scholarly journals The mean lives of excited neon atoms

1934 ◽  
Vol 143 (850) ◽  
pp. 588-604 ◽  
Keyword(s):  
Excited States ◽  
High Frequency ◽  
The State ◽  
Reliable Information ◽  
Neon Atom ◽  
Average Life ◽  
High Frequency Discharge ◽  
First Approximation ◽  
The Mean ◽  
Upper Level

Since the first experiments by Wien many methods have been used to find the average lives of the excited states of different atoms. Most of these methods are applicable to particular atoms only, and the amount of reliable information in this field is still surprisingly meagre. The method described here depends in effect on the measurement of the lag which exists between the excitation and emission of light from atoms in a high-frequency discharge. This lag, or rather quantity actually measured, is itself a first approximation to the average life τ of the state concerned, and it is shown later how a more accurate value of τ may be deduced from it. Results are given for six excited states of the neon atom, but the method may be used for any substance whose spectrum can be obtained from a high-frequency discharge. The values of τ for neon range from 3·9 to 20·10 -8 seconds, and it is shown that lines originating from the same upper level lead to the same value of τ for that level.

First passage time for the state of exact chemical equilibrium

1980 ◽  
Vol 45 (3) ◽  
pp. 777-782 ◽  
Author(s):  
Milan Šolc
Keyword(s):  
Chemical Equilibrium ◽  
First Passage Time ◽  
Passage Time ◽  
The State ◽  
Recurrence Time ◽  
First Passage ◽  
First Order ◽  
The Mean ◽  
Passage Times ◽  
Number Of Particles

The establishment of chemical equilibrium in a system with a reversible first order reaction is characterized in terms of the distribution of first passage times for the state of exact chemical equilibrium. The mean first passage time of this state is a linear function of the logarithm of the total number of particles in the system. The equilibrium fluctuations of composition in the system are characterized by the distribution of the recurrence times for the state of exact chemical equilibrium. The mean recurrence time is inversely proportional to the square root of the total number of particles in the system.

scholarly journals Sub-Level Stoping in an Underground Limestone Quarry: An Analysis of the State of Stress in an Evolutionary Scenario

2016 ◽  
Vol 61 (1) ◽  
pp. 199-216 ◽  
Author(s):  
Marilena Cardu ◽  
Sergio Dipietromaria ◽  
Pierpaolo Oreste
Keyword(s):  
Numerical Models ◽  
The State ◽  
In Situ Tests ◽  
Future Scenario ◽  
Limestone Quarry ◽  
Geomechanical Properties ◽  
State Of Stress ◽  
Upper Level ◽  
Pillar Structure

Abstract The aim of this study was to evaluate the state of stress of a „voids-pillar“ structure excavated by means of the sub-level stoping method in an underground limestone quarry near Bergamo (Italy). Both the current structure of the quarry (i.e. the rooms exploited till now) and a possible future scenario were analysed using the (FDM) FLAC 2D code. The quarry has been in operation since 1927; at present, exploitation is carried out underground via the sub-level stoping method. Exploitation involves two levels, with 5 rooms on the upper level and 9 rooms on the lower level. After analysing data obtained from laboratory and in situ tests carried out on rock samples and natural discontinuities, the geomechanical properties of the medium, knowledge of which is essential in order to establish the parameters that must be included in the numerical model, were evaluated. The implementation of three numerical models made it possible to study both the present conditions of quarry exploitation and the evolution of the exploited rooms, as well as a possible expansion involving a third level of rooms. Using the results obtained regarding the stress-strain present in the pillars, a potential change in room geometry was proposed aimed at reducing the stress state inside the pillars, decreasing plasticity and increasing overall quarry safety.

scholarly journals Genetic gain in the breeding program of common beans at IAC from 1989 to 2007

2010 ◽  
Vol 10 (4) ◽  
pp. 329-336 ◽  
Author(s):  
Alisson Fernando Chiorato ◽  
Sérgio Augusto Morais Carbonell ◽  
Roland Vencovsky ◽  
Nelson da Silva Fonseca Júnior ◽  
José Baldin Pinheiro
Keyword(s):  
Grain Yield ◽  
Common Bean ◽  
Genetic Gain ◽  
Grain Quality ◽  
The State ◽  
Breeding Program ◽  
Common Beans ◽  
The Common ◽  
The Mean ◽  
Second Period

The goal of the present work was to evaluate the genetic gain obtained in grain yield for the common bean genotypes from 1989 until 2007, at the Instituto Agronômico de Campinas, in the state of São Paulo. Genetic gain has been separated into two research periods; the first, from 1989 to 1996, and the second, from 1997 to 2007. In the first period, a genetic gain of 1.07 % per year was obtained, whereas for the second period, the gain was zero. However, the mean yield of the evaluated lines was approximately 1000 kg ha-1 superior to the figures obtained in the first period. The main cause for the absence of genetic gain in the second period is that the focus of the breeding program was changed to grain quality. The individualized analysis of the genotypes with carioca grains in the second period indicated the lack of genetic gain during the investigated period.

Skin friction and surface temperature of an insulated flat plate fixed in a fluctuating stream

1971 ◽  
Vol 46 (1) ◽  
pp. 165-175 ◽  
Author(s):  
Hiroshi Ishigaki
Keyword(s):  
Boundary Layer ◽  
Surface Temperature ◽  
Flat Plate ◽  
Skin Friction ◽  
High Frequency ◽  
Energy Equation ◽  
Oscillation Amplitude ◽  
Flow Oscillation ◽  
Velocity Amplitude ◽  
The Mean

The time-mean skin friction of the laminar boundary layer on a flat plate which is fixed at zero incidence in a fluctuating stream is investigated analytically. Flow oscillation amplitude outside the boundary layer is assumed constant along the surface. First, the small velocity-amplitude case is treated, and approximate formulae are obtained in the extreme cases when the frequency is low and high. Next, the finite velocity-amplitude case is treated under the condition of high frequency, and it is found that the formula obtained for the small-amplitude and high-frequency case is also valid. These results show that the increase of the mean skin friction reduces with frequency and is ultimately inversely proportional to the square of frequency.The corresponding energy equation is also studied simultaneously under the condition of zero heat transfer between the fluid and the surface. It is confirmed that the time-mean surface temperature increases with frequency and tends to be proportional to the square root of frequency. Moreover, it is shown that the timemean recovery factor can be several times as large as that without flow oscillation.

The Paraphilias: A Multiplicity of Deviant Behaviours*

1992 ◽  
Vol 37 (2) ◽  
pp. 104-108 ◽  
Author(s):  
John M.W. Bradford ◽  
J. Boulet ◽  
A. Pawlak
Keyword(s):  
High Frequency ◽  
True Nature ◽  
The Mean

The DSM-II and DSM-III both allow for multiple diagnoses. The DSM-III acknowledges that a patient may have multiple paraphilias but the true nature and extent of the multiplicity has only been documented recently. In order to study the degree of crossover between the various paraphiliac acts, a study of men who admitted to at least one paraphilia was conducted. A proportional index of multiple deviation was obtained. In addition, the mean number of admitted sexually deviant incidents per paraphilic category was computed as an estimate of the extent of deviant acts committed by this population. The results indicated that paraphiliacs tend to have multiple types of sexual aberrations as well as a high frequency of deviant acts per individual.

High-Frequency Discharge as an Ion Source

Nature ◽  
1946 ◽  
Vol 158 (4002) ◽  
pp. 61-61 ◽  
Author(s):  
P. C. THONEMANN
Keyword(s):  
High Frequency ◽  
Ion Source ◽  
High Frequency Discharge

Adaptive Estimation Using Multiagent Network Identifiers With Undirected and Directed Graph Topologies

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Teymur Sadikhov ◽  
Michael A. Demetriou ◽  
Wassim M. Haddad ◽  
Tansel Yucelen
Keyword(s):  
Directed Graph ◽  
Adaptive Estimation ◽  
Parameter Estimate ◽  
The State ◽  
Adaptive Observer ◽  
Parameter Estimates ◽  
Communication Architecture ◽  
Adaptive Identifier ◽  
The Mean ◽  
Additive Term

In this paper, we present an adaptive estimation framework predicated on multiagent network identifiers with undirected and directed graph topologies. Specifically, the system state and plant parameters are identified online using N agents implementing adaptive observers with an interagent communication architecture. The adaptive observer architecture includes an additive term which involves a penalty on the mismatch between the state and parameter estimates. The proposed architecture is shown to guarantee state and parameter estimate consensus. Furthermore, the proposed adaptive identifier architecture provides a measure of agreement of the state and parameter estimates that is independent of the network topology and guarantees that the deviation from the mean estimate for both the state and parameter estimates converge to zero. Finally, an illustrative numerical example is provided to demonstrate the efficacy of the proposed approach.

Ten Years of Extracorporeal Membrane Oxygenation: Neurodevelopmental Outcome

PEDIATRICS ◽  
1991 ◽  
Vol 87 (4) ◽  
pp. 549-555
Author(s):  
Dena Hofkosh ◽  
Heidi M. Feldman ◽  
Ann E. Thompson ◽  
Robert J. Nozza ◽  
Susan S. Kemp ◽  
...  
Keyword(s):  
Extracorporeal Membrane Oxygenation ◽  
High Frequency ◽  
Neurodevelopmental Outcome ◽  
Cognitive Testing ◽  
Neurologic Examination ◽  
Cognitive Score ◽  
School Aged Children ◽  
Membrane Oxygenation ◽  
The Mean

Of the 87 survivors of extracorporeal membrane oxygenation over a 10-year period, 67 participated in a follow-up study which included neurologic examination (n = 67), cognitive testing (n = 67), and audiologic assessment (n = 33). Matched control subjects for those older than 5 years were also evaluated. Outcome was defined as normal for cognitive scores ≥85 and normal neurologic examination results, suspect for cognitive scores 70 through 84 or nonfocal neurologic findings such as hypertonia/hypotonia, and abnormal for cognitive scores <70 or abnormal neurologic examination results. Of the 10 school-aged children studied, 9 were normal and there were no differences in mean cognitive scores between subjects and controls (IQ subjects = 109 ± 12 [SD], IQ controls = 107 ± 13). For preschoolers aged 2.7 through 4.11 years, the mean cognitive score was 91 ± 11 and 7 (70%) were normal. For infants 6 through 30 months, the mean cognitive score was 101 ± 22 and 27 (57%) were normal. A total of 7 children (21% of those studied) had abnormal audiologic assessments. Three children demonstrated mild high-frequency and 4 moderately severe high-frequency sensorineural hearing loss which was bilateral in 3 and of undetermined laterality in 1. Abnormal neurodevelopmental outcome was significantly associated with cerebral infarction and chronic lung disease. Outcome was not related to demographic or perinatal variables, illness severity prior to extracorporeal membrane oxygenation, or underlying diagnosis. Neurodevelopmental outcome among survivors of extracorporeal membrane oxygenation in this series is consistent with previous reports of morbidity among neonates with severe respiratory failure treated conventionally.

scholarly journals Differences in phosphatemia and frequency of consumption of dietary sources of phosphorus in hemodialysis patients in southern and northern Brazil

2019 ◽  
Vol 41 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Fabiana Baggio Nerbass ◽  
Edcléia Regina Canzi ◽  
Renata dos Anjos Araujo ◽  
Dyane Corrêa ◽  
Rafaela Gonzaga dos Santos ◽  
...  
Keyword(s):  
Total Sample ◽  
Inorganic Phosphorus ◽  
Cross Sectional Study ◽  
The State ◽  
Cross Sectional ◽  
Significant Difference ◽  
Phosphorus Sources ◽  
Northern Brazil ◽  
The Mean ◽  
Pork Sausages

Abstract Introduction: Hyperphosphatemia is associated with unfavorable outcomes, and the percentage of patients presenting with this condition in hemodialysis (HD) in kidney foundation units in the state of Santa Catarina (SC) is historically higher than that of patients in the state of Tocantins (TO). Objective: To assess the frequency of consumption of the main dietary sources of phosphorus and to compare them between the two states. Methodology: A cross-sectional study was carried out involving 123 patients, 66 of SC and 57 of TO: 52% were men, average age was 46.9 ± 15.7 years, and mean HD time 48 (57-71) months. A food frequency questionnaire (FFQ) with 33 items that are dietary sources of phosphorus was applied. A consumption score was calculated for sources of organic, inorganic, and total phosphorus, and the six-month average of phosphatemia was obtained. Results: The mean phosphatemia of SC patients was higher (6.2 ± 1.5 vs 4.7 ± 1.3 mg/dL, p <0001) than TO patients, as well as the prevalence of hyperphosphatemia (62% vs 28%; p <10001). In the total sample, the foods most frequently consumed were milk and beans. Comparing the frequency of consumption between the two states, a significant difference was found in 17 items. In TO, beef and beans were the foods most frequently consumed, and in SC, fourteen other items of the FFQ (pork, sausages, dairy products, etc.) were the most frequently consumed. Phosphatemia correlated with the frequency of consumption of inorganic phosphorus sources. Conclusion: the frequency of consumption of several items was different between the states, and this explains the differences in phosphatemia between the two regions.

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