Graphical determination of specific-volume anomaly and current

1951 ◽  
Vol 32 (5) ◽  
pp. 719 ◽  
Author(s):  
E. B. Callaway
Keyword(s):  
Specific Volume ◽  
Volume Anomaly

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 Determination of partial specific volume and absolute concentration by densimetry

1984 ◽  
Vol 219 (3) ◽  
pp. 1049-1052 ◽  
Author(s):  
P H Stothart
Keyword(s):  
Absorption Coefficient ◽  
Neutron Scattering ◽  
Prior Knowledge ◽  
Small Angle ◽  
Specific Volume ◽  
Small Angle Neutron Scattering ◽  
Partial Specific Volume ◽  
Absolute Concentration ◽  
Non Destructive

The apparent partial specific volume, phi, of a protein (or other macromolecule) and the absolute concentration, c, can be determined from the densimetry of solutions and diffusates in 1H2O, 2H2O and 1H2O/2H2O mixtures if the ratios of concentrations (relative concentrations) are known. The densimetry method allows a non-destructive check on total macromolecule concentrations without prior knowledge of specific u.v.-absorption coefficient. The method may be especially useful in small-angle neutron-scattering studies.

Infrared Determination of Dithianon

1969 ◽  
Vol 52 (3) ◽  
pp. 659-662
Author(s):  
R C Double
Keyword(s):  
Infrared Absorption ◽  
Spectrophotometric Method ◽  
Specific Volume

Abstract An infrared spectrophotometric method of analysis of dithianon in concentrates and formulated powders containing zineb and sulfur has been developed. Dithianon is extracted with chloroform from the concentrate or formulation; the extract is evaporated and diluted to a specific volume with chloroform; and the dithianon present is determined from the infrared absorption at 1275 cm-1. From 20 to 80 mg dithianon in 10 ml chloroform are readily determined.

Application of dn/dc Data for Determination of Partial Specific Volumes of Dissolved Macromolecules

1967 ◽  
Vol 40 (4) ◽  
pp. 1281-1295
Author(s):  
Wilfried Heller
Keyword(s):  
Specific Volume ◽  
Solution Process ◽  
Time Rate ◽  
Interpolation Procedure ◽  
Specific Volumes

Abstract The principles of a method are outlined whereby one can determine the partia specific volume of a solute, V, by means of measurements of dn/dc using a suitable pair of equations and a simple graphical interpolation procedure. The method yields V data which compare well with densitometrically obtained V data if the polarizability of both solvent and solute molecules is unaffected by the solution process. It is tested successfully on solutions of polystyrene in various solvents. The method appears to be particularly attractive for measurements of the change of V with temperature and also for conveniently following the time rate of changes in V such as during the coil → helix transition.

scholarly journals PARÂMETROS DE QUALIDADE DO PÃO FRANCÊS

2001 ◽  
Vol 19 (2) ◽  
Author(s):  
SILA MARY RODRIGUES FERREIRA ◽  
PATRÍCIA V. DE OLIVEIRA ◽  
DANIELA PRETTO
Keyword(s):  
Specific Volume ◽  
Dry Weight ◽  
Volume Density ◽  
Evaluation Methodology ◽  
Dry Extract ◽  
Physical Chemical ◽  
Product Classification ◽  
Selection Of

Devido à ausência de metodologia para avaliação da qualidade do pão francês em Sistema de Alimentação Coletiva, o presente trabalho teve como objetivo avaliar os parâmetros físicos, físico-químicos e sensoriais do pão francês, comercializado em cinco panificadoras de Curitiba. Nas análises físicas, em cinco repetições, as amostras foram submetidas à determinação do peso, volume, volume específico, densidade e peso seco. As análises físicoquímicas foram realizadas em triplicata de acordo com procedimento da Association of Official Analytical Chemists (AOAC). Para avaliar a qualidade do pão foi utilizada a metodologia do sistema de pontuação global, mediante análise sensorial dos seguintes atributos: cor da crosta, forma e simetria, características da crosta, aspecto da pestana, aspecto de quebra da crosta, cor do miolo, porosidade, textura, aroma e sabor. Atribuiu-se pontuação (de 0 a 5) para cada variável, a qual foi multiplicada pelo fator que expressa a importância relativa de cada variável (totalizando 100 pontos), obtendo-se a classificação dos produtos pela soma dos pontos. Os resultados dos testes físicos e físicoquímicos das cinco amostras de pão francês apresentaram média de 52,23 g de peso, 31,98% de umidade, 68,02% de extrato seco, 35,49 g de peso seco, 371,8 cm3 de volume, 7,23 cm3/g de volume específico e 0,15 g/cm3 de densidade. As amostras XA, XB e XC apresentaram os melhores resultados podendo ser consideradas como as melhores. Na classificação pelo sistema de pontuação global, as amostras apresentaram diferença em nível de 1% de significância em relação à qualidade. As amostras XA e XB apresentaram boa qualidade, seguidas pelas amostras XC e XE (regular), sendo a amostra XD classificada como ruim. Os resultados obtidos permitem sugerir a adoção desta metodologia de avaliação para seleção de pão francês, em Sistema de Alimentação Coletiva. QUALITY PATTERNS OF FRENCH BREAD Abstract Due to the absence of a methodology to evaluate the quality of French bread in a Production of Collective Meals System, the present work had as objective to evaluate the quality, physical, physical-chemical and sensorial parameters of the French bread marketed in five bakeries in Curitiba (Brazil). In the physical analyses, with five repetitions, the samples were submitted to the determination of weight, volume, specific volume, density and dry weight. The physical-chemical analysis was accomplished with three replicates in agreement with the AOAC procedure. To evaluate the quality of the bread, the methodology of global punctuation system was used, by sensorial analysis of the following attributes: color of the crust, form and symmetry, characteristics of the crust, aspect of the lash, aspect of crust break, color of the crumb, porosity, texture, aroma and flavor. For each variable a grade (from 0 to 5) was attributed, which was multiplied by a factor that expressed the relative importance of each variable (to a total of 100 points), obtaining the product classification by the sum of the points. The results of the physical and physical-chemical tests of the five samples of French bread presented an average of 52,23 g of weight; 31,98% of humidity, 68,02% of dry extract, 35,49 g of dry weight, 371,8 cm3 of volume, 7,23 cm3/g of specific volume and 0,15 g/cm3 of density. The samples XA, XB and XC presented better results and could be considered as the best. In the classification using the global punctuation system, the samples presented difference at the level of 1% of significance in relation to the quality. The samples XA and XB presented good quality, followed by the samples XC and XE (regular), being the sample XD classified as bad. The results obtained allow suggest the evaluation methodology for selection of French bread in a Production of Collective Meals System.

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