Nickel Silver Research Articles

GeGra: Approaching a generic model for quantitative grain size analysis from materials microscopy data using deep learning

Grain size has a significant impact on the properties of materials, and is crucial for predicting material properties. Traditional grain size measurement relies heavily on human operators, leading to subjective results, and existing machine learning methods are typically material-specific, requiring significant labeling and training efforts for each new material. This paper provides insight into developing a deep learning-based generic grain boundary detection model (GeGra) from different material micrographs. The model is trained on 1006 images from various microscopy techniques such as light optical, Kerr, and scanning electron microscopy, acquired at different magnifications for different materials such as copper, austenite, brass, sintered hard magnet, hard metal, bronze, nickel silver, and aluminum. The developed GeGra model effectively handles visual artifacts and substructures such as twin grains, which often pose challenges for material-specific, state-of-the-art grain boundary segmentation models. The developed model achieved an IoU score of 69 % on a diverse test set and enables accurate grain size analysis using external image analysis software in less than one minute, according to ASTM standards, which is more than 5 times faster than the manual method. The developed model prioritizes generality with objective that it can have broader applicability for various materials instead of high-precision grain boundary detection. Additionally, the model has the potential to be a foundational tool for generalized grain size analysis in material microscopy, reducing the effort required for such analysis and assisting both material science experts and machine learning users.

Preparation and NOx Reduction Performance of Ag-Ni-TiO2/Cordierite Catalyst for HC-SCR System

Selective catalytic reduction (SCR) technology in diesel engines is an exhaust after treatment system used for abatement of nitrogen oxide (NOx) emissions. In order to synthesize Ag-Ni-TiO2/Cordierite catalyst in the conducted study, a solution including silver nitrate (AgNO3), titanium dioxide (TiO2), and nickel (II) nitrate hexahydrate (Ni(NO3)2·6H2O) were used in the coating of the cordierite (2Al2O3-5SiO2-2MgO) main carrier structure. The prepared catalyst was characterized for morphological characteristics via scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) analysis. The NOx reduction measurements as catalytic was carried out at 20 °C intervals in the temperature range from 190 to 270°C at 1 kW and 3 kW motor loads and under 30000 h−1 space velocity (SV). Ethanol was used as a reductant during the experiments. As a results of the measurements, it was seen that the Ag-Ni-TiO2/Cordierite catalyst exhibited a good NOx conversion efficiency with 93.8 % at 270°C at 3 kW.

Multi‐analytical characterisation of Art Déco dinanderie: Single‐point and map analysis of Jean Dunand's metal artworks

AbstractJean Dunand (1877–1942) was a European artist internationally appreciated at his time for his innovative Art Déco housewares made of hammer‐beaten copper‐based alloys, known as dinanderie. Still uncertain was the nature of the constituting materials; therefore, for the first time, three objects, namely, a bowl, a trinket bowl and a vase, were the target of a multi‐modal work of characterisation. Mobile or benchtop X‐ray fluorescence, Fourier‐transform infrared (FTIR) and Raman spectroscopies were used to adapt the analyses to the shape and size of the artefacts. Elemental analysis verified that the vase consisted of brass Cu70Zn30, whereas the bowl and the trinket bowl were made of nickel silver Cu70Zn19Ni11. The black finishing present on all the artefacts was related to tenorite by Raman spectroscopy, ascribing the patina to an intentional artist's willing and not to spontaneous tarnishing processes. Metal soaps of copper and zinc were documented as degradation products by FTIR spectroscopy. The drawings adorning the vase and the trinket bowl were identified as silver‐based, contrary to what was hypothesised by conservators (i.e., tin‐based) due to conventional Dunand's inlaying technique. Besides single‐point analysis, Raman mapping was performed in‐situ, applying for the first time a Virsa™ Raman Analyser (Renishaw) in the field of cultural heritage. The fibre‐optic‐coupled instrument allowed to comply constantly with the artefacts' geometry thanks to the modular probe and the motorised focus‐tracking stand. The synergic combination of elemental and vibrational analyses resulted successful, providing new and unique information on artist's technique in view of possible restoration interventions.

Regulating H2/CO Ratios in Syngas via CO2 Electroreduction with the Silver–Nickel Bimetallic Electrocatalyst in a Solid-Electrolyte Membrane Electrode Assembly

Regulating H₂/CO Ratios in Syngas via CO₂ Electroreduction with the Silver–Nickel Bimetallic Electrocatalyst in a Solid-Electrolyte Membrane Electrode Assembly

Tuning the Ballistic Performance of a Single-Burning-Rate Grain Solid Rocket Motor via New Discontinuous Embedded Metal Wires

This work proposes a new effective method to realize variable thrust through discontinuous embedded metal wires in the solid rocket motor (SRM). We aimed to study the influence of discontinuous embedded metal wires on the performance of an SRM with a single-burning-rate grain. A model based on convection heat transfer, heat conduction, and heat radiation was established to calculate the heat transfer in the discontinuous embedded metal wires in the grain, to then obtain the burning rate ratio. Most importantly, a solid rocket motor was designed to verify the feasibility of variable thrust and of the present model prediction, with the embedded silver–nickel alloy wire divided into two segments in the grain. According to the SRM ignition experiment, the silver–nickel alloy wires raised the burning rate of the grain. The pressure varied regularly with changes in the discontinuous embedded metal wires. The theoretical burning rate ratio matched the experimental result well. Based on the verified model, the effects of the burning rate, pressure exponent, burning rate ratio, and number of wires on thrust were investigated. Burning rate, burning rate ratio, and pressure exponent were found to be positively correlated with thrust ratio. The thrust ratio could reach 12.5 when the burning rate ratio was 5. The ability to adjust thrust tended to increase with an increase in the number of wires. This study also provided a method to assess whether the consecutive embedded metal wires had been broken or not. The method using discontinuous embedded metal wires in the grain was proven to be feasible to realize multi-thrusts of single-burning-rate grain, which is a new idea for the design of a multi-thrust SRM.

Enhancement of the photocatalytic activity of rGO/NiO/Ag nanocomposite for degradation of methylene blue dye.

The current study focuses on boosting the photocatalytic ability of reduced graphene oxide (rGO) by decorating the rGO nano-sheets with nickel oxide (NiOx) and silver (Ag) nanomaterials. The developed ternary nanomaterials were investigated using FTIR, XRD, FESEM, TEM, Raman, and UV-vis to evaluate the photo-degradation process. The rGO/NiOx/Ag ternary system showed promising photocatalytic dye degradation under simulated sunlight irradiance. The addition of NiOx and Ag nanomaterials widened the catalytic activity spectrum from the visible region to the UV-region. Besides, these materials hindered the electron-hole recombination, boosting the catalytic activity. The reusability results also clearly showed that the synthesized ternary nanomaterials have good reproducibility and stability for photocatalytic degradation of industrial wastewater.

Silver and carbon nitride-doped nickel selenide for effective dye decolorization and bactericidal activity: in silico docking study.

In this study, nickel selenide (NiSe), Ag/C3N4-NiSe, and C3N4/Ag-NiSe nanowires (NWs) were synthesized via coprecipitation. The prepared NWs were employed for the degradation of the rhodamine B (RhB) dye in the absence of light using sodium borohydride (NaBH4), bactericidal activity against pathogenic Staphylococcus aureus (S. aureus) and in silico docking study to investigate the d-alanine ligase (DDl) and deoxyribonucleic acid (DNA) gyrase of S. aureus. NWs demonstrate a catalytic degradation efficiency of 69.58% toward RhB in a basic medium. The percentage efficacy of the synthesized materials was evaluated as 19.12-42.62% at low and 36.61-49.72% at high concentrations against pathogenic S. aureus. Molecular docking results suggest that both C3N4/Ag-doped NiSe and Ag/C3N4-doped NiSe possess inhibitory activities toward DDl and DNA gyrase of S. aureus, which coincides with the in vitro bactericidal activity. Based on the research outcomes, the synthesized NWs show potential as an effective agent for water purification and resistance to microbial contaminants.

Production and characterization of CuNiZnFe2O4 dispersed transformer and kerosene oil based magnetic nanofluids for heat transfer applications

This study produced nanofluids via a two-step method by dispersing copper–nickel–zinc (CuNiZnFe2O4) ferrite nanocomposites in transformer and kerosene oils. A sol–gel auto-combustion approach was adopted to synthesize ferrite nanoparticles. The prepared nanoparticles were analyzed through scanning electron microscopy, photoluminescence spectroscopy, and x-ray diffraction. The measured crystallite size varied between 11 and 13 nm. The SEM images show that the structures of the developed CuNiZn nanoparticles are irregular. The photoluminescence results give a bandgap of 1.91 eV and the emission lines of the nanoparticles. Transient hot wire analysis was performed to determine the thermal conductivity of the base fluid and the prepared nanofluids. It is observed that nanoparticles in the nanofluid enhance the heat transfer rate. It has been proven that CuNiZn/kerosene-based nanofluids have greater thermal conductivity than CuNiZn/transformer oil-based nanofluids. The viscosity of transformer oil-based nanofluids at room temperature is 12.53 mm2 s−1, which decreases to 12.49 mm2 s−1 at 40 °C. Similarly, the viscosity of kerosene-based nanofluids is 1.49 mm2 s−1 at room temperature and 1.16 mm2 s−1 at 40 °C. The sedimentation method revealed that CuNiZn/transformer oil-based nanofluids have greater stability than CuNiZn/kerosene-based nanofluids.

Analytical study of an 1899 Peruvian dinero: unveiling the mystery of a coin that wasn’t officially minted

The present paper presents the analytical study of an unusual Peruvian 1899 dinero coin whose authenticity has been questioned since the 1970’s. This coin, which is present in some numismatic collections although there is no record of having been minted officially, has been characterized using non-destructive techniques such as X-ray fluorescence (XRF), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM–EDS), and X-ray diffraction (XRD). Results are consistent with a cast counterfeit coin made at the turn of the 19th and 20th using a copper base alloy that was silver-platted to pass unnoticed among the public. The alloy used, generally known as german silver, was common for counterfeits in North America and Europe in that period. The historical reasons for the appearance of this unexpected coin in Peru during a time of economic difficulties, where the public experienced a shortage of small-change coins, are briefly outlined.

UV-Vis Sintering Process for Fabrication of Conductive Coatings Based on Ni-Ag Core-Shell Nanoparticles.

The UV-Vis sintering process was applied for the fabrication of conductive coatings composed of low-cost nickel-silver (Ni@Ag) nanoparticles (NPs) with core-shell structures. The metallic films were formed on a plastic substrate (polyethylene napthalate, PEN), which required their sintering at low temperatures to prevent the heat-sensitive polymer from destroying them. The UV-Vis sintering method, as a non-invasive method, allowed us to obtain metallic coatings with good conductivity at room temperature. In optimal sintering conditions, i.e., irradiation with a wavelength of 350-400 nm and time of 90 min, conductivity corresponding to about 30% of that of bulk nickel was obtained for the coatings based on Ni@Ag NPs.

Ask me anything: Catherine Foley

Cathy Foley is a solid-state physicist and Australia’s chief scientist. She previously spent more than 35 years at the CSIRO national science agency, where she also served as chief scientist. With research interests in nitride semiconductors and superconducting electronics, she developed a sensor for locating underground deposits of minerals such as nickel sulphide, silver and gold.

Effect of Different Concentrations of Nano-Fungicides on Mycelial Radial Growth of Phytophthora infestans

Potato (Solanum tuberosum L.) popularly known as the “King of Vegetables” is a starchy, tuberous crop, that belongs to the family Solanaceae. Potatoes play an important role in the daily human diet because they are a copious source of minerals, vitamins, antioxidants and micronutrient. The potato is a basically temperate crop, but it grows under a wide range of climatic conditions. Potato crop is generally affected by different types of biotic and abiotic diseases. Among all diseases, Late blight of potato, caused by the Phytophthora infestans (Mont) de Barry is one of the most devastating diseases of potato worldwide. In India, the losses caused by the disease are 10-20% in Uttar Pradesh, 10-15% in West Bengal and Punjab, 10-15% in Karnataka and Uttrakhand also have been reported during 2013-14. The management of the disease can be done through cultural, mechanical, use of the resistant variety, biological and chemical, etc. The efficacy of current strategies for the management of disease is limited. Considering the destructive nature of pathogen and lack of efficient control measures, the development of alternative or complementary approaches for the management of this disease is highly desirable. However reported use of the same chemicals may raise resistant strain among the pathogens. Therefore, the use of Nano-fungicidal control of spot blotch disease cannot be overstated. However, the disease can be managed with various nanofungicides under in vitro conditions assessed for their efficacy against the disease. The effect of four nanofungicides i.e., Agritec nanofungicide, Silver nanofungicide, Selenium nanofungicide and Nickel nanofungicide against P. infestance was evaluated at different concentrations (50, 75 and 100 ppm) by poison food technique. The in vitro experiment revealed a noticeable reduction in the radial mycelial growth of P. infestance as the concentration of nanofungicides increased. Specifically, at 7 days after inoculation (DAI), the following nanofungicides at a concentration of 100 ppm exhibited the highest levels of mycelial growth inhibition when compared to the control: Silver nanofungicide (72.45%), Agritec nanofungicide (70.21%), Selenium nanofungicide (68.77%), and Nickel nanofungicide (64.65%).

Hydrogen and oxygen production on Ag2O/NiO hybrid nanostructures via electrochemical water splitting

Among the different available methods, hydrogen production by electrocatalytic water splitting is the most attractive method. Here, Ag2O/NiO hybrid nanostructures with different molar ratios of silver and nickel ions were synthesized by co-precipitation method. Nickel oxide and silver oxide nanostructures was also prepared to compare with Ag2O/NiO nanocomposites. Investigations indicated that the as-prepared Ag2O/NiO nanocomposite with an equal molar ratio of metal ions shows high water splitting activity in 1 M KOH solution and only 430 and 140 mV are needed as overpotentials under a current density of 10 mA cm−2 for oxygen and hydrogen evolution reactions (OER and HER), respectively. Ag2O/NiO has the largest electrochemically active surface area, the lowest Tafel slope, the smallest semicircle diameter in the Nyquist plots, and the lowest charge transfer resistance for both OER and HER among all tested nanomaterials. Furthermore, Ag2O/NiO showed excellent stability for OER and HER for at least 30 h.

Enhanced properties of nickel–silver codoped hydroxyapatite for bone tissue engineering: Synthesis, characterization, and biocompatibility evaluation

Hydroxyapatite (HAp) is the most well-known bioceramic and widely utilized in bone tissue regeneration. Hydroxyapatite is biocompatible and bioactive however, it lacks osteogenesis, angiogenesis, and antibacterial properties. In the current study, we synthesized and evaluated a novel nickel (Ni) and silver (Ag) codoped hydroxyapatite (HAp) in comparison to undoped HAp and individually doped HAp samples. Extensive physicochemical characterizations like XRD, TEM, FE-SEM/EDS, FTIR, Raman spectroscopy, and TGA were performed, confirming the crystal structure and morphology of the synthesized HAp samples. All HAp samples exhibited elongated spherical-like nanoparticle morphologies with lengths between 34 and 44 nm and widths between 21 and 26 nm. The presence of dopant atoms, Ag and Ni, were observed in the doped/codoped HAp samples by EDS elemental mapping. Biocompatibility assessments using pre-osteoblast cells indicated high cell viability for all the doped and undoped HAp samples. Osteoinduction potential through alkaline phosphatase (ALP) activity measurements and alizarin red S (ARS) staining revealed enhanced calcium deposition in the presence of Ni–Ag codoped HAp compared to other HAp samples and control groups. This highlights the importance of Ni–Ag co-doping in promoting osteogenesis, surpassing the effects of silver doped HAp and nickel doped HAp. The potential of this novel Ni–Ag codoped HAp to induce osteogenesis in pre-osteoblast cells makes it a promising material for various applications in bone tissue engineering.

Improvement of a haptic feedback using Pb(Zr,Ti)O3 thin films on German silver foils

Improvement of a haptic feedback using Pb(Zr,Ti)O3 thin films on German silver foils

Silver–nickel core–shell nanostructure on cellulose fibers as biodegradable wearable paper heater

Silver–nickel core–shell nanostructure on cellulose fibers as biodegradable wearable paper heater

Microreactor Based on Trimetallic Nano-Oxides Obtained by In Situ Growth from German Silver

Nanostructured films of copper, zinc, and nickel oxides were obtained from a controlled oxidation of the ternary nickel silver (Cu-Zn-Ni) substrates through a one-pot, green, and low temperature vapor-based treatment. Brief contact of the alloy with ammonia and hydrogen peroxide vapors at room temperature originates a mixture of nanometric copper, zinc, and nickel oxides at its surface. The growths evolve with time and temperature, generating a layered film with highly dispersed copper nano-oxides/hydroxides on a base of zinc and nickel oxides. The composition, configuration, and way of obtaining these films make them green catalysts, which are highly active and stable for a carbon monoxide oxidation reaction.

Interfacial reaction and thermoelectric properties of Sr0.9La0.1TiO3 ceramic diffusion bonding joints with different electrode layers

n-Sr0.9La0.1TiO3 ceramic and Al2O3 substrate were welded by vacuum diffusion bonding with different electrode layers. Some intermetallic compounds could be observed at the interface when silver foil and nickel foil were applied as electrode layers. There was no obvious reaction product at the interface of joints when copper foil was employed as electrode layer. The joints fabricated using copper electrode layer showed the highest shear strength of 10.23 MPa. Furthermore, the thermoelectric properties of Sr0.9La0.1TiO3-20 wt %Ti/Cu joint were not significantly lower than that of intrinsic Sr0.9La0.1TiO3-20 wt %Ti thermoelectric material. In particular, the power factor value of Sr0.9La0.1TiO3-20 wt %Ti/Cu joint could reach 0.77 mW m−1 K−2 at 515 °C, which was 1.06 times that of intrinsic Sr0.9La0.1TiO3-20 wt %Ti thermoelectric material. After being aged in a vacuum environment at 675 °C for 15 days, the contact resistance of the SLT/Cu joint increased from 4.68 μΩ cm2 to 10.12 μΩ cm2, while the shear strength decreased from 10.23 MPa to 8.01 MPa. These results suggest that the interfacial properties, as characterized by contact resistance and shear strength, remained relatively stable and did not weaken significantly. The joints with copper electrode layer can meet the requirements of high-temperature application, which is beneficial to the production of high-temperature thermoelectric devices.

Plains Indian German silver from Oklahoma: the Smithsonian’s Davis collection

German silver jewelry has a historic and ongoing role in the social and ritual life of Indian people on the Southern Plains. A remarkably well-documented collection of German silverwork assembled in central Oklahoma in 1966 reveals much about the economics and social context of the craft at that time. The collection, now at the Smithsonian’s National Museum of Natural History, includes the work of seven smiths from five tribes, together with information on production and circulation. In addition to biographies of the craftsmen, the documentation positions the objects within social processes involving craftworkers, commercial outlets, the Peyote religion, Native consumers, and an elusive non-Native market.

Characterisation of binary (NiO)x (Ag2O)1−x nanoparticles synthesised via the thermal treatment route

In this study, binary nickel oxide silver oxide nanoparticles (NiO)x (Ag2O)1−x (NPs) were synthesised for the first time using the thermal treatment route at higher and lower precursor values. Two precursors and 5 g of polyvinyl pyrrolidone (PVP) were employed to obtain the (NiO)x (Ag2O)1−x NPs at 700 °C. The obtained NiO NPs documented cubic and hexagonal phases when assessed with X-ray diffraction (XRD) at (x = 0.4 and 0.6) and (x = 0.2 and 0.8), respectively. The cubic phase was confirmed for Ag2O NPs in all prepared samples. The smallest crystallite and particle sizes were found at x = 0.8. The particle size ranged from 23.0 to 45.0 nm, which was evaluated with a transmission electron microscope (TEM). Two shapes, NiO doped with porous Ag2O nanosheets, were observed with a scanning electron microscope (SEM). The purity of the products was evaluated via energy-dispersive X-ray (EDX) spectroscopy. The synthesised NPs were composed of nickel (Ni), silver (Ag), and oxygen (O). Moreover, the X-ray photoelectron spectroscopy (XPS) analysis performed during this study revealed the chemical states of the Ni, Ag, and O present, which confirmed the purity of the NPs. The ultraviolet–visible spectroscopy (UV–Vis) assessment conducted also demonstrated that the energy band gaps for nickel oxide (NiO) and silver oxide (Ag2O) increased with rising x values. The photoluminescence (PL) analysis performed in this study also verified the existence of two emission peaks attributable to NiO and Ag2O, indicating that the NPs possess good photocatalytic activity. Consequently, the NPs synthesised in the present study could be applied as antimicrobial agents in wastewater treatment.