Redistribution of soil water after infiltration

Soil Research ◽  
1971 ◽  
Vol 9 (2) ◽  
pp. 59 ◽  
Author(s):  
AJ Peck
Keyword(s):  
Moisture Content ◽  
Surface Zone ◽  
Order Ordinary Differential Equation ◽  
Mean Values ◽  
Wide Range ◽  
Two Factors ◽  
Homogeneous Soil ◽  
The Mean ◽  
The One ◽  
Different Soils

The one-dimensional vertical redistribution of water is studied following infiltration into deep homogeneous soil with an initially uniform moisture content. There is assumed to be no loss of water by evaporation or transpiration during the redistribution. Assuming two factors to be constants, a first-order ordinary differential equation is derived which can be integrated numerically to compute the mean moisture content in the surface zone of draining soil as a function of the redistribution time. The depth of the draining zone increases with time, and this can be calculated too. That these factors are relatively constant is indicated by analysis of data for several soils and wetting depths over a wide range of redistribution times. Using mean values of the factors for several soils, and only wetting values of the diffusivity and conductivity functions, predicted redistribution behaviour agrees well with experimental data in four of six soils. In the remaining cases calculation of the factors for the particular soils, using an approximate method which includes hysteresis data, gives better results. The model is applied to predict the redistribution behaviour of different soils under identical treatments, and of a single soil for various infiltration quantities and initial moisture contents.

scholarly journals Retinomotor movements in the Antarctic fish Trematomus newnesi Boulenger submitted to different environmental light conditions

2007 ◽  
Vol 24 (2) ◽  
pp. 457-462 ◽  
Author(s):  
Lucélia Donatti ◽  
Edith Fanta
Keyword(s):  
Pigment Epithelium ◽  
Antarctic Fish ◽  
Constant Darkness ◽  
Time Intervals ◽  
Mean Values ◽  
Environmental Light ◽  
The Mean ◽  
The Difference ◽  
The One ◽  
The Antarctic

The Antarctic fish Trematomus newnesi (Boulenger, 1902) occurs from benthic to pelagic habitats, in seasonally and daily varied photic conditions that induce retinomotor movements. Fish were experimentally kept under constant darkness or light, and 12Light/12Dark for seven days. The retinomotor movement of the pigment epithelium was established through the pigment index, while that of the cones was calculated as the length of the myoid. The retinomotor movement of the pigment epithelium in T.newnesi,revealed that the adaptation to constant light occurred in the one hour of exposure, remaining constant for the next seven days. However, the adaptation to constant darkness, was slower. The difference between the mean values of the pigment indices in the time intervals of sampling was significant in the first hours of the experiment, and only after six hours they were not significant any more. The myoid of cones became elongated in darkness and contracted in light. In the experiments where T.newnesiwas exposed initially to 12 hours light followed by 12 hours darkness 12 was evidenced that the speed and intensity of the retinomotor movements was higher when darkness changed into light, than when light changed into darkness.

Physiological and biophysical limits to work in the heat for clothed men and women

1978 ◽  
Vol 44 (6) ◽  
pp. 918-925 ◽  
Author(s):  
E. Kamon ◽  
B. Avellini ◽  
J. Krajewski
Keyword(s):  
Steady State ◽  
Vapor Pressure ◽  
Physiological Responses ◽  
Men And Women ◽  
Mean Values ◽  
Air Temperatures ◽  
Significant Difference ◽  
The Mean ◽  
Evaporative Heat Transfer ◽  
The One

Heat-acclimated, lightly clothed men and women (four of each) walked on a treadmill at 25% and 43% VO2 max, respectively, (M =194 W.m-2), under seven air temperatures (Ta) ranging from 36 to 52 degrees C. Each experiment involved 1 h of fixed and a 2nd h of progressively increasing ambient vapor pressure (Pa). The relative steady state of rectal temperature (Tre), mean skin temperature (Tsk), and heart rate (HR) reached in the 1st h were forced upward during the 2nd h by the rising Pa. The critical air vapor pressure (Pcrit) was identified by the Tre point of inflection for each Ta. One man did not fully reach steady state, but inflection could be determined for his physiological responses. The mean values of all points of inflection were calculated for Tre, Tsk, and HR. Significant sex difference in HR was found only by excluding the results of the one man. Tre and Tsk showed no significant difference between men and women. The coefficient for evaporative heat transfer (he), which could be derived using the Pcrit for the low Ta range, was 14.5 +/- 2.2 W.m-1 Torr-1.

scholarly journals DETERMINATION OF PHYSICAL AND ENGINEERING PROPERTIES OF TIGER NUT (Cyperus esculentus) RELEVANT TO ITS MECHANIZATION

2020 ◽  
Vol 5 (8) ◽  
Author(s):  
Tega A Emurigho ◽  
Canice O.O Kabuo ◽  
Arinze N Ifegbo
Keyword(s):  
Moisture Content ◽  
Static Friction ◽  
Major Axis ◽  
Angle Of Repose ◽  
Engineering Properties ◽  
Cyperus Esculentus ◽  
Mean Values ◽  
Principal Axes ◽  
Length Width ◽  
The Mean

The physical and engineering properties of fresh and dried tiger nut (Cyperus esculentus) were determined at moisture content of 41.20% and 16.40% on wet basis respectively. The mean values for the three principal axes (length, width and thickness) were 9.52mm, 8.16mm, and 8.16mm for fresh tiger nut and 9.14mm, 7.72mm and 8.03mm for dried tiger nut respectively, showing a decrease with decrease in moisture content and was significantly different at p?0.05. The mean values of the bulk density, true density and porosity of both fresh and dried tiger nut were 0.59g/cm3 , 0.97g/cm3 , 40.61 and 0.58g/cm3, 0.94g/cm3 , 40.35 respectively and were not significantly different at p?0.05. The mean angle of repose and coefficient of static friction over formica, stainless steel, glass and plywood surfaces of fresh tiger nut were 50.11o , 2.73, 2.45, 2.22 and 1.77 while that of dried tiger nut were 48.23o , 2.41, 2.03, 2.11 and 2.00 respectively. The mean rupture force increased with compression force of 90.08N on the major axis to 116.88N for fresh tiger nut and from 120.55N to 161.10N for dried tiger nut and were significantly different at p?0.05. These properties determined are necessary in the design and fabrication of hoppers, conveyor equipment and the force tiger nut can withstand before it is ruptured.

Sound emission and the acoustic far field of a singing acridid grasshopper (Omocestus viridulus L.)

1999 ◽  
Vol 202 (12) ◽  
pp. 1571-1577
Author(s):  
A. Michelsen ◽  
N. Elsner
Keyword(s):  
Sound Production ◽  
Sound Intensity ◽  
Movement Pattern ◽  
Forward Direction ◽  
Octave Band ◽  
Sound Emission ◽  
Mean Values ◽  
The Mean ◽  
The One ◽  
Sound Intensities

An array of eight microphones, all at a distance of 15 cm, was used to make simultaneous recordings of the sounds emitted by courting male acridid grasshoppers of the species Omocestus viridulus. In this species, the movement pattern for sound production differs in the two hindlegs, and in most cases the leg facing the female moves with the larger amplitude. The sonic sound intensity (the total sound in the one-third octave bands with centre frequencies from 5 to 20 kHz) is maximal ipsilateral to the leg stridulating with the larger amplitude (the dominant leg). A spontaneous switch of dominance to the other leg may cause a significant change in the emitted sound power. The sound intensities contralateral to the dominant leg and frontal to the animal are, on average, approximately half (−3 dB) of the ipsilateral value, whereas the mean sound intensities behind and above the singer are approximately one-fifth (−7 dB) of the ipsilateral value. In most singers, the patterns of sound radiation are close to these mean values, but in some singers the radiation patterns are radically different. The sound radiated in various directions differs not only in terms of sound intensity but also with respect to the frequency spectrum, which was studied up to the one-third octave band with a centre frequency of 31.5 kHz. In particular, the ratio between the ultrasonic and sonic components is much smaller in the forward direction than in other directions. This may allow the courted female to hear whether the courting male is oriented directly towards her.

scholarly journals Estimating the Young Generation’s Willingness to Pay (WTP) for PM2.5 Control in Daegu, Korea, and Beijing, China

2019 ◽  
Vol 11 (20) ◽  
pp. 5704
Author(s):  
Ning ◽  
Lee
Keyword(s):  
Willingness To Pay ◽  
Fine Particulate Matter ◽  
Control Measures ◽  
Young Generation ◽  
Explanatory Variables ◽  
Wide Range ◽  
Air Quality Improvement ◽  
The Mean ◽  
The One ◽  
Beijing China

This research aimed to examine the willingness to pay (WTP) of the young generation (the age group from 18 to 29) for the participatory solutions and actions on fine particulate matter (PM2.5) pollution control and abatement in Daegu, Korea, and Beijing, China. This study found out that Korean respondents and Chinese respondents shared a wide range of similarities, both in terms of socio-demographic characters like age, family size, and house/apartment ownership, as well as a number of perceptions related to environmental and social responsibilities. Around one-third of the Korean respondents and one-fifth of the Chinese respondents expressed negative WTP due to primary reasons such as lack of trust in the effectiveness of PM2.5 control measures (Korea) and limitation of budget (China). The mean estimated values of WTP with and without explanatory variables in Korea were merely slightly higher than those in China. The mean WTP without control variables in Korea was 11,882.97 KRW/month (10.61 USD/month) and the one in China was 65.09 CNY/month (9.48 USD/month). The mean WTP with explanatory variables for Daegu, Korea, was KRW 11,982.33 (USD 10.70) per person per month, and the one for Beijing, China, was CNY 64.84 (USD 9.40) per person per month. The annual total WTP for Daegu, Korea, was assessed around KRW 47572 million (USD 42.45 million), whereas the estimated total WTP for Beijing, China, was around CNY 3260.14 million (USD 474.94 million) per year. Based on the results and the findings, this study proposes to further strengthen the comprehensive cooperation between China and Korea in the field of air quality improvement, with a particular focus on PM2.5 control and abatement and cooperation in academic circles and among the general public.

scholarly journals Aerodynamic Properties of Makhobeli, Triticale and Wheat Seeds

2014 ◽  
Vol 28 (3) ◽  
pp. 389-394 ◽  
Author(s):  
Feizollah Shahbazi ◽  
Saman Valizadeh ◽  
Ali Dowlatshah
Keyword(s):  
Moisture Content ◽  
Drag Coefficient ◽  
Terminal Velocity ◽  
Mean Value ◽  
Probability Level ◽  
Mean Values ◽  
Aerodynamic Properties ◽  
The Mean ◽  
Content Range ◽  
Wheat Seeds

Abstract The objective of this study was the evaluation of the aerodynamic properties of Makhobeli, triticale and wheat seeds as a function of moisture content from 7 to 27% (w.b). The results showed that the terminal velocity of triticale and wheat seeds increased linearly from 5.37 to 6.42 and from 6.31 to 8.02 m s-1, respectively, as the moisture content increased from 7 to 27%. Over this same moisture content range, the terminal velocity of Makhobeli seeds varied following a polynomial relationship from 4.52 to 5.07 m s-1. Makhobeli seeds had terminal velocities with a mean value of 4.73 m s-1, at different moisture contents, compared to the mean values of 5.89 and 7.13 m s-1 for triticale and wheat seeds, respectively. The mean value of drag coefficient was 1.12 for Makhobeli compared to the values of 0.92 and 0.85 for triticale and wheat, respectively. The analysis of variance showed that there were significant differences between the terminal velocity (at 1 % probability level) and drag coefficient (at 5% probability level) of Mak-hobeli with triticale and wheat seeds, which suggests that aerodynamic separation of Makhobeli from triticale and wheat is possible.

Existence of a sharp transition in the peak propulsive efficiency of a low- pitching foil

2016 ◽  
Vol 800 ◽  
pp. 307-326 ◽  
Author(s):  
Anil Das ◽  
Ratnesh K. Shukla ◽  
Raghuraman N. Govardhan
Keyword(s):  
Power Coefficient ◽  
Energetic Cost ◽  
Mean Power ◽  
Thrust Coefficient ◽  
Propulsive Efficiency ◽  
Von Karman ◽  
Wide Range ◽  
The Mean ◽  
The One ◽  
Von Kármán

We perform a comprehensive characterization of the propulsive performance of a thrust generating pitching foil over a wide range of Reynolds ($10\leqslant Re\leqslant 2000$) and Strouhal ($St$) numbers using a high-resolution viscous vortex particle method. For a given $Re$, we show that the mean thrust coefficient $\overline{C_{T}}$ increases monotonically with $St$, exhibiting a sharp rise as the location of the inception of the wake asymmetry shifts towards the trailing edge. As a result, the propulsive efficiency too rises steeply before attaining a maximum and eventually declining at an asymptotic rate that is consistent with the inertial scalings of $St^{2}$ for $\overline{C_{T}}$ and $St^{3}$ for the mean power coefficient, with the latter scaling holding, quite remarkably, over the entire range of $Re$. We find the existence of a sharp increase in the peak propulsive efficiency ${\it\eta}_{max}$ (at a given $Re$) in the $Re$ range of 50 to approximately 1000, with ${\it\eta}_{max}$ increasing rapidly from about 1.7 % to the saturated asymptotic value of approximately $16\,\%$. The $St$ at which ${\it\eta}_{max}$ is attained decreases progressively with $Re$ towards an asymptotic limit of $0.45$ and always exceeds the one for transition from a reverse von Kármán to a deflected wake. Moreover, the drag-to-thrust transition occurs at a Strouhal number $St_{tr}$ that exceeds the one for von Kármán to reverse von Kármán transition. The $St_{tr}$ and the corresponding power coefficient $\overline{C_{p,}}_{tr}$ are found to be remarkably consistent with the simple scaling relationships $St_{tr}\sim Re^{-0.37}$ and $\overline{C_{p,}}_{tr}\sim Re^{-1.12}$ that are derived from a balance of the thrust generated from the pitching motion and the drag force arising out of viscous resistance to the foil motion. The fact that the peak propulsive efficiency degrades appreciably only below $Re\approx 10^{3}$ establishes a sharp lower threshold for energetically efficient thrust generation from a pitching foil. Our findings should be generalizable to other thrust-producing flapping foil configurations and should aid in establishing the link between wake patterns and energetic cost of thrust production in similar systems.

Urban Native Food in Johannesburg

Africa ◽  
1936 ◽  
Vol 9 (2) ◽  
pp. 277-290 ◽  
Author(s):  
Ellen Hellmann
Keyword(s):  
Urban Environment ◽  
Food Habits ◽  
Close Contact ◽  
Free Play ◽  
The Other ◽  
Factors Affecting ◽  
European Culture ◽  
Wide Range ◽  
Two Factors ◽  
The One

There are two factors affecting the diet of urban Natives: on the one hand there is the expansive influence of assimilation to and adoption of European food habits, and on the other hand there is active a restrictive influence in the shape of poverty. The urban Native, through his close contact with European culture which residence in an urban environment inevitably entails, has been introduced to an extraordinarily wide range of new foodstuffs and new ways of preparing food. Consequently the range of his food desires has been much increased. But his desires are not allowed free play among this new and wide selection. The factor which narrows down his choice and curbs his desire is his poverty. The urban Native eats according to the capacity of his pocket and his food is usually the first item of expenditure which is marked out for especial economy.

A new approach to the measurement of the quantitative effects of inherent and environmental factors on the composition of the milk of individual cows and of herds, with particular reference to lactose content

1968 ◽  
Vol 35 (1) ◽  
pp. 91-105 ◽  
Author(s):  
J. P. Walsh ◽  
J. A. F. Rook ◽  
F. H. Dodd
Keyword(s):  
Quantitative Estimation ◽  
Relative Importance ◽  
New Approach ◽  
Mean Values ◽  
Stage Of Lactation ◽  
Bulk Milk ◽  
Wide Range ◽  
The Mean ◽  
The Difference ◽  
Effect Of Age

Summary(1) A tentative scheme is proposed for the quantitative estimation of the effects of various factors on one major milk constituent, lactose, from analyses of the milk of individual cows within herds. The potential lactose content in the milk of individual cows is predicted from the observed potassium-to-lactose ratio in the milk, and the difference between the predicted potential and the actual lactose content is partitioned into fractions that are attributed to effects due to age, inter-quarter difference and changes with stage of lactation. The scheme was applied to 2 commercial herds, one (herd A) producing milk of low and the other (herd B) milk of normal SNF content.(2) Lactation mean values for fat, SNF and lactose contents of the milk of individual cows showed a wide range of the same order in each of the 2 herds. Of the mean difference in SNF percentage of 0·30 between the herds, 0·14, or 47%, was due to a difference in lactose content.(3) The predicted potential milk lactose content of the cows in the 2 herds ranged from 5·04 to 5·66 (g/100 g milk water). Herd mean values were 5·394 for herd A and 5·244 for herd B.(4) Herd mean values for the effect on the lactose content (g/100 g milk water) of age, of changes with stage of lactation and of inter-quarter difference were −0·127, −0·080, and 0·073 respectively in herd A, and −0·197, −0·058 and −0·078, respectively, in herd B.(5) The relative importance of the various factors in accounting for differences between the herds in the lactose content of their bulk milk were: predicted potential lactose content 61%, effect of age 28%, effect of changes with stage of lactation 9% and effect of inter-quarter difference 2%.(6) The errors attached to the estimation of potential milk lactose content and the effects of age, of changes with stage of lactation and of inter-quarter difference are discussed.

scholarly journals Comparison of Four Radiographic Angular Measures of Lumbar Lordosis

2018 ◽  
Vol 09 (03) ◽  
pp. 298-304 ◽  
Author(s):  
Francis Osita Okpala
Keyword(s):  
Standard Deviation ◽  
Lumbar Lordosis ◽  
Joint Angle ◽  
Mean Values ◽  
Normal Individuals ◽  
Wide Range ◽  
Normal Mean ◽  
The Mean ◽  
Range Of Values

ABSTRACT Background: Several attempts (radiographic and nonradiographic) have been made to measure the lumbar lordosis (LL), but the results differ substantially as investigators have used different parameters. Radiography is the gold standard, and the methods include lumbosacral angle (LSA), lumbosacral joint angle (LSJA), Cobb angle, and tangential radiologic assessment of LL (TRALL) angle. The traditional method, the Cobb technique, has a wide range of normal mean values, with a large standard deviation. Using a more reliable radiographic angle will hopefully simply and standardize LL measurement in the diagnosis, treatment, and follow-up of patients. Aim: To compare in normal individuals with fully developed LL the LSA, LSJA, TRALL, and Cobb angles, by determining (a) if any correlation exists between them and (b) the most reliable measures of LL, based on, least (i) number of measurement lines, (ii) range of values, (iii) mean, (iv) standard deviation, and (v) variance. Materials and Methods: The four angles were retrospectively measured in each supine lateral lumbosacral radiograph of 100 males and 100 females, aged 15 years and above. Data were analyzed with IBM SPSS Statistics 23.0 (NY, USA); P < 0.05 was considered statistically significant. Results: No correlation existed between the mean values of the four angles, and in each angle, there was no male-versus-female correlation. LSJA had the best reliability criteria for LL measurement. Conclusion: The mean LSA, LSJA, TRALL, and Cobb angles have no significant Pearson's correlation, and of the four angular measures of LL, LSJA was the most reliable.

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