scholarly journals A mathematical description of maize leaf area growth using a logistic curve

2013 ◽  
Vol 39 (2) ◽  
pp. 359-365
Author(s):  
M. Seidler ◽  
A. Gregorczyk
Keyword(s):  
Leaf Area ◽  
Growth Kinetics ◽  
Least Square Method ◽  
Least Square ◽  
Logistic Curve ◽  
Total Leaf Area ◽  
Constant Coefficients ◽  
Leaf Area Growth ◽  
Kinetics Of ◽  
Logistic Curves

In this paper, an attempt is made to apply the Verhulst-Pearl and the Robertson logistic curves to the description of maize plant growth. The changes with time of the total leaf area were taken as the parameter expressing the growth kinetics. The constant coefficients in the Verhulst-Pearl and Robertson equations were calculated with the help of a logarithmic transformation and the least square method. On this basis, the growth kinetics of the studied maize lines and hybrid were compared. The applicability of logistic curves to the description of completed growth processes was demonstrated as was the fact that Robertson's equation is better suited for mathematical calculations.

scholarly journals Application of the Richards function to the description of leaf area growth in maize (Zea mays L.)

2014 ◽  
Vol 63 (1) ◽  
pp. 5-7 ◽  
Author(s):  
Andrzej Grzegorczyk
Keyword(s):  
Zea Mays ◽  
Leaf Area ◽  
Nonlinear Regression ◽  
Growth Process ◽  
Zea Mays L ◽  
Logistic Function ◽  
Area Growth ◽  
Richards Function ◽  
Constant Coefficients ◽  
Leaf Area Growth

The leaf area growth in maize was approximated basing on the Richards function in the form of: y=A[l+b exp(-kt)]<sup>1/(1-m)</sup> . The constant coefficients of the Richards function were found by means of the Marquardt's method. The initial values of parameters were given basing on results of the preliminary approximation of the growth process by means of logistic function y = A[l+b exp(-kt)]<sup>-1</sup>. The procedure of nonlinear regression was found to be useful (curvilinear determination coefficient R<sup>2</sup> = 0.995). The Richards curve precisely describes the course of changes of the leaf area in maize since sprouting to a tassel flowering phase.

The evaluation of benzene and phenol biodegradation kinetics by applying non-structured models

2010 ◽  
Vol 61 (5) ◽  
pp. 1289-1298 ◽  
Author(s):  
D. E. G. Trigueros ◽  
A. N. Módenes ◽  
F. R. Espinoza-Quiñones ◽  
A. D. Kroumov
Keyword(s):  
Competitive Inhibition ◽  
Material Balance ◽  
Least Square Method ◽  
Least Square ◽  
Statistical Criterion ◽  
Biodegradation Kinetics ◽  
Batch Mode ◽  
Phenol Biodegradation ◽  
Operational Conditions ◽  
Kinetics Of

The biodegradation kinetics of the aromatic hydrocarbons benzene and phenol as single substrates and as a mixture were investigated through non-structured model analysis. The material balance equations involving the models of Monod and Andrews and representing the biodegradation kinetics of individual substrates in batch mode were numerically solved. Further, utilization of a benzene–phenol mixture was described by applying more sophisticated mathematical forms of competitive, noncompetitive and uncompetitive inhibition models as well as the sum kinetic interactions parameters (SKIP) model. In order to improve the performance of the studied models, some modifications were also proposed. The Particle Swarm Global Optimization method, coded in Maple, was applied to the parameter identification procedure of each model, where the least square method was used as a search statistical criterion. The description of the biodegradation kinetics of a benzene–phenol mixture by the competitive inhibition model was based on the information that the compounds could be catabolized via one metabolic pathway of Pseudomonas putida F1. Simulation results were in good agreement with the experimental data and proved the robustness of the applied methods and models. The developed knowledge database could be very useful in the optimization of the biodegradation processes of different bioreactor types and operational conditions.

scholarly journals 167 Nutrient Uptake and Growth Performance of OH87 and OH97 Pear Rootstocks

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 419A-419
Author(s):  
Shufu Dong ◽  
Lailiang Cheng ◽  
Pinghai Ding ◽  
Guihong Bi ◽  
Leslie H. Fuchigami
Keyword(s):  
Leaf Area ◽  
Nutrient Concentrations ◽  
Total Leaf Area ◽  
Absorptive Power ◽  
Total Leaf ◽  
Uptake Rates ◽  
Shoot Number ◽  
Maximum Uptake Rate ◽  
One Year ◽  
Kinetics Of

One-year-old (Old Home) OH87 and OH97 pear rootstocks were grown in 2-gallon containers under natural conditions at Corvallis, Ore., in in 1999. Uniform plants were harvested during August and September, and total leaf area, new shoot number and length, and root growth were measured. The kinetics of NH4+ and NO3- uptake by new roots of both rootstocks were determined with the ion-depletion technique. OH87 had larger total leaf area, and more and longer shoots than OH97. Total root biomass was similiar between the two rootstocks, but OH87 had a larger proportion of new roots and more extension roots than OH97. Both rootstocks had lower Km values for NH4+ absorption than for NO3- and therefore both had greater absorptive power for NH4+ than for NO3- at the low nutrient concentrations. The maximum uptake rates (Vmax) of OH97 were similiar for both NH4+ and NO3- absorption, but OH87 had a much higher maximum uptake rate for NO3- than for NH4+.

Growth kinetics of borided layers: Artificial neural network and least square approaches

2007 ◽  
Vol 253 (14) ◽  
pp. 6226-6231 ◽  
Author(s):  
I. Campos ◽  
M. Islas ◽  
G. Ramírez ◽  
C. VillaVelázquez ◽  
C. Mota
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Growth Kinetics ◽  
Least Square ◽  
Artificial Neural ◽  
Kinetics Of

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Direct Assessment of Effective Renal Plasma Flow from Renoscintigraphy with a Gamma Camera and an On-Line Computer

1981 ◽  
Vol 20 (06) ◽  
pp. 274-278
Author(s):  
J. Liniecki ◽  
J. Bialobrzeski ◽  
Ewa Mlodkowska ◽  
M. J. Surma
Keyword(s):  
Count Rate ◽  
Renal Plasma Flow ◽  
Early Period ◽  
Least Square Method ◽  
Least Square ◽  
Uptake Coefficient ◽  
Positive Linear Correlation ◽  
On Line ◽  
Best Fit ◽  
Plasma Activity

A concept of a kidney uptake coefficient (UC) of 131I-o-hippurate was developed by analogy from the corresponding kidney clearance of blood plasma in the early period after injection of the hippurate. The UC for each kidney was defined as the count-rate over its ROI at a time shorter than the peak in the renoscintigraphic curve divided by the integral of the count-rate curve over the "blood"-ROI. A procedure for normalization of both curves against each other was also developed. The total kidney clearance of the hippurate was determined from the function of plasma activity concentration vs. time after a single injection; the determinations were made at 5, 10, 15, 20, 30, 45, 60, 75 and 90 min after intravenous administration of 131I-o-hippurate and the best-fit curve was obtained by means of the least-square method. When the UC was related to the absolute value of the clearance a positive linear correlation was found (r = 0.922, ρ > 0.99). Using this regression equation the clearance could be estimated in reverse from the uptake coefficient calculated solely on the basis of the renoscintigraphic curves without blood sampling. The errors of the estimate are compatible with the requirement of a fast appraisal of renal function for purposes of clinical diagknosis.

Growth Kinetics of Quantum Size ZnO Particles

1998 ◽  
Vol 536 ◽  
Author(s):  
E. M. Wong ◽  
J. E. Bonevich ◽  
P. C. Searson
Keyword(s):  
Growth Kinetics ◽  
Ostwald Ripening ◽  
Chemical Potential ◽  
Colloidal Suspensions ◽  
Green Emission ◽  
Blue Shift ◽  
Constant Current ◽  
Mass Model ◽  
Zno Particles ◽  
Kinetics Of

AbstractColloidal chemistry techniques were used to synthesize ZnO particles in the nanometer size regime. The particle aging kinetics were determined by monitoring the optical band edge absorption and using the effective mass model to approximate the particle size as a function of time. We show that the growth kinetics of the ZnO particles follow the Lifshitz, Slyozov, Wagner theory for Ostwald ripening. In this model, the higher curvature and hence chemical potential of smaller particles provides a driving force for dissolution. The larger particles continue to grow by diffusion limited transport of species dissolved in solution. Thin films were fabricated by constant current electrophoretic deposition (EPD) of the ZnO quantum particles from these colloidal suspensions. All the films exhibited a blue shift relative to the characteristic green emission associated with bulk ZnO. The optical characteristics of the particles in the colloidal suspensions were found to translate to the films.

PENGARUH KNOWLEDGE MANAGEMENT, KOMPETENSI, MOTIVASI TERHADAP KINERJA KARYAWAN

2015 ◽  
Vol 5 (2) ◽  
pp. 1
Author(s):  
Miftahol Arifin
Keyword(s):  
Knowledge Management ◽  
Linear Regression ◽  
Significant Influence ◽  
Employee Performance ◽  
Least Square Method ◽  
Least Square ◽  
Analysis Tool ◽  
Ordinary Least Square ◽  
Competence Motivation ◽  
Performance Analyze

The purpose of this research is to analyze the influence of knowledge management on employee performance, analyze the effect of competence on employee performance, analyze the influence of motivation on employee performance). In this study, samples taken are structural employees PT.centris Kingdom Taxi Yogyakarta. The analysis tool in this study using multiple linear regression with Ordinary Least Square method (OLS). The conclusion of this study showed that the variables of knowledge management has a significant influence on employee performance, competence variables have an influence on employee performance, motivation variables have an influence on employee performance, The analysis showed that the variables of knowledge management, competence, motivation on employee performance.Keywords: knowledge management, competence, motivation, employee performance.

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