour, with EC assuming different values for falling and rising flow rate, respectively, as described, for instance, by Singley et al. (2017).&lt;/p&gt;&lt;p&gt;The ANN employed is of the Multilayer Perceptron (MLP) type, with stage, EC, change in stage and direction of change in EC of the M&amp;#246;dling data set (Schmid, 2020) as input variables. Summarising the stream characteristics, the M&amp;#246;dling brook can be described as a small Austrian stream with a catchment of fairly mixed composition (forests, agricultural and urbanized areas). The relationship of EC versus flow reflects dilution behaviour. Neural network configuration 4-5-1 (the 4 input variables mentioned above, 5 hidden nodes and discharge as the single output) with learning rate 0.05 and momentum 0.15 was found to perform best, with testing average RMSE (root mean square error) of the scaled output after 100,000 epochs amounting to 0.0138 as compared to 0.0216 for the (best performing) 2-5-1 MLP with stage and EC as inputs only. &amp;#160;&amp;#160;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References&lt;/p&gt;&lt;p&gt;Moatar, F., Abbott, B.W., Minaudo, C., Curie, F. and Pinay, G.: Elemental properties, hydrology, and biology interact to shape concentration-discharge curves for carbon, nutrients, sediment and major ions. Water Resources Res., 53, 1270-1287, 2017.&lt;/p&gt;&lt;p&gt;Schmid, B.H.: Enhanced flow rating using neural networks with water stage and electrical conductivity as predictors. EGU2020-1804, EGU General Assembly 2020.&lt;/p&gt;&lt;p&gt;Singley, J.G., Wlostowski, A.N., Bergstrom, A.J., Sokol, E.R., Torrens, C.L., Jaros, C., Wilson, C.,E., Hendrickson, P.J. and Gooseff, M.N.: Characterizing hyporheic exchange processes using high-frequency electrical conductivity-discharge relationships on subhourly to interannual timescales. Water Resources Res. 53, 4124-4141, 2017.&lt;/p&gt;&lt;p&gt;Tunqui Neira, J.M., Andr&amp;#233;assian, V., Tallec, G. and Mouchel, J.-M.: A two-sided affine power scaling relationship to represent the concentration-discharge relationship. Hydrol. Earth Syst. Sci. 24, 1823-1830, 2020.&lt;/p&gt;&lt;p&gt;Weijs, S.V., Mutzner, R. and Parlange, M.B.: Could electrical conductivity replace water level in rating curves for alpine streams? Water Resources Research 49, 343-351, 2013.&lt;/p&gt;


1974 ◽  
Vol 2 (5) ◽  
pp. 297-299 ◽  
Author(s):  
L. J. Gleeson ◽  
G. M. Webb

The purpose of this paper is to provide a new expression for < ṗ > the average time-rate-of-change of momentum of cosmic-ray particles propagating in the interplanetary region. The expression derived replaces the previously used adiabatic deceleration formula and it is arrived at by a rearrangement and reinterpretation of the well known equation of transport for cosmic-rays. Thus, although we provide a new expression for < ṗ > we maintain the equation of transport and do not render invalid results for differential intensity and differential current density of cosmic-ray particles obtained by its solution (Jokipii 1971; Gleeson 1972).


1994 ◽  
Vol 77 (4) ◽  
pp. 1671-1677 ◽  
Author(s):  
G. L. Brengelmann ◽  
M. V. Savage ◽  
D. H. Avery

The control of sweating in humans has been described quantitatively in terms of skin and core temperatures (Tsk and Tcore, respectively). However, the precision with which features of the relationship between sweat rate and Tcore at a given Tsk can be reproduced in the short term is not known. We focused on the threshold Tcore. We held Tsk at 38 degrees C until sweating began for two periods separated by a period of cooling with Tsk at 32 degrees C in six men and three women. The esophageal temperature (Tes) at which sweating began was invariably lower in the second period of heating (average difference 0.09 degree C; maximum 0.17 degree C). Also, the rate of rise in Tes was invariably higher (average 148%) during the second period of heating. Thus, although a threshold cannot be reproduced within the error of Tes measurement, the consistency and small magnitude of the downward shift recommend our protocol as a practical method for evaluating other influences on thermoregulation, provided that the effects are big enough to be seen against a background of an expected small decrease. From the fundamental point of view, the consistency of the downward displacement has provocative implications, e.g., the rate of change in Tcore influences sweating or thermosensitive units in slow-responding thermal compartments contribute to the Tcore input signal.


2019 ◽  
Vol 875 ◽  
pp. 254-285 ◽  
Author(s):  
David A. Buchta ◽  
Gregory Shallcross ◽  
Jesse Capecelatro

High-speed free-shear-flow turbulence, laden with droplets or particles, can radiate weaker pressure fluctuations than its unladen counterpart. In this study, Eulerian–Lagrangian simulations of high-speed temporally evolving shear layers laden with monodisperse, adiabatic, inertial particles are used to examine particle–turbulence interactions and their effect on radiated pressure fluctuations. An evolution equation for gas-phase pressure intensity is formulated for particle-laden flows, and local mechanisms of pressure changes are quantified over a range of Mach numbers and particle mass loadings. Particle–turbulence interactions alter the local pressure intensity directly via volume displacement (due to the flow of finite-size particles) and drag coupling (due to local slip velocity between phases), and indirectly through significant turbulence changes. The sound radiation intensity near subsonic mixing layers increases with mass loading, consistent with existing low Mach number theory. For supersonic flows, sound levels decrease with mass loading, consistent with trends observed in previous experiments. Particle-laden cases exhibit reduced turbulent kinetic energy compared to single-phase flow, providing one source of their sound changes; however, the subsonic flow does not support such an obvious source-to-sound decomposition to explain its sound intensity increase. Despite its decrease in turbulence intensity, the louder particle-laden subsonic flows show an increase in the magnitude and time-rate-of-change of fluid dilatation, providing a mechanism for its increased sound radiation. Contrasting this, the quieter supersonic particle-laden flows exhibit decreased gas-phase dilatation yet its time-rate-of-change is relatively insensitive to mass loading, supporting such a connection.


2006 ◽  
Vol 96 (3) ◽  
pp. 989-997 ◽  
Author(s):  
E. Gingl ◽  
H. Tichy

The warm cells of the spider tarsal organ respond very sensitively to low-amplitude changes in temperature and discharge continuously as the rate of change in temperature reaches zero. To test whether the continuous tonic discharge remains without sensory input, we blocked the warm cell's receptive region by Epoxy glue. The activity continued in this situation, but its dependence on temperature changes was strongly reduced. We interpret this to mean that the warm cells exhibit specific intrinsic properties that underlie the generation of the tonic discharge. Experiments with electrical stimulation confirmed the observation that the warm cells persist in activity without an external drive. In warm cells with blocked receptive region, the response curves describing the relationship between the tonic discharge and the level of depolarization is the same for different temperatures. In warm cells with intact receptive region, the curves are shifted upward with rising temperature, as if the injected current is simply added to the receptor current. This indicates a modulating effect of the receptor current on the tonic discharge. Stimulation causes a change in the tonic discharge rate and thereby enables individual warm cells to signal the direction in addition to the magnitude of temperature changes.


2011 ◽  
Vol 51 (5) ◽  
pp. 490
Author(s):  
Miguel Mellado ◽  
Cesar A. Meza-Herrera ◽  
José R. Arévalo ◽  
Maria A. De Santiago-Miramontes ◽  
Alvaro Rodríguez ◽  
...  

The aim of the present study was to use a non-linear regression approach to investigate the relationship between litter birthweight and litter size of five breeds of goat under intensive conditions in a hot arid environment. Litter-size and litter-weight data on 20�117 kids from 13�685 litters representing five breeds, namely Saanen, Toggenburg, French Alpine, Anglo-Nubian and Granadina, were compared to evaluate this relationship. Regardless of breed, birthweight for kids born as twins, triplets and quadruplets was, on average, 92%, 87% and 83%, respectively, of that of singleton kids; litter size accounted for 81% of the variation in litter weight. The coefficient of the power regression differed (P < 0.01) among breeds, with similar slopes for French Alpine, Toggenburg and Saanen goats and a smaller litter-weight increase for every additional fetus in Anglo-Nubian and Granadina goats than in other breeds of goat. These results support the hypothesis that, regardless of parity, litter weight in dairy and Granadina goats increases at a reduced rate with increases in litter size, although the rate of change with the increasing number of fetuses was moderate, as indicated by a power regression of the form y = axb between these variables across age categories and breeds of goat.


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