MODELING AND OPTIMIZING PROPERTIES OF NANOCLAY–NITRILE RUBBER COMPOSITES USING BOX–BEHNKEN DESIGN

2011 ◽  
Vol 84 (4) ◽  
pp. 455-473 ◽  
Author(s):  
Meera Balachandran ◽  
S. S. Bhagawan ◽  
R. Muraleekrishnan
Keyword(s):  
Layered Silicate ◽  
Silica Content ◽  
Response Surfaces ◽  
Regression Equations ◽  
Launch Vehicles ◽  
Elongation At Break ◽  
Box Behnken Design ◽  
Contour Plots ◽  
The Relationship ◽  
Good Agreement

Abstract The mechanical behavior of acrylonitrile butadiene copolymer (NBR)–organomodified layered silicate (nanoclay) was modeled using design of experiments approach. A Box–Behnken design with three factors and three levels was used to model the relationship between properties of NBR nanocomposites and the ingredients. The factors considered in the design were silica content, nanoclay loading, and dicumyl peroxide content. The nanocomposites were evaluated for tensile strength, modulus, elongation at break, oxygen permeation rate, and effect of oil and heat aging on mechanical properties. Regression equations were generated to model the properties of interest and generate response surfaces and contour plots. The predicted properties of the nanocomposites were in good agreement with the experimental results. The contour plots were overlaid within the applied constraints to identify the combination of factor ranges that gives the optimal performance of the nanocomposites for application as control system bladders in satellite launch vehicles.

Activities and Ionic Distributions in Cobalt Silicate Melts

1971 ◽  
Vol 49 (5) ◽  
pp. 683-690 ◽  
Author(s):  
I. B. Smith ◽  
C. R. Masson
Keyword(s):  
Silica Content ◽  
Silicate Melts ◽  
Molecular Weights ◽  
Polymer Theory ◽  
Linear Chains ◽  
Experimental Values ◽  
The Relationship ◽  
Gas Chromatographic Separation ◽  
Good Agreement ◽  
Binary Silicate

Activities of CoO in CoO–SiO2 melts were measured at 1450–1500 °C by equilibrating the melts, held in Pt–Rh containers, with atmospheres of known oxygen potential. Activities were calculated by the relationship[Formula: see text]where aCo, the activity of cobalt in the container, was determined in separate experiments.The results were compared with theoretical activity–composition curves based on the application of polymer theory to silicate melts. The results were in good agreement with theoretical curves calculated on the assumption of linear chains. In contrast, for all other binary silicate melts so far investigated the results are best represented in terms of theory in which all chain configurations are allowed. Ionic distributions and number average and weight average molecular weights were calculated as functions of the silica content from the experimental data. The calculated proportions of monomeric ion, SiO44−, dimer Si2O76−, and trimer Si3O108− were in reasonable agreement with experimental values based on trimethylsilylation and gas-chromatographic separation of the ionic constituents in quenched melts.

RESPONSE SURFACE METHODOLOGY: A TOOL FOR ASSESSING THE ROLE OF COMPOUNDING INGREDIENTS IN PEROXIDE VULCANIZATION OF NATURAL RUBBER

2016 ◽  
Vol 89 (2) ◽  
pp. 211-226 ◽  
Author(s):  
Rejitha Rajan ◽  
Siby Varghese ◽  
Meera Balachandran ◽  
K. E. George
Keyword(s):  
Zinc Oxide ◽  
Response Surface Methodology ◽  
Natural Rubber ◽  
Response Surface ◽  
Response Surfaces ◽  
Regression Equations ◽  
Face Centered ◽  
The Relationship ◽  
Density Regression

ABSTRACT Response surface methodology was used for assessing the role of various compounding ingredients, including zinc oxide, antioxidant, coagent, oil, and filler, in peroxide vulcanization of natural rubber. A face-centered central composite design with four factors at three different levels was used to obtain the relationship between vulcanizate properties and the level of ingredients. The four factors selected were filler and oil ratio and the contents of zinc oxide, antioxidant, and coagent. The filler and oil ratio was kept constant throughout the experiment. The vulcanizates were evaluated for their mechanical properties: tensile strength, elongation, modulus (M100), tear strength, hardness, compression set (70 and 100 °C), and crosslink density. Regression equations were generated to model the properties of interest, and response surfaces and contour diagrams were plotted.

Study of weld form and weld bead in bottom position at semi-automatic underwater wet welding

2021 ◽  
pp. 487-490
Author(s):  
V.A. Lebedev ◽  
D.N. Krazhanovsky
Keyword(s):  
Weld Metal ◽  
Experimental Research ◽  
Response Surfaces ◽  
Weld Bead ◽  
Regression Equations ◽  
Underwater Wet Welding ◽  
Electrode Wire ◽  
Bottom Position ◽  
Pulse Feed ◽  
Contour Plots

Some features of underwater mechanized and automatic wet welding with pulse feed of the electrode wire are considered. The conditions for experimental research to identify the parameters of forming of the weld metal at different parameters of pulse feed of the electrode wire are described. Regression equations describing the dependences of the size of the roll on the parameters of pulse feed and contour plots and response surfaces of the marked dependences are presented.

Optimization of diazo dye disappearance by the UV/H2O2 process using the Box–Behnken design

2019 ◽  
Vol 80 (9) ◽  
pp. 1731-1739
Author(s):  
Yasmine Laftani ◽  
Baylassane Chatib ◽  
Abdelghani Boussaoud ◽  
Mohammed El Makhfouk ◽  
Mohsine Hachkar ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Coefficient Of Determination ◽  
Slight Effect ◽  
Box Behnken Design ◽  
Independent Variables ◽  
Decolorization Efficiency ◽  
Contour Plots ◽  
Ponceau S ◽  
Optimal Values ◽  
The Relationship

Abstract The purpose of this study was to apply the experimental Box–Behnken design (BBD) to evaluate the effect and, therefore, the optimal values of three chosen factors on the efficiency of the UV/H2O2 process to decolorize Ponceau S (PS) aqueous solutions. The factors studied at three levels were the irradiated volume of dye solution, the dye solution turbidity and the H2O2 dosage. The equations generated, analysis of variance (ANOVA), contour plots and response surface plots were used to analyze the relationship between independent variables and the outcomes of experiments. The fitted model was significant, with an adjusted coefficient of determination (adj-R2 = 0.9835). The results showed that factors such as H2O2 dosage and irradiated volume were the main parameters that affected the decolorization efficiency of the PS aqueous solution, while the turbidity had a slight effect on the response. In addition, significant values were obtained for irradiated volume and H2O2 dosage interaction and square terms of all studied factors. Furthermore, the optimal conditions for decolorization of the PS aqueous solution were found to be an irradiated volume of 257.59 mL, a turbidity of 13 NTU and an H2O2 dosage of 1.76 mM.

Determination of Combined and Second Order Factor Effects for Simultaneous Optimization of Physical and Mechanical Properties of NR/BR Blend System

2014 ◽  
Vol 42 (4) ◽  
pp. 290-304
Author(s):  
Rajarajan Aiyengar ◽  
Jyoti Divecha
Keyword(s):  
Physical And Mechanical Properties ◽  
Second Order ◽  
Simultaneous Optimization ◽  
Order Effects ◽  
Elongation At Break ◽  
Five Factors ◽  
Rubber Compounds ◽  
Polybutadiene Rubber ◽  
Contour Plots

ABSTRACT The blends of natural rubber (NR), polybutadiene rubber (BR), and other forms of rubbers are widely used for enhancing the mechanical and physical properties of rubber compounds. Lots of work has been done in conditioning and mixing of NR/BR blends to improve the properties of its rubber compounds and end products such as tire tread. This article employs response surface methodology designed experiments in five factors; high abrasion furnace carbon black (N 330), aromatic oil, NR/BR ratio, sulfur, and N-oxydiethylene-2-benzothiazole sulfenamide for determination of combined and second order effects of the significant factors leading to simultaneous optimization of the NR/BR blend system. One of the overall optimum of eight properties existed at carbon 44 phr, oil 6.1 phr, NR/BR 78/22 phr with the following values of properties: tensile strength (22 MPa), elongation at break (528%), tear resistance (30 kg/mm), rebound resilience (67%), moderate hardness (68 International rubber hardness degrees) with low heat buildup (17 °C), permanent set (12%), and abrasion loss (57 mm3). More optimum combinations can easily be determined from the NR/BR blend system models contour plots.

Multilayer Polymeric Nano composite Membrane for Oxygen Separation

2019 ◽  
Vol 1 (2) ◽  
pp. 1-11
Author(s):  
Gobi Nallathambi ◽  
Hazel Dhinakaran
Keyword(s):  
Polymer Concentration ◽  
Sio2 Nanoparticles ◽  
Air Separation ◽  
Regression Equations ◽  
Permeate Flux ◽  
Nano Composite ◽  
Box Behnken Design ◽  
Oxygen Selectivity ◽  
Multilayer Membrane ◽  
Spun Fiber

Air separation is a process of separating primary components from the atmospheric air. Development of membrane technologies plays a key role in air separation. Multi-layer polymeric nanocomposite membranes have been developed by a novel technique using Polyacrylonitrile (PAN) and cellulose acetate (CA) along with nano silica particles (SiO2) to obtain a higher oxygen selectivity and permeability. For the construction of the multilayer membrane, the Box-Behnken design has been used by employing three independent variables namely PAN Electro spinning time, the SiO2 percentage in the PAN polymer and CA/PEG polymer concentration. The developed membranes have been characterized for its surface morphology and physical properties. Along with the analysis of compound desirability, the results were also subject to statistical analysis in order to form regression equations. The electro spun fiber diameter increases along with the concentration of SiO2 nanoparticles and the range is from 50 nm to 400 nm. Moreover, the maximum pore size on the surface of the membrane lies between 200 to 400 nm whereas the maximum percentage of oxygen purity obtained is 48 with the permeate flux of 5.45 cm3/cm2/min.

THE MODEL FOR MANAGING INVESTMENTS IN THE MOSCOW ENVIRONMENT BASED ON A POWER REGRESSION EQUATION

2020 ◽  
Vol 2 (7) ◽  
pp. 91-99
Author(s):  
E. V. KOSTYRIN ◽  
◽  
M. S. SINODSKAYA ◽  
Keyword(s):  
Solid Waste ◽  
Influencing Factors ◽  
Pair Correlation ◽  
Approximation Error ◽  
Regression Equation ◽  
Regression Equations ◽  
The Impact ◽  
The Relationship ◽  
Average Approximation ◽  
Average Approximation Error

The article analyzes the impact of certain factors on the volume of investments in the environment. Regression equations describing the relationship between the volume of investment in the environment and each of the influencing factors are constructed, the coefficients of the Pearson pair correlation between the dependent variable and the influencing factors, as well as pairwise between the influencing factors, are calculated. The average approximation error for each regression equation is determined. A correlation matrix is constructed and a conclusion is made. The developed econometric model is implemented in the program of separate collection of municipal solid waste (MSW) in Moscow. The efficiency of the model of investment management in the environment is evaluated on the example of the growth of planned investments in the activities of companies specializing in the export and processing of solid waste.

Optimization and Quality by Design Approach for Piroxicam Fast Dissolving Tablet Formulations Using Box-Behnken Design

2020 ◽  
Vol 15 (2) ◽  
pp. 152-165
Author(s):  
Harekrishna Roy ◽  
Sisir Nandi ◽  
Ungarala Pavani ◽  
Uppuluri Lakshmi ◽  
Tamma Saicharan Reddy ◽  
...  
Keyword(s):  
Quality By Design ◽  
Methyl Cellulose ◽  
Statistical Technique ◽  
Quadratic Model ◽  
Contour Plot ◽  
Compression Technique ◽  
Disintegration Time ◽  
Box Behnken Design ◽  
The Impact ◽  
The Relationship

Background: The present study deals with the formulation and optimization of piroxicam fast dissolving tablets and analyzes the impact of an independent variable while selecting the optimized formulation utilizing Quality by Design (QbD) and Box-Behnken Design (BBD). Methods: Seventeen formulations were prepared by direct compression technique by altering the proportion of cross carmellose sodium, spray dried lactose and hydro propyl methyl cellulose (HPMC K4M). The BBD statistical technique was used to optimize formulations and correlate the relationship among all the variables. Also, the powder mixture characteristics and tablet physiochemical properties such as hardness, friability, drug content, Disintegration Time (DT) and dissolution test were determined using 900 ml of 0.1N HCl (pH-1.2) at 37 ± 0.5°C. Results: Significant quadratic model and second order polynomial equations were established using BBD. To find out the relationship between variables and responses, 3D response surface and 2D contour plot was plotted. A perturbation graph was also plotted to identify the deviation of the variables from the mean point. An optimized formula was prepared based on the predicted response and the resulting responses were observed to be close with the predicted value. Conclusion: The optimized formulation with the desired parameter and formulation with variables and responses can be obtained by BBD and could be used in the large experiment with the involvement of a large number of variables and responses.

scholarly journals Experimental studies on the transformation from firn to ice in the wet-snow zone of temperate glaciers

1997 ◽  
Vol 24 ◽  
pp. 181-185 ◽  
Author(s):  
Katsuhisa Kawashima ◽  
Tomomi Yamada
Keyword(s):  
Experimental Studies ◽  
Ice Formation ◽  
Compression Tests ◽  
Densification Rate ◽  
Overburden Pressure ◽  
Proportionality Constant ◽  
Wet Snow ◽  
Water Saturated ◽  
The Relationship ◽  
Good Agreement

The densification of water-saturated firn, which had formed just above the firn-ice transition in the wet-snow zone of temperate glaciers, was investigated by compression tests under pressures ranging from 0.036 to 0.173 MPa, with special reference to the relationship between densification rate, time and pressure. At each test, the logarithm of the densification rate was proportional to the logarithm of the time, and its proportionality constant increased exponentially with increasing pressure. The time necessary for ice formation in the firn aquifer was calculated using the empirical formula obtained from the tests. Consequently, the necessary time decreased exponentially as the pressure increased, which shows that the transformation from firn in ice can be completed within the period when the firn aquifer exists, if the overburden pressure acting on the water-saturated firn is above 0.12–0.14 MPa. This critical value of pressure was in good agreement with the overburden pressure obtained from depth–density curves of temperate glaciers. It was concluded that the depth of firn–ice transition was self-balanced by the overburden pressure to result in the concentration between 20 and 30 m.

scholarly journals Sodium Metasilicate Cemented Analogue Material and Its Mechanical Properties

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Songlin Yue ◽  
Yanyu Qiu ◽  
Pengxian Fan ◽  
Pin Zhang ◽  
Ning Zhang
Keyword(s):  
Complex Geometry ◽  
Sodium Metasilicate ◽  
Raw Material ◽  
Fine Aggregate ◽  
Regression Equations ◽  
Deformation And Failure ◽  
Orthogonal Experiments ◽  
Low Modulus ◽  
New Type ◽  
The Relationship

Analogue material with appropriate properties is of great importance to the reliability of geomechanical model test, which is one of the mostly used approaches in field of geotechnical research. In this paper, a new type of analogue material is developed, which is composed of coarse aggregate (quartz sand and/or barite sand), fine aggregate (barite powder), and cementitious material (anhydrous sodium silicate). The components of each raw material are the key influencing factors, which significantly affect the physical and mechanical parameters of analogue materials. In order to establish the relationship between parameters and factors, the material properties including density, Young’s modulus, uniaxial compressive strength, and tensile strength were investigated by a series of orthogonal experiments with hundreds of samples. By orthogonal regression analysis, the regression equations of each parameter were obtained based on experimental data, which can predict the properties of the developed analogue materials according to proportions. The experiments and applications indicate that sodium metasilicate cemented analogue material is a type of low-strength and low-modulus material with designable density, which is insensitive to humidity and temperature and satisfies mechanical scaling criteria for weak rock or soft geological materials. Moreover, the developed material can be easily cast into structures with complex geometry shapes and simulate the deformation and failure processes of prototype rocks.

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