Regular (nonsingular) space-times are given that describe the formation of a (locally defined) black hole from an initial vacuum region, its quiescence as a static region, and its subsequent evaporation to a vacuum region. The static region is Bardeen-like, supported by finite density and pressures, vanishing rapidly at large radius and behaving as a cosmological constant at small radius. The d...

We present new static spherically-symmetric exact solutions of Einstein equations with the quintessential matter surrounding a black hole charged or not as well as for the case without the black hole. A condition of additivity and linearity in the energy-momentum tensor is introduced, which allows one to get correct limits to the known solutions for the electromagnetic static field implying the...

We herein report a case of a renal pelvic tumor that developed in the residual left renal pelvis after right nephroureterectomy, left ureterectomy and total cystectomy in a patient with multiple urothelial tumors. The tumor was endoscopically ablated through a nephrostomy tract, and mitomycin C irrigation was carried out. We designed a novel constant-pressure irrigation system for effective and...

In this paper we consider space-times containing matter expanding or contracting according to a time-dependent scale factor. Cosmologies with vanishing, positive or negative cosmological constant are considered. In the case of vanishing or negative cosmological constant open and closed spatial surfaces are solutions while in the case of positive cosmological constant only closed surfaces exist....

The effects of varying concentration Acrylamide copolymer (an effective fluid loss control additive) and temperature on in oil well cementing was studied. neat cement (Dyckerhoff Class G), property slurry with acrylamide copolymer, were investigated at range 48-82oC bottom hole circulating pressure 3500 psi. concentrations the studied 0.25, 0.50 0.75 percentage by weight cement. Thickening time...

In this study, ground state binding energy of heavy hole magneto exciton in GaAs/In0.47Ga 0.53As cylindrical quantum well wires (CQWWs) were calculated using variational technique depending on wire size and external parameters. We can briefly the change with hydrostatic pressure, temperature, radius magnetic field strength as follows. With increasing temperature for constant pressure field, dec...

Static formation temperature (SFT) is required to determine the thermophysical properties and production parameters in geothermal and oil reservoirs. However, it is not easy to determine SFT by both experimental and physical methods. In this paper, a mathematical approach to predicting SFT, based on a new model describing the relationship between bottom hole temperature (BHT) and shut-in time, ...

The Einstein-conformally coupled scalar field system is studied in the presence of a cosmological constant. We consider a massless or massive scalar field with no additional self-interaction, and spherically symmetric black hole geometries. When the cosmological constant is positive, no scalar hair can exist and the only solution is the Schwarzschild-de Sitter black hole. When the cosmological ...