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Mathematics ◽  
2022 ◽  
Vol 10 (2) ◽  
pp. 200
Author(s):  
Abdulmohsen D. Alruwaili ◽  
Aly R. Seadawy ◽  
Syed T. R. Rizvi ◽  
Sid Ahmed O. Beinane

In this work, we study a time-fractional ion sound and Langmuir waves system (FISLWS) with Atangana–Baleanu derivative (ABD). We use a fractional ABD operator to transform our system into an ODE. We investigate multiwaves, periodic cross-kink, rational, and interaction solutions by the combination of rational, trigonometric, and various bilinear functions. Furthermore, 3D, 2D, and relevant contour plots are presented for the natural evolution of the gained solutions under the selection of proper parameters.


2022 ◽  
Vol 2159 (1) ◽  
pp. 012008
Author(s):  
A S Pérez-Valdovinos ◽  
S Arceo-Díaz ◽  
E E Bricio-Barrios ◽  
J A Ojeda-Sánchez ◽  
J R Moreno-Peña ◽  
...  

Abstract This research evaluates if adding crushed macadamia nutshell to a mixture of cement and sand could result in lighter and more resistant constructive materials. The mechanical resistance under compression of cement blocks made from two different experimental mixtures, in which a certain amount of sand is replaced with crushed nutshell, is compared against two control groups. Results show that blocks made from one of the proposed mixtures got an average resistance around 50% above the controls group while being 3% lighter. Additionally, the physical dependence of the strength of the blocks on the granulometry of the aggregated endocarp fragments, and their percentage to the volume of cement, was studied thanks to contour plots developed from a factorial design of the data.


Author(s):  
D. Prasanthi ◽  
Shreya Ajay Rajguru ◽  
C. Aishwarya ◽  
Aisha Rahman

Objective: Fexofenadine hydrochloride is a selective peripheral H1-blocker, used for allergy symptoms, such as hay fever and urticaria. Allergic symptoms are aggressive during early morning hours, so a pulsatile delivery system with a lag time of 4-5 hours was formulated and optimized by Box-Behnken design. Materials and Methods: Pulsincap system using formaldehyde-treated capsules and hydrogel plug.  Box-Behnken design was applied for optimization in which three independent variables, X1= Drug: polymer ratio, X2 = Polymer: polymer ratio (Ethylcellulose: HPMC E15) and X3 = Plug weight were selected. Three dependent variables R1 = Percent release of drug after 4 hours, R2 = percent release after 10 hours and R3 = Lag time were selected. Results: FTIR and DSC studies confirmed compatibility of drug and excipients. The empty formaldehyde-treated capsules were evaluated for physical appearance, solubility, capsule dimensions and formaldehyde content. Hydrogel plugs, powder blend and pulsincap formulations were evaluated for Physico-chemical parameters and all the parameters were within acceptable limits. Contour plots and Response surface plots indicated that as Drug: Polymer ratio (X1) and Plug weight (X3) increased, Lag time increased but% drug release decreased. As Polymer: Polymer ratio (X2) increased, the lag time was at a moderate level. Predicted vs actual responses showed the correlation of 0.786 for% release in 4hrs, 0.9744 for% release in 10hrs and 0.6281 for lag time. Optimized formulation G1 was suggested by design (with criteria 4.5-6hrs lag time, 10-20% release in 4hrs & 60-70% drug release within 10hrs). The optimised formulation was stable. Conclusion: Pulsincap system of Fexofenadine hydrochloride can be obtained by using retarding polymers like ethyl cellulose, HPMC E15 and formaldehyde cross-linked capsules.


Aviation ◽  
2021 ◽  
Vol 25 (4) ◽  
pp. 268-277
Author(s):  
Volodymyr Dzyura ◽  
Pavlo Maruschak ◽  
Stoyan Slavov ◽  
Diyan Dimitrov ◽  
Dimka Vasileva

The basic regularities in the influence of processing parameters on the geometrical characteristics of the partially regular microreliefs, formed on the rotary body face surface, are established. Combinations of partially regular microreliefs are formed by using a contemporary CNC milling machine, and an advanced programing method, based on previously developed mathematical models. Full factorial experimental design is carried out, which consist of three factors, varied on three levels. Regression stochastic models in coded and natural form, which give the relations between the width of the grooves and the deforming force, feed rate and the pitch of the axial grooves, are derived as a result. Response surfaces and contour plots are built in order to facilitate the results analysis. Based on the dependencies of the derived regression stochastic models, it is found that the greatest impact on the width of the grooves has the magnitude of the deforming force,followed by the feed rate. Also, it is found that the axial pitch between adjacent toolpaths has the least impact on the width of the grooves. As a result of the full-factorial experiment, the average geometric parameters of the microrelief grooves were obtained on their basis. When used, these values will provide for the required value of the relative burnishing area of the surface with regular microreliefs, and, accordingly, the specified operational properties.


Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2013
Author(s):  
Maksim Larin ◽  
Yakov Pevzner ◽  
Svetlana Shalnova ◽  
Pavel Petrovskiy

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.


Author(s):  
Palash Roy Choudhury ◽  
Korimilli Eswar Prasad ◽  
John K. Schueller ◽  
Abhijit Bhattacharyya

Tribological characteristics of boron modified as-cast Ti6Al4V alloys are not very well known, but these alloys enjoy improved as-cast mechanical properties and favourable manufacturing economy. Experimental results are reported here for the effects of sliding speed and normal load on the wear rate and the coefficient of friction in dry sliding of these alloys on hardened EN 31 steel. Alloys having 0%, 0.30%, and 0.55% boron by weight were tested. A full factorial experiment assessed the effects of boron content, speed, and load on wear and friction. Interactions between speed and load were found to be statistically significant in influencing the wear rate and the coefficient of friction. Regression models are developed to predict the wear rate and coefficient of friction responses. The developed contour plots can assist designers in choosing operating conditions when selecting these alloys even if the wear mechanisms are unknown. Evidence shows that the wear resistance of Ti6Al4V can be improved by boron addition, and wear regimes are sensitive to boron content.


Author(s):  
Sanjaya K. Mohanty ◽  
Sachin Kumar ◽  
Manoj K. Deka ◽  
Apul N. Dev

In this paper, we investigate two different constant-coefficient nonlinear evolution equations, namely the Schamel Burgers equation and the Schamel equation. These models also have a great deal of potential for studying ion-acoustic waves in plasma physics and fluid dynamics. The primary goal of this paper is to establish closed-form solutions and dynamics of analytical solutions to the Schamel Burgers and the Schamel equations, which are special examples of the well-known Schamel–Korteweg-de Vries (S-KdV) equation. We derive completely novel solutions to the considered models using a variety of computation programmes and a newly proposed extended generalized [Formula: see text] expansion approach. The newly formed solutions, which include hyperbolic and trigonometric functions as well as rational function solutions, have been produced. The annihilation of three-dimensional shock waves, periodic waves, single soliton, singular soliton, and combo soliton, multisoliton as well as their three-dimensional and contour plots are used to show the dynamical representations of the acquired solutions. These results demonstrate that the proposed extended technique is efficient, reliable and simple.


Author(s):  
Yashvir Singh ◽  
Avani Kumar Upadhyay ◽  
Nishant Kumar Singh ◽  
Abhishek Sharma ◽  
Amneesh Singla ◽  
...  

In today’s scenario, biodiesel is one of the best alternatives to diesel for application as an eco-friendly product. In this work, jojoba oil is transesterified using solar energy for heating purposes. A solar parabolic trough collector having 6.4 m2 and 89% reflectivity is used to concentrate solar rays on a sealed container containing jojoba oil and catalyst-alcohol mixture, placed at the focus of the dish. The performance parameters like molar ratio (MR), reaction time (RT), and catalyst concentration (CC) are optimized. The result showed the highest yield of 89.67% at the optimum condition of molar ratio 9:1, reaction time 120 min, and catalyst concentration 0.8 wt.%. The highest contribution of 55.13% is measured for the molar ratio, followed by reaction time and catalyst concentration. Later, the interaction between MR, RT, and CC is established by response surface/contour plots; and their effects on biodiesel yield are discussed. Subsequently, the various physicochemical properties of raw jojoba oil and jojoba oil methyl ester are also measured and discussed as per ASTM standards. The unsaturated acid content in the biodiesel is also measured by gas chromatography. Hence, the blends of linseed oil with diesel fuel can be used in the IC engines with little or no modifications in engine parameters. Therefore, the use of solar energy could effectively reduce the use of electricity to cut down the processing cost in biodiesel production. Also, the methods should be established for methanol recovery from glycerine.


Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2755
Author(s):  
Yuya Tone ◽  
Toru Tanzawa

Memory chips need large capacitors in their periphery to drive boosted word-lines and bit-lines for read and write operations. In a previous work, scalable capacitors were proposed for 3D crosspoint memory to keep the area for the capacitors constant over technology generations. This paper proposes the capacitance models of three types of wiring capacitors: (1) vertical capacitor, (2) vertical and horizontal capacitor with next-neighbor wires connected with the other terminal, and (3) vertical and horizontal capacitor with next-neighbor pairs connected with the other terminal. These models are based on Wong’s crossover capacitor model to determine the capacitor structure with the highest capacitance density in 3D crosspoint memory technology. One can determine the best structure through optimizing the process parameters such as the height H of the insulation material between the metal wires and the thickness T of the metal wires and the design rules such as the width W and space S of metal wires. The model accuracy was in good agreement with the measurement of twelve types of capacitor structures fabricated in a 180 nm 6 metal standard CMOS process with the maximum error of 20%. Contour plots of the capacitance density across H vs. S where it is assumed that W = T = S are shown. As a result, the boundary condition regarding H and S is determined per 3D crosspoint memory technology with three, four, or five levels of wires.


2021 ◽  
Vol 23 (11) ◽  
pp. 78-85
Author(s):  
Sidhant Konwar Roy ◽  
◽  
Abhishek Mahesh Sharma ◽  

This paper deals with the analysis of vehicle handling with the variation of downforce. A vehicle with aero package were taken and the values of aerodynamic downforce and front downforce distribution for different front and rear ride heights were taken. This was followed by the generation of yaw moment diagram at original ground clearance of 30mm. Aero map data were collected and individual yaw moment diagrams were collected from which vehicle handling parameters are noted. Different contour plots were made to understand the variation of vehicle handling with different ride heights (aerodynamics downforce and downforce distribution). The paper concludes with the sensitivity study where effects of aerodynamic downforce were recorded on vehicle control and stability.


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