Specific Heat of the Ca-Intercalated Graphite Superconductor CaC6_6

The superconducting state of Ca-intercalated graphite CaC6 has been investigated by specific heat measurements. The characteristic anomaly at the superconducting transition (Tc = 11.4 K) indicates clearly the bulk nature of the superconductivity. The temperature and magnetic field dependence of the electronic specific heat are consistent with a fully-gapped superconducting order parameter. The estimated electron-phonon coupling constant is lambda = 0.60 - 0.74 suggesting that the relatively high Tc of CaC6 can be explained within the weak-coupling BCS approach.Comment: 4 pages, 4 figs, submitted to Phys. Rev. Let

Effect of Pressure on Superconducting Ca-intercalated Graphite CaC6_6

The pressure effect on the superconducting transition temperature ($T_c$) of the newly-discovered Ca-intercalated graphite compound CaC$_6$ has been investigated up to $\sim$ 16 kbar. $T_c$ is found to increase under pressure with a large relative ratio $\Delta$$T_c$/$T_c$ of $\approx$ +0.4 %/kbar. Using first-principles calculations, we show that the large and positive effect of pressure on $T_c$ can be explained in the scope of electron-phonon theory due to the presence of a soft phonon branch associated to in-plane vibrations of Ca atoms. Implications of the present findings on the current debate about the superconducting mechanism in graphite intercalation compounds are discussed.Comment: 6 pages, 5 figs, final PRB versio

Design and Analysis of Energy Absorbent Bioinspired Lattice Structures

The increasing demand for energy absorbent structures, paired with the need for more efficient use of materials in a wide range of engineering fields, has led to an extensive range of designs in the porous forms of sandwiches, honeycomb, and foams. To achieve an even better performance, an ingenious solution is to learn how biological structures adjust their configurations to absorb energy without catastrophic failure. In this study, we have attempted to blend the shape freedom, offered by additive manufacturing techniques, with the biomimetic approach, to propose new lattice structures for energy absorbent applications. To this aim we have combined multiple bio-inspirational sources for the design of optimized configurations under compressive loads. Periodic lattice structures are fabricated based on the designed unit cell geometries and studied using experimental and computational strategies. The individual effect of each bio-inspired feature has been evaluated on the energy absorbance performance of the designed structure. Based on the design parameters of the lattices, a tuning between the strength and energy absorption could be obtained, paving the way for transition within a wide range of real-life applicative scenarios

Design and analysis of energy absorbent bioinspired lattice structures

The increasing demand for energy absorbent structures, paired with the need for more efficient use of materials in a wide range of engineering fields, has led to an extensive range of designs in the porous forms of sandwiches, honeycomb, and foams. To achieve an even better performance, an ingenious solution is to learn how biological structures adjust their configurations to absorb energy without catastrophic failure. In this study, we have attempted to blend the shape freedom, offered by additive manufacturing techniques, with the biomimetic approach, to propose new lattice structures for energy absorbent applications. To this aim we have combined multiple bio-inspirational sources for the design of optimized configurations under compressive loads. Periodic lattice structures are fabricated based on the designed unit cell geometries and studied using experimental and computational strategies. The individual effect of each bio-inspired feature has been evaluated on the energy absorbance performance of the designed structure. Based on the design parameters of the lattices, a tuning between the strength and energy absorption could be obtained, paving the way for transition within a wide range of real-life applicative scenarios

Titration of the Iranian white spot virus isolate, on crayfish Astacus leptodactylus and Penaeus semisulcatus

White Spot Virus (WSV) is currently the most serious viral pathogen of shrimp worldwide; it causes mortality up to 100% within 7-10 days in commercial shrimp farms. Infected Indian white shrimp Fenneropenaeus indicus samples were collected from Guatr shrimp site in Sistan and Baluchestan province in south of Iran and WSV infection was confirmed by Nested PCR. WSV was isolated from infected shrimp samples by centrifugation and filtration and multiplied in crayfish by intramuscular inoculation, the isolated virus was called WSV/IRN/1/2010. In order to determine the dilution resulting in 90-100% mortality in Penaeus semiculcatus, diluted virus stock in steps from 10^0 till 10^5 times in sterile PBS was injected intramuscularly to 14 shrimps in each group. Also the virus stock was diluted in steps from 1/2 till 1/32 times in sterile PBS and injected intramuscularly in Astacus leptodactylus crayfish. Therefore the LD50 of live virus stock in Astacus leptodactylus and Penaeus semiculcatus crayfish were calculated by the Karber method 10^3.29 /ml and 10^5.35 /ml, respectively