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In a cylindrical cavity, the convection and entropy of the hybrid nanofluid were studied. We have introduced a rectangular fin inside the cylinder; the fin temperature is at Th. The right waving wall is cooled to Tc. The upper and lower walls are insulated. This study contains the induction of a constant magnetic field. The Galerkin finite element method (GFEM) is utilized to treat the controlling equations obtained by giving Rayleigh number values between Ra (103–106) and Hartmann number ratio Ha (0, 25, 50, 100) and Darcy ranging between Da (10−2–10−5) and the porosity ratio is ε (0.2, 0.4, 0.6, 0.8), and the size of the nanoparticles is ϕ (0.02, 0.04, 0.06, 0.08). The range is essential for controlling both fluid flow and the heat transport rate for normal convection. The outcomes show how Da affects entropy and leads to a decline in entropy development. The dynamic and Nusselt mean diverge in a straight line. The domain acts in opposition to the magnetic force while flowing. Highest entropy-forming situations were found in higher amounts of Ra, Da, and initial values of Ha. Parameters like additive nanoparticles (ϕ) and porosity (ε) exert diagonal dominant trends with their improving values.

In this work is proposed to use the profilometer based on thin cylindrical ionization chambers as a tool for electron beam diagnostics. The suggested device is based on multi-angle scanning method. To test this profilometer system experimental studies on microtron MT-25 were conducted in which were measured transverse distributions of electron beam intensity at different distances. Results show the efficacy of using a novel profilometer with set of ionization chambers as part of detector system for measurement the real spatial characteristics of a given electron beam.

In this paper, a sequence of passive micromixers with spiral patterns on the side wall of cylindrical chambers are designed, optimized, prepared and tested. The simulation studies show that the vortex magnitude and continuity in the mixing chamber are the most important factors to determine mixing performance, while the inlet position and structural parameters are secondary influences on their performance. According to the above principles, the performance of a micromixer with a continuous sidewall spiral finally wins out. The total mixing length is only 14 mm, but when Re = 5, the mixing index can reach 99.81%. The multi-view visual tests of these mixer chips prepared by 3D printing are consistent with the simulation results. This paper provides a new idea for optimizing the micromixer with spiral patterns on the side wall and the problems of floor area and pressure loss are significantly improved compared to the conventional spiral structure.

The performance evaluation of cavity cylindrical ionization chamber dosimeters is the basis for the evolution of radiotherapy treatment processes. Studies focused on the statistical and physical performances of the ionization chamber dosimeter used in the radiotherapy department at the hospital oncology CHU-Fez-Morocco. This allowed having a qualitative and quantitative critical view, which is based on previous studies and works. The diagnostic of the dispersion results was calculated between measurements that were taken by the same dosimeter under different test conditions. These tests were then rechecked against two different operators. The general purpose of our study is to optimize measurement and treatment processes, with the desired level of quality according to international standards and protocols. The evaluation of this dosimeter is made by a source of pulsed radiation. This evaluation is carried out using an ELEKTA linear accelerator, using photon beams (6, 10 and 18 Mev). Experimental Results confirmed that the response of the cylindrical ionization chamber depends on several parameters, which influence the performance of the device/machine. The study reveals a total dosimeter uncertainty of the order 3.25 %, which is in the international standards. Even, this can cause an effect on the performance of the ionization chamber detector.

The integration of oscillating water column (OWC) wave energy converters into a coastal structure (breakwater, jetty, pier, etc.) or, more generally, their installation along the coast is an effective way to increase the accessibility of wave power exploitation. In this paper, a theoretical model is developed based on the linear potential flow theory and eigenfunction matching method to evaluate the hydrodynamic performance of an array of OWCs installed along a vertical straight coast. The chamber of each OWC consists of a hollow vertical circular cylinder, which is half embedded in the wall. The OWC chambers in the theoretical model may have different sizes, i.e. different values of the radius, wall thickness and submergence. At the top of each chamber, a Wells turbine is installed to extract power. The effects of the Wells turbine together with the air compressibility are taken into account as a linear power take-off system. The hydrodynamic and wave power extraction performance of the multiple coast-integrated OWCs is compared with that of a single offshore/coast-integrated OWC and of multiple offshore OWCs. More specifically, we analyse the role of the incident wave direction, chamber size (i.e. radius, wall thickness and submergence), spacing between OWCs and number of OWCs by means of the present theoretical model. It is shown that wave power extraction from the coast-integrated OWCs for a certain range of wave conditions can be significantly enhanced due to both the constructive array effect and the constructive coast effect.

In this paper, a cylindrical trimming method is applied to fit the hemisphere, and the total reflectivity on a certain boundary is analyzed through a series of derivations and calculations. An equation that is used to calculate the reflectivity of the trimming cylindrical anechoic chamber is obtained, and obviously, it has no relationship with the spherical coordinate radius r and can be utilized to optimize the trimming size. The proposed scheme of the non-standard anechoic chamber is proved to be a simplified and effective way to optimize the anechoic chamber. An anechoic chamber is constructed to illustrate the correctness of the theory. The simulation results show that S 11 has achieved good results in most frequency bands.

During the last two decades, the Inertial Electrostatic Confinement Fusion (IECF) device has gained popularity as a table-top neutron/proton source due to its uncomplicated design and comparatively smaller volume which has the potential of providing high fusion rate. The basic concept of the device is to accelerate lighter ions like deuterium, tritium, etc., to collide and produce fusion-relevant energies by the application of a converging electrostatic field inside a spherical or cylindrical chamber. In the present work, we have discussed the ion dynamics in a single and triple-grid arrangement of the cylindrical IECF device by making use of an open-source particle-in-cell code known as XOOPIC. A comparative study of ion density and potential profiles has been performed at different input potentials. The simulated outcomes are compared with the experimentally obtained results. A detailed study on the obtained results has been presented here.

A negative pressure wall-climbing robot is a special robot for climbing vertical walls, which is widely used in construction, petrochemicals, nuclear energy, shipbuilding, and other industries. The mobility and adhesion of the wheel-track wall-climbing robot with steering-straight mode are significantly decreased on the cylindrical wall, especially during steering. The reason is that the suction chamber may separate from the wall and the required driving force for movement increases, during steering. In this paper, a negative pressure wall-climbing robot with omnidirectional movement mode is developed. By introducing a compliant adjusting suction mechanism and omni-belt wheels, an omnidirectional movement mode is formed instead of the steering-straight mode, and the performances of adhesion and mobility are improved. We establish the safety adhesion model for the robot on a cylindrical wall and obtain the safety adhesion forces. We designed and manufactured an experimental prototype based on the analysis. Experiments showed that the robot has the ability of full maneuverability in cylindrical walls.

The initiation and combustion of propane-oxygen (P0 = 1 atm) are experimentally studied by using multispark discharges (ranging from 1 to 9 in number), which are differently located in the cylindrical chamber 72 mm in diameter and 4 mm high. The methods of synchronous recording and measurements of parameters of force pulses with 26 µs resolution piezodynamometer were used in the studies. It was shown that for identical gas charges, the duration of generation of force pulses decreases by 30 % as the number of initiation sparks rises in comparison to one-spark initiation in the center of the chamber.

This study investigates the effects of blends of diethyl ether, biodiesel, and Jet A-1 fuel on exhaust emissions and flame characteristics in a conical swirl burner. The tested fuels included pure Jet A-1 fuel (B0) and blends of diethyl ether and biodiesel (B5, B10, B5D40, and B10D40), where biodiesel was produced from used waste cooking oil via an ultrasound-assisted transesterification process. The fuel-air mixture was pre-vaporized at 300°C and burned in a cylindrical combustion chamber (diameter-to-length ratio of 3.75:12.5) using a screw burner (swirl number: 0.55) with a lean equivalence ratio (ϕ) of 0.80. Key parameters analyzed were exit temperature, CO, O 2 concentration, NO x emissions, blend ratio (BR), fuel flow rate, and local equivalence ratio (ϕ local ). As ϕ local approached stoichiometry (ϕ local = 1.0), chamber temperatures increased, while NO x and CO concentrations decreased. Conversely, when ϕ local neared the overall equivalence ratio (0.80), exit temperatures and NO x levels dropped but CO levels rose. Increasing the blend ratio, which raises the waste cooking oil methyl ester (WCOME) content, led to lower temperatures and higher CO emissions. All tests achieved stable flames, with the highest temperature of 1570 K using the B10 blend. Adding 40% diethyl ether to the blends notably reduced emissions and improved flame temperature, making this blend ratio ideal for better emission control and flame performance.