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On the basis of the thermal equation-of-state a simple theoretical model is developed to study the pressure dependence of melting temperature. The model is then applied to compute the high pressure melting curve of 10 metals (Cu, Mg, Pb, Al, In, Cd, Zn, Au, Ag and Mn). It is found that the melting temperature is not linear with pressure and the slope $d{T}_m/dP$ of the melting curve decreases continuously with the increase in pressure. The results obtained with the present model are also compared with the previous theoretical and experimental data. A good agreement between theoretical and experimental result supports the validity of the present model.

Synthesis of Cobalt nanoparticles often entails toxic and expensive physical-chemistry methods. Fabrication of pure cobalt nanoparticles (NPs) using a simple and low-cost electric arc discharge method in ethylene glycol (EG) is suggested for the first time. The effect of different arc discharge currents (10, 20 and 30 A) on the size and optical absorption of the NPs are studied. Dynamic light scattering (DLS) and UV-visible spectroscopy result indicate that at an arc current of 10 A NPs of about 92.95 nm are produced and increasing the arc current leads to larger NPs. UV-visible spectroscopy data shows that the solvent gets more and more transparent with time. Sonication proves that this effect is related to agglomeration of the NPs. Formation of the pure Co NPs are evidenced by means of X-ray diffraction (XRD) measurements which gives an average size of about 21 nm using Scherrer's relation. Magnetization measurements of the samples are carried out by Alternating Gradient Force Magnetometer (AGFM). The results demonstrate the ability of the arc discharge method for direct formation of Co NPs in EG medium.

We have used a method for determining volume dependence of the Grüneisen parameter in the Lindemann law to study the pressure dependence of melting temperatures in case of 10 metals viz. Cu, Mg, Pb, Al, In, Cd, Zn, Au, Ag and Mn. The reciprocal gamma relationship has been used to estimate the values of Grüneisen parameters at different volumes. The results for melting temperatures of metals at high pressures obtained in this study using the Lindemann law of melting are compared with the available experimental data and also with the values calculated from the instability model based on a thermal equation of state. The analytical model used in this study is much simpler than the accurate DFT calculations and molecular dynamics.

From femtosecond spectroscopy (fs-spectroscopy) of metals, electrons and phonons reequilibrate nearly independently, which contrasts with models of heat transfer at ordinary temperatures ($T>100$ K). These electronic transfer models only agree with thermal conductivity $(k)$ data at a single temperature, but do not agree with thermal diffusivity $(D)$ data. To address the discrepancies, which are important to problems in solid state physics, we separately measured electronic (ele) and phononic (lat) components of $D$ in many metals and alloys over $\sim$290–1100 K by varying measurement duration and sample length in laser-flash experiments. These mechanisms produce distinct diffusive responses in temperature versus time acquisitions because carrier speeds $(u)$ and heat capacities $(C)$ differ greatly. Electronic transport of heat only operates for a brief time after heat is applied because $u$ is high. High $D_{\mathrm{\text{ele}}}$ is associated with moderate $T$, long lengths, low electrical resistivity, and loss of ferromagnetism. Relationships of $D_{\mathrm{\text{ele}}}$ and $D_{\mathrm{\text{lat}}}$ with physical properties support our assignments. Although $k_{\mathrm{\text{ele}}}$ reaches $\sim 20\times k_{\mathrm{\text{lat}}}$ near 470 K, it is transient. Combining previous data on $u$ with each $D$ provides mean free paths and lifetimes that are consistent with $\sim 298$ K fs-spectroscopy, and new values at high $T$. Our findings are consistent with nearly-free electrons absorbing and transmitting a small fraction of the incoming heat, whereas phonons absorb and transmit the majority. We model time-dependent, parallel heat transfer under adiabatic conditions which is one-dimensional in solids, as required by thermodynamic law. For noninteracting mechanisms, $k\cong \mathrm{\Sigma }{C}_i{k}_i\mathrm{\Sigma }{C}_i/(\mathrm{\Sigma }{C}_i^2)$. For metals, this reduces to $k=k_{\mathrm{\text{lat}}}$ above $\sim$20 K, consistent with our measurements, and shows that Meissner’s equation $(k\cong k_{\mathrm{\text{lat}}}+k_{\mathrm{\text{ele}}})$ is invalid above $\sim$20 K. For one mechanism with multiple, interacting carriers, $k\cong \mathrm{\Sigma }{C}_i{k}_i/(\mathrm{\Sigma }{C}_i)$. Thus, certain dynamic behaviors of electrons and phonons in metals have been misunderstood. Implications for theoretical models and technological advancements are briefly discussed.

Autism is a complex disorder with both genetic and environmental factors. Metal disturbances have been reported in autistic individuals. In particular, exposure to ethylmercury (EtHg) in the vaccine preservative thimerosal and exposure to methylmercury (MeHg) through fish consumption have been implicated as environmental contributors to the autism spectrum disorder (ASD) phenotype. Metallothioneins (MTs) are small sulfhydryl (–SH)-rich metal-binding proteins that have important functions in metal homeostasis and protection against metalinduced toxicity. MT1 and MT2 have a high affinity for toxic heavy metals and are induced following mercury (Hg) exposure. It has been suggested that altered or dysfunctional MTs could enhance susceptibility to Hg-induced toxicity, and that alterations in Hg metabolism may contribute to the neurodevelopmental phenotypes present in ASD. One proposed treatment of autism is to attempt to restore MT function; however, there is no evidence in the peer-reviewed literature that MT restoration is an effective treatment for autistic symptoms. To date, there is no evidence for the efficacy of MT in ameliorating MeHg- or EtHg-induced neurotoxicity. Currently, there is nothing in the literature that suggests altered MT homeostasis is a contributing factor to the development of autism.

Based on the characteristics of secondary electron emission and the relationships among parameters of secondary electron yield $\delta$ in the low-energy range of $E_{p0}\leqq E_{p0m}\leqq 800$ eV (low-energy $\delta$), the universal formula for low-energy $\delta$ as a function of $E_{p0}$, $E_{p0m}$ and maximum $\delta ({\delta }_m)$ was deduced, where $E_{p0}$ and $E_{p0m}$ are the incident energies of primary electron and of ${\delta }_m$, respectively. From the deduced universal formula and experimental low-energy $\delta$ from metals, semiconductors and insulators, special formula for low-energy $\delta$ from metals as a function of $E_{p0}$, $E_{p0m}$ and ${\delta }_m$ and that for low-energy $\delta$ from semiconductors and insulators as a function of $E_{p0}$, $E_{p0m}$ and ${\delta }_m$ were deduced, respectively. The results were analyzed, it can be concluded that the two deduced special formulae can be used to calculate low-energy $\delta$ from metals, semiconductors and insulators, respectively.

An unconventional nonlinear elastic theory is advocated for solids undergoing large compression as may occur in shock loading. This theory incorporates an Eulerian strain measure, in locally unstressed material coordinates. Analytical predictions of this theory and conventional Lagrangian theory for elastic shock stress in anisotropic single crystals of aluminum, copper and magnesium are compared. Eulerian solutions demonstrate greater accuracy compared to atomic simulation (aluminum) and faster convergence with increasing order of elastic constants entering the internal energy. A thermomechanical framework incorporating this Eulerian strain and accounting for elastic and plastic deformations is outlined in parallel with equations for Lagrangian finite strain crystal plasticity. For several symmetric crystal orientations, predicted values of volumetric compression at the Hugoniot elastic limit of the two theories begin to differ substantially when octahedral or prismatic slip system strengths exceed about 1% of the shear modulus. Predicted pressures differ substantially for volumetric compression in excess of 5%. Predictions of Eulerian theory are closer to experimental shock data for aluminum, copper, and magnesium polycrystals.