Studying joint influence of a number of factors on borehole cleaning

Studying the behavior of cuttings transport under various conditions using experimental observations and computational fluid dynamics is the main method for analyzing the influence of cuttings, fluid and operating parameters on well cleaning. Despite the existing abundant models and recommendations of researchers, still there are problems with the accuracy of determining the cuttings layer height, critical velocity and other key parameters, which complicates the task of effective solution of the problem of borehole cleaning. The purpose of the study is to analyze the models obtained via the organization of a full factorial experiment and variance analysis to identify the influence of such factors as viscosity and flow rate of the drilling fluid in the annular space and the inclination angle of the well on the degree of cuttings transport. The studies of the kind are carried out using special devices called flow loops. Experimental data were taken from literature sources. To organize a full factorial experiment, the data of the dependent variable were combined into a combinational square, which simplified the coding of factor values. After setting the full factorial experiment, the models were obtained that made it possible to assess the contribution of the studied factors to the process of destruction product removal within the intervals determined while setting the research tasks. The obtained models allowed to determine the influence degree of each of the factors on the process under investigation. The results of the succeeding analysis of variance confirmed the indicated degree of influence and determined the rank of each of the factors in percentage.

Estimation of ergonomic indicators of special purpose clothing for patients with thermal injuries

This article discusses the determination of the optimal design allowances for a full factorial experiment in the development of special-purpose clothing for patients with thermal injuries in a hospital. To assess the ergonomic performance of special-purpose clothing, was used of pressure exerted by clothing on the human body. Based on the results of the study, a mathematical model was developed based on a full factorial experiment. In accordance with the presented mathematical models, the minimum values of contact pressures are obtained for the following values of construction parameters: for a cut with a sewn-in sleeve Warmhole = 15 cm, Ifa = 5,0 cm, Ic = 9 cm, Hse = 10 cm; for a cut with a raglan sleeve Warmhole = 15 cm, Ifa = 6 cm, Ic = 10 cm; for a cut with a one-piece sleeve Warmhole = 16 cm, Ifa = 6 cm, Ic = 11 cm.

Laser Welding Modes Optimization of the Selective Laser Melted Ti-6Al-4V Thin-Thickness Parts with Complex Shape

The paper studies laser welding of thin-thickness Ti-6Al-4V parts, manufactured by selective laser melting (SLM). A full factorial experiment was carried out in order to construct a regression model of the technological parameters (laser power, welding speed, and defocusing amount) which influence the weld shape. Metallographic analysis was carried out and it was found that thermal cycles of product printing and laser welding are equivalent. The microhardness analysis also showed no differences between the weld metal and the base metal. The contour plots of the parameters influence on the response function was constructed, and the area of welding modes was determined.

Factorial experimentation on photodegradation of historical paper by polychromatic visible radiation

Quantification of the degradation behaviour of heritage objects is essential to manage the rate of degradation and hence optimise their lifetime. In this research, a 23 full factorial experiment was carried out to deepen the understanding of the photodegradation of historical rag paper induced by continuous polychromatic visible radiation. Oxygen concentration, relative humidity and illuminance were investigated as the three environmental factors of primary concern. The effects of these factors on the rate constant of change in diffuse reflectance and tristimulus discolouration were investigated by analysis of variance and multiple linear regression. The three main effects were found to contribute the most to the rate of photodegradation of historical paper, among which relative humidity played the most important role whereas illuminance played the least. This observation is likely to hold when extrapolating the experimental conditions to real conditions in collection storage and display.

Extrusion of wheat semolina and cocoa shells

Extrusion of wheat semolina and milled cocoa shells using a single screw extruder Brabender 20DN was carried out. Full factorial experiment 23 was used to investigate the effect of the quantity of cocoa shells, moisture of the material and temperature of the matrix on the density and expansion index of extrudates. Feed screw speed and screw speed were fixed at 30 and 200 rpm, respectively. Compression ratio of the screw was 4:1. Expansion index values range between 2.0 and 3.36 and a density between 0.099 and 0.223 g/cm3. The increase in moisture content and quantity of cocoa shells leads to a decrease expansion index, while density of extrudates an increase.

A selection mechanism using multi-criteria evaluation and hierarhical classifying tree for resume data processing

The paper considers a problem of optimal feature selection for resume data processing by means of combining multicriteria evaluation technique and hierarhical classifying trees technology what makes it possible to build a selection mechanism without necessity to collect data for the learning purposes of real applicants. Instead, the learning data are generated by means of the technique used in a full factorial experiment with quite a restricted number of samples. The suggested approach minimizes the number of the features used in selection the best candidates and does not use the quantitative ratings of candidates replacing them with multi-phases classifying procedure. These peculiarities of the suggested selection mechanism make it more flexible and form a basis for applying it in conditions characterized by vagueness and fuzziness of the applicant data.

Principles of exposure of polymer materials to heat, moisture and UV-radiation and study of their properties by full factorial experiment: A review

The work is dedicated to the effects of climatic factors on polyethylene terephthalate (PET) in terms of changes in the structure and interaction of polymer molecules. The kinetic concept of the strength of PET has been developed, and the factors influencing the strength have been considered. Effects of moisture, thermal oxidative destruction, and UV-radiation on the structure of PET have been investigated. Polymers’ properties predicting, durability and their computer modeling have been analyzed. A model of changes in PET properties under the influence of temperature, moisture and UV-radiation was constructed using the methods of a full factorial experiment. It has been shown that in the initial period of exposure, adsorption and diffusion of moisture, hydrolysis and surface oxidation occur; prolonged and constant exposure to UV-radiation break the bonds formed by moisture, then the C–C and C–O bonds in the PET molecule brake and new intermolecular bonds are formed. In the amorphous state of PET, the breaking of bonds in the polymer chain and the formation of bonds between two adjacent polymer chains, the formation of more densely packed nodes, the destruction of the polymer and its aging, are equally probable. Temperature has a secondary effect, facilitating both hydrolysis and oxidation and polymer degradation.

PERFORMANCE PROPERTIES OF THREAD SEAMS OF KNITTED-BASED MEMBRANE MATERIALS

The article is devoted to the study of the strength and wear resistance of thread seams of membrane materials on a knitted basis. The characteristics of the composite membrane three-layer material are given and the modes of its stitching and the test method are substantiated. Investigations of material cutting through with a needle were carried out and the geometry of the sewing needle point was chosen. The results of the study of the strength of thread seams made along of the front layer of the material before and after modelling the operational tensile loads along and across the seam are presented. 15000 load-unload cycles were simulated, stretching the sample by 10 % of the seam length. As a result of a full factorial experiment, it was found that the linear density of the threads and the diameter of the needle have the greatest effect on the strength and wear resistance of the thread seams of the composite material. The influence of the sewing frequency is ambiguous for the parameter of the wear resistance of the seam when stretched along and across the line.

Effects of Forming Parameters on Fatigue Life in Incremental Sheet Punching

In order to investigate the effects of main forming parameters on the fatigue life in incremental sheet punching, wavelength and amplitude were selected as factors, and fatigue life of truncated pyramids and virgin material was selected as indicator. The effects of the parameters were identified whereby the design of full factorial experiment, fatigue comparative test, analysis of variance, Tukey test, and t-test. It was found that wavelength and amplitude significantly affect the fatigue life. In addition, the improvement of fatigue life decreased with the increment of wavelength and increased with the increment of amplitude when it is less than a certain value, followed by decreasing.