Bianchijev kozmološki model tipa-III sa strunama, volumnom viskoznošću i promjenljivim članom Λ

We study Einstein’s field equations in Bianchi type-III string cosmological models with bulk viscosity and variable cosmological term Λ. Exact solutions of the field equations are obtained by assuming the conditions: the bulk viscosity is proportional to the expansion scalar, ξ ∝ θ, expansion scalar is proportional to shear scalar, θ ∝ σ, and Λ is proportional to the Hubble parameter. The corresponding physical interpretations of the cosmological solutions are also discussed.Proučavamo Einsteinove jednadžbe polja u Bianchijevim kozmološkim modelima tipa III sa strunama, volumnom viskoznošću i promjenljivim kozmološkim članom Λ. Postigli smo egzaktna rješenja jednadžbi polja pretpostavivši uvjete: volumna viskoznost je razmjerna skalaru širenja, ξ ∝ θ, skalar širenja je razmjeran skalaru posmika, θ ∝ σ, i Λ je razmjerno Hubbleovom parametru. Raspravljaju se fizikalna tumačenja kozmoloških rješenja

Kantowski-Sachsovi kozmološki modeli s vremenski-promjenljivim G i Λ

Kantowski-Sachs cosmological models with perfect fluid and time varying G and Λ are presented. Exact solutions of the field equations are obtained by using the scalar of expansion proportional to the shear scalar θ ∝ σ, which leads to a relation between the metric potentials A = Bn, where n is a constant. The corresponding physical interpretation of the cosmological solutions are also discussed.Predstavljamo Kantowski-Sachsove kozmološke modele s vremenski-promjenljivim G i Λ koji sadrže perfektnu tekućinu. Izvodimo egzaktna rješenja jednadžbi polja primjenom skalara razvoja koji je razmjeran posmičnom skalaru, θ ∝ σ, što vodi na relaciju među metričkim potencijalima A = Bn, gdje je n stalan. Raspravljamo i fizičko tumačenje kozmoloških rješenja

Mercury or Mercury Free Restorations in Oral Cavity

Amalgam is basically a concoction of metals that has been used as a potent filling material in dentistry for the last 150 years. Amalgam usually consists of silver, mercury, tin and copper. Dental amalgam is a material used to fill cavities of tooth. Over the years, amalgam has become a topic of concern because it contains mercury. Mercury is a naturally occurring metal in the environment. Mercury exists as a liquid in room temperature but when heated, it becomes a gas. Flexibility of amalgam as a filling material is due Mercury. An alloy powder, a compound that is soft in nature when mixed with mercury makes it enough to mix and condense into the tooth. It hardens quickly and offers strong resistance to the forces of biting and chewing. There are studies reported on the safety of amalgam fillings. In 2005, European Union launched a comprehensive mercury strategy to reduce use of mercury. In 2008, countries like Norway and Denmark restricted the use of dental amalgam containing mercury. In 2009, this research was evaluated by U.S. Food and Drug Administration (FDA) and found no rationale to limit the use of amalgam. There are certain restorative materials that are available commercially that are mercury free in nature like Gold, Porcelain, Gallium alloys, Composite resin restoratives etc. They offer many advantages over amalgams containing mercury like: seals the dentin from future decay, reinforces remaining tooth structure, provides smooth and bonded margins, conservative and it blends naturally

Failure Investigation of a Boiler Pipe

The damaged boiler pipe from the cochran horizontal pipe type boiler was investigated to study the cause of its failure. The damaged pipe having a through hole of about 4mm size was studied from both water and fire side with the help of visual inspection, physical measurements, optical micrograph, x-ray diffraction (XRD) and Electron probe microanalysis (EPMA).It was concluded that water side corrosion was more predominant than the fire side corrosion in reducing the thickness of the plate and eventually causing a through hole. The higher rate of corrosion from water side may he attributed mainly due to the presence of large amount of inclusions which led to preferential dissolution of matrix around them. The water side corrosion product was non adherent, fragile and powdery whereas fire side corrosion product was adherent

The Phylogeography of Rabies in Grenada, West Indies, and Implications for Control

In Grenada, West Indies, rabies is endemic, and is thought to be maintained in a wildlife host, the small Indian mongoose (Herpestes auropunctatus) with occasional spillover into other hosts. Therefore, the present study was undertaken to improve understanding of rabies epidemiology in Grenada and to inform rabies control policy. Mongooses were trapped island-wide between April 2011 and March 2013 and examined for the presence of Rabies virus (RABV) antigen using the direct fluorescent antibody test (dFAT) and PCR, and for serum neutralizing antibodies (SNA) using the fluorescent antibody virus neutralization test (FAVN). An additional cohort of brain samples from clinical rabies suspects submitted between April 2011 and March 2014 were also investigated for the presence of virus. Two of the 171 (1.7%) live-trapped mongooses were RABV positive by FAT and PCR, and 20 (11.7%) had SNAs. Rabies was diagnosed in 31 of the submitted animals with suspicious clinical signs: 16 mongooses, 12 dogs, 2 cats and 1 goat. Our investigation has revealed that rabies infection spread from the northeast to the southwest of Grenada within the study period. Phylogenetic analysis revealed that the viruses from Grenada formed a monophyletic clade within the cosmopolitan lineage with a common ancestor predicted to have occurred recently (6–23 years ago), and are distinct from those found in Cuba and Puerto Rico, where mongoose rabies is also endemic. These data suggest that it is likely that this specific strain of RABV was imported from European regions rather than the Americas. These data contribute essential information for any potential rabies control program in Grenada and demonstrate the importance of a sound evidence base for planning interventions