Contact Materials Research Articles

Microstructure and arc-induced degradation of Ag/Ti3AlC2 composites with varying particle size of Ti3AlC2

Nano-layered ternary compounds Mn+1AXn phases combine properties of both ceramics and metals, holding promising prospect for various applications. In this work, the microstructure evolution of coarse Ti3AlC2 particles, as well as the microstructure, physical properties and arc-induced degradation of Ag/Ti3AlC2 electrical contact materials (ECMs) with varying particle sizes of Ti3AlC2 were investigated. The Ti3AlC2 particles milled by vibration were inhomogeneous, whereas those milled through high energy ball milling for 3 h were basically uniformly refined and delaminated to nano-flakes with edge length of ∼100–350 nm without obvious decomposition. With decreasing particle size, the interaction between Ag and Ti3AlC2 was enhanced, thus mitigating the decrease of density and hardness after sintering. Though fine Ti3AlC2 particles led to increased hardness, easier decomposition of finer Ti3AlC2 during both sintering and arc erosion resulted in greater thermal accumulation and accelerated erosion process, thus negatively impacting the arc erosion resistance of Ag/Ti3AlC2 ECMs.

Past human decision-making based on stone tool performance: Experiments to test the influence of raw material variability and edge angle design on tool function

One of the main interests in the interpretation of the archaeological record and its variability within and through time and space is the production and use of past human stone tool technologies. Tool design and function are inevitably intertwined and strongly related to tool use. Understanding tool design provides information about early human technological adaptations and reflects human behaviour in the sense of conscious or unconscious decision-making. Nevertheless, the reason for major changes (including novelties, innovations, and loss) in past human stone tool technology is still poorly understood. A comprehensive approach focusing on tool function (What was the tool meant for?) and use (What was the tool used for?) can help to overcome this gap. While tool function (including performance) can be investigated experimentally, tool use can be addressed with use-wear analyses. These questions can be best investigated on technological systems showing little tool variability but strong evidence of maintenance and long-term use, such as Middle Palaeolithic industries.The Late Middle Palaeolithic record of Central and Eastern Europe is marked by the emergence of an asymmetric tool-type called Keilmesser (bifacial backed knives). Due to their sophisticated morphology, Keilmesser as a case study offer the potential to address aspects of raw material selection, tool production, maintenance, and reworking.This paper presents the results of an experiment designed to study the tool performance of Keilmesser from three archaeological sites, namely Balver Höhle, the Upper site of Buhlen and Grotte de Ramioul by testing raw material, edge angle and movement as independent variables. A highly controlled, sequential experiment was conducted using a mechanical device performing unidirectional cutting and carving movements on hard contact material. Results demonstrate the possibility to perform the mentioned task with 35° and 45° edge angles, maintaining function, albeit at differing levels of efficiency. The data has a direct impact on the interpretation of the archaeological assemblages regarding aspects such as stone tool morphology and resharpening. At the same time, the study highlights the importance of raw material analysis to understand the variability in the archaeological record and the implications on past human decision-making strategies.

Band Alignment Tunning via the Facets of CdS Nanocrystals with g‐C3N4 for Unveiling Their Enhanced Photocatalytical Property

AbstractThe heterojunction is a great approach to profit the photogenerated electrons and holes separation and then enhance the photoelectric current for the photochemical reactions, such as the hydrogen evolution reaction. The intrinsic of the enhanced electrons and hole separation is ascribed to the appropriate band alignment between the two contact materials and plenty of research has reported the different band alignments formed by the different contacted bulk nanomaterials. Few studies focus on the precious crystal structure‐related band alignment. Here, the polyheptazine structured g‐C3N4 together with the wurtzite CdS is investigated, and different band alignments are formed through the different exposed crystal planes of CdS. It is found that along with the annealing temperature, the CdS will dominantly expose with the (110) facets and then form the S‐scheme heterojunction with the g‐C3N4. The formed built‐in electric field between the valence band of CdS and the conductive band of g‐C3N4 accelerates the recombination between the photogenerated electrons from CdS and holes from g‐C3N4. Meanwhile, it promotes the separation of the photogenerated electrons with holes from g‐C3N4, resulting in the superior photocatalytic HER performance. The study supplies a new venue for preciously tunneling the band alignments between the heterogeneous catalysts for optimizing the photoelectric properties.

Interfacial thermal resistance between mechanically exfoliated nm-thick MoS2 and silicon from −60 °C to 50 °C based on ns-ET Raman technique

In the miniaturization and integration development of micro-devices, the large thermal contact resistance significantly affects the overall performance of micro-devices, which is influenced by both interfacial contact condition and material properties. However, the temperature dependence of interfacial thermal resistance of realistic materials remains unclear. In this work, the interfacial thermal resistance between nm-thick MoS2 nanosheets and Si substrate is measured by using the ns energy transport state-resolved Raman (ns ET-Raman) technique. By comparing the experimental data with finite difference numerical simulation, the real value of the interfacial thermal resistance is determined. By changing the ambient temperature from -60 °C to 50 °C, the interfacial thermal resistance against temperature curve is obtained. As the environmental temperature deviates from room temperature, a large increasement of the interfacial thermal resistance can be observed. As temperature goes back to room temperature, the unreversible interfacial thermal resistance indicates that the large thermal expansion mismatch deteriorates the contact situation. In the last, the interfacial thermal resistance evolution under varying environmental temperatures from both experiments and modeling results in literatures are compared and discussed to illustrate the effect of different interface formation methods. For epitaxial and CVD grown materials, the interfacial thermal resistance generally reduces with raising ambient temperature. While for mechanically exfoliated samples, the effect of thermal expansion mismatch and the resulting gaps dominate the interfacial thermal resistance, which leads to non-monotonous temperature dependency with a valley located at room temperature.

MoS2-based charge trapping layer enabled triboelectric nanogenerator with assistance of CNN-GRU model for intelligent perception

Self-powered sensing technology and smart perception technology have broad application prospects in flexible and wearable electronics. In this work, a flexible triboelectric nanogenerator (RMP-TENG) based on a room-temperature vulcanized silicone rubber (RTV)@(Molybdenum disulfide (MoS2)/Polyvinyl chloride (PVC)) functional layer is developed using a layer-by-layer self-assembly and material doping strategy. The RTV@(MoS2/PVC) functional layer is divided into a charge-generating layer (RTV/PVC) and a charge-trapping layer (RTV/MoS2). The synergistic effect of PVC and MoS2 has improved the surface roughness and charge transfer efficiency of RMP-TENG, doubling its output performance to 1055 V and 112 μA. In order to further improve the tactile sensing accuracy of RMP-TENG, a deep learning model based on Convolutional Neural Network (CNN) and Gated Recurrent Unit (GRU) is developed. It predicts the type of contact material based on the features of tactile signals, achieving a prediction accuracy of 93.975%. Additionally, by combining mobile smart terminals, the CNN-GRU model, and RMP-TENG, a wireless access control system based on self-powered tactile sensing and intelligent material recognition is developed. Through the optimization of these experiments and algorithms, RMP-TENG has achieved real-time material recognition capabilities. This demonstrates the broad application prospects of RMP-TENG in wearable energy supply, intelligent sensing, human-computer interaction, and other areas.

Effect of Nb Doping on the Electrical Contact Properties of AgNi Contact Materials

AgNi contact materials have received widespread attention with the acceleration of the process of replacing AgCdO contact materials. However, the practical applications of AgNi contact materials are limited due to its disadvantage of poor resistance to melting welding. Firstly, following the first principles of the density functional theory, we simulated and tested an interfacial model of AgNi doped with varying amounts of Nb. Next, we fabricated AgNi electrical contact materials. Subsequently, we conducted electrical contact tests. Finally, the impact of Nb doping on the arc erosion behavior of AgNi electrical contact materials was analyzed. The results indicate that, with an increase in Nb doping content, the electrical contact performance and the degree of arc erosion exhibit a trend of initially decreasing and then increasing, which aligns with the simulation results. The mean values of arc energy, arc duration, and welding force for the material doped with 4.55% Nb were 181.02 mJ, 9.43 mS, and 38.45 cN, respectively. Moreover, the anode is more responsive to changes in Nb content compared to the cathode. The introduction of Nb enhances the viscosity of the molten pool in the AgNi electrical contact. Furthermore, the mechanisms of grain boundary strengthening and solid solution strengthening by Nb improve the weld performance resistance of the contact.

First-Principles and Experimental Study of Ge, V, Ta-Doped AgNi Electrical Contact Materials

To explore the stability, electrical, and mechanical characteristics of undoped AgNi alongside AgNi doped with elemental Ge, V, and Ta, we performed calculations on their electronic structures using density functional theory from first-principles. We also prepared AgNi(17) and AgNi-x(Ge, V, Ta) electrical contact materials using the powder metallurgy technique, and they were subsequently assessed experimentally. The electrical properties of these materials were evaluated under a 24 V/15 A DC-resistive load using the JF04D contact material testing system. A three-dimensional morphology scanner was employed to examine the contact surface and investigate the erosion patterns of the materials. Our findings indicate that doping with metal elements significantly enhanced the mechanical properties of electrical contacts, including conductivity and hardness, and optimizes arc parameters while improving resistance to arc erosion. Notably, AgNi-Ge demonstrated superior conductivity and arc erosion resistance, showing significant improvements over the undoped AgNi contacts. This research provides a theoretical foundation for selecting doping elements aimed at enhancing the performance of AgNi electrical contact materials.

Impact of Dynamic Wheel Loading on Flexible Pavement Responses for Non-Free Rolling Conditions

Since 2000, pavement design methodologies have transitioned from empirical to mechanistic-empirical procedures. However, the complexities of loading patterns, contact stress distribution, material characterization, vehicle maneuvering, and dynamic load amplification are still not fully considered, despite their significant effect on pavement performance. In this study, state-of-the-art numerical models were used to investigate the changes in critical pavement responses derived from the combined effect of roughness-induced dynamic loading and vehicle maneuvering. A decoupled vehicle–tire–pavement interaction approach composed of a random process to generate artificial road roughness profiles, a mechanical full truck model, and three-dimensional finite element tire and flexible pavement models allow the prediction of the impact of road roughness on vehicle dynamics. In addition, the study quantifies the effect of dynamic loading on contact stresses, and consequently, on pavement critical responses. Because of the expected increase in axle weight from truck electrification, overweight scenarios were also considered. Changes in load history and distribution of strain fields were assessed for two typical pavement structures (thin and thick). The combined effect of roughness-induced dynamic loading and vehicle maneuvering greatly altered the critical pavement responses associated with bottom-up fatigue cracking, near-surface cracking, and rutting. Under the most adverse conditions, the critical tensile strains at the bottom of the asphalt concrete increased up to 125%, the shear strain increased up to 100%, and the compressive strain escalated to 120% when compared with the reference cases. Higher temperatures exacerbated the impact of dynamic wheel loading and vehicle maneuvering.

Identification and quantification of per- and polyfluorinated alkyl substances (PFAS) migrating from food contact materials (FCM)

Per- and polyfluorinated alkyl substances (PFAS) can be added to food contact materials (FCM) to increase their water and/or grease repellent properties. Some well-known PFAS are perfluoroalkyl carboxylic acids (PFCA), perfluoroalkyl sulfonic acids (PFSA), and polyfluorinated telomer alcohols (FTOH). Due to the strength of the carbon-fluorine bond, PFAS are chemically very stable and highly resistant to biological degradation, posing a risk to human health and the environment.To examine the presence of PFAS in paper-based FCM, various samples were collected, including popcorn bags, muffin cups, and pizza boxes with high total organic fluorine (TOF) content from the Danish and Spanish markets. The FCM composition was characterised by FTIR. Quantification of some well-known PFAS such as PFCA, PFSA, and FTOH was performed in food simulants using LC-MS/MS, and in addition a non-targeted screening approach was performed by LC-Orbitrap-HRMS.Among analysed samples, the highest concentrations of PFAS were found in a muffin cup made of cellulose (PFCA ∼ 1.41 μg kg−1 food, FTOH ∼ 11.5 μg kg−1 food), and the results were used to estimate dietary exposures to PFAS migrated from this FCM. Compared to measured TOF value in this sample, the fluorine from all quantified PFAS accounted for only 0.6%. Thus, a more powerful analytical approach was used to further investigate PFAS occurrence in this sample. Using non-targeted screening, an additional twenty compounds were identified, among them five with confidence level 1 and ten with confidence level 2. Many of them were either fluorotelomer carboxylic acids or sulfonic acids or ether-containing compounds.

Gluten migration from biodegradable food contact materials poses a risk to celiac disease patients

Due to the ban of certain single-use plastics in the European Union, food contact materials (FCM) from biobased and/or biodegradable polymers are increasingly being used. Some FCM are made from wheat or rye and therefore contain gluten, which is a food allergen and known to cause celiac disease. Legislation currently does not require allergen labelling on FCM and there is only some first information that gluten from FCM can migrate into gluten-free foods. Our aim was to analyze the extent of gluten migration from six different FCM into a variety of liquid and solid foods to assess the risk of exposure for wheat allergy and celiac disease patients. We show that the extent of gluten migration depended on the properties of the material, the liquid or solid food it comes into contact with and contact time. There was no clear effect of temperature or pH value. Of the six FCM studied, wheat bran-based plates had the highest potential to release gluten with concentrations of up to 203.0 mg/L of gluten in deionized water after 30 min. To protect patients, it is important to raise awareness of the risk of gluten migration from such FCM and help patients identify and avoid gluten-containing FCM. Further, legislation needs to be adapted urgently to include mandatory labelling of allergens on these biodegradable FCM.

Comparative Study of Silver and Gold Source/Drain Contacts for Organic Thin‐Film Transistors with Low Contact Resistance

AbstractFlexible low‐voltage organic thin‐film transistors (TFTs) with Ag source/drain contacts are fabricated, and the contact resistance is measured using the transfer length method. The TFTs are fabricated in the inverted coplanar (bottom‐gate, bottom‐contact) device architecture, using the vacuum‐deposited small‐molecule semiconductor dinaphtho[2,3′b:2′,3′‐f]thieno[3,2‐b]thiophene (DNTT). Prior to the semiconductor deposition, the contact surface is functionalized with a chemisorbed monolayer of pentafluorobenzenethiol (PFBT). For comparison, TFTs with PFBT‐functionalized Au source/drain contacts are fabricated on the same substrate. Overall, the performance of the TFTs with the Ag contacts is very similar to that of the TFTs with the Au contacts, and the contact resistance of the TFTs with the Ag contacts (377 Ωcm) is the smallest reported to date for p‐channel organic TFTs with a contact material other than Au or Pt.

Prevalence of synthetic phenolic antioxidants in food contact materials from China and their implications for human dietary exposure through take-away food

The application of disposable tableware has increased substantially in recent times due to the rapidly growing food delivery business in China. Synthetic phenolic antioxidants (SPAs) are widely used in food contact materials (FCMs) to delay the process of oxidation; however, their compositions, concentrations, and potential health hazards remain unclear. Therefore, FCMs comprised of five materials obtained from 19 categories (n = 118) in China were analyzed for SPAs concentrations. FCMs have been found to contain a variety of SPAs, with ∑SPAs concentrations ranging from 44.18 to 69,485.12 μg/kg (median: 2615.63 μg/kg). The predominant congeners identified in the sample include 2,4-di-tert-butylphenol (2,4-DTBP), 2,6-di-tert-butylphenol (2,6-DTBP), and 2,6-di-tert-butyl-p-benzoquinone (BHT-Q) with a median concentration of 885.75, 555.45 and of 217.44 μg/kg, respectively. Milky tea paper cups, instant noodle buckets, milky teacups, and disposable cups showed high levels of SPAs. 2,2′-methylenebis(4-methyl-6-tert-butylphenol) (AO 2246) was predominantly detected in polyethylene and polyethylene terephthalate-based products. The migration test identified disposable plastic cups and bowls as the predominant FCMs and 2,4-DTBP as the dominant SPA. The exposure risk of SPAs decreased with age. In children, the estimated daily intake of ∑SPAs from FCMs was determined to be 17.56 ng/kg body weight/day, which was 8.3 times higher than that of phthalic acid esters. The current findings indicate the potential ingestion risk of SPAs during the daily life application of multiple FCM categories.

Layer-by-Layer Construction of Antibacterial and Anticoagulant Blood Contacting Materials.

Vascular transplantation is a common treatment for Cardiovascular disease (CVD). However, the mismatch of mechanical, structural, or microenvironmental properties of materials limits the clinical application. Therefore, the functional construction of artificial vessels or other blood contact materials remains an urgent challenge. In this paper, the composite nanofibers of polycaprolactone (PCL) with dopamine and polyethylenimine (PEI) coating are first prepared, which are further self-assembled by anticoagulant hirudin (rH) and antimicrobial peptide (AMP) of HHC36 through layer-by-layer (LBL) method. The results of FTIR and XPS analysis show that hirudin and AMP are successfully loaded on PEI-PDA/PCL nanofibers and the hydrophilicity is improved. They also show good mechanical properties that the ultimate tensile strength and elongation at break are better than natural blood vessels. The antibacterial results show that the antibacterial effect is still 93% against E. coli on the fifth day because of the stable and continuous release of HHC36 and rH. The performance of anticoagulant activity also exhibited the same results, which APTT is even 9.7s longer in the experimental group than the control group on the fifth day. The novel materials would be effectively solve the formation of thrombosis around artificial blood vessel grafts and the treatment of inflammation.

Formation and evolution of apple (Malus pumila Mill.) bruising based on high-speed camera verification and finite element method

To analyse the characteristics and internal mechanical changes of bruising formed on apples under different working conditions, this paper explored the formation mechanism of bruising using finite element method. A composite model of peel and flesh was established by reverse engineering, and the accuracy of the apple model was validated two aspects: drop velocity and bruise volume, with a maximum error of 2.51 %. The collision velocity, contact force, stress, and energy of apple bruising were analysed using commonly used contact materials (wood and rubber) at falling heights of 600, 900, 1200, 1500, 1800, and 2100 mm. The characteristics of apple bruising after formation were analysed and the susceptibility of apple bruising were explored. The findings suggest that as the height increased, so does the maximum stress and bruise susceptibility. At a height of 2100 mm, the apple’s bruise susceptibility was measured at 24955.87 mm3 J−1 (wood) and 24710.18 mm3 J−1 (rubber), respectively. This study offers valuable insights into understanding the mechanism behind bruising in fruits, and has a guiding role in the control of bruising and the optimal design of related machinery.

Determination of total extractable organofluorine (EOF) in food contact materials and target and non-target analysis of per- and polyfluoroalkyl substances using LC–MS/MS and LC–HRMS simultaneously coupled to ICP-MS

Food contact materials (FCMs) from three countries were analysed for all extractable organofluorines (EOFs) from the materials and subsequently by target and non-target analysis for per- and polyfluoroalkyl substances (PFAS). The EOF varied by two orders of magnitude for FCM from UK and Saudi Arabia ranging between 2.14 and 483 ng cm−2 (0.2–48 ng g−1) showing that one quarter of all samples were above the Danish regulation for PFAS in FCM. Target PFAS showed high variability in composition and accounted for less than 1% of the EOF. Non-target PFAS screening using HPLC–ICP-MS and coupled simultaneously to HRMS showed the occurrence of organofluorines which were identified by neither LC–MS/MS nor LC–HRMS. This illustrates that the current target PFAS approaches fail to identify EOFs from FCM, which would be a problem with the new EU proposal to ban all PFAS.

Thermal analysis of fire effects on fire doors using the finite element method

The goal of this paper is to use the finite element method and computer simulation to prove the effectiveness in assessing the fire resistance of building construction elements, specifically on the example of the fire resistance of fire doors. For that purpose, data from the building where fire doors with defined characteristics were installed were used. For simulation purposes, numerical modelling with thermal and structural analysis will be used. In this way, the parameters of the temperature distribution on the fire door and the contact material due to fire will be obtained, as well as the distribution of strain and stresses, which will indicate the fire resistance of the used structure. Computer simulation with numerical modelling offers a number of advantages both in the speed of providing results of a larger number of variants of the simulation model and in the accuracy of the results obtained once the model is calibrated. Also, the mentioned type of predicting the effect of fire can be applied to other elements of the structure of the construction object, which can significantly influence the decision-making that will prevent the negative consequences of the occurrence of a possible fire.

Design a cross-linked film based on cellulose nanocrystals doping for enhancing the interfacial performance and desensitization of CL-20

Despite the extensive researches on CL-20 crystals, the mechanical safety issues and process problems of CL-20 applications have not been studied in-depth. Herein, the cellulose nanocrystals (CNC) was doped in microcrystalline wax (MW), oxidized microcrystalline wax (OMW) and hydrogel (PPC) to design and fabricate the cross-linked CL-20 composites by simple water-suspension melting and freeze-drying methods. The composites were characterized by SEM, XPS, TG-DSC, XRD, mechanical sensitivity device and inclined chute tester. It is found that the CNC@OMW composite film exhibits excellent coating effect (99.96%) on CL-20 due to the cross-linking results. The Ea of CL-20 is increased from 190.92 to 388.71 kJ/mol under the synergistic effect of the excellent compatibility between components and the compact coating structure of CNC@OMW. Additionally, the film enhances the Tp0 of CL-20 from 218.15 to 222.66 ℃ and Tb from 220.27 to 223.73 ℃, respectively. While, the PPC@CNC only promoted Ea, Tp0 and Tb of CL-20–292.89.71 kJ/mol, 224.22 ℃ and 225.66 ℃, respectively. Besides, the XRD results confirms that three composite films dose not cause a transformation of the ε-CL-20 crystal phase. Most importantly, the cross-linked film brings mechanical sensitivity of CL-20 from 60 N and 3.5 J to a level of over 360 N and 10.4 J, comparable to WO3/Al nanothermite with 5 wt% polyaniline (360 N) and composite with 95 wt% LLM-105 and 5 wt% ternary (11–12 J). This improvement enables the composite explosives to be handled using standard procedures. Furthermore, the ability of the particles to accumulate electrostatic charge after cross-linking coating is significantly reduced, and PVC is more suitable as the contact material of CL-20 and composite particles than copper for use in the transportation and packaging. These findings can serve as a reference for wide application of CL-20.

A study of the migration behavior of formaldehyde in different concentrations of ethanol in paper food materials.

To ensure the safety of food contact materials, a liquid chromatography method was established to determine the migration of formaldehyde in paper packaging with various food simulants (10%, 25%, 50%, 75%, and 95% ethanol by volume) and to investigate the migration behavior of formaldehyde after various durations and with various materials. The results showed that the method has good linearity with a correlation coefficient of R2 > 0.9990, a detection limit of 0.0011 ~ 0.0027mg L-1, and a spiked recovery of 89.7 ~ 103.2% in the range of formaldehyde determination; the migration of formaldehyde in all six paper contact materials showed a trend of gradual increase with time until equilibrium was reached. At the same time and temperature, the migration of formaldehyde in paper packaging was the highest in low-concentration ethanol. With the same food simulants and materials, the maximum migration of formaldehyde in printed materials was greater than that in nonprinted materials; with different materials and the same food simulant, the thickness value was higher, with the use of water-based ink as a printing material, and the maximum migration value of formaldehyde by offset printing technology was low.

Safety assessment of the substance amines, di-C14-C20-alkyl, oxidised, from hydrogenated vegetable oil, for use in food contact materials.

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of amines, di-C14-C18-alkyl, oxidised, renamed by the Panel as amines, di-C14-C20-alkyl, oxidised, from hydrogenated vegetable oil. The substance amines, bis(hydrogenated tallow alkyl) oxidised, consisting of the same components, but originating from tallow, is currently authorised as FCM substance No 768. The vegetable-sourced substance is intended to be used at up to 0.1% w/w as antioxidant and/or stabiliser in the manufacture of polyolefin food contact materials (FCM) and articles intended for contact with dry, aqueous and acidic foods. The substance is a mixture consisting of linear N,N-dialkyl hydroxylamines and their corresponding amine, nitrone and oxime derivatives, as well as further components: tert-N-oxides, secondary amides and carboxylic acids. Specific migration was tested from polyethylene samples in 10% ethanol and 3% acetic acid for 2 h at 100°C followed by 10 days at 60°C. None of the non-authorised components were detected to migrate at detection limits (LoD) in the range 0.003-0.029 mg/kg. The LoD of authorised carboxylic acids was 0.35 mg/kg. The Panel reassessed the genotoxicity studies carried out on FCM No 768 and evaluated two new bacterial reverse mutation tests on the nitrone and oxime derivatives as well as new (qualitative/quantitative) structure-activity relationship (Q)SAR analyses on other components. The Panel concluded that the substance did not raise a concern for genotoxicity. The Panel concluded that the substance is not of safety concern for the consumers if it is used as an additive at 0.1% w/w in the manufacture of polyolefin FCM intended to be in contact with foods simulated by food simulants A, B, C and E, except for infant formula and human milk, for storage above 6 months at room temperature and below, including hot-fill conditions and heating up to 100°C for 2 h.

Interfacial wettability and electrical properties of Ni-doped Ag/Bi2Sn2O7 electrical contact materials

Interfacial wettability and electrical properties of Ni-doped Ag/Bi2Sn2O7 electrical contact materials