Plate Type Research Articles

A W-Band High-Gain Bilayer Transmit-Array Antenna Employing Huygens’ Resonance

A special type of transmissive phase plate, named Huygens' metasurfaces (HMS), is capable of efficiently manipulating transmitted electromagnetic wavefronts with extremely low back-scattering. Here, in contrast to conventional planar multilayer lens arrays, a transmit-array (TA) antenna based on Huygens' resonance is proposed for high-gain applications at <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">W</i> -band. The proposed meta-cell is comprised of a pair of parallel metallic strips on opposite sides of a single dielectric substrate connected by a pair of vias, and can independently control the electric and magnetic dipole responses and induce the desired Huygens' resonance. An equivalent circuit model (ECM) is used to describe its operation principle in detail. A full 360 degrees phase coverage and a high transmission amplitude can be obtained simultaneously using the proposed unit cell. To experimentally verify the proposed concept and design, a TA antenna is fabricated and tested. The Huygens' TA prototype exhibits good radiation performance. The measured peak gain of the TA prototype is 34.341 dBi at 87 GHz with an aperture efficiency of 45.7%, and the measured 3-dB gain bandwidth is from 79 to 90 GHz.

Nonlinear free vibration modeling of anisogrid lattice sandwich plates based on a weak formulation analysis

This research examines the geometrically nonlinear free vibrations of a type of sandwich plate. This plate consists of an anisogrid lattice core and two nanocomposite face sheets. The lattice core is made up of a set of straight and oblique ribs with rectangular cross-sections that meet at nodes that are not all in the same place (anisogrid nodes). The nanocomposite skins are reinforced with carbon nanotubes (CNTs) based on the various functionally graded models. The displacement field of the sandwich plate is estimated based on the third-order shear deformation plate theory. Also, the nonlinear von-Kármán strain–displacement relations are used. Based on the Hooke and Hamilton laws, the motion equations of the system for nonlinear free vibrations are derived in a weak form. Then, the nodal weak formulation method based on the Lagrange interpolation functions and Gauss–Lobatto–Chebyshev node distribution, for the first time, is employed to calculate the time-dependent equations. The residuals of the obtained equations are minimized by the Galerkin method. Next, a displacement control iterative technique is applied to compute the nonlinear frequency of the sandwich plate. The effect of anisogrid lattice core characteristics and nanocomposite face sheets properties on the linear and nonlinear frequencies and also mode shapes are examined in the results.

On simplified deformation gradient theory of modified gradient elastic Kirchhoff–Love plate

A concise modified gradient elastic Kirchhoff–Love plate model with two length-scale parameters is proposed based on simplified deformation gradient theory. A sixth-order basic differential equation and boundary conditions applicable to arbitrary shapes are obtained by applying the principle of minimum potential energy and combining with the generalized strain energy related to classical strain, strain gradient and rotation gradient. By introducing couple stress, the classical bending stiffness corresponding to the fourth-order terms and force-related boundary conditions in the typical gradient elastic Kirchhoff–Love plate model are modified, and the bending deformation of thin plates can be described more flexibly. Under certain conditions, the modified gradient elastic Kirchhoff–Love plate model can be reduced to typical gradient elastic thin plate model, couple stress thin plate model and classical Kirchhoff–Love plate model. The bending boundary value problems of gradient elastic thin plates are further studied, and the specific modified classical boundary conditions and non-classical higher-order boundary condition acceptable to the sixth-order basic equation in Cartesian coordinates are derived. The analytical and numerical bending solutions to gradient Navier-type and Levy-type thin plates with various boundary conditions, including simply supported, clamped and free boundaries are presented, and the size-dependent bending stiffness that is jointly determined by geometric dimensions and length-scale parameters is defined to describe the size effect of thin plates comprehensively.

DESIGN OF PLATE HEAT EXCHANGER FOR HEAT TREATMENT INDUSTRY

This study discusses the design of plate type heat exchangers (PHE). Conventional heat exchangers have many drawbacks, including difficult maintenance, high cost, and increased area usage. In contrast, plate heat exchangers have a number of benefits over traditional heat exchangers. Because the liquid spreads across the plate, PHE has a bigger surface area. The study discusses and explains the design of the plate type heat exchanger, plate material, chevron angle, and gasket material since the plate allows for faster heat transmission. Key Words: Plate heat exchanger, Design, materials.

Comparative study on bipolar plate geometry designs on the performance of proton exchange membrane fuel cells

Bipolar plates are designed to provide structural rigidity to Proton Exchange Membrane Fuel Cell (PEMFC) and contribute 80 % of the total weight of the cell. Over 40 % of the total cost of the cell originates from the type of bipolar plate used in the development of the cell. The present study draws inspiration from existing conventional serpentine and parallel channel designs in developing novel tapered dual serpentine channel (TDSC), tapered parallel channel design (TPCD) and the tapered dual maze channel (TDMC) in ANSYS Fluent. The results highlighted the fact that tapered inlet and outlet channel geometry designs had significant impact on the overall cell performance. That is, pressure build up within the cell, the velocity of the reacting species and even their distribution are largely influenced by the flow plate geometry design. There was 2.163 % increase in the current flux density magnitude for the TDMC fuel cell compared to the TDSC and 1.421 % increase in current flux density magnitude compared to the TPCD. 0.52 W/cm2 was recorded as power density for TDMC, 0.44 W/cm2 for the TPCD and 0.38 W/cm2 TDCS. The TDMC further showed 13.67 % increase in current density compared to the TPCD and 22.78 % increase in current density compared to the TDSC. These results corroborate with Bernoulli’s principle, that an increase in the velocity of a fluid results in a decrease in static pressure which in the case of Proton Exchange Membrane Fuel Cells (PEMFC) lead to higher rate of reaction and easy dissipation of the product water. This phenomenon buttresses the justification for the increase in cell performance due to thermal and water management improvement. The outcome of the investigation also showed that the pressure drop in the channel geometry was lower in the case of the TDMC compared to the other types (TPCD and TDSC). Due to the improved pumping power of the cell, uniform temperature distribution and pressure, the maze channel geometry design showed better prospects for their application in the automotive industry. This study will, however, serve as a reference point in designing and developing flow plate for a proton exchange membrane fuel cell to accelerate its commercialisation.

Performance evaluation of delta-nabla channel configuration in a solar absorber with thermal energy storage

A novel configuration of solar absorber containing water channels of triangular cross-section in a delta-nabla arrangement, has been experimentally investigated. Traditionally, the triangular channeled solar absorbers are in use for space heating, but their effectiveness in solar water heating systems is yet to be explored. In addition to the performance investigation of the absorber, the effect of an integrated phase change material (PCM) based thermal energy storage (TES) has also been examined under solar and off-solar conditions. The highest temperature of 80 °C is obtained on the right side of the absorber containing hot water outlet in contrast to the left side where the cold-water inlet is located. Moreover, the average temperature gradient exists along the surface normal from the channel contours to the outside glazing. Integration of paraffin-based TES provides 62 L of water above 30 °C during off solar conditions. The efficiency of TES increases with smaller delays after charging and for higher flow rates because of reduced heat losses from the storage to the atmosphere. A delta-nabla configuration comparison with a conventional flat plate type solar absorber shows a prominent improvement in the overall performance.

Wide-awake local anesthesia No tourniquet (WALANT) for reconstruction of flexor pollicis longus ruptures following volar plate fixation of distal radius fractures- A Case series

BackgroundThe flexor pollicis longus tendon rupture following distal radius fractures is a known complication and reconstruction with interposition tendon graft achieved a good outcome. Therefore, this study aims to analyze the outcome of FPL tendon reconstruction using the wide-awake local anesthesia no tourniquet (WALANT) technique. MethodsSeven patients with attritional FPL rupture were retrospectively analyzed between 2014 and 2021. All these patients had FPL reconstruction using palmaris longus interposition graft under WALANT. The patient demographics, Soong volar plate prominence classification, volar plate type, and functional outcome assessment were reviewed. ResultsThe FPL tendon rupture occurred at a mean of 1.1 years (range, 6 months −3 years) following volar plate fixation. The patients had T-buttress (n ​= ​6) and volar locking plates (n ​= ​1). The mean follow-up of our study was 16.5 months (range 12–19 months). The total interphalangeal joint movement, grip strength, pinch strength, and Kapandji score were significantly less than the uninjured hand (p ​< ​0.05). The mean DASH Score was 14 (range 4.5–28). All surgeries were daycare, and WALANT provided effective analgesia and a comfortable patient experience. ConclusionsFPL reconstruction using WALANT achieves a good functional outcome. In addition, the intraoperative assessment of tendon excursion, adjusting the tension, and educating early rehabilitation are the advantages of the WALANT. Level of evidenceIV, Retrospective case study.

Design of New Fan-Shaped Combined Wear-Resistant Plate for Super Tonnage Spherical Bearing

In order to improve the bearing and wear resistance of the sector composite wear plate, a new sector composite wear plate is designed based on the finite element method. By establishing the finite element calculation models of integral, segmented small circle inlaid and new fan-shaped combined anti-wear plate ball bearings, the pressure bearing and wear resistance of three types of wear plates are analyzed, calculated and compared. The results show that the three types of wear plates can meet the pressure bearing capacity. The pressure bearing capacity of the new fan-shaped composite wear-resistant plate is similar to that of the integral type, which is superior to that of the segmented small circle inlaid type. Because of the advantages in structure, processing and installation of the new fan-shaped composite wear-resistant plate, it is particularly worth popularizing and applying in the super spherical bearing.

Accurate license plate recognition system for different styles of Iraqi license plates

Automatic license plate recognition (ALPR) used for many applications especially in security applications, including border control. However, more accurate and language-independent techniques are still needed. This work provides a new approach to identifying Arabic license plates in different formats, colors, and even including English characters. Numbers, characters, and layouts with either 1-line or 2-line layouts are presented. For the test, we intend to use Iraqi license plates as there is a wide range of license plate styles written in Arabic, Kurdish, and English/Arabic languages, each different in style and color. This variety makes it difficult for recent traditional license plate recognition systems and algorithms to recognize all these license plate types using the same algorithm. In this work, a new method has been proposed to efficiently recognize all these types of license plates. This has been done by utilizing a series of algorithms for preprocessing and recognition with new identification strategies. The results show that the system recognized license plate numbers with higher accuracy, reaching up to 97.85%. However, the method field to detect license plates when there are some high deformations in plate numbers or when they are partially covered with mud, which makes it difficult to distinguish numbers.

The Effect of Design and Size of the Fluid-Bed Equipment on the Particle Size-Dependent Trend of Particle Coating Thickness and Drug Prolonged-Release Profile

The focus of the current work is to study and demonstrate the impact of the design, the scale, and settings of fluid-bed coating equipment on the differences in pellet coating thickness, which in case of prolonged-release pellets dictates the drug release. In the first set of coating experiments, the pellet cores were coated with the Tartrazine dye with the aim of estimating the coating equipment performance in terms of coating thickness distribution, assessed through color hue. In the second set, drug-layered pellets were film-coated with prolonged-release coating and dissolution profile tests were performed to estimate the thickness and uniformity of the coating thickness among differently sized pellets. In both study parts, film coating was performed at the laboratory and the pilot scale and essentially two types of distribution plate and different height adjustments of the draft tube were compared. The dye coating study proved to be extremely useful, as the results enable process correction and the optimal use of the process equipment in combination with the appropriate process parameters. Preferential film coating of larger drug-containing pellets was confirmed on the laboratory scale, while on the pilot scale, it was possible to achieve preferential coating of smaller pellets using rational alternatives of settings, which is desirable in terms of particle size-independent drug release profile of such prolonged-release dosage forms.

Neutron-Physical and Radiation Characteristics of Different Low Enrichment Fuels (Thorium and Uranium) in a Proposed JRTR Research Reactor

Abstract: The Jordan Research and Training Reactor (JRTR) is a 5-MWth, open-pool type, light-water moderated and cooled reactor with a heavy-water reflector system. The core consists of standard Material Testing Reactor (MTR), the plate type of fuel assemblies with low enriched fuel of 19.75% U-235 enrichment. One of the most important purposes of JRTR is producing several radioisotopes e.g. (99Mo/99mTc, 131I and 192Ir isotopes) by using the neutron activation technology. A new computational model has been developed for different low enrichment fuels (Thorium and Uranium) in the JRTR by using the Serpent Monte Carlo code. The purpose of this paper is to validate Th-U233 fuel by comparison of the calculation results of important neutronics parameters, like keff, flux distribution, kinetics parameters, power peaking factors, heat decay and activity of spent fuel. Keywords: U3Si2, Th3Si2, JRTR, Light-water Reactors (LWRs), Extended cycle lengths.

3D printed plates based on generative design biomechanically outperform manual digital fitting and conventional systems printed in photopolymers in bridging mandibular bone defects of critical size in dogs.

Conventional plate osteosynthesis of critical-sized bone defects in canine mandibles can fail to restore former functionality and stability due to adaption limits. Three-dimensional (3D) printed patient-specific implants are becoming increasingly popular as these can be customized to avoid critical structures, achieve perfect alignment to individual bone contours, and may provide better stability. Using a 3D surface model for the mandible, four plate designs were created and evaluated for their properties to stabilize a defined 30 mm critical-size bone defect. Design-1 was manually designed, and further shape optimized using Autodesk ® Fusion 360 (ADF360) and finite element analysis (FE) to generate Design-2. Design-4 was created with the generative design (GD) function from ADF360 using preplaced screw terminals and loading conditions as boundaries. A 12-hole reconstruction titanium locking plate (LP) (2.4/3.0 mm) was also tested, which was scanned, converted to a STL file and 3D printed (Design-3). Each design was 3D printed from a photopolymer resin (VPW) and a photopolymer resin in combination with a thermoplastic elastomer (VPWT) and loaded in cantilever bending using a customized servo-hydraulic mechanical testing system; n = 5 repetitions each. No material defects pre- or post-failure testing were found in the printed mandibles and screws. Plate fractures were most often observed in similar locations, depending on the design. Design-4 has 2.8-3.6 times ultimate strength compared to other plates, even though only 40% more volume was used. Maximum load capacities did not differ significantly from those of the other three designs. All plate types, except D3, were 35% stronger when made of VPW, compared to VPWT. VPWT D3 plates were only 6% stronger. Generative design is faster and easier to handle than optimizing manually designed plates using FE to create customized implants with maximum load-bearing capacity and minimum material requirements. Although guidelines for selecting appropriate outcomes and subsequent refinements to the optimized design are still needed, this may represent a straightforward approach to implementing additive manufacturing in individualized surgical care. The aim of this work is to analyze different design techniques, which can later be used for the development of implants made of biocompatible materials.

Mechanical assessment of two hybrid plate designs for pancarpal canine arthrodesis under cyclic loading.

Pancarpal canine arthrodesis (PCA) sets immobilization of all three carpal joints via dorsal plating to result in bony fusion. Whereas the first version of the plate uses a round hole (RH) for the radiocarpal (RC) screw region, its modification into an oval hole (OH) in a later version improves versatility in surgical application. The aim of this study was to mechanically investigate the fatigue life of the PCA plate types implementing these two features-PCA-RH and PCA-OH. Ten PCA-RH and 20 PCA-OH stainless steel (316LVM) plates were assigned to three study groups (n = 10). All plates were pre-bent at 20° and fixed to a canine forelimb model with simulated radius, RC bone and third metacarpal bone. The OH plates were fixed with an RC screw inserted either most proximal (OH-P) or most distal (OH-D). All specimens were cyclically tested at 8Hz under 320N loading until failure. Fatigue life outcome measures were cycles to failure and failure mode. Cycles to failure were higher for RH plate fixation (695,264 ± 344,023) versus both OH-P (447,900 ± 176,208) and OH-D (391,822 ± 165,116) plate configurations, being significantly different between RH and OH-D, p = 0.03. No significant difference was detected between OH-P and OH-D configurations, p = 0.09. Despite potential surgical advantages, the shorter fatigue life of the PCA-OH plate design may mitigate its benefits compared to the plate design with a round radiocarpal screw hole. Moreover, the failure risk of plates with an oval hole is increased regardless from the screw position in this hole. Based on these findings, the PCA plate with the current oval radiocarpal screw hole configuration cannot be recommended for clinical use.

Einfluss der Mikrohärte der Ober- flächenschutzschicht auf den Verschleiß und die Lebensdauer von elektrischen Kontakten bei Reibverschleißbelastung

The lifetime of electrical contacts is influenced by various factors. Micromotions due to fluctuations in temperature and vibration in the field lead to fretting wear and fretting corrosion of electrical contacts. In case of the contacts with noble coatings, the fretting wear results in the wear through of the coating causing the exposure of the underlying non-noble metal to the surrounding atmosphere which in turn leads to fretting corrosion. These degradation mechanisms lead to an increase in electrical contact resistance and eventual failure of the system. In this study, the extent of contact degradation due to fretting war of galvanically silver-plated electrical contacts is investigated. To compare the extent of war occurring at different stages of the contacts’ lifetime, the fretting tests are conducted up to predefined fretting cycles. XRF measurements of the coating thickness before after the tests are performed and the wear depth after the given fretting cycles is determined via confocal microscopy. The results of two different types of silver plating are compared. Based on this, a prognosis regarding the wear behavior and expected lifetime of different coating systems can be made possible.

PRELIMINARY INVESTIGATION INTO MECHANICAL PROPERTIES AND MICROSTRUCTURAL BEHAVIOUR OF INCONEL ALLOY UNDER WELDED AND UNWELDED CONDITIONS

This work focusses on analysing mechanical properties and microscopic assessment into Inconel-718 plates in welded and unwelded conditions. Welding was performed by tungsten inert gas welding technique. Two mechanical tests such as tensile test and hardness were performed on both the types of plates to compare the properties of welded joint and unwelded plate. Although Inconel 718 possesses good weldability, the strength, ductility, and hardness of welded joint were reported lesser than these of Unwelded plate. The microstructural images revealed that metal carbides present in Inconel plate had reduced after welding. The ultimate tensile stress and elongation before breaking of welded joint were 16% and 72% lower than Unwelded plate. The fractography analysis of the ruptured part revealed that Unwelded plate possessed higher ductility than welded plate.

Effect of nonlinear material behavior on progressive failure analysis of pin-joint composites

In this study, the mechanical performances of glass fiber-reinforced notched and pin-connected composite plates were investigated experimentally and numerically. For this purpose, composite plates with a circular hole, semicircular double-edge notched, U-edge notched, and single and double pin joints were prepared from layer glass fiber composites. Tensile tests were carried out on the obtained specimens. The effect of notch type, number of pins, and position of pins on plate damage load and type was investigated for linear and non-linear material behavior. Progressive failure analysis was performed using the Hashin damage criteria. Subprogram codes were written in the Ansys program using the finite element method. According to the obtained data, it was determined that the type of notch and the number of pins have a significant effect on the damage loads of the plates and the behavior of the material is important in terms of convergence to the experimental results in numerical solutions. In single-pin composites, the type of damage changed from net-tension to shear out as the pin approached the free edge of the plate. It was observed that the distance between the pins did not have any effect on the damage type of the composites in the double-pin joint structure. Compared to single-pin joint composites, double-pin joint composites were found to carry a maximum of 34% more damage load. The convergence rate of experimental and numerical data was obtained as a minimum of 92.1% for nonlinear material behavior and a minimum of 73.4% for linear material behavior

COMPUTER MODELING OF PROPERTIES OF A COMPOSITE MATERIAL WITH POROUS FILLERS

The article is devoted to forecasting of heat-shielding and mechanical properties of composite materials based on porous fillers.Analytical dependencies for determining the thermal conductivity coefficient of materials of homogeneous and heterogeneous structure are given. Based on the finite element method, there has been developed a method for numerical determination of the thermal conductivity coefficient of composite materials with a variotropic structure.The results of computer studies are in line with the dependences obtained on analytical models. The expediency of using multilayer composite materials based on porous fillers in load-bearing and enclosing structures of shell and plate types has been shown.

Portion control tableware differentially impacts eating behaviour in women with and without overweight

Portion control tableware has been described as a potentially effective approach for weight management, however the mechanisms by which these tools work remain unknown. We explored the processes by which a portion control (calibrated) plate with visual stimuli for starch, protein and vegetable amounts modulates food intake, satiety and meal eating behaviour. Sixty-five women (34 with overweight/obesity) participated in a counterbalanced cross-over trial in the laboratory, where they self-served and ate a hot meal including rice, meatballs and vegetables, once with a calibrated plate and once with a conventional (control) plate. A sub-sample of 31 women provided blood samples to measure the cephalic phase response to the meal. Effects of plate type were tested through linear mixed-effect models. Meal portion sizes (mean ± SD) were smaller for the calibrated compared with the control plate (served: 296 ± 69 vs 317 ± 78 g; consumed: 287 ± 71 vs 309 ± 79 g respectively), especially consumed rice (69 ± 24 vs 88 ± 30 g) (p < 0.05 for all comparisons). The calibrated plate significantly reduced bite size (3.4 ± 1.0 vs 3.7 ± 1.0 g; p < 0.01) in all women and eating rate (32.9 ± 9.5 vs 33.7 ± 9.2 g/min; p < 0.05), in lean women. Despite this, some women compensated for the reduced intake over the 8 h following the meal. Pancreatic polypeptide and ghrelin levels increased post-prandially with the calibrated plate but changes were not robust. Plate type had no influence on insulin, glucose levels, or memory for portion size. Meal size was reduced by a portion control plate with visual stimuli for appropriate amounts of starch, protein and vegetables, potentially because of the reduced self-served portion size and the resulting reduced bite size. Sustained effects may require the continued use of the plate for long-term impact.

The application of cumulating lattice to accelerate diffusion during thermal diffusion chromiing

The creation of coatings on parts with improved corrosion resistance, throughput at low and high temperatures, wear resistance makes it possible to expand the possibilities of using low and medium alloy steels. Traditional methods for creating protective coatings are various types of chemical-thermal treatment and thermal diffusion chromium plating, in particular. In recent decades, attempts have been repeatedly made to increase the efficiency of the process of thermal diffusion saturation of chromium metal, mainly due to complex saturation with vanadium, boron and other elements, as well as the use of external physical influences that accelerate diffusion. Previously, in the works of the authors, it was shown that the introduction of electron-emitter metal powder into the composition of the metal part of the filling ensures the acceleration of diffusion processes during thermal diffusion chromium plating due to the action of an internal emission field. A similar effect is also observed when replacing corundum in the separating part of the filling with powders of solid electrolytes (minerals such as serpentine and scheelite, which are emitters of electrons and anions of the oxygen when heated). An additional enhancement of the internal emission field was noted when cumula-tive nickel and molybdenum lattice were used, however, the effect of the geometric characteristics of these lattice on the magnitude of the thermal emission of electrons and oxygen anions and, as a result, the diffusion acceleration was not established. The paper presents the results of saturation of samples of steel X35CrNi2-3 at a temperature of 1000°C for 24 hours using cumulative lattice that differ in the density of holes per unit area: 20, 10 and 6 holes/cm2. The control of the elemental composition of the diffusion layer was carried out on transverse sections in the direction from the saturated surface to base metal of the sample using a JEOL JSM-6460LV universal scanning (scanning) electron microscope. X-ray phase analysis was performed on an Ultima IV diffractometer, the radiation used was Cu-Kα. The microstructure was studied using an optical microscope Axio Observer D1.m. The microhardness of the coatings was measured using an FM-800 microhardness tester. It has been established that the use of cumulative nickel lattices provides an increase in the depth of the diffusion layer in the base metal by at least 25% and additional alloying coating with a grating metal element with a hole density of 10 pieces/cm2 or more. At a lower density of perforating the lattice, the opposite effect is observed

Slag from Modern Copper Production Found in Bergwerk, Burgenland, Austria

The investigated slags from Bergwerk (Burgenland, Austria) are from the 17th century and a byproduct of a copper smelting process. These slags are typical plate slags but metallographic studies have shown that these slags are atypical compared to alpine slags. There is an elongated texture running across the slag but the typical fayalite dendrites are absent. Noticeable are high sulfur and Fe levels. SEM-EDX element mappings show that FeO and FeS coexist locally, suggesting that a eutectic FeO-FeS mixture exists. The melting point could have been lowered to 930 °C by the FeO-FeS eutectic. CaSO4 was also detected in the slag. The glass phase, containing all the slag impurities, is located between the fayalite and the FeO-FeS mixture. The smelting process, in which these slags were formed, is currently unknown. It has been unproven as well, what advantages such a copper smelting process could have.