Wear and corrosion properties of AM70 magnesium alloy subjected to equal channel angular pressing (ECAP) were investigated using pin-on-disc dry sliding wear test and electrochemical impedance spectroscopy (EIS), respectively. Wear test was conducted with 30 and 40 N loads with sliding distance of 5000 m and at a constant speed of 3 m/s. Reduced coefficient of friction (COF) and wear mass loss of ECAP processed samples showed increased wear resistance. Worn surface analysis by scanning electron microscope (SEM) showed the presence of delamination, wear debris, and plowing. Energy dispersive X-ray spectrometer (EDS) revealed the occurrence of oxidation, and the wear mechanism was identified as abrasion and oxidation wear. EIS plots showed the improvement in corrosion resistance of ECAP processed magnesium alloy compared to initial condition due to grain refinement and homogeneous distribution of secondary particles.

We have investigated theoretically the role of Cr-d states in the electronic and optical properties of the CdCr2X4 (X = S, Se) normal ferromagnetic spinels using the framework of an all-electron full-potential linearized augmented plane wave method. The calculations are performed using Coulomb corrected Perdew–Burke–Ernzerhof (PBE+U) and Tran–Blaha modified-Becke–Johnson (TB-mBJ) approximations with the adding of spin–orbit coupling in both schemes. The lattice parameters have been optimized and are in agreement with the existing experimental values. We found band gap values 1.606 eV and 0.972 eV of CdCr2X4 (X = S, Se), respectively, using the TB-mBJ scheme. Analysis of the site and momentum projected densities shows that the larger splitting of Cr-d states is responsible for the larger band gap by the use of the TB-mBJ scheme. Optical properties along the directions of lattice constants are studied on the basis of band to band transitions. We found the isotropic nature of the optical properties. Reflectivity stays low up to 1.6 eV, consistent with the energy gaps obtained using the TB-mBJ scheme in both the compounds. The refractive index, n(ω), and the extinction coefficient, k(ω), are also studied by the PBE and the TB-mBJ schemes.

To investigate the recrystallization behavior of large sized Nb–V microalloyed steel rods during thermomechanical controlled processing (TMCP), a series of isothermal hot compression tests were conducted on a Gleeble 1500 thermomechanical simulator. The kinetics and microstructure evolution models of dynamic recrystallization, static recrystallization, metadynamic recrystallization and the grain growth model of the tested steel were developed. Based on the developed models, a finite element (FE) model coupled with the recrystallization behavior of large sized Nb–V microalloyed steel rods during TMCP was established. Then, the distributions and evolutions of recrystallization fraction and grain size during the whole deformation process are obtained and analyzed. Finally, the predicted results were compared with experimental ones, and they show good agreement. This illustrates that the recrystallization models of the tested steel are valid and the developed FE model of large sized Nb–V microalloyed steel rods during TMCP is effective.

For Sn–Pb eutectic solder alloy, uniaxial tensile tests were conducted to dog-bone type specimens annealed at different temperatures (60–180 °C) and durations (2–48 h). Low strain rates ranging from 10−4 s−1 to 10−3 s−1 were applied to study the competition between creep and plasticity and also the rate dependent effect of annealing condition. It is found that the influence of annealing temperature on material properties is more than that of annealing duration. Higher temperature up to 180 °C generally leads to higher yield and ultimate stresses and ultimate strain of annealed specimens. The optimal annealing condition is suggested to be 180 °C for 6 h for stable and efficient improvements in both strength and ductility. By proposing a concise unified creep and plasticity constitutive model, the sensitivity to strain rate and annealing condition is quantified with consideration of both creep and hardening properties. Parameter calibration theoretically confirms the observed optimal annealing condition in experiments.

Several methods for determination of elastic–plastic parameters by instrumented spherical indentation tests have been presented in the past few years. Each method was established according to a specific constitutive model. Identification of the constitutive models of new materials has become an indispensable step in order to choose an appropriate indentation method to extract the elastic–plastic parameters. In the present work, the half depth energy accumulation rate and Meyer's index were related to the elastic–plastic constitutive models via qualitative and numerical analyses. A method for identification of the elastic–plastic constitutive models by instrumented spherical indentation test was proposed.

Cellular activity upon osmotic stress is related to the occurrence of several disease conditions. The real-time monitoring of the cell response to this kind of stress can give insight into the comprehension of mechanisms involved in cellular shrinkage. Currently the dynamics of the osmotic stress is studied using dedicated and tricky methodologies, not suited to the in vivo testing. We show that a disposable electronic device is very effective for studying the early stage of the osmotic stress induced on human lung adenocarcinoma cells, A549, by a hyperosmotic environment. Our findings corroborate the experimental results obtained by a standard complementary analysis.

Calcium-based renal calculi demonstrated significant heterogeneity in the structure, density, mineral composition, and material hardness not elucidated by routine clinical testing. Mineral density distributions within calcium oxalate stones revealed differential areas of low (590±80 mg/cc), medium (840±140 mg/cc), and high (1100±200 mg/cc) densities. Apatite stones also contained regions of low (700±200 mg/cc), medium (1100±200 mg/cc), and high (1400±140 mg/cc) densities within layers extending from single or multiple nucleation sites. Despite having lower average mineral density, calcium oxalate (CaOx) stones demonstrated higher material hardness compared to apatite stones, suggesting other chemical components might be involved in determining stone hardness properties. Carbon concentrated sites were identified between morphologic layers in CaOx stones and in stratified layers of apatite stones. Elemental analyses revealed numerous additional trace elements in both stone types. Despite the widespread assumption that stone mineral density is an indicator of susceptibility to lithotripsy, calcium stone mineral density estimates do not directly correlate with actual ex vivo stone hardness. Underlying stone heterogeneity in both structure and mineral density could explain why historical approaches have failed in accurately predicting response of stones to lithotripsy.

Mesoporous silicon sponge (MSS) is considered as a promising anode material for lithium ion batteries because of its preformed meso/macro porous structures that can accommodate large volume expansion during the lithiation process and its superior electrochemical performance. Temperature dependent hyperpolarized (HP) 129Xe NMR was applied to characterize the structure and porosity of MSS materials with varying pores and particle sizes. Our results reveal irregular pore structures with the presence of micropores inside the larger meso/macropore channels and each MSS material has its own characteristic pore environment with a varying degree of nonuniformity and connectivity of pores. This study demonstrates that HP 129Xe NMR is a potentially useful tool for providing a fingerprint of the structure and connectivity of the pores for each material, complementary to other characterization techniques.

Lithium-ion capacitors utilizing graphite (G) and reduced graphite oxide (RGO) as negative electrode materials were investigated. Various reduction methods of graphite oxide were applied to compare properties of modified materials. The hybrid cells showed the energy density at mild current regimes of ca. 70–100 Wh/kg. However, at higher rates, only the capacitor with chemically RGO maintained this tendency. Moreover, the system demonstrated the energy density of 34 Wh/kg at a power density of 26 kW/kg. The electrochemical measurements were conducted in three-electrode systems to record responses of positive and negative electrodes separately.

As an atomic-thick layer material, graphene has a large specific surface area, high electron mobility, and high sensitivity to electronic perturbations from the binding of molecules, all of which are attractive properties for developing electronic sensing devices. This article focuses on graphene-based electronic sensors [field effect transistor (FET) sensors] for detecting biomolecules, including DNA, protein, and bacteria, among others. This article will cover three morphologies of graphene materials in biosensing applications: graphene nanosheet, graphene nanoribbon, and vertically-aligned graphene. The unique structure and electronic properties of graphene enable the FET sensor for the low concentration and rapid detection of biomolecules, thereby addressing the limitations of conventional optical sensing technologies such as ELISA, Western Blot, and electrochemical method. The advantages of graphene-based sensing technology are highlighted and recent progress on graphene-based electronic sensors for detecting biomolecules is reviewed and discussed.

Sheets made of 316 stainless steel (100 × 100 × 1 mm3) were irradiated by laser at 1, 5, 10, and 15 passes under natural and forced cooling. Results showed that the deflection angle increased with the number of radiation passes. The bending angle after 15 passes of exposure under forced cooling was 5° higher than under natural cooling. The grain size under natural cooling increased from approximately 23–35 μm. By contrast, under forced cooling, the grain size decreased from approximately 37–27 μm. The sample hardness declined under natural cooling from approximately 212–200 HV. By contrast, sample hardness increased from approximately 216–233 HV under forced cooling. Polarization results show that the breakdown potential versus the number of lasing passes increased from −0.14 to −0.08 V under natural cooling and −0.16 to −0.06 V under forced cooling.

Morphology can play a critical role in determining function in organic photovoltaic (OPV) systems. Recently molecular acceptors have showed promise to replace fullerene derivatives as acceptor materials in bulk heterojunction solar cells and have achieved >10% efficiencies in single junction devices. The nearly identical mass/electron densities between the donor (polymer) and acceptor (molecule) materials results in poor material contrast compared to fullerene-based OPVs and therefore morphology characterization using techniques that rely on mass/electron density variations poses a challenge. This inhibits a fundamental understanding of the structure–property relationships for non-fullerene acceptor materials. We demonstrate that low angle annular dark field scanning transmission electron microscopy and resonant soft X-ray scattering form a set of complementary tools that can provide quantitative characterization of fullerene as well as non-fullerene based organic photovoltaic systems.

Starting from polydisperse diatomaceous earth (DE), we proposed an efficient separation method for obtaining different morphologies of biosilica from diatoms. DE is a very low-cost source of silica containing all the differently nanostructured elements. By a glucose gradient/dialysis, three types of biosilica morphologies were achieved: rods, valves, and clusters. We fully characterized the diatom fractions and we used them to produce fluorescent biosilica platforms (“tabs”). These supports exhibited good resistance in water, ethanol, and soft scraping. A preliminary biologic application by testing Saos-2 proliferation was also performed to check osteoblasts-like cells biologic attitude for this scaffolds with tunable nanostructure.

We address the competitive precipitation and coprecipitation of three types of secondary phases, i.e., Cu-rich precipitates (CRPs), reverted austenite (RA), and alloyed carbide, in a high-strength low-alloy steel with austenite reversion treatment at 675 °C by using electron back-scatter diffraction, transmission electron microscopy, and atom probe tomography. There is a strong competitive diffusion of Ni and Cu participating in austenite reversion and Cu precipitation with the fact that no CRPs are detected in and around the RA. Meanwhile, there is also a strong competitive diffusion of austenite stabilizing element Ni and carbide-forming elements Cr and Mo into the pre-existing C-rich zone, leading to the formation of nonequilibrium alloyed carbide deviating from the stoichiometric composition. On the other hand, the alloyed carbide and CRPs provide constituent elements for each other and make the coprecipitation thermodynamically favorable. The knowledge on the interactive formation of these three features provides versatile access to tailor the distributional morphology of CRPs, RA, and alloyed carbide via a multistage heat treatment and thus realize their beneficial effect on strength and toughness.