Experimental and Numerical Investigation of a Semispherical Solar Still, Chamber Stepwise Basin, with and without a PV Powered Electrical Heater

The world's need for drinkable water is increasing with a growing population. The desalination process using solar energy is the cheapest and most straightforward method that can be used to generate pure water from saline water by utilizing energy from the sun's free heat source. A semispherical and chamber stepwise basin solar still with an inclined glass cover, with and without PV powered electrical heaters as another power source can increase the rate of evaporation of saline water, thus increasing the productivity of semispherical solar still. In this investigation, a conventional solar still and semispherical solar still with and without PV-powered electrical heaters were invented and worked in parallel with the experimental setup to make a good comparison between these models. The experimental results show that stepped semispherical with PV-powered electrical heater and without PV-powered electrical heater solar stills enhanced the productivity of freshwater from a conventional solar still by 156.6% and 72.5%, respectively. The theoretically simulated model is obtained using Mathcad software, and is compared with experimental results. Semispherical solar still productivity increases with increased solar intensity and with a PV-powered electrical heater as an additional power source. The theoretical results concluded from the mathematical model are in good agreement with experimental results.

2D PROBLEM FOR A SPHERE IN THE FRACTIONAL ORDER THEORY THERMOELASTICITY TO AXISYMMETRIC TEMPERATURE DISTRIBUTION

In the present article, we implement the fractional thermoelasticity theory to a 2D issue for a sphere whose surface is free from traction, subject to a provided axisymmetric temperature distribution of heat. The medium is supposed to be quiescent initially. A direct method is used to get a solution and the Laplace transform technique is used. Mathematical models for copper material are designed as a particular instance. Numerical results are computed with help of Mathcad software and graphically represented and the fractional-order parameter effect has been explained.

Equations of motion of masses of the Chelomey pendulum model

To verify the provisions stated by V.I. Bogomolov, B.I. Puzanov. and Linevich E.I. about the possibility of performing over-unit work by inertial forces, a closed mechanical system in the form of kinematically connected rotating masses is proposed for consideration. The research aimed, within the framework of Newtonian mechanics, to study the fulfillment of the laws of conservation of momentum, angular momentum and energy, to establish the possibility of performing work by inertial forces (centrifugal and Coriolis), to assess the change in kinetic parameters using the example of the Chelomey pendulum model. For the complex radial-circular motion of the masses of the Chelomey pendulum model, resolving equations are obtained. To verify the analytical calculations, algorithms for numerical solutions of the above problems have been developed and implemented in the MathCAD software package

Design and Analysis of a Laminated Composite Tube

Piping is an important material for fluid transportation in modern industry, and well-structured piping can reduce losses due to maintenance and replacement downtime. Therefore it is necessary to design and analyze the pipes in order to optimize their structure. This paper focuses on composite laminated pipes. In this design case, the structural analysis of this pipe will be carried out by applying the laminate theory, and the structural analysis model will be established by using Mathcad software. The stress and strain of each laminate will be calculated by entering the winding angle and the corresponding equations in this software. The final optimal winding Angle can be determined by verifying the winding angles that can be maintained under maximum stress failure criteria using Mathcad contours and detailed tables of winding and torsion angles.

Closed-Loop Recycling Dual-Mode Counter-Current Chromatography with Specified Sample Loading Durations: Modeling of Preparative and Industrial-Scale Separations

We previously reported on a new counter-current chromatography (CCC) operating mode called closed-loop recycling dual-mode counter-current chromatography (CLR DM CCC), which incorporates the advantages of closed-loop recycling (CLR) and dual-mode (DM) counter-current chromatography and includes sequential separation of compounds in the closed-loop recycling mode with the mobile x-phase and in the inverted-phase counter-current mode with the mobile y-phase. The theoretical analysis of several implementations of this separation method was carried out under impulse sample injection conditions. This study is dedicated to the further development of CLR DM CCC theory applied to preparative and industrial separations, where high-throughput operation is required. Large sample volumes can be loaded via continuous loading within a specified time. To simulate CLR DM CCC separations with specified sample loading durations, equations are developed and presented in “Mathcad” software.

Имитационная модель исследования структуры объекта методом послойной цифровой комптоновской радиографии

A simulation model of the object structure by the layered digital Compton radiography (tomography) is proposed. The developed model takes into account the geometry of experiment, the parameters of the source and the gamma radiation detectors equipped with a special system of collimators. The simulation model is implemented as a program in the MathCAD software. The capabilities of the simulation model and the corresponding code are demonstrated for an aluminum barrier with spherical local inclusions.

LOADING ON THE CARRYING STRUCTURE OF A FLAT WAGON IN TRANSPORTATION OF MILITARY EQUIPMENT

The article presents the results of determining the loads on the carrying structure of a flat wagon transported military equipment. The authors suggest that stable fixation of military equipment can be provided with special rings mounted on the flat wagon structure. The results of the strength calculation confirmed the efficiency of this solution. The study deals with the mathematical modelling of the dynamic loads on the carrying structure of a flat wagon with a military tank. The research was made for the plane coordinates. The following oscillations were taken into account: longitudinal plane oscillations, jumping oscillations and galloping oscillations. The differential equations were solved by the Runge–Kutta method in MathCad software suite. The maximum accelerations on the carrying structure of a flat wagon in the longitudinal plane were about 34 m/s2, and in the vertical plane were about 5.0 m/s2. Thus, these accelerations values were within the admissible ones.The study also presents the results of the computer modelling of the dynamic loads on the flat wagon. The calculations were made in SolidWorks Simulation (CosmosWorks) software suite with the finite element method. The study presents the distribution fields of the accelerations relative to the carrying structure of a flat wagon and the numerical values of these accelerations.The models of the dynamic loads on the carrying structure of a flat wagon were verified with an F-test. It has been found that the hypothesis on adequacy is not rejected.The study also included determination of the natural frequencies of the carrying structure of a flat wagon. It was found that the values of the natural frequencies were within the permissible values. This research will contribute to better operation efficiency of the rolling stock with consideration of some military-strategic issues, and will be of help for anyone concerned with development and research into innovative rolling stock structures

Equations of motion of masses of the Chelomey pendulum model

To verify the provisions stated by V.I. Bogomolov, B.I. Puzanov. and Linevich E.I. about the possibility of performing over-unit work by inertial forces, a closed mechanical system in the form of kinematically connected rotating masses is proposed for consideration. The research aimed, within the framework of Newtonian mechanics, to study the fulfillment of the laws of conservation of momentum, angular momentum and energy, to establish the possibility of performing work by inertial forces (centrifugal and Coriolis), to assess the change in kinetic parameters using the example of the Chelomey pendulum model. For the complex radial-circular motion of the masses of the Chelomey pendulum model, resolving equations are obtained. To verify the analytical calculations, algorithms for numerical solutions of the above problems have been developed and implemented in the MathCAD software package.

Analysis of the combination of the slider-crank and cam mechanism to drive the automatic bandsaw blade grinder

A slide crank and cam mechanism can be combined and used to drive a bandsaw blade grinder. The movement of these mechanisms must ensure a harmonious combination to avoid the impacts of a collision and dynamic load that appears on the cam and roller surfaces. The technical parameters can be determined by methods of geometry, or 3D simulation, or analytical methods. In order to flexibly design the cam and slide crank mechanism, this study uses the analytic method. By setting up mathematical formulas and applying Mathcad software, it allows to quickly determine and change the initial parameters of the mechanisms, evaluates their changes to the stroke and structural profile. Simultaneously, the graphs of the stroke, velocity, and acceleration of the cam mechanism allow the designer to evaluate and select suitable parameters.