Metal Cylinder Research Articles

Effects of Diallium and Ziziphus honey in Second-Degree Burns on Wistar Rats

Background: Nowadays, the use of honeys in the treatment of burns and wounds has aroused growing interest due to its anti-inflammatory, antioxidant and healing properties. Aim: The aim of this study was to evaluate the effects of Diallium and Ziziphus honey in second degree burns on wistar rats. Methodology: A metal cylinder with a diameter of 3 cm was heated for five minutes. In order to cause experimental burns, the rats' shaved skin was lightly pressed with the cylinder for twenty seconds so as to induce second-degree burns. Results: The daily application of honey induces a healing dependent on typology and concentration. The healing rate is higher with DZ, with a score of 1.00 ± 0.63 vs 1.25 ± 0.43 for JUJ which induces almost complete tissue repair after 21 days of treatment. Conclusion: Findings from the research confirm the use of traditional honeys for burns and wound healing.

Calibration of Dual-Polarised Antennas for Air-Coupled Ground Penetrating Radar Applications

Radar polarimetry is a technique that can be used to enhance target detection, identification and classification; however, the quality of these measurements can be significantly influenced by the characteristics of the radar antenna. For an accurate and reliable system, the calibration of the antenna is vitally important to mitigate these effects. This study presents a methodology to calibrate Ultra-Wideband (UWB) dual-polarised antennas in the near-field using a thin elongated metallic cylinder as the calibration object. The calibration process involves measuring the scattering matrix of the metallic cylinder as it is rotated, in this case producing 100 distinct scattering matrices from which the calibration parameters are derived, facilitating a robust and stable solution. The calibration procedure was tested and validated using a Vector Network Analyser (VNA) and two quad-ridged antennas, which presented different performance levels. The calibration methodology demonstrated notable improvements, aligning the performance of both functioning and under-performing antennas to equivalent specifications. Mid-band validation measurements indicated minimal co-polar channel imbalance (<0.3 dB), low phase error (<0.8°) and improved cross-polar isolation (≈48 dB).

Wound Healing Activity of Two Honeys from the Southern Regions of Senegal (Casamance)

Aim: The aim of this study was to evaluate the healing activity of two honeys from Casamance (Senegal) in a second-degree experimental burn model in the Wistar strain rat. Methodology: Experimental burns were induced using a metal cylinder 3 cm in diameter and heated for 5 min. The cylinder was applied for 20 seconds, pressing lightly on the surface of the rats' shaved skin to induce second-degree burns. Results: The daily application of honey induces a healing dependent on concentration and typology. The healing rate is higher with AF, with a score of 0.60 ± 0.48 vs 1.00 ± 0.00 for MZ which induces almost complete tissue repair after 21 days of treatment. Conclusion: The results of this study demonstrate the use of traditional honey in wound healing and burns.

Analytical relations for fields and currents in magnetic-pulsed «expansion» of tubular conductors of small diameter

Introduction. This work was initiated by the problems of cardiovascular diseases, which are one of the main causes of mortality of the population of our planet. More than ten years ago, in 2012, approximately 3.7 million people died of acute coronary syndrome worldwide. The fight against such pathologies is carried out with the help of so-called stents, the manufacture of which can be carried out by the method of magnetic pulse «expansion» from hollow metal cylinders. The limited production possibilities of magnetic pulse «expansion» were caused by the minimum cross-sectional size of the inductor-instrument, which can be practically manufactured. Other tools are required to perform this operation. Novelty. A system of magnetic-pulse expansion of thin-walled pipes of small diameter with an inductor that excites an azimuthal electromagnetic field in the case of direct current passing through the processing object and in the absence of its connection in an electric circuit with an inductor is proposed. Purpose. The main analytical dependencies for the characteristics of the electromagnetic processes taking place in the inductor systems for the expansion of cylindrical conductive pipes of small diameter when direct passage of current through the processed object and when it is not connected to an electric circuit with an inductor (insulated billet) is derived. Methods. The solution of the boundary value problem with given boundary conditions was carried out by applying Laplace transforms and integrating Maxwell’s equations. Results. Analytical expressions were obtained for the main characteristics of the processes: the intensities of the excited electromagnetic fields and currents in the system depending on the parameters of the studied systems. The analysis of possible technical schemes for solving the given problem indicated the choice of the optimal variant of an effective system of magnetic-pulse «stretching» of thin-walled cylindrical conductors of small diameter. Practical value. Based on the qualitative analysis of the obtained results, recommendations for the practical implementation of the proposed system were formulated. The obtained dependences allow us to give numerical estimates of the effectiveness of excitation of magnetic pressure forces on the object of processing and to choose directions for further improvement of the magnetic pulse technology for solving such problems. References 23, figures 2.

Estimation of Surface Temperature and Heat Flux over a Hollow Cylinder and Slab using an Inverse Heat Conduction Approach

A non-iterative approximation of the inverse heat conduction problem has been developed through energy balance between the control volumes. The heat flow domain along the surface normal was divided into three control volumes and studied in three cases, specifically on a heated hollow metallic cylinder cooled in crossflow of air, a heating flat plate in still air, and a heated flat plate when cooled in still air with random air blows. The time derivatives of temperature and heat flux estimates at the surface appearing in derived equations were evaluated by approximate expressions. Both estimates were obtained from the derived equations by simultaneous measurement of temperature-time histories at two locations: one at the inner surface and the other anywhere within the control volume along the surface normal. The deviation was checked by real-time simultaneous measurement of temperature-time history at the outer surface along the normal surface. Comparison between the estimated surface temperature-time history using the derived equations and the real-time measurement showed deviations within 0.5 % for the cylinder, within 0.03 % for the plate in still air and within 0.5 % when air blows were given. Heat fluxes estimated using these time histories were correspondingly arrived at consistent and close approximations for all cases. Estimates from the derived equations were compared with reported equations from the literature, and a wind tunnel experiment for the validation of circumferential distribution of heat transfer was conducted, for which they also showed reasonably good agreements.

A case study on single basin solar still augmented with wax filled metallic cylinders

This experimental study introduces a novel approach to enhancing solar still performance through the integration of wax-filled rods, marking a significant advancement in solar desalination technology. These rods, innovatively designed to absorb and store both sensible and latent heat during peak solar radiation hours, release this stored energy gradually, particularly during the evening and night. This unique mechanism results in a notable and consistent increase in water temperature within the modified solar still after 17:00, setting it apart from conventional models. The study's findings reveal that the modified solar still achieves a 12.8 % higher cumulative distillate yield and a 16.3 % increase in efficiency compared to traditional solar stills. Furthermore, this enhancement translates into a 6.3 % reduction in distillate production costs, underscoring the economic viability and superior performance of the modified design.

3D‐structure coupled monopole designs with lower frequency resonance

AbstractIn this study, we investigated three‐dimensional configurations involving a monopole‐coupled wired ring, a hollow metallic cylinder, and wired helix spring to achieve resonance lower than quarter‐wave resonance. The resonance frequency of a quarter‐wave monopole, originally 2.05 GHz, was significantly lowered by 54.53% through effective coupling with a wired ring, and a quarter‐wave monopole properly coupled with a hollow metallic cylinder experienced a large decrease of 64.34%. The primary incentive for connecting a wired ring to a hollow metallic cylinder is to significantly reduce resonance frequency. Efforts were also made to lower resonance frequency in a wired helix spring with a length close to that of the wired ring, resulting in a substantial 78.83% reduction in resonance frequency. The −10 dB bandwidth was 14.63% for the quarter‐wave monopole, 27.21% for the monopole‐coupled wired ring, 33.71% for the monopole‐coupled hollow metallic cylinder, and 4.69% for the monopole‐coupled helix spring. The ka values for the monopole‐coupled wired ring, hollow metallic cylinder, and helix spring were 0.35, 0.27, and 0.16, respectively. Hence, these antennas can be classified as electrically small antennas. The achieved resonant frequencies have applications in various wireless communication scenarios. The experimental results from the fabricated prototype agree well with the simulation results.

Amplification of electromagnetic fields by a rotating body

In 1971, Zel’dovich predicted the amplification of electromagnetic (EM) waves scattered by a rotating metallic cylinder, gaining mechanical rotational energy from the body. This phenomenon was believed to be unobservable with electromagnetic fields due to technological difficulties in meeting the condition of amplification that is, the cylinder must rotate faster than the frequency of the incoming radiation. Here, we measure the amplification of an electromagnetic field, generated by a toroid LC-circuit, scattered by an aluminium cylinder spinning in the toroid gap. We show that when the Zel’dovich condition is met, the resistance induced by the cylinder becomes negative implying amplification of the incoming EM fields. These results reveal the connection between the concept of induction generators and the physics of this fundamental physics effect and open new prospects towards testing the Zel’dovich mechanism in the quantum regime, as well as related quantum friction effects.

Dynamic Response and Damage Assessment of Partially Confined Metallic Cylinders Under Transverse Blast Loading

An analysis of the dynamic response and damage assessment of partially confined metallic cylinders under transverse air-blast loading is presented in this paper. The examination of the blast shock wave load distribution and the consequences of standoff distances on the plastic deformation of cylinders was conducted with meticulous attention in the experimental testing. The charges of TNT were determined to have masses of 16.3 kg and 29.5 kg, while the distances at which they were placed from the target varied between 1.5 m and 4.25 m. Three unique deformation modes were found to exist in the unilaterally supported cylinder, all of which were directly connected to the distribution of the blast load. In order to obtain an improved understanding of the dynamic behaviors exhibited in cylinders, a finite element simulation model was utilized and subsequently validated using an examination of the experimental results. The assessment of shock wave damage was conducted by utilizing the residual deformation of the metallic cylinder as an equivalent characterization under lateral blast shock wave loading. The duration of the positive pressure zone of the shock wave was determined to be between one-fourth and ten times the vibration period of a unilaterally supported cylinder, indicating that the P-I (overpressure-impulse) criterion could be utilized for damage evaluation. The incorporation of the P-I criterion was subsequently employed to evaluate the detrimental consequences, taking into consideration the radial distribution of residual deformation identified in metal cylindrical shell constructions subjected to lateral blast shock wave loading. This research contributed to a better comprehension of the dynamic behavior of partially confined metallic cylinders subjected to lateral blast loading and highlights the significance of the P-I criterion for evaluating and mitigating the damage effects in such scenarios.

Soil Health of Rubber Plantations in Southern Côte D'ivoire: The Case of Cnra Anguédédou Rubber Plantations

The rubber tree, a species of Amazonian forest tree, is cultivated for its natural rubber-rich latex. Its cultivation is of economic, social, climatic and environmental importance. However, it has been criticized as a soil-destroying crop. To clear up this ambiguity, a study was launched to assess the health of soils under rubber cover in southern Côte d'Ivoire. The methodology involved selecting rubber plantations of [1 to 5 years], [6 to 10 years], [11 to 20] and [20-40 years], and two (02) 42-year-old rubber tree plantations, abandoned for 8 years, were compared to those of a forest. In these biotopes, soil samples were taken using an auger and a metal cylinder, then analyzed in the laboratory to determine soil fertility and ecological parameters. The results showed that the saturated soils of young plantations aged 6 to 10 years are poor in organic matter and cation exchange capacity, mainly calcium and magnesium. However, organic carbon stocks are high in abandoned plantations (182.38 mg/ha) and plantations over 20 years old (164.5 mg/ha). The assessed deterioration index reveals that soils in young plantations aged 6 to 10 years are degraded, with an SDI = -40%. These soils recovered as the plantations aged, with a SDI of 151% in abandoned plantations.

3D Modelling of Electro Vortex Flow Inside Liquid Metal and Effect of External Magnetic Fields

Electrovortex flow emerges when the current inside conducting liquids interacts with its self-induced magnetic field. The flow structure and strength of the flow are dictated by the current value and the presence of an external magnetic field. We present here 3D simulations for the electrovortex flow inside a liquid metal cylinder. The results presented reveal a typical electrovortex structure for low currents. Higher currents induce turbulence inside the electrovortex flow without any presence of an external magnetic field. In presence of Earth’s magnetic field, the flow structure is affected significantly. Cyclone, tornado, and rope tornado are observed inside the domain due to the earth’s magnetic field depending on the ratio of current applied and the earth’s magnetic field.

Spinning spoof surface plasmons and their topological responses

Spoof surface plasmons (SSPs) mimic characteristics of optical surface plasmons in microwave and terahertz frequencies. Manipulating SSPs has attracted widespread attention for extending plasmon applications into the low-frequency range. In this Letter, we show that spinning SSPs can be excited on a twisted groove (TG) metallic cylinder by oblique incident waves. The incident angle of waves and the twist angle of the grooves play essential roles in manipulating the propagation orientation and the rotation direction of spinning SSPs (SSSPs). Finally, we discuss an application of the SSSPs in topological photonic systems. By periodically arranging the TG cylinders, we show that this spinning feature will lead to topologically non-trivial bands in such a photonic crystal, where the topologically protected edge modes arise near the boundary.

All-fiber-coupled mid-infrared quartz-enhanced photoacoustic sensors

Infrared laser-based gas sensors are mature to take the leap from laboratory prototype to outdoor operation. Considering the demand of high robustness and compactness, the reliability of the optical alignment in a sensor is the top priority. This paper proposes a solution designing an optical system embedded within a sealed metallic cylinder containing an aspheric micro-lens to couple a single-mode interband cascade laser with an indium fluoride glass fiber. The fiber output is plug & play connected to an acoustic detection module of a quartz-enhanced photoacoustic sensor (QEPAS) equipped with a fiber port, avoiding the use of any free-space optics, from the source to the detection module. To demonstrate the operability, three all-fiber-coupled QEPAS sensors were realized for detection of CH4, CO2 and NO reaching sub-ppm ultimate detection limits with a signal integration time of 100 ms.

Fresnel–Arago laws: an easily feasible demonstration and laboratory exercise for students

The basic premise of this work was to create a simple experimental setup for the demonstration of Fresnel–Arago laws and the realization of an experimental exercise. An Iceland calcite is used as a beam splitter, and by adding a diverging lens (commonly used to magnify the image), a large image of overlapping spots is obtained at a short distance, visible to a wide audience. Additionally, by placing a diverging lens at different distances from the calcite, the level of the spots overlapping can be changed. The interference image is photographed by a smartphone and processed by one of the available applications for quantitative image processing. The experiment was carried out using red and green laser light. The same setup, with a diverging lens, also allows the reconstruction of the original Fresnel and Arago experiment with a thin metal cylinder. Quick and easy construction, relatively simple processing of the interference image, without the use of expensive devices (CCD camera, beam splitter, beam expander), and the good agreement between the nominal and measured laser light wavelengths, make this setup very suitable for realization as a student exercise for undergraduate and master’s students.

Analysis of Moving Bodies with a Direct Finite Difference Time Domain Method

This paper proposes an original and thorough analysis of the behavior of electromagnetic waves in the presence of moving bodies by using the finite difference time domain (FDTD) method. Movements are implemented by changing positions of the objects at each time step, through the classical FDTD time loop. This technique is suitable for non-relativistic speeds, thus for most encountered problems in antennas and propagation domain. The numerical aspects that need to be considered are studied. Then, different bodies in motion are examined: plane wave source with matching resistors, observation point, inclined partially reflecting surface (PRS), line source, and metallic cylinder illuminated by a plane wave. The results are compared with those of special relativity which are considered as the references. Some aspects of special relativity are present in the direct FDTD approach, such as the independence of the velocity of electromagnetic wave propagation with the speed of the source and Lorentz local time (with a different physical interpretation). It is shown that the amplitude of the electric field for a moving plane wave source does not increase with the speed of motion, if the impedance of the source is small. Moreover, for a moving scattering metallic wire, one can observe a phenomenon similar to shock waves.

An efficient parameter-retrieval-based surrogate-assisted optimization of on-platform honeycomb absorbing structures

An electromagnetic parameter-retrieval-based surrogate-assisted optimization (PSAO) algorithm is presented to reduce radar cross section (RCS) by optimizing the on-platform honeycomb absorbing structures. To facilitate the optimization process, the honeycomb structure is transformed to an anisotropic homogeneous slab, and the effective parameters of the slab are extracted by the retrieval algorithm. A multi-fidelity model is employed to reduce the computing-time consumption, in which a Gaussian process (GP) regression model is used as the substitute for the coarse model. The GP model establishes a relationship between the geometry of the honeycomb structure and the RCS response of the target coated with the equivalent slab. Finally, the optimization result of the fine model is achieved through a space mapping strategy. The accuracy of the parameter extraction algorithm is verified by analyzing the honeycomb absorbing structure. Subsequently, the proposed optimization method is applied to a metal plate and a metal cylinder, resulting in a 10 dB reduction of RCS in broadband and wide-angle scenarios. This demonstrates the applicability of the proposed PSAO algorithm to both planar and conformal on-platform honeycomb absorbing structures. Furthermore, an NACA0015 foil is analyzed, showing an average RCS reduction of 10 dB and a minimum RCS reduction of 5 dB in the X-band. These results indicate that the PSAO approach can effectively apply to complicated targets. Additionally, the proposed method exhibits significant advantages in terms of computational accuracy and efficiency compared to the traditional genetic algorithm.

A versatile design method applied to reconfigurable metasurfaces

This paper introduces a versatile design method for reconfigurable metasurfaces based on the Pancharatnam–Berry phase theory. Unlike traditional reconfigurable metasurfaces that require designing independent surfaces for specific applications, leading to a significant time investment for designers to learn and create, this study proposes a foundational, invariant metasurface. By selectively metallizing holes or inserting metal cylinders, it achieves nine available functionalities. Regardless of the chosen operating function, the metasurface demonstrates high efficiency at 8.2 GHz, with amplitude loss less than 1 dB. Additionally, when operating in phase modulation mode, the design provides a 360° phase adjustment range and a 30° phase step. A prototype containing 31×31 units (425.6×425.6mm2) has been fabricated and tested under function 7 (TM and RHCP transmission phase modulation). Measurement results confirm the metasurface’s capability for polarization conversion and phase modulation at the frequency of 8.2 GHz.

Analytical Formulation to Predict Residual Stresses in Thick-Walled Cylinders Subjected to Hoop Winding, Shrink-Fit, and Conventional and Reverse Autofrettages

Abstract Shrink-fit, wire-winding, and autofrettage processes and their combinations can be effectively used to increase the strength and fatigue life of metallic thick-walled cylinders for a given volume. While several numerical solutions have been developed for determining the residual stress profile through the thickness of thick-walled cylinders for different combinations of the shrink-fit and autofrettage processes, there are no analytical solutions available to predict the residual stress profile induced by the combination of the shrink-fit and inner and outer autofrettage processes with the hoop winding. In this study, the analytical formulations to predict the residual stress distribution for various combinations of the three processes (hoop-winding, shrink-fit, and autofrettage) have been formulated considering the same manufacturing sequences. The results demonstrate that combinations that include the wire-winding process significantly improve the residual stress profile through the wall thickness of single- or two-layer thick-walled cylinders. Specifically, when the wire-winding process is included, the residual stress at the inner surface increases by 25% in single-layer configurations and by 12% in two-layer thick-walled cylinders, respectively, compared to configurations without the wire-winding process.

Small-Scale High-Pressure Hydrogen Storage Vessels: A Review.

Nowadays, high-pressure hydrogen storage is the most commercially used technology owing to its high hydrogen purity, rapid charging/discharging of hydrogen, and low-cost manufacturing. Despite numerous reviews on hydrogen storage technologies, there is a relative scarcity of comprehensive examinations specifically focused on high-pressure gaseous hydrogen storage and its associated materials. This article systematically presents the manufacturing processes and materials used for a variety of high-pressure hydrogen storage containers, including metal cylinders, carbon fiber composite cylinders, and emerging glass material-based hydrogen storage containers. Furthermore, it introduces the relevant principles and theoretical studies, showcasing their advantages and disadvantages compared to conventional high-pressure hydrogen storage containers. Finally, this article provides an outlook on the future development of high-pressure hydrogen storage containers.

Evaluation of a water-based spacer fluid with additives for mud removal in well cementing operations

This research evaluates the crucial role of effective well cementing in enhancing petroleum production, with a specific emphasis on the utilization of spacer fluids for pre-cementing well cleaning. Investigating the performance of a water-based spacer fluid enriched with barite, Xanthan Gum, potato starch, and Poly-Anionic Cellulose additives, this study systematically designs and evaluates three distinct spacer fluids featuring varied additive concentrations for optimal mud removal efficiency. Notably, Spacer B1, incorporating 0.51% PAC-LV and 0.51% starch, emerges as the most successful, exhibiting an impressive 67.84% mud removal rate. The flow behavior of the spacers is aptly described by the Herschel-Buckley model, providing valuable insights into their rheological characteristics. Rigorous compatibility tests affirm the absence of fluid incompatibility, instilling confidence in the chosen spacer compositions. Introducing a 5% surfactant results in a noteworthy 7–8% average increase in mud removal from the metal cylinder wall. In summary, this study contributes valuable perspectives on optimizing both well cementing practices and spacer fluid formulations, ultimately elevating efficiency in petroleum production processes.