Modified factor analysis of the circular dichroism spectra, applied to a series of cyclodipeptides containing L-proline

1979 ◽  
Vol 44 (4) ◽  
pp. 1296-1311 ◽  
Author(s):  
Petr Pančoška ◽  
Ivo Frič ◽  
Karel Bláha
Keyword(s):  
Mathematical Model ◽  
Factor Analysis ◽  
Hilbert Spaces ◽  
Principal Components ◽  
Structural Characteristics ◽  
Cd Spectra ◽  
Modified Method ◽  
Minimum Number ◽  
Related Compounds

A mathematical model has been developed which uses the theory of Hilbert spaces and the modified method of the principal components of the factor analysis to the determination of the minimum number of subspectra sufficient to describe a set of experimental CD curves of a series of structurally related compounds. The use of this method has been demonstrated on the CD spectra of nine cyclodipeptides containing (besides L-proline) glycine, L or D alanine, L or D valine, L or D leucine, and L or D tert-leucine, measured in acetonitrile and 2,2,2-trifluoroethanol. Relation is discussed between the calculated subspectra and the structural characteristics of the measured systems.

Impairment and Disability in Patients with Facial Neuromuscular Dysfunction

1997 ◽  
Vol 117 (4) ◽  
pp. 315-321 ◽  
Author(s):  
Jennifer S. Brach ◽  
Jessie Van Swearingen ◽  
Anthony Delitto ◽  
Peter C. Johnson
Keyword(s):  
Factor Analysis ◽  
Facial Nerve ◽  
Clinical Outcomes ◽  
Principal Components ◽  
Social Function ◽  
Grading System ◽  
Temporal Characteristics ◽  
Neuromuscular Dysfunction ◽  
Comprehensive Picture

Integration of impairment measures and disability measures may provide clinicians with an accurate and comprehensive picture of the patient's dysfunction. The purpose of this study was to indicate the usefulness of two new scales of measuring facial impairment and disability in describing characteristics of individuals with facial neuromuscular dysfunction. Fifty-one individuals with unilateral facial neuromuscular dysfunction and a House-Brackmann grade of III or higher were included in the study. The subjects' movement impairments were assessed using the Facial Grading System (FGS). The subjects reported their physical and social function on the Facial Disability Index (FDI). Nine variables were subjected to a confirmatory principal-components factor analysis to indicate important factors in describing patients with facial nerve disorders. The confirmatory principal-components factor analysis identified three factors, impairment, disability, and temporal characteristics of disease, accounting for 72% of the variance in describing individuals with facial neuromuscular dysfunction. Integration of these measures may provide clinicians with an accurate and comprehensive picture of the patient's dysfunction, thus aiding in the determination of intervention and the measurement of clinical outcomes.

scholarly journals Experimental and Theoretical Investigation on the Thermochemistry of 3-Methyl-2-benzoxazolinone and 6-Nitro-2-benzoxazolinone

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 24
Author(s):  
Ana L. R. Silva ◽  
Vânia M. S. Costa ◽  
Maria D. M. C. Ribeiro da Silva
Keyword(s):  
Gas Phase ◽  
Structural Characteristics ◽  
Enthalpies Of Formation ◽  
Calvet Microcalorimetry ◽  
Static Bomb ◽  
High Level ◽  
The Relationship ◽  
Related Compounds ◽  
Enthalpies Of Sublimation

The determination of the reliable thermodynamic properties of 2-benzoxazolinone derivatives is the main goal of this work. Some correlations are established between the energetic properties determined and the structural characteristics of the title compounds, and the reactivity of this class of compounds is also evaluated. Static-bomb combustion calorimetry and high-temperature Calvet microcalorimetry were used to determine, respectively, the standard molar enthalpies of formation in the solid state and the standard molar enthalpies of sublimation, both at T = 298.15 K. Using the results obtained for each compound, the respective gas-phase standard molar enthalpy of formation was derived. High-level quantum chemical calculations were performed to estimate the same property and the results evidence good accordance. Moreover, the gas-phase relative thermodynamic stability of 2-benzoxazolinone derivatives was also evaluated using the respective gas-phase standard molar Gibbs energy of formation. In addition, the relationship between the energetic and structural characteristics of the benzoxazolinones is presented, evidencing the enthalpic increments associated with the presence of a methyl and a nitro groups in the molecule, and this effect is compared with similar ones in other structurally related compounds.

Capillary Scanning of a Porous Matrix. Experimental Techniques and Processing of its Results

2019 ◽  
Vol 7 (4) ◽  
pp. 29-42
Author(s):  
А. Синцов ◽  
A. Sintsov ◽  
Владимир Девисилов ◽  
Vladimir Devisilov
Keyword(s):  
Mathematical Model ◽  
Porous Structure ◽  
Structural Characteristics ◽  
Experimental Methods ◽  
Porous Matrix ◽  
Experimental Setup ◽  
Porous Structures ◽  
Porous Sample ◽  
Starting Position

The article presents an analysis of the possibilities of the previously unused method for the experimental study of porous permeable materials and the determination of their structural characteristics. The purpose of the experiment is to determine the geometric parameters of the porous matrix, which integrates the characteristics of the porous material. An example of analytical scanning of a porous structure is considered. A review of existing experimental methods is given. A scheme of the experimental setup, methods for conducting a capillary experiment and processing the data obtained are proposed. As an example, a mathematical model of the experiment is used, illustrating the possible results of the study of a porous sample. It is shown how the results of experiments are transformed into a porous matrix and are interpreted as its capillary scanning. It is proved that this model of porous structure can be used as a starting position in the mathematical calculations of the processes occurring in porous structures.

scholarly journals Determination of the structural and chemisorption characteristics of granulated active charcoal on the basis of coconut shell

2004 ◽  
Vol 58 (9) ◽  
pp. 416-422
Author(s):  
Dragan Milenkovic ◽  
Stanisa Stoiljkovic ◽  
D.R. Ilic
Keyword(s):  
Mathematical Model ◽  
Aqueous Solution ◽  
Structural Characteristics ◽  
Active Charcoal ◽  
Wastewater Purification ◽  
Industrial Plants ◽  
Coconut Shells ◽  
Kinetics Of ◽  
Regression Correlation

Wastewater purification and the acquirement of drinking water from water streams that are in most cases recipients of various industrial plants, present a significant problem nowadays. The structural characteristics of granulated active charcoal (GAC) obtained by the carbonization of coconut shells and activated by steam are presented in this paper. The established kinetics of suspending cyanide from aqueous solution using GAC impregnated with copper(II) acetate were studied and a mathematical model estabkusged by a regression - correlation analysis.

DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

2020 ◽  
pp. 19-26
Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar
Keyword(s):  
Mathematical Model ◽  
Surface Friction ◽  
Building Structures ◽  
Maximum Torque ◽  
Military Equipment ◽  
Military Vehicles ◽  
Force Magnitude ◽  
Vehicle Mobility ◽  
The Mathematical Model

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.

Determination of the minimum number of technological bases of a part

2020 ◽  
pp. 73-75
Author(s):  
B.M. Bazrov ◽  
T.M. Gaynutdinov
Keyword(s):  
Cost Price ◽  
Labor Input ◽  
Part Surface ◽  
Technological Base ◽  
Size Accuracy ◽  
Minimum Number ◽  
The Cost ◽  
Input Cost ◽  
Selection Of

The selection of technological bases is considered before the choice of the type of billet and the development of the route of the technological process. A technique is proposed for selecting the minimum number of sets of technological bases according to the criterion of equality in the cost price of manufacturing the part according to the principle of unity and combination of bases at this stage. Keywords: part, surface, coordinating size, accuracy, design and technological base, labor input, cost price. [email protected]

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