Type Of Metal Research Articles

Cobalt based bimetallic catalysts for heterogeneous electro-Fenton adapting to vary pH for HEDP and MIT degradation

ABSTRACT Most of the materials studied as catalysts in the electro-Fenton system are variants of iron oxide or iron hydroxide. However, iron-based catalysts often exhibit weak catalytic capabilities under neutral and alkaline conditions. In this work, we synthesized three cobalt based bimetallic oxides, Co2CuOx, Co2AlOx, and Co2NiOx, using hydrothermal method and evaluated them as catalysts for the heterogeneous electro-Fenton system to remove 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) and Methylisothiazolinone [2-methyl-4-isothiazolin-3-one] (MIT). Co2NiOx has the highest catalytic degradation activity for HEDP, and Co2CuOx has the best catalytic degradation effect for MIT. Based on characterization results of the catalysts, the reasons for the differences in the pollutant removal efficiency were analysed, and the optimal pH for the three cobalt based oxides to remove HEDP and MIT was investigated. The results showed that the optimal pH values of the three cobalt based bimetallic oxides are not only influenced by the second metal type, but also by the properties of pollutants. Therefore, suitable cobalt based catalysts can be selected based on the different properties of pollutants, or the composition of cobalt based catalysts can be adjusted to meet the different pH requirements of target wastewater. The three cobalt based bimetallic oxides exhibited good degradation of HEDP and MIT under neutral conditions, which to some extent solved the problem of narrow pH range in the practical application of the electro-Fenton process.

Från djävulsmusik till konstnärligt uttryck

From Devil's Music to Artistic Expression. The Korpela Movement, Black Metal, and Cultural PolicyThis text explores Korpelarörelsen, a Black Metal band that presents an audiovisual performance depicting a religious movement in Tornedalen during the early 20th century. In 2020 they received prolific funding from the Swedish Arts Grants Committee to conceive, rehearse and tour with the band. The article describes the band's unique portrayal of local history through the use of black metal music, while also discussing the boundaries between art and music, its implications for arts funding and the Black Metal genre's position in cultural hierarchies. The study draws on interviews, concert observations, and analysis of applications and documents outlining the funding decision from the Swedish Arts Grants Committee. The historic religious Korpela movement has been described as a doomsday cult, which believed that practicing music and dance, extrovert “childlike behavior” and even nudity and free sex, was the path to salvation. The band Korpelarörelsen depicts this through raw Black Metal, atmospheric elements, spoken word passages, and peculiar onstage-rituals. Visual aesthetics, including black robes, corpse paint, and blood-like smears, contributed to the atmosphere of mystique, darkness, and death. Korpelarörelsen’s application for cultural funding strategically positioned the project as a collaboration between various art forms and emphasized the interaction between Black Metal aesthetics and music industry methods. Korpelarörelsen's innovative approach and funding success might offer possibilities for extreme music within culturally funded systems. This case study demonstrates how a Black Metal band from Tornedalen could potentially have cultural and political impact and pave the way for other extreme music groups seeking recognition and support.

Non-oxidative ethane dehydrogenation reaction over molybdenum and chromium incorporated MgO encapsulated carbon-core catalysts in microwave reactor

Chromium and molybdenum incorporated MgO and MgO–C catalysts were synthesized for hydrogen production from a non-oxidative ethane dehydration reaction. Hydrogen production studies were carried out using a microwave-heated reactor system. The study investigated the effects of reaction temperature, type of active metal, and catalyst preparation method (physical mixture or core–shell structure) on hydrogen selectivity and ethane conversion during dehydrogenation reactions. The results showed that the optimal reaction temperature for the non-oxidative ethane dehydration reaction was 450 °C. Above this temperature, the selectivity of undesired byproducts increased. Catalysts containing molybdenum exhibited higher ethane conversion. Moreover, a comparison of MgO–C-supported catalysts with MgO-supported catalysts revealed that the core–shell catalysts exhibited superior ethane conversion. Notably, the 5Mo@MgO–C catalyst demonstrated exceptional catalytic activity, achieving a high ethane conversion rate of 72% along with excellent stability.

Understanding Antibiotic Detection with Fluorescence Quantum Dots: A Review.

The utilization of fluorescent quantum dots (FL QDs) has gained significant traction in the realm of antibiotic detection, owing to their exceptional FL properties and versatility. Various types of QDs have been tailored to exhibit superior FL characteristics, employing diverse capping agents such as metals, surfactants, polymers, and biomass to protect and stabilize their surfaces. In their evolution, FL QDs have demonstrated both "turn-off" and "turn-on" mechanisms in response to the presence of analytes, offering promising avenues for biosensing applications. This review article provides a comprehensive overview of the recent advancements in antibiotic detection utilizing FL QDs as biosensors. It encompasses an extensive examination of different types of FL QDs, including carbon, metal, and core-shell QDs, deployed for the detection of antibiotics. Furthermore, the synthesis methods employed for the fabrication of various FL QDs are elucidated, shedding light on the diverse approaches adopted in their preparation. Moreover, this review delves into the intricate sensing mechanisms underlying FL QDs-based antibiotic detection. Various mechanisms, such as photoinduced electron transfer, electron transfer, charge transfer, Forster resonance energy transfer, static quenching, dynamic quenching, inner filter effect, hydrogen bonding, and aggregation-induced emission, are discussed in detail. These mechanisms provide a robust scientific rationale for the detection of antibiotics using FL QDs, showcasing their potential for sensitive and selective sensing applications. Finally, the review addresses current challenges and offers perspectives on the future improvement of FL QDs in sensing applications. Insights into overcoming existing limitations and harnessing emerging technologies are provided, charting a course for the continued advancement of FL QDs-based biosensing platforms in the field of antibiotic detection.

Low insertion loss interposer approach for RF applications based on commercial LTCC tape, alkaline-free glass and printed metallization

Materials with high RF performance are in increasing demand due to the needs of modern telecommunications. Glass and low-temperature co-fired ceramics (LTCCs) are both interesting candidates for the design of complex signal transmission systems. Glass can be processed in large panels, and has suitable structure dimensions for silicon processing, but its multilayer capability is limited. LTCC is a mature technology for complex multilayer assemblies, but the structure dimensions and conductor line resolution are restricted by the need to use screen printing technology. The approach presented here combines the advantages of both technological domains: a thin glass sheet is bonded with no additional material to a LTCC multilayer ceramic and sintered to form a tight joint. Metallization of the glass is created using printable pastes and electroplating. Two fabrication routes are compared: etching of printed thick film metal layers, and semi-additive structuring. The results of RF measurements show a low attenuation per unit length for both types of metallization, indicating that our approach is a promising one for the integration of heterogeneous systems of RF transmission modules.

C2H2 selective hydrogenation over metal-doped CeO2 catalysts: Unraveling the role of metal and surface frustrated Lewis acid-base pair in tuning catalytic performance

Doping the second metal into CeO2 is used as a generally regarded strategy to promote C2H2 selective hydrogenation. This work employs DFT calculations and microkinetic modeling to explore the performance of CeO2 doped with different Cu, Ni, Pd, Pt, or Co atom towards C2H2 selective hydrogenation. The results show that the doped metal not only promotes the formation of surface oxygen-vacancy, but also generate different types of FLPs with surface O atom. FLPs promote H2 heterolytic dissociation to produce Ce-H/M-H and O-H species. Different forms of surface H species affect the performance of C2H2 selective hydrogenation. C2H4 selectivity follows a U-shaped dependence on surface Ce atom charge transfer amount. The screened catalyst Co/CeO2 presents excellent C2H4 production activity and selectivity, which could well prevent the generation of green oil. This work provides new insights for designing highly efficient metal-doped CeO2 catalysts by tuning the doped metal type.

Understanding the adsorption properties of CO2 and N2 by a typical MOF structure: Molecular dynamics and weak interaction visualization

An extensible molecular dynamics (MD) force field for a typical metal–organic framework (MOF) has been developed and verified in comparison with experimental data. The visualization of the important weak interactions based on density functional theory (DFT) calculations is performed. The dynamic process of CO2 and N2 adsorption by MOF was then studied by MD methods. The gas adsorption and desorption during temperature and pressure swing were also investigated. It is found that the structural features of MOF have an important effect on the regional range and strength of the weak interactions, and the region of the van der Waals potential surface of the MOF can determine the gas density distribution. The adsorption is dominated by van der Waals interactions on the whole and the variation of the total weak interaction energy can reflect that of the adsorbed amount. The sorption/desorption responds more slowly to temperature swing than to pressure swing.

Boundary Gaussian Distance Loss Function for Enhancing Character Extraction from High-Resolution Scans of Ancient Metal-Type Printed Books

This paper introduces a novel loss function, the boundary Gaussian distance loss, designed to enhance character segmentation in high-resolution scans of old metal-type printed documents. Despite various printing defects caused by low-quality printing technology in the 14th and 15th centuries, the proposed loss function allows the segmentation network to accurately extract character strokes that can be attributed to the typeface of the movable metal type used for printing. Our method calculates deviation between the boundary of predicted character strokes and the counterpart of the ground-truth strokes. Diverging from traditional Euclidean distance metrics, our approach determines the deviation indirectly utilizing boundary pixel-value difference over a Gaussian-smoothed version of the stroke boundary. This approach helps extract characters with smooth boundaries efficiently. Through experiments, it is confirmed that the proposed method not only smoothens stroke boundaries in character extraction, but also effectively eliminates noise and outliers, significantly improving the clarity and accuracy of the segmentation process.

Effects of the Type and Loading of Rare-Earth Metals (Pr, Yb, Ho) on the para-Selectivity of HTsVM Zeolite in Toluene Ethylation

Effects of the Type and Loading of Rare-Earth Metals (Pr, Yb, Ho) on the para-Selectivity of HTsVM Zeolite in Toluene Ethylation

A Theoretical Benchmark of the Geometric and Optical Properties for 3d Transition Metal Nanoclusters via Density Functional Theory.

Understanding structure-property relationships in atomically precise metal nanoclusters is vital in finding selective and tunable catalysts. In this study, density functional theory (DFT) was used to benchmark seven exchange correlation functionals at different basis sets for 17 atomically precise nanoclusters against experimentally determined geometries, band gaps, and optical gaps. The set contains both monometallic and bimetallic clusters that possess at least two types of 3d transition metals (specifically, Cu, Ni, Fe, or Co). The benchmark highlights that PBE0 is a good functional to use regardless of the basis set, and Minnesota functionals do well with respect to specific metals. Further, while long-range corrected functionals overestimate band and optical gaps, they model absorption features better than the other considered functionals. The study additionally looks at the photoinduced hydrogen evolution reaction (HER) and the CO2 reduction mechanism on nanoclusters reported from the literature.

OVERVIEW OF CHANGES IN THE STRUCTURE OF ASSORTMENTS AND COSTS OF BUILDING PROFILES IN UKRAINE

Purpose. The main purpose of the publication is a qualitative and quantitative analysis of the changes associated with the implementation of new standards for rolled steel in recent years in the domestic regulatory framework. Also, an additional purpose is to estimate changes in the cost structure of certain types of rolled metal in Ukraine over the past 5 years. Methodology. In order to achieve the main purpose, both the rolled steel standards currently in force in Ukraine and the canceled previous standards were examined in detail. Comparison of standards for sheet profiles was carried out according to the criteria of the number of standard sizes and the profiles themselves in the standard. Comparison of standards for shaped profiles was carried out according to several criteria – the number of available standard sizes of profiles, the number of profiles themselves, the mass indicators of the largest and smallest profiles, as well as the efficiency indicators (nuclear distance and the square of the radius of inertia) of the largest and smallest profiles according to the standard. To assess changes in the cost structure of assortment profiles of various types, a quantitative comparison of their absolute and relative market value was carried out based on data from open electronic resources for the past 5 years. Findings. At present, in the part of standards for the range of steel products in Ukraine, a systematic and full-fledged update of the regulatory framework is taking place, with the full preservation of our own national heritage. The need to develop and implement a standard for flat hot-rolled broad-banded sheet, specialized and improved standards for hot-rolled bars and for cold-bent square and rectangular profiles, as well as the need to provide the official status of the standard for I-bars with parallel edges of the shelves are the main problematic issues in the part of the assortment normative base at the moment. Originality. In this publication, a theoretical estimation of modern changes in the current normative base of Ukraine, which regulates the issue of the range of steel rolled metal, is presented. In particular, 2 types of sheet metal, 5 types of shaped hot-rolled steel and 3 types of shaped cold-bent profiles, which are the most widely used for steel building structures, were analyzed. The main performance indicators of profiles according to old and new standards are calculated. Practical value. In the practical part of the completed review, changes in the cost structure of the main types of rolled steel over the past 5 years in Ukraine were estimated. The main problematic issues of the current assortment base of Ukraine are separately identified and practical recommendations for their elimination are provided.

Effective characterization for the dynamic indentation and plastic parameters acquisition of metals

As a fundamental test technique for the mechanical properties of materials, indentation shows broad application prospects. Compared to the well-studied quasi-static indentation, relatively few and incomplete studies on the dynamic indentation test and characterization have been performed. In this work, a dynamic indentation test technique based on the split Hopkinson pressure bar system is developed, and the corresponding “three-wave method” is proposed to effectively acquire the time-resolved dynamic indentation load and depth. Systematic indentation tests under different loading rates and indenter cone angles are conducted on typical metal materials such as Cu, α-Fe, and α-Ti. Based on the dynamic indentation contact stiffness analysis and indentation theory the indentation hardness under different loading conditions are determined. A procedure for plastic parameter inversion of metal materials, including strain hardening and strain rate strengthening terms based on dynamic indentation, is provided. The effectiveness is verified by the traditional compression test results, providing a new method for characterizing the dynamic mechanical properties of metal materials.

FAKTOR-FAKTOR PENDORONG KONSUMSI MUSIK GENRE METAL PADA GENERASI MILLENNIAL BERDASARKAN PRINSIP HEAVINESS

This study aims to detect several factors that drive millennials to consuming metal genre music based on the heaviness principle and determine dominant sub-genre which millennials preferred and self-emotional on each. By using a qualitative approach throughout semi-structural interviews for 20 millennials with a snowball sampling technique, then analyzed by thematic analysis. Results found that the driving factors of millennials to consuming musicals with the metal genre start from knowing metal music, then using it as a means of expression, continuing to participate in events, bands and communities, then exploring subgenres, artistic as well as emotional expression.

Accumulation of typical persistent organic pollutants and heavy metals in bioretention facilities: Distribution, risk assessment, and microbial community impact

Bioretention facilities have proven highly effective in removing pollutants from runoff. However, there is a concerning paucity of research on the contamination characteristics and associated risks posed by refractory pollutants in these facilities following long-term operation. This research focuses on the distribution, sources, microbial community impact, and human health risks of pollutants in eight bioretention facilities that have been operational for 5–11 years. The results showed that the distribution of Cu, Zn, and Cd was closely related to anti-seepage measures. PAHs, PCBs, and OCPs primarily accumulated in the surface, with concentrations ranging from 7.42 to 20.34 mg/kg, 31.8–77.3 μg/kg, and 60.5–163.6 μg/kg, respectively. Their concentrations inversely correlate with the depth of the media. Although the majority of contaminants remained below their respective risk thresholds, their concentrations typically exceeded those of background soil values, indicating an enrichment phenomenon. Source analysis revealed that PAHs primarily originate from oil combustion, PCBs were linked to their related industrial products, DDTs had their main sources in technical DDx and residues from the use of dicofol, while HCHs were traced back to historical residues from agricultural activities. Microbial α-diversity (Chao 1 and Shannon) decreased by 8.3–23.4% and 0.8–4.4%, respectively, in different facilities after long-term operation. The most dominant microbial phylum in the facilities was Proteobacteria (all relative abundances >48%). The total relative abundance of dominant genera was 6.7–34.3% higher than the control site, and Pseudomonas, a typical POPs-heavy metal degrading bacterium, had the highest relative abundance (>1.2%). Cu, Zn, and Cd present no non-carcinogenic risks and have low potential ecological risks. However, the lifetime cancer risk for PAHs is 10−6 ∼10−4 in most facilities and is of concern. The cancer risk for PCBs is acceptable, while OCPs pose a low cancer risk only for children.

DFT Study on Effect of Metal Type and Coordination Environment on CO2 ECR to C1 Products over M-N-C Catalysts.

Electrocatalytic reduction (ECR) of CO2 to chemical products is an important carbon emission reduction method. This work uses DFT to study the stability of N-doped graphene-supported four metal single-atom catalysts (M-N-C) and the effects of the coordination environment and metal centers on the selectivity of CO2 ECR to C1 products. The results show that Fe, Co, Ni, and Cu have good stability. The coordination environment has a significant modulating effect on product selectivity, and the change of the number of ligand nitrogen atoms will affect the size of the potential-limiting step of each product. When the number of nitrogen ligands is the same, the different metal centers of the M-N-C catalyst have a significant effect on the selectivity of different products. In addition, the introduction of nitrogen atom ligands can adjust the electronic structure of the graphene-supported metal center, increase the d-band center of most metals, and improve the reaction activity.

TiO2 nanotubes modification by photodeposition with noble metals: Characterization, optimization, photocatalytic activity, and by-products analysis

Self-organized TiO2 nanotubes (TNTs) with 4 µm length were obtained by anodization method and calcined to obtain anatase crystallite phase. The photocatalysts were further decorated with Au, Ag, Pt or Pd nanoparticles (NPs), varying the metal loads (0.50, 0.75, 1, 2 and 5 mol%) by photodeposition. The material characterization confirmed the presence of nanoparticles in the TNTs surface, signs of the localized surface plasmon resonance (LSPR) effect for some samples and a bandgap energy of 3.1–3.2 eV. Photoluminescence measurements also confirmed that most of the samples with metallic nanoparticles had the recombination of photogenerated carriers lowered due to the trapping effect of the deposited metal NPs. The photoactivity was evaluated by phenol degradation using UV-Vis or visible radiation. Under UV-Vis, the best samples (2 and 5 mol% of Au-TNTs and 0.75, 1, and 2 mol% of Pd-TNTs) led to 97% phenol removal in 60 min while pristine TNTs reached 92% removal. Under visible radiation, the pristine and the Au-TNTs led to about 3% removal, with the best sample being 2 mol% Pd-TNTs with 14% removal in 60 min. Similar results were obtained for 1 and 5 mol% Pd-TNTs (12% and 13% of phenol removal, respectively). The by-products analysis suggest different degradation mechanisms and it is observed different kinetic rates for different metal types, metal loads or types of radiation.

Experimental investigation on the thermal behavior of two typical stainless steel roof systems

SummaryUnder long‐term exposure to solar radiation and temperature difference, metal roof systems produce a noticeable thermal behavior. The thermal behavior experiment of two typical metal roof systems in engineering was studied. The temperature stress and displacement of the two typical metal roof systems under different influencing factors are compared and analyzed. The results show that the thermal behavior of the stainless steel roof system is significant. The peak stress accounts for about 69.9% of the stainless steel yield strength, and the peak displacement accounts for 3/3500 of the slab span. The loading rate and temperature difference greatly influence the thermal behavior of the two typical roof systems. The maximum influence of temperature difference and loading rate on the thermal behavior is 77.8% and 67.3%, respectively. The holding temperature time has a minor influence on the thermal behavior of the two typical roof systems, and the maximum influence range is less than 7%. The research conclusions provide a valuable reference for the thermal design of metal roof systems.

Deposition of Pd, Pt, and PdPt Nanoparticles on TiO2 Powder Using Supercritical Fluid Reactive Deposition: Application in the Direct Synthesis of H2O2.

In this study, we investigated the catalytic properties of mono- and bimetallic palladium (Pd) and platinum (Pt) nanoparticles deposited via supercritical fluid reactive deposition (SFRD) on titanium dioxide (TiO2) powder. Transmission electron microscopy analyses verified that SFRD experiments performed at 353 K and 15.6 MPa enabled the deposition of uniform mono- and bimetallic nanoparticles smaller than 3 nm on TiO2. Electron-dispersive X-ray spectroscopy demonstrated the formation of alloy-type structures for the bimetallic PdPt nanoparticles. H2O2 is an excellent oxidizing reagent for the production of fine and bulk chemicals. However, until today, the design and preparation of catalysts with high H2O2 selectivity and productivity remain a great challenge. The focus of this study was on answering the questions of (a) whether the catalysts produced are suitable for the direct synthesis of hydrogen peroxide (H2O2) in the liquid phase and (b) how the metal type affects the catalytic properties. It was found that the metal type (Pd or Pt) influenced the catalytic performance strongly; the mean productivity of the mono- and bimetallic catalysts decreased in the following order: Pd > PdPt > Pt. Furthermore, all catalysts prepared by SFRD showed a significantly higher mean productivity compared to the catalyst prepared by incipient wetness impregnation.

Effects of Oxygen Content on Low-Temperature Bonding Using Organic-Free Silver Nanostructured Film with Different Types of Substrate Metallization

Effects of Oxygen Content on Low-Temperature Bonding Using Organic-Free Silver Nanostructured Film with Different Types of Substrate Metallization

Boosting photocatalytic water splitting of TiO2 using metal (Ru, Co, or Ni) co-catalysts for hydrogen generation

The photocatalytic activity of titanium dioxide (TiO2) nanoparticles toward hydrogen generation can be significantly improved via the loading of various metals e.g., Ru, Co, Ni as co-catalysts. The metal co-catalysts are loaded into TiO2 nanoparticles via different deposition methods; incipient wet impregnation (Imp), hydrothermal (HT), or photocatalytic deposition (PCD). Among all of the tested materials, 0.1 wt% Ru–TiO2 (Imp) provided the highest initial hydrogen catalytic rate of 23.9 mmol h−1 g−1, compared to 10.82 and 16.55 mmol h−1 g−1 for 0.3 wt% Ni–TiO2 (Imp) and 0.3 wt% Co–TiO2 (Imp), respectively. The loading procedures, co-catalyst metals type, and their loading play a significant role in elevating the photocatalytic activity of pristine TiO2 semiconductors toward hydrogen generation. Redox transition metals e.g., Co and Ni exhibit comparable photocatalytic performance to expensive elements such as Ru.