scholarly journals Field method for determination of the performance parameters of an operating structure and its heating system

1977 ◽  
Author(s):  
A L Berlad
Keyword(s):  
Heating System ◽  
Field Method ◽  
Performance Parameters

Determination of levitated molten metal shape in axisymmetric induction heating system using sensitivity analysis

1995 ◽  
Vol 31 (3) ◽  
pp. 2158-2161 ◽  
Author(s):  
Ghun-Deok Suh ◽  
Hong-Bae Lee ◽  
Song-Yop Hahn ◽  
Tae-Kyung Chung ◽  
Il-Han Park
Keyword(s):  
Sensitivity Analysis ◽  
Molten Metal ◽  
Induction Heating ◽  
Heating System ◽  
Induction Heating System ◽  
Metal Shape

Rapidly extracted (0.02 M CaCl2-soluble) reactive aluminum as a measure of aluminum toxicity in soils

Soil Research ◽  
1989 ◽  
Vol 27 (4) ◽  
pp. 663 ◽  
Author(s):  
EA Close ◽  
HKJ Powell
Keyword(s):  
Salicylic Acid ◽  
White Clover ◽  
Aluminum Toxicity ◽  
Maximum Yield ◽  
Acid Soils ◽  
Aluminium Toxicity ◽  
Field Method ◽  
Colorimetric Analysis ◽  
Aluminium Species

This paper examines the use of short extraction times, and the determination of aluminium with chrome azurol S (CAS), for the estimation of 0.02 M CaCl2-soluble aluminium in soils. It reports the correlation between CAS-reactive aluminium in 5 min extracts and percent maximum yield of white clover (Trifolium repens) for a series of acid soils. The reactivity of soluble and colloidal aluminium species with the metallochromic reagent CAS has been assessed. ~ l ( a q ) ~ + , simple hydroxy species and complexes of weakly binding ligands (salicylic acid, tannins) are CAS-reactive (2 rnin). In contrast, complexes of strongly binding ligands (citric acid, fulvic acid) are not CAS-reactive ([Al] ~ [L] ~ [CAS] ~ 1-2~10-5 M). For a series of six limed phosphated topsoils and subsoils (pH 4.2-5.5), 0.02 M CaCl2- soluble aluminium, as determined with CAS, was negatively correlated against the percent maximum yield of white clover; r2 = -0.73** (5 min extraction), n = 20. This correlation is similar to that for yield against total aluminium as determined by atomic absorption spectroscopy after 60 min extraction (r2 = -0.77**). However, the colorimetric analysis is more convenient and sensitive; further, it does not measure colloidal and polymeric aluminium species (which may not be plant-available). The satisfactory correlation achieved for short extraction times suggests use of CAS for a rapid field method for aluminium toxicity in soils.

scholarly journals Determination of bearing capacity of shallow foundations without using superposition approximation

2003 ◽  
Vol 40 (2) ◽  
pp. 450-459 ◽  
Author(s):  
D Y Zhu ◽  
C F Lee ◽  
K T Law
Keyword(s):  
Bearing Capacity ◽  
Field Method ◽  
Ultimate Bearing Capacity ◽  
Shallow Foundation ◽  
Closed Form Expression ◽  
Safe Side ◽  
Superposition Approximation ◽  
Bearing Capacity Factor ◽  
Rigorous Procedure

The Terzaghi superposition assumption has been widely used to determine the bearing capacity of shallow footings. Although this assumption always errs on the safe side, a rigorous procedure to calculate the bearing capacity is still of engineering value. This paper presents such a procedure that is free from errors as a result of the superposition assumption. It demonstrates that the ultimate bearing capacity can be precisely expressed by the Terzaghi equation, except that the bearing capacity factor Nγ is dependent upon the surcharge ratio. A recently developed numerical method, i.e., the critical slip field method, is used to calculate the modification coefficient for modifying Nγ. It is found that this modification coefficient increases with the surcharge ratio at small values of surcharge ratio and then remains constant for large values of surcharge ratio. However, the errors invoked by the superposition assumption do not exceed 10%. On the basis of numerical calculations, a simple closed-form expression of the modification coefficient is proposed that yields the theoretically rigorous ultimate bearing capacity. In the later part of the paper, errors in bearing capacity calculations owing to the use of conventional procedures are analyzed. It is concluded that the continued use of conventional procedures is justified, but the inherent errors should not be neglected in assessing the performance of shallow foundations.Key words: shallow foundation, strip footing, ultimate bearing capacity, critical slip field.

scholarly journals Experimental and Theoretical Study on Three Combustion Models for the Determination of the Performance Parameters of Nitrocellulose - Based Propellants

2020 ◽  
Vol 71 (9) ◽  
pp. 87-97
Author(s):  
Titi Paraschiv ◽  
Tudor Viorel Tiganescu ◽  
George Ovidiu Iorga ◽  
Raluca Elena Ginghina ◽  
Octavian Constantin Grigoroiu
Keyword(s):  
Chemical Composition ◽  
Energetic Materials ◽  
Specific Volume ◽  
Flame Temperature ◽  
Performance Parameters ◽  
Heat Of Explosion ◽  
Combustion Gases ◽  
Combustion Models ◽  
Double Base

Nitrocellulose based propellants are the main materials used for ballistic and rocket applications. The chemical composition of the propellants, the loading density and propellant grain geometry are the decisive parameters that influence the performance parameters in ballistic application. In this paper the authors evaluate three models of combustion for energetic materials for the determination of heat of explosion and specific volume together with the adiabatic flame temperature. The authors select six types of propellant (two simple base propellants, two double base propellants based on nitroglycerine and two triple base propellants based on nitroguanidine) and the authors determined the heat of explosion and specific volume using a bomb calorimeter and a Julius-Peters device. The results obtained from the combustion models were compared to the experimental results and assumptions were done on the influence of pressure and temperature on the chemical composition of combustion gases produced by the confined deflagration of nitrocellulose-based propellants.

scholarly journals Field method for the determination of molybdenum in plants

Circular ◽  
1951 ◽  
Author(s):  
Laura E. Reichen ◽  
F.N. Ward
Keyword(s):  
Field Method

A New Field Method for the Determination of Organolead Compounds in Air

1961 ◽  
Vol 33 (9) ◽  
pp. 1175-1180 ◽  
Author(s):  
L. J. Snyder ◽  
S. R. Henderson
Keyword(s):  
Field Method ◽  
Organolead Compounds
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