Different Types Of Metals Research Articles

Numerical analysis of plasmonic metasurfaces for fluorescence enhancement

The paper presents an extensive numerical analysis performed by three-dimensional (3D) simulations using the finite difference in time and space (FDTD) method to identify the optimal geometry, size and configuration of the nano-antennas that constitute a plasmonic metasurface. The aim was to achieve the highest resonance at various wavelengths (NIR-VIS), for local enhancement of the excitation field and collection efficiency of emitted photons. We investigated ten different types of metals, two shapes (disks and U-shape resonators) and various geometrical parameters for the nanoresonators composing the metasurface. The best results for Rhodamine 6G excitation and emission were obtained using silver resonators with 105 nm diameter of the cylinder elements in a rectangular array with a 110 nm period, and with 110 nm long U-shape placed at a period of 40 nm.

Sustainable Dyeing of Silk with Natural Dyes Using Natural Sources of Water

River water containing different types of metals and heavy metals are far more efficient in promoting surface colour strength and all round colourfastness properties of silk fabrics when dyed with aqueous extract of Ceriops decandra and Diospyros malabarica. However, pre-mordanting with aluminium and/or ferrous sulphate would promote the depth of shade and colourfastness properties further. Calcium and magnesium are found to be present in appreciable amount in the different river water considered in this study and are found to be higher than that present in water collected from Kolkata Municipality Corporation. Analysis of different river and aquifer water showed the presence of different metals and heavy metals and their value stays well below the specified permissible limit as mentioned in WHO standard. The presence of such trace amount of different metals played a significant role in promoting dye uptake and all round colourfastness properties also. The presence of such metal in the dyed fabric also appeared to stay much below the limit of Oeko-Tex standard referred often for producing environment friendly textiles.

Characterization of different types of electronic waste: heavy metal, precious metal and rare earth element content by comparing different digestıon methods

Electronic waste is one of the fastest-growing waste streams. The content of this waste has critical importance for the development or adoption of new recycling techniques and safe waste management practices. In this study, printed circuit boards and screens of three different types of electronic wastes, such as old mobile phones, smartphones, and laptops were characterized for their heavy metal, precious metal, and rare earth element contents. Three different digestion methods were applied to the samples prior to ICP-OES analysis. Results showed that Cu, Fe, Zn, Ni, Pb, and Al were found to be the main heavy metals in all samples. Nd, Ag, and Au were found as the major precious metals, followed by Pt, La, Dy, Pr, and Ce in the rare earth element category. The contents indicated that there is an urgent need to develop recycling techniques for the recovery of these valuable materials. When the digestion methods were compared to each other, it was found that different methods performed better on different types of metals. U.S.EPA.3050B is advised for Nd, Pd, Pr, Ag, Dy, Pt, Mn, Ce, Cd, Cr, Co, Al, Pb, while U.S.EPA.3051A performed better for Au, Mo, Zn, Cu, and Ni, and MMDM for La. Graphic abstract

Popularity and Visibility Appraisals for Computing Olympic Medal Rankings

ObjectiveThe ranking of countries in the Olympic Games generates a great deal of interest among analysts, academics, and fans. This article proposes an innovative approach to provide Olympic medals (gold, silver, and bronze) with different weights based on metrics of popularity and media visibility and create an alternative historical ranking.MethodsThe analysis uses “Google Trends” and “MERIT” appraisals to capture content and news articles on the Internet that relate to the different types of metals. Figures on weekly relative search intensity in Google and content in the Internet registered monthly are used to track changes over time and thus to control for differences between Summer and Winter Olympic Games.ResultsThe results show that gold medals gather far more attention than silver and bronze medals. By applying the estimated multiplying factors, we create an alternative historical ranking of countries that shows some relevant changes.ConclusionThe use of weights based on popularity and visibility has managerial implications and opens new avenues for future research.

Assessment of Spectroscopic and Morphological Properties of some Fruit Crops under the Influence of Pollution with Heavy Metals Using Remote Sensing Techniques

Dietary exposure to a variety of heavy metals, including Ni, Cd, Cr, Pb, Zn, and Hg, has been identified as a danger to human health through fruits and vegetables, contamination of heavy metals is known as a grave risk to our climate. The study aims to develop empirical models to predict the concentration of heavy metals (Ni, Cd, Cr, Pb, Zn, and Hg) in the leaves of Citrus and Mango crops. The study was carried out in an observation site in Giza governorate that is cultivated by varied herbaceous and tree cover crops. This study area is suffering from severe pollution caused by near industrial district. The sample collected from deferent zones that are divided to six spatial zones and coded by from zone (2, 3, 4, 5, and 6). The distance between each Zone 10 Km that extends from the north to south and covers 60% from the Agriculture area in the Giza governorate. The main inputs of the generated models were spectroscopic remotely sensed data and laboratory analytical measurements of heavy metals in crop leaves. ASD (Analytical Spectral Devices) field spectro-radiometer was used to calculate hyper-spectral vegetation indices. Modeled heavy metal concentrations were tested against laboratory analysis through two common statistical tests; the Correlation of determination (R2) and Root Mean square (RMSE) error between predicted modeled heavy metals. Results shown the correlation coefficient of the generated models, red and near-infrared spectral bands demonstrated high precision and sufficiency for mango and citrus leaves to predict heavy metals. The models produced refer to specific regions with the same conditions. The overall results imply that hyper-spectral vegetation indices could be correlated with heavy metal content, while heavy metal content in plants may be influenced by many others. Remote sensing spectroscopy is a possible and promising technology to track the environmental pressures on agricultural vegetation. Additional ground remote sensing experiments are needed to assess the possibility of hyper-spectral reflectance spectroscopy in monitoring the stress of different types of metals on various plants.

Design and analysis of erosion in electrochemical machining tool

The electro chemical machining system is the type of system in which it is used in the machining operations. In our project we have analyse the erosion in the electro chemical machining tool. The main disadvantage of the electrochemical machining system is that, due to repeated use of electrochemical machining tool there may be occurance of erosion in the machining tool. This effect is due to the presence of oxygen content in the electrolyte. We compared different types of metal like beryllium copper, copper tungsten, copper and brass with the electrolyte combination of sodium chloride and sodium nitrate. Normally the electrolyte used in the electro chemical machining system is that the sodium chloride and sodium nitrate [5]. So that we have used to compare the metals and electrolytes and used to find the best among them. Finally we have concluded that the beryllium copper has the best results. So the use of berylliumcopperwiththeelectrolyteofsodiumchloridewill havethereductionintheerosion.

Assessment of strategic raw materials in the automobile sector

A conventional passenger car demands almost 50 different types of metals, along other raw materials. Some of these metals, such as tantalum, indium, niobium or rare earths elements, are considered critical by the European Commission and many other institutions. Additionally, their functional recycling is practically absent. The transition to fully electric vehicles will require more electrical and electronic devices, motors and batteries, that will need an increasing amount of critical metals. A methodology has been developed to identify strategic elements for the automobile sector. This approach defines a variable called Strategic Metal Index (SMI) which is calculated for each metal. This index is the result of combining the following parameters: (1) Automobile sector demand with respect to world production; (2) known resources compared to total cumulative demand and (3) Supply risk. The index has been applied to 50 metals used by different types of vehicle powertrains. The assessment covers metal demand from 2018 to 2050 according to vehicle sales projections. Using this approach, the most strategic elements for the automobile manufacturing sector are Ni, Li and Co (used in batteries), Nd and Dy (permanent magnets), Tb (lighting and fuel injectors), Sb, Bi and and B (steel alloys, paintings), Au and Ag (electronics), In (screens) and Te (steel alloys, electronics). The search for substitutes, implementation of eco-design measures and the increase of the functional recyclability of these elements should be strongly encouraged in the sector.

Microstructural characterization of different metal matrix composite claddings reinforced by TiC through YAG laser cladding

In this work, a YAG laser was used to clad TiC-reinforced metal matrix composite layers on the surface of different types of metals; low carbon steel, high C–Cr bearing tool steel, spheroidal graphite cast iron and commercially pure titanium. The cladding processes were carried out at heat inputs ranging from 175 J mm−1 to 700 J mm−1 and at a fixed traveling speed of 4 mm s−1. The microstructures of the cladding layers were investigated in detail. In all cases, TiC-surface metal matrix composite layers were successfully formed at different laser heat inputs on all the metal surfaces. A few TiC particles seemed as fine dendrites after the laser treatment. The amount of dendritic TiC has a direct relationship with the laser heat input. For low carbon steel, the clad layer showed a martensitic structure, with sound metallurgical bonding to the base metal and without any defects at the highest laser heat input used in this study (700 J mm−1). In the case of high C–Cr bearing tool steel, lower laser heat inputs were enough to form a sound clad layer consisting of fine TiC dendrites distributed in a matrix of martensite laths, some retained austenite and acicular carbides. Laser heat input of 175 J mm−1 was enough to build a defect-free clad layer on spheroidal graphite cast iron. The matrix comprised of cementite, martensite, and some blocks of retained austenite. Cracking appears at a higher heat input of 500 J mm−1 in the spheroidal graphite cast iron. The matrix of the clad layer on pure Ti substrate was α′-Ti martensite, which decreased by increasing the laser heat input.

Photocatalytic Reductive Defluorination of Fluorinated Compounds in Aqueous Alcohol Suspensions of a Metal‐loaded Titanium(IV) Oxide

AbstractSelective elimination of the fluorine element in organic fluorinated compounds under mild conditions is desired in order to resolve the environment and energy resource issues. Selective reductive defluorination of fluorine‐containing organic compounds in 2‐propanol‐water suspensions of metal‐loaded titanium(IV) oxide (TiO2) photocatalysts is described in this paper. The effects of different types of metal co‐catalysts, adsorption behavior of fluorobenzene (FB), stoichiometry, redox balance, scope, chemoselectivity and reaction temperature were examined. Photocatalytic defluorination of FB occurred over platinum‐loaded TiO2 at room temperature, and benzene and fluoride ion were produced with a high stoichiometry without degradation of the benzene structure, while hydrogen (H2) production occurred as a competitive electron‐consuming reaction. A slight elevation in the reaction temperature greatly accelerated defluorination and suppressed H2 evolution, resulting in FB defluorination free from H2 production at 333 K. Kinetic parameters of FB defluorination and H2 evolution were determined, and the results obtained are explained on the basis of these parameters.

Toxicity of Metal Implants and Their Interactions with Stem Cells: A Review

The development of biomaterials has increased rapidly in order to alter the fate of stem cells and use them in therapeutic applications. Currently, many biomaterials are used in the biomedical industry. Biomaterials act as a “nitch” which is an environment regulating the development and self-renewal behaviour of stem cells. The stem cells receive signals from the “nitch” and proceeds accordingly. In order to control the behaviour of stem cells, the chemical and physical properties of the biomaterial should be taken into consideration. This review paper focuses on the different type of metals used in biomaterials, identifying their current issues and challenges including fatigue, corrosion resistance, and the toxicity caused by metal ions released in the body. It also provides detailed explanations about the impact of various metal implants such as stainless steel, cobalt-chromium, and titanium on stem cells and the toxicity caused by the interaction of biomaterials and various trace elements with the hostile body environment.

Distinct Profiles in Microbial Diversity on Carbon Steel and Different Welds in Simulated Marine Microcosm.

The main studies on the corrosion of metals induced by microorganisms are directed only to the surface of the metal, without considering the presence of welds between these surfaces. For this reason, we evaluated the difference of microbial community grown in carbon steel coupons, and two different types of welds, E7018 and Tungsten electrodes, exposed under simulated microcosm. After 30days, they were recovered, the biofilms scraped and the microbial communities analyzed by 16S rRNA gene sequencing. The results showed that there was a differentiated distribution among the three samples collected. Proteobacteria phylum composed most of the species described in all samples. At the class level, Gammaproteobacteria was the most detected, followed by Alphaproteobacteria and Flavobacteriia. The most prevalent order was Alteromonadales, which was present in Weld2, followed by Rhodobacteriales, which was more prevalent in Fe1020 and Weld1. The orders Cytophagales, Sphingomonadales, and Burkholderiales were described in higher number in Fe1020, whereas Oceanospirillales, Thiotrichales, Flavobacteriales, Rhodospirillales, and Kordiimonadales were higher in samples Weld1 and Weld2. The analyses between the three evaluated conditions show the presences of bacterial groups preferred by different types of metal, suggesting that approaches in the control of biocorrosion should take into account the chemical composition of the metal.

The influences of the crude oils on the decay of metals

Crude oils are the essential resources for the usages of industrial purposes in various forms and the refining is a key process of separating the mixture of raw crude oils. In the existing research there were expected to investigate the impact of salts, organic acids, mercaptans and elemental sulfur of crude oils on the corrosion rates of seven different types of ferrous metals in both qualitatively and quantitatively. The chemical compositions of such selected ferrous metals and the above mentioned corrosive properties of two different types of crude oils were measured by the standard instruments and methodologies. A set of similar sized metal coupons were prepared from seven different types of metals and the corrosion rates of such metals were determined by the relative weight loss method. In addition, that the corroded metal surfaces were analyzed under the microscope, decayed metal concentrations and deductions of the initial hardness of metal coupons were measured. According to the obtained results that there were observed the lower corrosion rates from stainless steels with at least 12% of chromium and nickel, higher corrosive impact from salt, formations of FeS, Fe2O3, corrosion cracks and pitting corrosion.

Specific heavy metal/metalloid sensors: current state and perspectives.

Heavy metal(loid)s play pivotal roles in regulating physiological and developmental aspects in living organisms depending on their concentration. For example, a trace amount of heavy metal(loid)s is essential for living organisms, but heavy metal(loid)s in high concentrations negatively affect their physiology and development. Because of rapid industrial developments, heavy metal(loid)s have been accumulating in environmental systems, thereby becoming a threat to human health and the earth's ecosystem. Thus, the development of tools to quantify and monitor heavy metal(loid)s in environmental systems has become essential. Typically, risk has been determined through instrument-based analysis, regardless of the shortcomings regarding expense and duration. Nowadays, the need for alternative tools, besides instrumental analysis, to detect heavy metals has prompted the development of new techniques, and many different methods have been reported from various research areas, including new techniques based on electrochemistry and biological systems. Nonetheless, it seems that the gap between laboratory and fieldwork is still greater than it should be when it comes to applying these systems. In this mini-review, we discuss the current status of heavy metals/metalloid detection techniques, with an emphasis on biosensors. Moreover, we discuss the advantages and disadvantages as well as the mechanisms behind newly developed sensors and make suggestions to improve applicability and to develop new objective targeting sensors. Although many different types of metal(loid) sensors are available, we focused on metal sensors based on biological systems. Additionally, we suggest potent approaches to developing new biosensor systems based on current metal sensor mechanisms.

Visualization of shockwave behavior in water and gelatin

Explosive welding is a popular method that is utilized to bond different types of metals. In particular, with the use of underwater explosive welding technique, the uniform acceleration of a thin plate over a very short flying distance is possible, which makes the technique suitable for the welding of thin plates onto a base plate to modify various properties of the surface of interest for protection against extreme environments. However, the use of water complicates the setup of the assembly, and therefore, in this study, we attempt to use other pressure-transmitting media, such as gelatin, which exhibits shockwave propagation similar to water. The similarity of shockwave propagation of the two materials is confirmed via optical observations utilizing a high-speed camera for two types of explosives. Thus, our findings confirm the viability of the use of gelatin as a pressure-transmitting medium for explosive welding.

Effect of Shielding Gas and Filler Metal to Microstructure of Dissimilar Welded Joint Between Austenitic Stainless Steel and Low Carbon Steel

Welding of dissimilar metals involves different types of metals which have different chemical composition, mechanical and thermal properties. This paper presents a study on dissimilar metal weld between type 304 stainless steel and SS400 carbon steel. The steel plates were welded by using different filler metals (solid wire, flux-cored wire) and different shielding gases (100%CO2, 90%Ar+10%CO2). Then the weldments were observed by optical microscope, scanning electron microscope and EDX analysis. It seems that the weldments which were welded by using 100%CO2 shielding gas have significant amount of inclusions in weld metal compared to 90%Ar+10%CO2 shielding gas mixture. The EDX analysis shown the inclusions are oxides which consist of some elements (C, Si, Cr, Mn) with O. The weldment which was welded by using 90%Ar+10%CO2 shielding gas mixture and solid wire has much less inclusions in weld metal.

Constitutive Topics in Physical Chemistry of High-Temperature Nonferrous Metallurgy: A Review—Part 2. Reduction and Refining

In this Part 2 of the review, we demonstrate the roles of phase rule, free energy and activity in the reduction and refining of different nonferrous metals categorized as common, reactive, rare and refractory. Based on the discussions in the following sections, the reader will appreciate the contributions of phase rule, activity and free energy in the selection of particular steps in the extraction of different types of metals. It also demonstrates how difficult reactions like the removal of nickel from blister copper can be made feasible by generating conditions according to the van’t Hoff isotherm.

Constitutive Topics in Physical Chemistry of High-Temperature Nonferrous Metallurgy—A Review: Part 1. Sulfide Roasting and Smelting

The prime objective of this review series is to demonstrate the significant role of physicochemical principles in the development and improvement of extraction technologies for different types of metals categorized as common, reactive, rare and refractory. In this part we highlight the roles of phase rule, free energy and activity in roasting and smelting of sulfides. Continuing development of new technologies and reduction in the number of steps in the production of copper, lead, zinc and nickel have been possible because of the thorough understanding and application of the physical chemistry of reactions involved in different extraction steps. The theoretical bases behind the development of several new technologies and the difficulties in realizing certain worthwhile concepts in industrial practices are explained.

Evaluation of metal artefacts reduction by application of monoenergetic extrapolation of dual-energy CT: A phantom study with different metal implants

The aim of this study was to evaluate the application of monoenergetic (ME) extrapolation technique of dual-energy computed tomography (DECT) for metal artefact reduction using phantom study. This study involved phantom study with a customized phantom consisting different types of metal implant such as titanium and stainless steel. The phantom was scanned using a single-source DECT scanner (SOMATOM Definition AS+, Siemens Healthcare, Germany) with dual-energy mode of 140/80 kV spectrum. The commercially available post-processing software (Syngo DE, Siemens) was applied to generate ME image datasets with different extrapolated energies ranged from 55 to 160 keV. The reduction of artefacts was measured qualitatively and quantitatively using region of interests (ROIs) statistical analysis. The results show 60% of metal streak regions were reduced significantly at higher extrapolated energy which is 160 keV. Quantitative analysis also resulted in lower HU readings within the region of artefact for 160 keV. However, higher extrapolated energy resulted in higher noise and lower signal-to-noise (SNR) value. ME images at 160 keV appear noisier while ME images at 64, 70 and 80 keV appear smoother. Metal artefacts induced by both metal implants were reduced significantly using DECT ME extrapolation and diagnostic quality of CT images also improved. It can be achieved by using higher ME of DECT. However, image noise is higher, and SNR is reduced with higher ME extrapolated energy.

Classification of different types of metal from recyclable household waste for automatic waste separation system

Nowadays, solid waste has become a major problem in Malaysia. However, most people in Malaysia are not aware and take this problem for granted. The rising number of population and massive development in recent years indirectly generated an enormous value of household waste, making the household waste the main generator for solid waste in Malaysia. It stated that only 5 percent of an average 30,000 tons of waste have been recycled in Malaysia. The purpose of the paper is to design a system to separate the metal recyclable household waste automatically and record the data waste collected. There are total of four detectors used to separate the non-metal, steel, copper and aluminum metal waste. The average time used to complete metal separation process by using the proposed prototype is 14.5 seconds. This paper includes a mechanical part, programming part, an electronic design and also the data collected from this proposed system. The system will be programmed using Arduino Mega as a microcontroller to control all the electronic component in the system.

Syngas production via CO2 reforming of CH4 over Ni-based SBA-15: Promotional effect of promoters (Ce, Mg, and Zr)

The promotional effect of different types of metals (Ce, Mg, and Zr) over Ni/SBA-15 which synthesized using ultrasonic co-impregnation technique were scientifically evaluated via CO2 reforming of CH4 (CRM). Characterizations including XRD, BET, FTIR, CO2-TPD were done to examine their physical attributes, metal-support interactions, and basicity properties. XRD results suggested that NiO particles were not distributed homogeneously within the confined framework of SBA-15 for Ni-Ce/SBA-15. Nevertheless, Mg and Zr promoters could effectively improve Ni dispersion over the SBA-15's siliceous framework and controlled the NiO crystallize sizes. The smallest NiO crystallite size of 9.3 nm was obtained by Ni-Zr/SBA-15. BET results verified the alteration of pore structure without changing the ordered structure of SBA-15 upon promoter addition. FTIR results suggested the partial transformation of Si–OH groups to the Si–O–X bond (X = Ce, Mg and Zr), whereas, CO2-TPD results confirmed the moderate basic sites present in Ni-Zr/SBA-15. H2-TPR evidenced the strongest metal-support interaction in Ni-Zr/SBA-15 owing to its high temperature reduction behaviour. At operating condition of P = 1.0 bar and WHSV = 15,000 mLg−1h−1, catalytic performance and stability ascended the trend of un-promoted < Ce-promoted < Mg-promoted < Zr-promoted Ni/SBA-15, in which Zr-promoted Ni/SBA-15 manifested the best catalytic activity (CO2 conversion = 93.8%; CH4 conversion = 88.3%; H2/CO ratio = 0.82). The ascendency catalytic activity and stability of Ni-Zr/SBA-15 catalyst were attributed to its favourable properties such as strong Si–O–Zr bond formation, smallest NiO crystallite size and a moderate amount of basic sites, which crucial for sintering restriction of NiO particles and carbon deposition, thus facilitated CRM reaction.