Plate Research Articles

All-Metal Metamaterial-Based Sensor with Novel Geometry and Enhanced Sensing Capability at Terahertz Frequency

This research proposes an all-metal metamaterial-based absorber with a novel geometry capable of refractive index sensing in the terahertz (THz) range. The structure consists of four concentric diamond-shaped gold resonators on the top of a gold metal plate; the resonators increase in height by 2 µm moving from the outer to the inner resonators, making the design distinctive. This novel configuration has played a very significant role in achieving multiple ultra-narrow resonant absorption peaks that produce very high sensitivity when employed as a refractive index sensor. Numerical simulations demonstrate that it can achieve six significant ultra-narrow absorption peaks within the frequency range of 5 to 8 THz. The sensor has a maximum absorptivity of 99.98% at 6.97 THz. The proposed absorber also produces very high-quality factors at each resonance. The average sensitivity is 7.57/Refractive Index Unit (THz/RIU), which is significantly high when compared to the current state of the art. This high sensitivity is instrumental in detecting smaller traces of samples that have very correlated refractive indices, like several harmful gases. Hence, the proposed metamaterial-based sensor can be used as a potential gas detector at terahertz frequency. Furthermore, the structure proves to be polarization-insensitive and produces a stable absorption response when the angle of incidence is increased up to 60°. At terahertz wavelength, the proposed design can be used for any value of the aforementioned angles, targeting THz spectroscopy-based biomolecular fingerprint detection and energy harvesting applications.

Clinical Efficacy of Three-Dimensional-Printed Pure Titanium Fracture Plates with Locking Screw Systems in Distal Tibia Fractures

Background and Objectives: Distal tibia fractures are high-energy injuries characterized by a mismatch between standard plate designs and the patient’s specific anatomical bone structure, which can lead to severe soft tissue damage. Recent advancements have focused on the development of customized metal plates using three-dimensional (3D) printing technology. However, 3D-printed metal plates using titanium alloys have not incorporated a locking system due to the brittleness of these alloys. Therefore, this study aimed to determine whether a locking mechanism can be effectively implemented using 3D-printed pure titanium and further evaluate the clinical outcomes of such implants in patients with distal tibia fractures. Materials and Methods: Between March 2021 and June 2022, nine patients who underwent open reduction and internal fixation for distal tibia fractures using 3D-printed pure titanium plates were enrolled. Pure titanium powder (Ti Gr.2, Type A, 3D Systems, USA) was spread to a thickness of 30 μm and partially sintered using a 500 W laser to produce the 3D-printed metal plates. The locking screws were fabricated using a milling process. Open reduction and internal fixation were performed on the nine patients using 10 customized plates. The clinical efficacy was analyzed using the union rate, and complications, such as infection and skin irritation, were evaluated to ensure a comprehensive outcome assessment. Results: Surgical treatment was successfully performed on nine patients, with nine of ten plates remaining stable and undamaged. However, one patient with neurofibromatosis experienced a fractured metal plate, which necessitated revision surgery using a metal rod. No screw loosening or surgical wound complications occurred. Conclusions: This study showed that 3D-printed pure titanium plates with integrated locking screw systems provide a viable and effective solution for managing distal tibia fractures. Three-dimensional printing and pure titanium show promise for orthopedic advancements.

Reducing the Radioactive Surface Contamination Level of Cobalt-60-Contaminated Material with PVA-Glycerol-EDTA Combination Gel

Decommissioning of nuclear facilities can be performed in stages. One of the stages and processes in decontamination is the decontamination process before dismantling or facility area recovery activities. Decontamination can be performed using various methods, primarily physical and chemical. One chemical method involves using a gel made of polymers for decontamination. In this study, a gel consisting of a mixture of 15 g polyvinyl alcohol (PVA), 15 mL of glycerol, and 2 g Na-EDTA was dissolved in 100 mL. The three materials were dissolved in hot conditions until they dissolved, and a gel was formed. The formed gel was applied to the material contaminated by Co-60 with a radioactivity of 81 µCi, as much as 5 µL. The decontamination radioactive efficiency test results range from 53% to 98%, with the highest decontamination efficiency observed on glass media. This study also showed that higher EDTA concentrations can increase the ability of the PVA-glycerol gel to absorb and bind Co. This study also found that decontamination efficiency was influenced by the type of contaminated material and the concentration of EDTA. It can be concluded that gels with a composition of PVA, glycerol, and EDTA can reduce the level of contamination on the surface of materials made of glass, ceramics, and metal plates.

Monofluorinated acetal electrolyte for high-performance lithium metal batteries

High degree of fluorination for ether electrolytes has resulted in improved cycling stability of lithium metal batteries due to stable solid electrolyte interphase (SEI) formation and good oxidative stability. However, the sluggish ion transport and environmental concerns of high fluorination degree drive the need to develop less fluorinated structures. Here, we depart from the traditional ether backbone and introduce bis(2-fluoroethoxy)methane (F2DEM), featuring monofluorination of the acetal backbone. High coulombic efficiency and stable long-term cycling in Li||Cu half cells can be achieved with F2DEM even under fast Li metal plating conditions. The performance of F2DEM is further compared with diethoxymethane (DEM) and 2-[2-(2,2-difluoroethoxy)ethoxy]-1,1,1-trifluoroethane (F5DEE). A significantly lower overpotential is observed with F2DEM, which improves energy efficiency and enables its application in high-rate conditions. Comparative studies of F2DEM with DEM and F5DEE in anode-free lithium iron phosphate (LiFePO4) LFP pouch cells and high-loading LFP coin cells further show improved capacity retention of F2DEM electrolyte, demonstrating its practical applicability. More importantly, we also extensively investigate the underlying mechanism for the superior performance of F2DEM through various techniques, including X-ray photoelectron spectroscopy, scanning electron microscopy, cryogenic electron microscopy, focused ion beam, electrochemical impedance spectroscopy, and titration gas chromatography. Overall, F2DEM facilitates improved Li deposition morphology with reduced amount of dead Li. This enables F2DEM to show superior performance, especially under higher charging and slower discharging rate conditions.

Surfactant usage in nitrile rubber film development through metal plate dipping process

Developing rubber film in the lab is important for studying the mechanical changes on gloves with different developed formulation. The process in the lab differs from the factory, as the rubber film is formed from dipping a metal plate into the compounded mixture, while the factory uses a well-crafted former to make their gloves in a controlled environment. One issue arises during preparation rubber film in laboratory is the coagulant was unable to uniformly coat the metal plate, which result in producing uneven rubber films. Thus, this work focuses on the incorporation of surfactant into the coagulant solution (Ca(NO3)2) to allow a uniform coating. Two concentrations of two types of surfactants are tested by measuring the contact angle of coagulant to the metal plate. 0.5% of Wetpol 800 surfactant provides an even coating of rubber film on the metal plate after dipping through visual inspection compared to the Ca(NO3)2 alone. The rubber film formed has an average thickness of 0.065 mm, tensile strength of 22.348 MPa, ultimate elongation 1388.4 %, modulus E100 and E300 of 1.377 and 0.731 respectively.

Indented metallic bipolar plates for vanadium redox flow batteries

The standard industrial vanadium redox flow battery (VRFB) stack is made of thick graphite bipolar plates to support the flow field required for optimal circulation of electrolyte. These thick plates suffer from electrolyte seepage, poor mechanical properties, and high machining and processing costs. In the present study, we report on the use of metallic bipolar plates for the construction of the VRFB cell. We show, through comprehensive electrochemical and hydrodynamic investigations, that Hastelloy C276, a corrosion-resistant high Nickel alloy, is a suitable bipolar plate material in VRFB cells. We show further that surface texture modification, in the form of a mix of concave and convex spherical indentations on the metallic bipolar plate, can have beneficial effects on cell performance. Comparative experiments on medium-size cells of a nominal area of 440 cm2 operating in the current density range of 75–125 mA/cm2 show that discharge energy gains of 25% or higher can be obtained together with a 10–15% reduction in pressure drop in comparison with similar cells with flat bipolar plates. It is posited that the concave indentations spread over the entire area ensure uniform electrolyte circulation while regions of low and high electrode compression create flow channeling possibilities that lead to reduced pressure drop.

Metallic perforated plate lattices with superior buckling strength

Metallic perforated plate lattices with superior buckling strength

Investigation and evaluation of formability of thin metallic bipolar plates by stamping process

Investigation and evaluation of formability of thin metallic bipolar plates by stamping process

Artisanal Longline Fishing for Greenland Halibut (Reinhardtius hippoglossoides) Operated Under Sea Ice Using a Metal Plate Kite in Northwest Greenland

Understanding the deployment ranges and behavior of fishing gear in relation to fishery efficiency will help us grasp the potential impact of future shifts in the fishery on resources and fishing activities. Fisheries for Greenland halibut are conducted by boat in open water during the summer. However, in winter, fishermen travel to fishing grounds on the sea ice using dog sleds, drill holes in the ice, and deploy longlines using metal plate kites. While the scale of deployment varies between boat and ice longlining, the movement of kites used in ice longlining and their effect on the deployment range of the line is not well understood. We conducted experiments using an accelerometer to determine the underwater movement of kites and their effect on the horizontal range of longline deployment. This is the first report describing specific operational information on longline fishing under sea ice, specifically on the effects of the kite on longline deployment. The kite is attached to the leading end of the mainline and deploys the longlines horizontally as it moves downward towards the sea floor. When the kite and mainline are dropped into the sea, the kite extends the line horizontally while shifting forward-facing long side, and forward-aligned short side. The motion resembles a fluttering action primarily influenced by the Reynolds number and moment of inertia. When the mainline is held, the kite descends in a circular motion. With repeated fishing operations and the passage of time, the kite's movement is expected to decrease in both range and speed due to the buoyancy and tension of the mainline. These kite movements suggest that the deployment range of longlines could extend several hundred meters. Conversely, it can be inferred that the impact of winter ice fishing on the Greenland halibut stock is relatively low due to the limited deployment range of the longline when using the kite.

Design of an adjustable low-temperature linear microwave plasma source for atmospheric pressure applications

Linear plasmas, compared to small-area low-temperature plasma jets, offer a larger single-treatment area with a brush-like pattern, making them highly promising for various applications. This paper introduces the design of an adjustable low-temperature linear plasma source that operates under atmospheric pressure at 2.45 GHz. The design integrated microwave theory with dielectric barrier discharge principles, utilizing a resonant structure based on a microstrip power divider with one end open and the other shorted. The ground plane of the microstrip structure was replaced by a metal plate featuring a large groove. Argon gas was introduced from the short-circuited end and exited through the groove at the open end, where plasma excitation occurred. Experimental results demonstrated that the device, operating at atmospheric pressure, can achieve adjustable linear plasma widths ranging from 10 mm to 50 mm by varying the incident power between 30 and 100 W. Optical emission measurements confirmed the uniformity of the linear plasma, and the gas temperature 5 mm away from the discharge area remained at only 65 °C, even with a microwave incident power of 100 W. This study offers a novel approach to designing linear atmospheric pressure microwave plasma sources, with significant potential for diverse material treatment applications.

Probing sodium structures and dynamics in hard carbon for Na-ion batteries using 23Na operando solid-state NMR spectroscopy

In this study, we aim to (i) provide an in-depth analysis of the formation and composition of the SEI, (ii) understand and differentiate the sodium storage processes, and (iii) distinguish between Na metal plating and dendrite growth.

Study of Adhesive Bonded Joints between Metallic Plates and Composite Laminates

Many researchers studied influences of various parameters on the failure behavior on the composites. One of the challenges in the analysis and design of bonded joints is the valuation of the stress and strain fields at the adhesive layer and adherents. The present investigation deals with the analysis of adhesively bonded dissimilar material single lap joints (SLJ) between mild steel and unidirectional carbon fibres reinforced polymer (CFRP) laminates. The primary objective of this study is to investigate the effects of various parameters, such as bonding strength, overlap length, adherend thickness, and adhesive thickness, on the failure load and failure mode of joints with dissimilar materials. Failure process, mode and strength of unidirectional composite to mild steel single lap adhesive bonded joints were investigated numerically by using finite element methods. Numerical methods based on finite element models can be very useful in describing the stress and strain responses for each load step. The SLJ specimens are done nonlinear analysis and predict the force -displacement and force- strains curves and conclusions regarding joint stiffness and strength are obtained for different cases of SLJ

LEVERAGING ARABIC CALLIGRAPHY SYSTEMS AND ISLAMIC ARCHITECTURAL SYMBOLS TO ENRICH THE AESTHETIC VALUES OF METAL PAINTING

This study aimed to investigate the potential for utilizing Arabic calligraphy and the symbols of Islamic architecture to enrich the aesthetic values of metal painting. The study presented a conceptual framework that included an exploration of calligraphy, its letters, plastic values, expressive values, and select symbols of Islamic architecture. The study employed a descriptive-analytical approach, as well as a quasi-experimental method. It examined the linear systems that can be created through various types of lines in terms of form, as well as the diverse relationships that can be achieved between those line types. An evaluation tool based on frequencies and percentages was utilized, and its validity and reliability were verified. The study sample consisted of 15 specialized arbitrators who assessed the executed metal plates. A total of 12 meta l paintings were analyzed, with their content and components described and analyzed according to the study variables. The results indicated that it is possible to benefit from linear systems in creating metal panels with diverse aesthetic values. Linear systems possess the characteristics of diversity to generate formal and expressive relationships in combination with the elements and symbols of Islamic architecture, making them suitable as a primary basis for the design and construction of metal paintings. The linear system also contributed to achieving multiple functions with the metal painting and enhancing artistic values in general. The study recommends an in-depth examination of the vocabulary of Islamic architecture and Arabic calligraphy in terms of their compositional structure, to extract the fundamental principles for creating metal panels inspired by their integration. Additionally, the study suggests adapting the aesthetic and plastic capabilities of metals and employing them in new plastic formulations, both in terms of design and performance methods.

A Time Series Proposal Model to Define the Speed of Carbon Steel Corrosion in an Extreme Acid Environment.

This article shows the behavior of the corrosive effect of acid mine water on carbon steel metal alloys. Mining equipment, composed of various steel alloys, is particularly prone to damage from highly acidic water. This corrosion results in material thinning, brittle fractures, fatigue cracks, and ultimately, equipment failure. For this purpose, a set of carbon steel metal plates similar to those found in mine facilities were immersed into mine leachates of an AMD (Acid Mine Drainage) polluted river from the Tharsis Mine (Huelva, Spain). In these leachates, physicochemical variations occur, directly correlated with the alterations produced in the metal plates, manifested with the appearance of dissolved materials and particulate matter. Weight loss of up to 37 g in 30 weeks for plates of about 140 grs occurred and an increase in EC up to 45.64 mS/cm from 5.40 mS/cm and an increase in TDS from 2600 mg/L to 17,100 mg/L. STATGRAPHICS Centurion, a powerful data analysis tool was used for performing the time series analysis that was used for the first time to statistically define the corrosion effects on metal alloys. As a result, a significant variability in the physical and chemical factors of the leachates was observed due to the redox and precipitation-dissolution processes occurring within the system: an increase in total dissolved solids (TDS), electrical conductivity (EC) and temperature (T) (the corrosion process is an exothermic reaction) and a decrease in pH. It was also demonstrated that the longer the exposure time, the plates noticeably lost more material and became further weakened. Finally, these results allowed the formulation of a simple algorithm to define weight loss as a function of exposure time to acidic water.

Shear behavior of metal plate joints of laminated bamboo lumber at different angles or sizes

ABSTRACT To determine the shear behavior and slip resistance of metal plate joints of laminated bamboo lumber (LBL), considering the influence of sizes (length and width) and angles of metal plates, 100 specimens were tested. When the angle of the metal plate is different, the force modes can be divided into three types: pure shear, shear-tension, and shear-compression modes. According to the test results, the shear-tension modes of metal plate joints have the strongest bearing capacity, followed by the pure shear mode in second place and the shear-compression mode in last. The change in the size of the joints dramatically influences the ultimate load. Based on the test, the load-slip curves of the shear metal plate connected joints of LBL were fitted by the Foschi formula, and the fitting results were in good agreement with the test results. Finally, the ultimate shear strength of LBL joints was compared with that of other wood/bamboo composites. The results show that the shear performance of metal plate joints of LBL is better than that of ordinary wood materials. The test provided a reference for the engineering structures and finite element numerical simulation analysis of metal plate connected joints of LBL.

Experimental Investigation of the Effect of Different Parameters on Plate and Frame Heat Exchanger Effectiveness

Plate & frame heat exchangers use a series of metal plates to conduct heat transfer between fluids. These fluids are directed through specific channels, ensuring they remain isolated while allowing efficient heat exchange. In recent years, researchers have looked at how different characteristics affect heat exchanger performance. The purpose of this study is to examine the impact of various factors on the effectiveness of the heat exchanger. The experimental analysis was conducted using pure water, considering different Re numbers ranging from 6000 to 30000 and varying hot fluid inlet temperatures between 25℃ and 35℃. It was observed that under turbulent flow conditions, the heat transfer effectiveness increased of 13.6% when the Reynolds number varied between Re = 6000 – 20000 at constant Th,in=35℃. However, the extent of this increase diminished significantly within the Re = 20000-30000 range. When the inlet temperature of hot fluid was raised Th,in=25℃ to 35℃ the plate & frame heat exchanger effectiveness increased of 4.3%. This study provides a basis for future studies on heat exchangers used in industrial applications with different geometries and different fluids. It is considered that the results of this study could be used in the future to design more modular and efficient plate heat exchangers for industrial applications.

From copper‐based alloys to coins—Part I: Metallurgical characterization from complex manufacturing processes of imitation coins dated to the third century CE

AbstractThe evidence for imitation coinage found on the Gallo‐Roman site of Châteaubleau (Seine‐et‐Marne, France) has been attested for several years. Successive excavations and findings related to the production of imitation coins, both struck and cast, have revealed major minting activity during the second half of the third century CE. This paper presents the study of 11 archaeological samples issued from this counterfeiting workshop site, which is today considered the most important in the north‐western provinces of the Roman Empire. These samples, which correspond to different stages in the production chains leading to coins, mainly radiates (antoniniani, double sestertii), were characterized by metallography, energy‐dispersive X‐ray fluorescence (EDXRF), scanning electron microscopy with energy‐dispersive spectroscopy (SEM‐EDS) and the Vickers hardness test, in order to understand the different manufacturing processes, especially the ‘rod to coin’ one. This project is divided into two parts. The first, which is the subject of this paper, focuses on the chemical and metallurgical study of the archaeological artefacts. This has enabled us to identify and characterize the manufacturing processes thanks to the highly characteristic microstructure of the samples from the rod‐to‐coins process. Some of the cylinders derived from this process were also silvered by plating a foil of silver or silver–copper on a flan of pure copper in order to obtain irregular radiates. As regards fake double sestertii, several manufacturing techniques were identified: direct moulding of coins in stacked terracotta moulds, the casting of flans to strike double sestertius and the cutting of flans from metal plate is also a technique used in Châteaubleau. Characteristic composition and microstructures were also observed in these samples. This paper will be followed by a second focused on two experimental archaeology sessions carried out in order to reproduce the process ‘from rod to coins’ and then to compare the reproduced samples with the archaeological samples.

Mechanical stability of the proximal tibia with different bone formations after plate removal in medial opening-wedge high tibial osteotomy: a finite element analysis

BackgroundNo clear agreement exists on the degree of bone formation required to remove a metal plate without correction loss after medial opening-wedge high tibial osteotomy (MOWHTO). We aimed to investigate the mechanical stability of the proximal tibia with different bone formations after plate removal in MOWHTO using finite element models and determine the extent of bone formation when the plate can be removed without correction loss.MethodsThe MOWHTO models with 5, 10, and 15 mm opening gaps were generated. The mechanical stability of proximal tibial models with different extents of bone formation (from the lateral cortex of the osteotomy wedge to 20% (zone 1), 40% (zone 2), 50% (zone 2.5), 60% (zone 3), 70% (zone 3.5), 80% (zone 4), and 100% bone formation medially) after plate removal was analyzed using finite element analysis. Bone stress and strain and micromotion were evaluated to investigate fracture risk and bone stability, respectively, in various types of tibial models.ResultsPeak von Mises stress was lower than yield strength when bone formation reached zone 3.5 (70%) or more in 5- and 10-mm osteotomy gap models, and zone 4 (80%) or more in a 15-mm gap model. Maximal principal strains were lower than 6,130 microstrain when bone formation reaches zone 3.5 (70%) or more in models with osteotomy gaps of 5, 10, and 15 mm.ConclusionsThis indicates that plate removal without correction loss after MOWHTO may be possible when bone formation reaches zone 3.5 (> 70%) or more during 5- and 10-mm osteotomy gap corrections, and zone 4 (> 80%) or more during 15-mm gap correction. The present study results suggest that it would be safer to perform plate removal after obtaining sufficient bone formation rather than performing it near the osteotomy gap center (50%) to avoid correction loss considering both coronal and sagittal plane aspects.

Additive Manufacturing of Watertight ABS Parts and Its Use for Chemical Metal Plating

AbstractOne of the most frequently used polymers in the galvanic industry as well as for Fused Filament Fabrication (FFF) is the terpolymer of acrylonitrile butadiene styrene (ABS). Its surface is etched in chromosulfuric acid to enable the chemical deposition of a metal. The use of chromium (Cr)(VI) compounds is restricted in the European Union (EU) since 2017. A new plating process is proposed here that does not rely on etching. Instead, double bonds on the ABS surface are converted to epoxides, followed by grafting of a polyethylenimine (PEI) to the surface. The so modified plastic is an ideal starting point for metal plating. Printing often leads to the formation of voids between strands and layers, which hinders subsequent wet processing. The plating process introduced here requires high demands on the water tightness of parts. The proposed printing procedure reduces the degree of penetration of water from 50% to less than 0.1% at 2 bar water pressure. The combination of the new printing procedure with the new plating process results in the deposition of industrial relevant nickel (Ni) layers. The cross‐hatch test followed by a peel test exhibits values of zero, pointing to the high adhesion of Ni to ABS.

Biomechanical stability of magnesium plate and screw fixation systems in LeFort I osteotomy: a three-dimensional finite element analysis

BackgroundTitanium (Ti–6Al–4 V) is used for fixation in LeFort I osteotomy, a procedure for treating midface deformities. This study assessed the biomechanical stabilities of two Mg alloys (WE43 and ZK60) as biodegradable alternatives and compared them against Ti using finite element analyses. The LeFort I osteotomy procedure was simulated, and various plate and screw configurations were tested. The maximum principal and peak von Mises stresses in the metal plates and bone screws were measured under four load conditions, and the stability was evaluated.ResultsThe holes in the Mg screws, as compared with the Ti counterparts, exhibited higher and lower stress levels in the cortical and cancellous bones, respectively. The Mg screws also exhibited a higher fracture risk. The ZK60 plate, as compared with the Ti and WE43 plates, exhibited a lower fracture risk under all load conditions. ZK60 exhibited higher biomechanical stability in terms of maintaining the gap between osteotomy surfaces and lower fracture risk; the osteotomy surfaces with Ti im-plants underwent bone impaction, resulting in gap closure.ConclusionsAlthough the Mg implants exhibited better stress distribution, their screw strength requires improvement. Appropriate improvements can promote the use of Mg alloys in bone fixation applications.