The theoretical mechanism for realizing a negative refractive index material in an optical frequency range with an atomic gas system of electromagnetically induced transparency (EIT) is studied. It is shown that under certain conditions such a dense gas can exhibit simultaneously negative permittivity and negative permeability, and negligibly small loss.

[1] We explore the permeability evolution of fractures in carbonate rock that results from the effects of mechanical stress and nonequilibrium chemistry (pH of fluid). Core plugs of Capitan limestone are saw cut to form a smooth axial fracture that is subsequently roughened to simulate a natural fracture with controlled surface topography. Aqueous solutions of ammonium chloride (pH 5 7) transit...

We present simulation results of a design for negative index materials that uses magnetic resonators to provide negative permeability and metal films for negative permittivity. We also discuss the possibility of using semicontinuous metal films to achieve better manufacturability and enhanced impedance matching.

The recent interest in negative refractive-index (NRI) metamaterials stems from Veselago’s early work predicting media that simultaneously exhibit negative permittivity and negative permeability. Metamaterial structures, such as split-ring resonator and stripwires and planar-loaded transmission line grids, are artificial dielectrics, made of periodically arranged inclusions. Thus, the design of...

Pulmonary fat embolism occurs frequently after trauma but its functional significance is often unclear. To obtain direct evidence of lung damage caused by fat embolism we have measured changes in permeability of the alveolar-capillary interface. A permeability index was derived from the half time clearance from lung to blood (T1/2LB) of 99mTcDTPA introduced into the lung in a 1 ml bolus. Three ...

BACKGROUND Ethyl pyruvate (EP) was recently identified as an experimental therapeutic agent in a wide variety of model systems for inflammation-mediated tissue and cellular injury. OBJECTIVE To evaluate the effect of ethyl EP on improving the survival in mice with LPS-induced acute lung injury (ALI). METHODS ALI was induced by administering lipopolysaccharide (LPS) intratracheally. The mice...

OBJECTIVES It is largely unknown why extravascular lung water may increase during fluid loading in the critically ill with presumed hypovolemia. In this study we evaluated the hemodynamic predictors of such an increase. DESIGN A prospective observational study. PATIENTS Sixty-three presumed hypovolemic mechanically ventilated patients (22 septic and 41 nonseptic patients). INTERVENTION Fl...

OBJECTIVES The objectives of this study were to assess dermal exposure of cell workers to nickel at a South African base metal refinery and to characterize their skin condition by measuring the skin hydration and trans epidermal water loss (TEWL) indices. METHODS The skin hydration index of the index finger, palm, neck, and forehead was measured before, during and at the end of the shift. The...

The refractive index of natural transparent materials is limited to 2-3 throughout the visible wavelength range. Wider controllability of the refractive index is desired for novel optical applications such as nanoimaging and integrated photonics. We report that metamaterials consisting of period and symmetry-tunable self-assembled nanopatterns can provide a controllable refractive index medium ...

Abstract: This paper presents the results of experimental determination of fiber bed permeability variation with porosity. Flow measurement experiments were designed to measure fiber mat permeability for fiber beds with various fiber volume fractions. Woven fiberglass, chopped fiberglass, and carbon fiber mats were used as reinforcements. The effects of reinforcement type and porosity on fiber ...