Thermal conductivity and diffusion-mediated localization in Fe_{1-x}Cr_{x} Alloys

We apply a new Kubo-Greenwood type formula combined with a generalized Feynman diagram- matic technique to report a first principles calculation of the thermal transport properties of disordered Fe_{1-x}Cr_{x} alloys. The diagrammatic approach simplifies the inclusion of disorder-induced scattering effects on the two particle correlation functions and hence renormalizes the heat current operator to calculate configuration averaged lattice thermal conductivity and diffusivity. The thermal conductivity K(T) in the present case shows an approximate quadratic T-dependence in the low temperature regime (T < 20 K), which subsequently rises smoothly to a T-independent saturated value at high T . A numerical estimate of mobility edge from the thermal diffusivity data yields the fraction of localized states. It is concluded that the complex disorder scattering processes, in force-constant dominated disorder alloys such as Fe-Cr, tend to localize the vibrational modes quite significantly.Comment: 5 pages, 5 figure

INTERNET OF THING BASED CAR PARKING SYSTEM

In the current era, we are facing a new problem of parking of vehicles. It is a major problem in urban cities. The problem is more tough because of continues growing number of vehicle and also size of vehicles. Car parking is not just a major problem in India but also in all over the world. We know that one million vehicles burn oil every day. In this paper, we propose an automatic and real-time system for automated car parking. This system would be implemented by the use of internet of things (IOTs). IOT refers as any physical thing that is connected to internet or exchanging information or data between internet and physical device. Arduino Uno is a microcontroller used in IOT. It is used for building digital devices, and interactive objects that can sense and control physical devices. Our smart parking will be implementing using Arduino Uno board for car parking and Ethernet shield to connect parking area with web or internet. By using our automated parking system, a user can save much time for searching free parking space. An infrared sensor has to be employed in each slot to check that a particular plot is vacant or not. Searching smart parking system helps people to search parking space accessible with the ease of IOT automation by supplying parking slot free information. The user can book in advance the parking slot and update the information to the server. Every user has a unique id and password. In case a car in stolen and enter the parking IOT the server checks the database and inform the police.Â

Structural, Electronic and Elastic Properties of TMAl (TM=Co, Ni and Ru) Intermetallics: An ab-initio Study

The structural, electronic, elastic, mechanical and thermal properties of transition metal aluminides (CoAl, NiAl and RuAl) have been investigated systematically using first principle density functional theory (DFT). Ground state properties such as lattice constant (a0), bulk modulus (B) and its pressure derivative (B?) are calculated which show well agreement with the experimental and other theoretical results. The electronic properties have been analyzed quantitatively. The values of elastic constants are also reported. The ductility of these compounds has been analyzed using the Pugh’s rule, Cauchy’s pressure (C12-C44) and electronic structure.  Our calculated results indicate that NiAl is ductile while CoAl and RuAl are brittle. The elastic properties such as Young's modulus (E), Poisson's ratio (?) and anisotropic ratio (A) are also reported. We have also correlated the ductility and bonding behaviour of these compounds. Keywords: Density functional theory; intermetallic compounds; electronic properties; ductility; thermal properties

Structural, Electronic, Thermal and Elastic Properties of Ductile PdSc and PtSc Intermetallic Compounds

The ab-initio calculations were performed to investigate structural, electronic, thermal and elastic properties of the binary ductile intermetallic compounds PdSc and PtSc with B2 (CsCl-type) structure using full potential linear augmented plane wave method (FP-LAPW) on the basis of density functional theory (DFT).The generalized gradient approximation (PBE-GGA and WC-GGA) is applied for PdSc and PtSc. The calculated equilibrium properties such as lattice constant (a0), bulk modulus (B) and its first derivative (B') are in better agreement with experimental and theoretical results. The elastic constants (C11, C12 and C44) of these compounds are reported first time. The value of B/GH ratio for both the compounds are larger than 1.75, indicating the ductile manner of these materials. From density of states and Band structure, it is observed that these intermetallic compounds are metallic in nature. We report first time mechanical and thermal properties which are predicted from the calculated values of elastic constants. Keywords: Intermetallic compounds, Ab-initio calculations, Thermal properties, Mechanical properties, Density of states, Ductilit

Ab-initio Study of Structural, Electronic and Elastic Properties of ErCu

First principles density functional calculations were performed to study the structural, electronic, elastic and mechanical properties of erbium copper intermetallic compound (ErCu). The calculations are carried out within the generalized gradient approximation (GGA) for the exchange and correlation potential. The total energy as a function of volume is obtained by performing spin-polarized calculation. Magnetically the ErCu compound is stable in ferromagnetic (FM) state and its crystal structure is CsCl-type. Ground state properties such as lattice constant (a0), bulk modulus (B), its pressure derivative (B?) and magnetic moment (?B) are calculated. The density of states at the Fermi level, N(EF) and specific heat coefficient are also estimated in majority and minority spin channels. The electronic properties such as band structure and density of states (DOS) reveal that no band gap lead to metallic character of ErCu. The elastic constants (C11, C12 and C44) and mechanical properties such as Poisson’s ratio (? ), Young’s modulus (E), shear modulus (GH), anisotropic factor (A) are also calculated .  Ductility for these compounds is further analyzed by calculating  the ratio of (B/GH )  and Cauchy pressure (C12 - C44). Keywords: Density functional theory, Band structure, Density of states, Lattice constant, Bulk Modulus, Specific heat

First Principles Study of Electronic, Elastic and Thermal Properties of B2-type RECd (RE =La, Ce and Pr) Compounds

The electronic, elastic and thermal properties of RECd (RE =La, Ce and Pr) intermetallic compounds crystallizing in B2-type structure have been studied using first principles density functional theory within generalized gradient approximation (GGA), and the local spin density approximation (LSDA) for the exchange correlation potential. From energy band structure and density of states we found that these intermetallics are metallic in nature. The thermal and mechanical properties are predicted from the calculated values of elastic constants. The ductility of these compounds is determined by calculating the bulk to shear ratio B/GH. Our calculated results indicate that PrCd is most ductile amongst all the RECd compounds. To the best of our knowledge this is the first theoretical prediction of the elastic properties of these compounds. Keywords: Intermetallics, Density Functional Theory, Elastic Constant, Ductility

First Principles Study on Structural, Electronic, Elastic and Thermal Properties of Equiatomic MTi (M = Fe, Co, Ni)

We have investigated the structural, electronic, elastic and thermal properties of MTi (M = Fe, Co and Ni) using ab-initio full potential linearized augmented plane wave (FP-LAPW) method within generalized gradient approximation (GGA) and local spin density approximation (LSDA). We have calculated the ground state and electronic properties such as lattice constant (a0), bulk modulus (B), pressure derivative of bulk modulus (B') and density of states at Fermi level N(EF) which are in good agreement with experimental and available other theoretical results. The elastic constants (C11, C12 and C44) and mechanical properties such as Poisson’s ratio (? ), Young’s modulus (E), shear modulus (GH), anisotropic factor (A) are also calculated which are agree well with the experimental and other theoretical results. Ductility for these compounds have been analyzed by Pugh’s rule (B/GH ratio) and Cauchy pressure (C12 - C44). Our calculated results reveals that NiTi is most ductile amongst the MTi (M = Fe, Co and Ni) compounds.Keywords: Ab-initio, electronic properties, elastic properties, thermal properties

Chemical Stabilisation of Sand Part IX: Orthophthalate type Unsaturated Polyester Resin for Inducing Fast setting Behaviour and High Strength

Polymer concrete composites have been made from orthophthalate-type unsaturated polyester resin, methyl ethyl ketone peroxide as initiator, cobalt naphthenate as accelerator and desert sand as filler. Composites preferred using resin (10-25 per cent), initiator (4 per cent) and accelerator (2 per cent) with representative desert sand samples of different particle sizes (0.2-0.02 mm, 2-0.2 mm and 4-2 mm) as filler recorded unconfined compression strength ranging from 4 to 442 kg/cm/sup 2/ after curing at 50 degree centigrade in an oven for 0.5-24 h. Using coarse and fine sand samples with 10 and 15 per cent resin systems the maximum strength of 391 and 326 kg/cm/sup 2/ respectively was attained after 2 h of curing at 50 degree centigrade. The fast setting resin system with strength in this range is quite adequate for the construction of chemically stabilised surfaces, which withstand trafficability of vehicles, operation of helicopters and aircraft's requiring a maximum strength up to 275 kg/cm/sup 2/. These composites may prove useful for rapid repair of roads, helipads and runways damaged during operational activities. A mathematical model has been developed for predicting resin percentage needed for obtaining composite material of requisite strength. The observed and model predicted values have been found to show close agreement

Functionality of primary hepatic non-parenchymal cells in a 3D spheroid model and contribution to acetaminophen hepatotoxicity.

In addition to hepatocytes, the liver comprises a host of specialised non-parenchymal cells which are important to consider in the development of in vitro models which are both physiologically and toxicologically relevant. We have characterized a 3D co-culture system comprising primary human hepatocytes (PHH) and non-parenchymal cells (NPC) and applied it to the investigation of acetaminophen-induced toxicity. Firstly, we titrated ratios of PHH:NPC and confirmed the presence of functional NPCs via both immunohistochemistry and activation with both LPS and TGF-β. Based on these data we selected a ratio of 2:1 PHH:NPC for further studies. We observed that spheroids supplemented with NPCs were protected against acetaminophen (APAP) toxicity as determined by ATP (up to threefold difference in EC50 at day 14 compared to hepatocytes alone) and glutathione depletion, as well as miR-122 release. APAP metabolism was also altered in the presence of NPCs, with significantly lower levels of APAP-GSH detected. Expression of several CYP450 enzymes involved in the bioactivation of APAP was also lower in NPC-containing spheroids. Spheroids containing NPCs also expressed higher levels of miRNAs which have been implicated in APAP-induced hepatotoxicity, including miR-382 and miR-155 which have potential roles in liver regeneration and inflammation, respectively. These data indicate that the interaction between hepatocytes and NPCs can have significant metabolic and toxicological consequences important for the correct elucidation of hepatic safety mechanisms