Metal Loss Research Articles

Ultrafast and low power all-optical switching in the mid-infrared region based on nonlinear highly doped semiconductor hyperbolic metamaterials

Guided wave modes in the uniaxial anisotropic hyperbolic metamaterials (HMMs) based on highly doped semiconductor instead of metal in the mid-infrared region are investigated theoretically. The heavily doped semiconductor is used to overcome the restrictions of the conventional metal-based structures caused by the lake of tunability and high metal loss at mid-infrared wavelengths. The unit cells of our proposed metamaterial are composed of alternating layers of undoped InAs as a dielectric layer and highly doped InAs as a metal layer. We numerically study the linear and nonlinear behavior of such multilayer metamaterials, for different arrangements of layers in the parallel (vertical HMM) and perpendicular (horizontal HMM) to the input wave vector. The effect of doping concentration, metal to dielectric thickness ratio in the unit cell (fill-fraction), and the total thickness of structure on the guided modes and transmission/reflection spectra of the metamaterials are studied. Moreover, the charge redistribution due to band-bending in the alternating doped and undoped layers of InAs is considered in our simulations. We demonstrate that the guided modes of the proposed hyperbolic metamaterial can change by increasing the intensity of the incident lightwave and entering the nonlinear regime. Therefore, the transition from linear to the nonlinear region leads to high-performance optical bistability. Furthermore, the switching performance in the vertical and horizontal HMMs are inspected and an ultrafast, low power, and high extinction ratio all-optical switch is presented based on a vertical structure of nonlinear highly doped semiconductor hyperbolic metamaterials.

Loss Analysis of Thin Film Microstrip Line With Low Loss at D Band

The D-band (110~170 GHz) thin film microstrip line (TFML) with easy integration, low loss, and easy fabrication is presented in this work. It is composed of copper (Cu) signal line on the top layer, ultra-thin Benzocyclobutene (BCB) dielectric on the interlayer and Cu ground plate on the bottom. This study presents the calculation formulas, extraction methods, reduction solutions of metal loss, dielectric loss, and radiation loss. The calculation results well agree with the simulation results. Metal loss caused by skin effect and surface roughness is the main part of loss, accounting for 89%. The introduced micro-electro-mechanical-systems (MEMS) process could precisely manufacture samples in batches. The tested loss after thru-reflect-line (TRL) de-embedding is 0.6 dB/mm, which is higher than the simulated loss of 0.4 dB/mm. The simulated loss corrected after considering the roughness effect has good agreement with the tested loss. The proposed TFML and its loss analysis help to design planar passive devices with low loss at D band.

Impact of remanufacturing on the reduction of metal losses through the life cycles of vehicle engines

Remanufacturing gives a full new service life for every usage cycle of a product. Since remanufacturing avoids material dissipation, it is conceivably superior to material recycling. However, quantifying the effectiveness of remanufacturing is difficult due to the fundamental lack of indicators and supporting tools designed for the task. In this study, the volume of avoided material dissipation was adopted as an evaluation indicator to measure the effect of product service life extension. The circulation path of remanufacturing was incorporated to a dynamic material flow analysis model called the MaTrace model to quantify the effect of remanufacturing on the extent to which material dissipation was avoided over time through product life cycles. Through a case study of vehicle engines over a period of 50 years by applying the extended MaTrace model, a comparison with a case where used products were all recycled, revealed that extending product service life cycles through remanufacturing reduces the overall physical loss of steel, Ni, and Cr in the vehicle's engine by 3%, 2% and 5%, respectively. These results quantitatively clarify the superiority of engine remanufacturing over material recycling with respect to the effect of avoiding material dissipation in a circular resource system.

Influence of Robust Drain Openings and Insulation Standoffs on Corrosion Under Insulation Behavior of Carbon Steel

Corrosion under insulation (CUI) is among the key concerns for the integrity of process equipment and pipelines. Various measures to detect and fix the damages from CUI pose significant maintenance expenditures in hydrocarbons processing facilities. The key reason behind CUI is the limitation of thermal insulations to absorb the moisture and soak the underneath metal from wicking action. Other than CUI, trapped moisture in the soaked thermal insulations causes heat loss from process systems, thereby posing the risk of additional damage mechanisms and increased operating expenditures. This study addresses the impact of robust drain openings and insulation standoffs on the CUI rate of carbon steel under four different testing conditions, namely isothermal wet, isothermal wet-dry, cyclic wet, and cyclic wet-dry, respectively. Corroded specimens were further characterized using surface topography and scanning electron microscope. The impacts of temperature and moisture cycling on the corrosion attributes were also characterized using the linear polarization resistance method followed by an investigation of corrosion modes via optical microscopy. Insulation standoffs in conjunction with robust drain opening resulted in the lowest corrosion rate. With insulation standoffs and drain openings, the cyclic temperature conditions caused higher metal loss than that in isothermal conditions.

350-GHz Bandpass Filters Using Superconducting Coplanar Waveguide

On-chip filters play an invaluable role in most detectors and instruments, blocking unwanted, harmonic, or mirrored signals. In this article, two coplanar waveguide bandpass filters working at 350 GHz are designed based on quarter-wavelength stepped impedance resonators, which can be easily integrated in on-chip systems. A second-order filter with a classical Chebyshev response and a fourth-order filter with quasi-elliptical characteristic is developed together to define the roll-off performance. Both filters are patterned based on superconducting niobium film by the optical lithography and lift-off process, which could reduce the significant metallic loss in high terahertz band. All the chips integrated with transitions are evaluated through a quasi-optical system, which is built based on the sensitive superconductor-insulator-superconductor tunnel junction detector at cryogenic temperature. The calibrated transmission responses, which are matched with simulations, have indicated that such superconducting coplanar waveguide filters can be enabled in future terahertz astronomical spectrometer.

Nature of dust and smoke generation during gas-oxygen blasting in converter bath

The article presents the study of the nature of dust and smoke generation during gas-oxygen blasting of a converter bath. The main reasons causing metal waste have been determined. Influence of the process main parameters on metal loss has been studied during dust removal and evaporation of iron in the reaction zone. The authors have estimated the process of metal pulverization due to CO bubbles floating, determined by the rate of their rise to the bath surface. Specifics of temperature regime of the reaction zone and heat balance have been determined when adding fuel to the oxygen flow. Adding fuel to oxygen makes it possible to increase heat input into the bath, while reducing the rate of decarburization. This enables reduction of dust discharge during rupture and crush of metal films by gas bubbles. The effect of combustion products oxygen use on metal impurities oxidation is considered. By the example of blasting carbon and alloyed steel for mill rolls, it has been shown that the degrees of CO2 and H2O decomposition in the bath are the main qualities of gas-oxygen blasting. These indicators determine the oxidizing and heating properties of the blast. Assessment of change in total, consumed heat and its losses with exhaust gases, depending on degree of the oxygen flow dilution with natural gas (methane), has been carried out. Under these conditions, use of submersible combustion torches with change in their oxidizing ability makes it possible to solve various technological tasks, including provision of an effective way to reduce dust emission in converter process.

Magnetic Internal Corrosion Detection Sensor for Exposed Oil Storage Tanks.

Corrosion in the oil and gas industry represents one of the major problems that affect oil production and transportation processes. Several corrosion-inspection technologies are in the market to detect internal and external corrosion of oil storage tanks, but inspection of storage tanks occurs every 3 to 7 years. In between inspection interval, aggressive corrosion can potentially occur, which makes the oil and gas industry vulnerable to accidents. This study proposes a new internal corrosion detection sensor based on the magnetic interaction between a rare-earth permanent magnet and the ferromagnetic nature of steel, used to manufacture oil storage tanks. Finite element analysis (FEA) software was used to analyze the effect of various sensor parameters on the attractive force between the magnet and the steel. The corrosion detection sensor is designed based on the FEA results. The experimental testing of the sensor shows that it is capable of detecting internal metal loss due to corrosion in oil storage tanks within approximately 8 mm of the internal surface thickness. The sensor showed more than two-fold improvement in the detection range compared to previous sensor proposed by the authors. Furthermore, the sensor of this paper provides a monitoring rather than occasional inspection solution.

Machine Learning for Automating the Design of Millimeter-Wave Baluns

We propose a framework to analyze mm-wave baluns directly from physical parameters by adding a dimension of Machine Learning (ML) to existing electromagnetic (EM) methods. From a generalized physical model of mm-wave baluns, we train physical-electrical Machine Learning models that both accurately and quickly compute the electrical parameters of mm-wave baluns from physical parameters, reducing the need for full-wave simulations and advancing several aspects of mm-wave designs. One of the advancements is a fully automated design process that accurately generates full EM designs of mm-wave baluns when given an electrical specification and a metal option. The automated technique only takes several seconds to complete, compared to hours-weeks of the current trial-and-error methods, and notably the approach can optimize mm-wave baluns directly for the lowest metal loss. Another advancement is the theoretical interpretation of several high-level and abstract questions concerning mm-wave designs, in which we quantify the optimum transistor sizes for the last stage of a class-AB differential power amplifier on an on-chip process and derive the rule of thumb describing the inverse relationship between the optimum device sizes and mm-wave frequencies.

Direct Single-Step Printing of Conductive Grids on Curved Surfaces Using Template-Guided Foaming.

Advanced transparent conductors have been studied intensively in the aspects of materials, structures, and printing methods. The material and structural advancements have been successfully accomplished with various conductive nanomaterials and spring-like structures for better electrical conductivity and high mechanical flexibility of the transparent conductors. However, the capability to print submicrometer conductive patterns directly and conformally on curved surfaces with low processing cost and high throughput remains a technological challenge to achieve, primarily because of the original two-dimensional (2D) nature of conventional lithography processes. In our study, we exploit a liquid-mediated patterning approach in the development of flexible templates, enabling printing of curvilinear silver grids in a single-step and strain-free manner at a submicrometer resolution within several minutes with minimum loss of noble metals. The template can guide arrays of receding liquid-air interfaces on curved substrates during liquid evaporation, thereby generating ordered 2D foam structures that can confine and assemble silver nanoparticles in grid patterns. The printed silver grids exhibit suitable optical, electrical, and Joule-heating performances, enabling their application in transparent heaters. Our technique has the potential to extend the existing 2D micro/nanofluidic liquid-mediated patterning approach to three-dimensional (3D) control of liquid-air interfaces for low-cost all-liquid-processed functional 3D optoelectronics in the future.

Synergetic loss of heavy metal and phosphorus: Evidence from geochemical fraction and estuary sedimentation

The synergetic loss mechanism of heavy metals (HMs) and phosphorus (P), as well as the relationships between their different geochemical fractions remain unclear. This study employs field research, source identification and sedimentary geochemistry in Yellow River basin to investigate the internal mechanisms of the different geochemical fractions, terrestrial source signatures, and synergetic loss fluxes. The average contents of As, Cd, Cr, Cu, Pb, Zn and P in the basin were 8.29 mg/kg, 0.15 mg/kg, 47.52 mg/kg, 11.78 mg/kg, 10.65 mg/kg, 46.56 mg/kg and 578.78 mg/kg, respectively. Based on Pearson’s correlation and redundancy analyses, the impact factors on the transport of HMs and P, and the internal relationships between different geochemical fractions were analyzed. According to the constant rate of supply (CRS) model, the terrestrial losses of As, Cd, Cr and Cu showed significant positive relationships with the TP flux, with r2 value of 0.981, 0.991, 0.996 and for 0.984, respectively. It has been proven that the extensive fine particles in the Yellow River basin carry a large amount of diffuse pollutants, thus ultimately increasing the estuarine pollutant load. This research provides new insights from the level of microscopic fractions to macroscopic fluxes to investigate the impacts of anthropogenic activity on regional environmental changes.

An investigation into potential pathways for nickel and cobalt loss during impurity removal from synthetic nickel laterite pressure acid leach solutions via partial neutralisation

The primary pathways by which nickel (Ni) and cobalt (Co) loss could occur from acidic sulfate solution during partial neutralisation of synthetic nickel laterite pressure acid leach solutions (to pH 4 at 85 °C) was investigated. Knowledge of the avenues by which Ni and Co loss occurs will enable minimisation of valuable metal losses through optimisation of the partial neutralisation process. Precipitation of Ni and Co as their hydroxides did not appear to be a pathway by which metal loss occurred during partial neutralisation. Additionally, co-precipitation of Ni and Co with either Fe(III) or Al was not found to be a significant route for valuable metal loss. Adsorption onto freshly precipitated hydrous oxides of Al and Fe(III), as well as haematite, a major component of nickel laterite pressure leach discharge solids, appeared to be the primary route by which Ni and Co loss occurs during partial neutralisation. There was a preference for Co to adsorb onto haematite and ferric iron precipitates whilst Ni preferentially adsorbed onto Al precipitates. The molar ratio of Al to Fe(III) in the synthetic feed liquor was found to be a key variable controlling Ni and Co loss during partial neutralisation. Final Ni losses initially increased with increasing Al/Fe molar ratio in the feed, being at their highest in the absence of Fe(III) (10.7% Ni loss), and when the Al/Fe molar ratio in solution was unity (11.9% Ni loss), then decreased significantly when the Al/Fe ratio in the feed liquor was greater than or equal to 2 (2% Ni loss). Cobalt losses generally decreased with increasing Al/Fe ratio in solution except for in the presence of haematite where Co losses were 3.30%, confirming that Co adsorption onto haematite is a significant route by which loss of this valuable metal occurs during partial neutralisation.

Role of Fe dynamic in release of metals at Rio Doce estuary: Unfolding of a mining disaster

The role of Fe oxyhydroxides dynamic on metal bioavailability was studied in the Rio Doce estuary after the largest mining disaster in the world. Soon after the disaster in 2015, metals were associated with Fe oxyhydroxides under a redox-active estuarine environment. Our results indicate that organic matter inputs from plant colonization on deposited tailings over estuarine soils led to a reductive dissolution of Fe oxyhydroxides within two years. Soil pseudo-total Fe content decreased by 70% between 2015 and 2017, while the total metal contents (Cr, Cu, Ni, Pb, and Zn) decreased by 79% in the soil. The losses of Fe and metals coupled to changes in Fe oxides crystallinity reveal a future ephemeral control of Fe oxyhydroxides over metal immobilization. Our results suggest a potential chronic contamination at the estuary and points to an aggravating scenario for the following years due to the increasing dominance of poorly crystalline Fe oxyhydroxides.

Electric conversion treatment of cobalt-containing wastewater.

Long-term accumulation of cobalt-containing wastewater may also pollute groundwater and cause a large amount of loss of valuable metals. Therefore, the comprehensive utilization of cobalt-containing wastewater must be realized, especially as cobalt itself is a very important strategic resource. This paper proposes a membrane electroconversion method to separate cobalt ions from cobalt-containing wastewater and prepare cobalt hydroxide. In addition, the electrolysis process was optimized, and single-factor experiments such as the initial concentration, cobalt ions, current density, temperature etc., and economic calculations such as current efficiency were explored. The electrolysis product was calcined as the precursor to obtain the oxide Co3O4, and the calcination experiment was also optimized. In this concentration range, more than 90% of cobalt can be recovered within 2 h.

Layer-by-layer N, P co-doped carbon materials with gradient electric field to suppress the shuttle effect for lithium sulfur batteries

The shuttle effect of lithium-sulfur batteries leads to passivation of the lithium metal anode surface and loss of active sulfur, which seriously restricts its development. In order to eliminate the shuttle effect, a layer-by-layer N and P doped heterogeneous carbon materials (MC@CN@CNP) with gradient electric fields are rationally designed to limit the dissolution of polysulfide anions. Such heterogeneous structure is prepared by a simple MOF self-sacrificing template strategy via changing the types of organic ligands in the synthesis of multilayer MOF, thus realizing the gradient doping of N and P heteroatoms from the inner layer to the outer layer. DFT calculation proves that the doping of N and P heteroatoms can change the electronic structure of carbon materials and tune their electron cloud density. The hybrid atom gradient doping also induces the construction of gradient energy level. The gradient of electron cloud density increases to form an internal electric field, which restricts the diffusion of polysulfides to the anode and alleviates the loss of active sulfur caused by shuttle effect. At the same time, the doping of N and P heteroatoms enhances the conductivity of MOF derived carbon, promotes the charge transfer, and enhances the reaction kinetics. As a result, when the MOF derived carbon material (MC@CN@CNP) was used to modify the commercial PP separator, the lithium-sulfur battery shows excellent electrochemical properties with superior rate capability and robust cycling stability (737.2 mAh g−1 after 500 cycles at 1.0 C with a small capacity decay of 0.034% per cycle).

Combined role of polarization matching and critical coupling in enhanced absorption of 2D materials based on metamaterials.

Since 2D materials are typically much more efficient to absorb in-plane polarized light than out-of-plane polarized light, keeping the light polarization in-plane at the 2D material is revealed to be a crucial factor other than critical coupling in light absorption enhancement in a 2D material integrated with a light coupling structure. When the composite of a metal-insulator-metal structure and a 2D material changes from the magnetic resonator form to the metasurface Salisbury screen one, the field polarization at the 2D material changes from a mainly out-of-plane status to a mainly in-plane status. As a result, for graphene, the absorptance enhancement is increased by 1.6 to 4.2 times, the bandwidth enlarged by 3.6 to 6.4 times, and the metal loss suppressed by 7.4 to 24 times in the mid- to far-infrared range, leading to the absorptance of graphene approaching 90% in the mid-infrared regime and 100% in the THz regime. For monolayer black phosphorus, the absorptance enhancement at the wavelength of 3.5 µm is increased by 5.4 times, and the bandwidth enlarged by 1.8 times. For monolayer MoS2, the averaged absorptance in the visible-near infrared range is enhanced by 4.4 times from 15.5% to 68.1%.

Quasi‐Bound States in the Continuum with Temperature‐Tunable Q Factors and Critical Coupling Point at Brewster's Angle

AbstractQuasibound state in the continuum (quasi‐BIC) is a long‐lived state with a high quality factor (Q factor). Here quasi‐BICs in nematic liquid crystal (LC) layer embedded between a distributed Bragg reflector (DBR) and a metal layer are studied. First, a special class of true BICs between the DBR and the metal film with field localization provided by the Brewster transverse electric (TE) reflection in the DBR is experimentally demonstrated. It is demonstrated that the Q factor of the quasi‐BIC can be tuned by the LC optical axis rotation in a wide range being only restricted by metal losses. The change of coupling with the radiation channel leads to a critical coupling condition, providing a total absorption of incident light. The acquired quasi‐BIC resonance is extremely sensitive to the temperature due to the narrow nematic temperature range of the LC. The quasi‐BIC transforms to BIC at the LC‐isotropic clearing point, due to closing of the radiation channel.

Effects of varying sources of Cu, Zn, and Mn on mineral status and preferential intake of salt-based supplements by beef cows and calves and rainfall-induced metal loss.

Three studies were completed to evaluate the effects of Cu, Zn, and Mn source on preferential intake, trace mineral status, and rainfall-induced metal loss of salt-based mineral supplements. Mineral supplements were formulated to contain 2,500, 5,500, and 4,000 mg/kg of Cu, Zn, and Mn, respectively. Supplements differed only by source of Cu, Zn, and Mn, which were hydroxychloride, organic, or sulfate sources. In Exp. 1, the three formulations were offered simultaneously for 18 wk to preweaned beef calves (four pastures; 17 calves per pasture) within separate containers inside covered cow-exclusion areas. Consumption averaged 21 ± 2.4 g/calf daily (sum of all three sources), with a greater (P < 0.001) percentage of the total intake coming from the hydroxychloride vs. organic or sulfate sources of Cu, Zn, and Mn. In Exp. 2, the same sulfate and hydroxychloride formulations were randomly assigned to pastures (n = 4 pastures per treatment) containing 18 to 20 cow–calf pairs/pasture. Treatments were offered for 20 wk within covered areas designed to assess cow and calf intake separately. At weaning, liver biopsies were collected from four cow–calf pairs/pasture (n = 16 cows and calves per treatment). Source of Cu, Zn, and Mn had no effect on voluntary mineral intake among calves (P = 0.44) and cows (P = 0.14). Calves consuming mineral containing hydroxychloride sources of Cu, Zn, and Mn tended (P = 0.06) to have greater average daily gain over the 20-wk period compared with calves consuming sulfate sources of the same elements (1.09 vs. 1.06 kg/d; SEM = 0.013). Mineral status of cows and calves was not affected (P ≥ 0.17) by source of Cu, Zn, and Mn. In Exp. 3, each of the mineral formulations from Exp. 1 was exposed to a 10.2-cm precipitation event delivered in three equal 3.4-cm applications within a week. To accomplish this, 750 g of mineral was placed into Buchner funnels (177 cm2) on 20- to 25-µm pore filter paper. Deionized water (pH adjusted to 5.6) was poured over the mineral. Total leaching losses of Cu, Zn, and Mn were less (P < 0.001) for formulations containing hydroxychloride vs. organic and sulfate sources. These results imply that, when offered a choice, calves preferentially consume mineral supplements formulated with hydroxychloride vs. sulfate or organic sources of Cu, Zn, and Mn. In addition, hydroxychloride sources of Cu, Zn, and Mn are less susceptible to rainfall-induced leaching losses compared with sulfate and organic sources.

In Situ X-ray Tomography Observations of Initiation and Propagation of Pits During Atmospheric Corrosion of Aluminium Alloy AA2024

In-situ synchrotron X-ray tomography has been used to observe the initiation and propagation of pits during atmospheric corrosion of aluminium alloy AA2024 under droplets of NaCl and simulated seawater at 21 ± 2 °C and a relative humidity of 85% over a period of 120 min. Each complete tomogram took 300 s to collect (pixel size 0.74 μm). Two metastable pits initiated at intermetallic particles, forming a crevice around the edge of the particles. Three other metastable pits formed at sites with no obvious micron-sized features. Only one pit, which had initiated under a fragment of debris, continued to stable growth. Metastable pits initiated sequentially, and all initiation events were accompanied by the formation of one or more bubbles, presumed to be hydrogen. Pit propagation was spatially non-uniform, with rapid growth in local regions while the remainder of the pit remained passive. The growth rate was highest parallel to the rolling direction of the plate. The highest local current density was estimated from the loss of metal between successive measurements to be ∼0.5 A cm−2. This is the first time that the transition from initiation to propagation of individual localised pits in an aluminium alloy has been characterised in situ.

The Introduction of Clay Placer Dredging Preparation Technology

A large number of placer deposits in the Trans-Baikal Territory and other regions of the Far East and Siberia feature large amounts of clay (30% and more). In such conditions, their development and preparation are complicated. The dredger performance reduced by 10-15%, and metal loss during preparation, especially small and fine-grained gold, amount to 30-50% and sometimes even more. Therefore, we face a problem of weakening the cleat between mineral grains and clay particles acting as an adhesive. Besides, we need to develop efficient technology for clay and cemented placer deposits for dredging. We developed and introduced into production a clay sand weakening technology. It was used on a dredging site in the Zabaykalye territory and resulted in a significant improvement of the dredger performance and gold output.

Evolution of metal-loss severity criteria: Gaps and a path forward

This paper considered integrity management (IM) based on the convergence of inspection technologies with those for defect assessment, as occurred circa 2000. A reformulation of the assessment criterion PCORRC, termed R-PCORRC, was presented, which now embeds a function of the steel’s strain-hardening response. Relative to full-scale tests for Grades from B up through and beyond X100 (L690) this criterion was shown accurate within 1%, with a low coefficient of variation of just 0.077. In contrast, B31G and Modified B31G showed significant bias, and scatter. The highly selective sometimes significant effect of width was shown to depend on the structural stiffness within the metal loss as compared to the stiffness of the pipe surrounding it. Defect assessment based on ILI of real corrosion was considered next, to identify technology gaps in the practical applications of this technology. It was apparent that improvements in MFL signal interpretation will help to resolve the issues with boxing criteria. While such concerns currently can be managed using the concept of plausible paths, as feature size and interaction are better characterized this concern will diminish. In such cases the predictive outcome of the plausible paths concept will in the limit tend toward that of B31G.The need for and benefits of accurate precise predictive schemes for metal-loss severity were illustrated. It was shown that a conservative prediction of failure pressure gives rise to a non-conservative prediction of defect size, leading to a non-conservative re-inspection interval for a pipeline. Finally, it was also shown that using an accurate scheme can result in significantly reduced maintenance, with a related benefit in a reduced scope of field digs to demonstrate the viability of inspection-based IM.