Research of the Mechanism of Destruction of Compression Molds for Casting under Pressure of Color Alloys

2018 ◽  
Vol 284 ◽  
pp. 326-331 ◽  
Author(s):  
R.V. Gavariev ◽  
I.A. Savin
Keyword(s):  
Vapour Deposition ◽  
Optimum Structure ◽  
Pilot Studies ◽  
Method Of Calculation ◽  
Operational Characteristics ◽  
Building Surfaces

In the article various approaches to a research of the mechanism of destruction of form-building surfaces of compression molds for the casting under pressure (CUP) are considered. The main reasons for emergence of various defects of working surfaces of form-building details are defined. Method of calculation of the parameters allowing to define operability of concrete products are specified. The option of production of form-building surfaces with the raised operational characteristics drawing sheetings by method of phisical vapour deposition (PVD). is offered. Results of pilot studies on determination of optimum structure of a covering for a form-building surface are given.

scholarly journals Operational Characteristics of Filtering Partitions from Wire Grids with Cells of Micron Sizes

10.12737/2163 ◽  
2013 ◽  
Vol 2 (6) ◽  
pp. 52-57 ◽  
Author(s):  
Новиков ◽  
Yu. Novikov ◽  
Спиридонов ◽  
V. Spiridonov ◽  
Большаков ◽  
...  
Keyword(s):  
Hydraulic Resistance ◽  
Permeability Coefficient ◽  
Large Scale ◽  
Channel Model ◽  
Grid Cell ◽  
Resistance Coefficient ◽  
Pilot Studies ◽  
Set Size ◽  
Operational Characteristics

Results of pilot studies related to hydraulic resistance of wire woven grids with cells of micron sizes in laminar mode of a filtration have been presented. For assessment of grids hydraulic resistance the permeability coefficient value has been used. To overcome the effect of a large-scale factor on conducted researches results the dimensionless size of this parameter in the form of permeability coefficient relation to a square of the grid cell size is entered. The researches have been conducted on free-flow hydraulic installation by specially developed technique providing high precision determination of this parameter. Influence like wires interlacing at a size of dimensionless coefficient of permeability is established. Nature of influence like wires interlacing at a size of this parameter is confirmed with results of wire grids internal structure analysis. On the basis of obtained data the choice technique like grid has been developed for production of a filtering partition with optimum characteristics at the set size of filtering nominal subtlety. On the basis of porous body channel model the assessment of hydraulic resistance coefficient value of wire grids with various type of wires interlacing has been carried out. Dependence of this parameter on wires interlacing type has been established. Groundlessness of interstice’s tortuosity coefficient use at assessment of grids hydraulic resistance has been shown.

scholarly journals Dual 2-Hydroxypropyl-β-Cyclodextrin and 5,10,15,20-Tetrakis (4-Hydroxyphenyl) Porphyrin System as a Novel Chiral-Achiral Selector Complex for Enantioseparation of Aminoalkanol Derivatives with Anticancer Activity in Capillary Electrophoresis

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 993
Author(s):  
Błażej Grodner ◽  
Mariola Napiórkowska
Keyword(s):  
Capillary Electrophoresis ◽  
Anticancer Agents ◽  
Chiral Discrimination ◽  
Combined Effects ◽  
Pilot Studies ◽  
Repeatability And Reproducibility ◽  
The Stability ◽  
Short Time ◽  
High Separation

In this study, a complex consisting of 2-hydroxypropyl-β-cyclodextrin and 5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin, (named dual chiral-achiral selector complex) was used for the determination of two novel potential anticancer agents of (I) and (II) aminoalkanol derivatives. This work aimed at developing an effective method that can be utilized for the determination of I (S), I (R), and II (S) and II (R) enantiomers of (I) and (II) compounds through the use of a dual chiral-achiral selector complex consisting of hydroxypropyl-β-cyclodextrin and 5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin system by applying capillary electrophoresis. This combination proved to be beneficial in achieving high separation selectivity due to the combined effects of different modes of chiral discrimination. The enantiomers of (I) and (II) compounds were separated within a very short time of 3.6–7.2 min, in pH 2.5 phosphate buffer containing 2-hydroxypropyl-β-cyclodextrin and 5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin system at a concentration of 5 and 10 mM, respectively, at 25 °C and +10 kV. The detection wavelength of the detector was set at 200 nm. The LOD for I (S), I (R), II (S), and II (R) was 65.2, 65.6, 65.1, and 65.7 ng/mL, respectively. LOQ for I (S), I (R), II (S), and II (R) was 216.5, 217.8, 217.1, and 218.1 ng/mL, respectively. Recovery was 94.9–99.9%. The repeatability and reproducibility of the method based on the values of the migration time, and the area under the peak was 0.3–2.9% RSD. The stability of the method was determined at 0.1–4.9% RSD. The developed method was used in the pilot studies for determining the enantiomers I (S), I (R), II (S), and II (R) in the blood serum.

Temperature Preference and Avoidance Responses of the Crayfish, Orconectes obscurus, and Associated Statistical Problems

1982 ◽  
Vol 39 (4) ◽  
pp. 548-553 ◽  
Author(s):  
Dilip Mathur ◽  
Robert M. Schutsky ◽  
Edmund J. Purdy Jr.
Keyword(s):  
Acclimation Temperature ◽  
Published Data ◽  
Temperature Preference ◽  
Preferred Temperature ◽  
Field Collection ◽  
Method Of Calculation ◽  
Final Preferred Temperature ◽  
Statistical Problems ◽  
Avoidance Responses

Acute temperature selection and avoidance responses of the crayfish, Orconectes obscurus, acclimated at field collection temperatures of 1.5–26.0 °C and determined in a spatial thermal gradient, were similar to those noted for fishes. Acclimation temperature was positively correlated with the acute preferred and avoided temperatures; both were several degrees higher than the acclimation temperature. A large proportion of the total variance in these data was unexplained. Most variable responses occurred at low acclimation temperatures. The estimated final preferred temperature ranged from 29.8 to 33.9 °C depending upon the method of calculation. Methods of estimating final preferenda from acute tests are considered arbitrary due to statistical problems and the associated high variability. Statistical problems were also noted in the determination of avoidance temperatures of crayfish due to nonindependence of observations on the same organism. No differences were noted (P < 0.05) between the preferred or avoided temperatures when the direction of field temperatures was rising or falling. A statistical comparison of the new and published data on this species revealed general similarities, particularly over an acclimation temperature range of 18.0–30.0 °C. The analysis minimizes the importance of site-specific studies on this species using the current acute testing methods.Key words: crayfish, temperature preference, avoidance, populational variation, statistics, experimental and statistical problems

Calcul des éléments dipolaires et quadrupolaires de la matrice de transition moléculaire dans Na2

1990 ◽  
Vol 68 (4-5) ◽  
pp. 365-368 ◽  
Author(s):  
K. Hussein ◽  
O. Babaky
Keyword(s):  
Numerical Integration ◽  
Electronic States ◽  
Transition Elements ◽  
Simple Method ◽  
Selection Rules ◽  
Variable Formula ◽  
Method Of Calculation ◽  
Analytical Integration ◽  
Fifth Order

In this paper, we study a calculation of the transition elements [Formula: see text] between electronic states of the diatomic molecules Na2. We show the necessary selection rules for the determination of these operators by a method of analytical integration on the variable [Formula: see text], combined with a numerical integration to fifth order. The values found by this simple method of calculation are very reasonable and show that the important transitions [Formula: see text], [Formula: see text]; and [Formula: see text] of the dimer Na2 are dipolar. [Traduit par la revue]

Determination of Ardacin in Various Silage Feed Diets by a Rapid Liquid Chromatographic Assay

1995 ◽  
Vol 78 (1) ◽  
pp. 16-21
Author(s):  
Sylvia V B Fagan ◽  
Connie Gombatz ◽  
Hafez Abdel-Kader ◽  
Govind Menon
Keyword(s):  
Mobile Phase ◽  
Solid Phase ◽  
Chromatographic System ◽  
Method Of Calculation ◽  
Feed Formulation ◽  
Sample Extract ◽  
Liquid Chromatographic ◽  
Solid Phase Extract ◽  
Cyano Column

Abstract A method is presented for the detection and quantitation of Ardacin in silage feed diets by liquid chromatography, using a cyano column and an acetonitrile–methanol water mobile phase modified with trifluoroacetic acid. This method includes comprehensive procedures for extracting Ardacin from various silage feed formulations, cleaning up the extracted sample by using solid-phase extractions, and analyzing the eluted solid-phase extract with a suitable liquid chromatographic system. Ardacin was extracted from the silage feed formulations with 50% acetonitrile and 50% 0.1 M KOH. The extract was cleaned up with a wide-pore butyl solidphase extraction cartridge. The sample extract was chromatographed and quantified at 220 nm, using an external method of calculation. Recoveries of the medicated silage feed formulation ranged from 72.1 ± 1.7% to 109.1 ± 2.4%, depending on the sites and types of formulation analyzed.

scholarly journals A critical evaluation of the methods for the determination of required volumes for detention tank

2018 ◽  
Vol 45 ◽  
pp. 00088 ◽  
Author(s):  
Mariusz Starzec
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Catchment Area ◽  
Critical Evaluation ◽  
Design Parameters ◽  
Method Of Calculation ◽  
Rainfall Duration ◽  
Detention Tank ◽  
Artificial Neural

Simplified methods allow a straightforward and quick determination of parameters of interest. A simplified method of calculation to be used must provide sufficiently accurate simulation results. This paper presents the results of tests completed to evaluate the effects of the parameters which describe a sewer catchment area and network on the value of Tp, a parameter applied in the Dziopak method [18]. The results of 2997 hydrodynamic simulations allowed to formulate an artificial neural network the application of which enabled the determination of the value of Tp dependent on the design parameters of a sewer catchment area and network. The artificial neural network had a very low error R2 = 0.9972 between the expected and determined values of Tp. The completed tests indicated a relationship by which an increase of the rainfall duration, a parameter used in the dimensioning of detention tank, is concomitant to an increase in the value of Tp. The calculations made so far included an assumption that the Tp value is constant irrespective of the design rainfall duration for the dimensioning of detention tank; this assumption has led to gross calculation errors. The paper also provides proof that the inclusion of these relationships allows a more precise determination of the service volume required for a multi-chamber detention tank.

A note on the methods for determining soil water diffusivity

Soil Research ◽  
1982 ◽  
Vol 20 (1) ◽  
pp. 61
Author(s):  
HS Acharya
Keyword(s):  
Quadratic Programming ◽  
Soil Water ◽  
Water Distribution ◽  
Soil Column ◽  
Experimental Methods ◽  
Soil Columns ◽  
Method Of Calculation ◽  
Water Diffusivity ◽  
Horizontal Infiltration

In experimental methods for determination of soil water diffusivity using the water distribution from horizontal infiltration into a soil column, hand smoothing of the experimentally obtained distribution introduces uncertainties in the calculations. A method of calculation involving techniques of quadratic programming has been used to minimize the possible errors caused by inhomogeneous packing of the horizontal soil columns. Examples are given to illustrate the method of calculations.

Automated Determination of Protein-Nitrogen in Cereals and Grains

1977 ◽  
Vol 60 (6) ◽  
pp. 1238-1242
Author(s):  
Robert N Revesz ◽  
Norman Aker
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Organic Material ◽  
Combustion Products ◽  
Direct Reading ◽  
Protein Nitrogen ◽  
Operational Characteristics ◽  
Temperature Sample ◽  
Automated Determination

Abstract This paper presents the design, performance, and operational characteristics of a new direct reading instrument for determining nitrogen in cereal and grain. Precision, accuracy, range, speed, ease of operation, sensitivity, sample size, and flexibility of the instrument are presented. Results on various cereals and grains are presented and compared with those obtained by the Kjeldahl technique. The apparatus is the result of research for a rapid method for determining nitrogen in organic material. The instrument uses a combination of a unique high temperature sample oxidation, a sampling valve for separating combustion products, and thermal conductivity detection for the liberated nitrogen in a helium carrier gas.

A Multi-Purpose Planetary Gear Testing Machine for Studies of Gear Drive Dynamics, Efficiency, and Lubrication

1973 ◽  
Vol 95 (4) ◽  
pp. 1123-1130 ◽  
Author(s):  
R. Kasuba ◽  
E. I. Radzimovsky
Keyword(s):  
Gear Tooth ◽  
Measurement Techniques ◽  
Testing Machine ◽  
Planetary Gear ◽  
Gear Drive ◽  
Operational Characteristics ◽  
Surface Durability ◽  
Drive Dynamics ◽  
Selection Of

Feasibility of a multi-purpose testing machine for research studies in gearing has been demonstrated with construction of a unique gear testing machine with a differential planetary gear drive. This machine was used in such interdependent studies as determination of instantaneous gear tooth engagement loads, minimum film thicknesses, and gear efficiencies. With minimal structural and mechanical modifications, this gear research machine can be used for studies of surface durability, thermal distribution in gear meshing zones, and effects of variable torques and torsional oscillations on performance of gearing. Most of these studies could be conducted simultaneously. Upon selection of appropriate gear ratios, this machine was operated either with one or two stationary gears. Presence of stationary gears simplified greatly the measurement techniques and increased the reliability of tests. This machine can accommodate spur, helical or any special type of gearing. Design and operational characteristics of this machine, as well as a short summary of research projects performed on this machine, are presented in this paper.

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