Some electromagnetic materials present, in a given frequency range, an effective dielectric permittivity and/or magnetic permeability which are negative. We are interested in the reunion of such a “negative” material and a classical one. More precisely, we consider here a scalar model problem for the simulation of a wave transmission between two such materials. This model is governed by a Helmh...

It is well known that processes of first order phase transitions may have occurred in the inflationary era. If one or more occurred well before the end of inflation, the nucleated bubbles are stretched to large scales and the primordial power spectrum contains a scale dependent non-Gaussian component provided by the remnants of the bubbles. We predict the anisotropies in the cosmic microwave ba...

BACKGROUND A meta-analysis was conducted to investigate the diagnostic performance of computed tomography (CT) imaging features of ground-glass opacity (GGO) to predict invasiveness. METHODS Two reviewers independently searched PubMed, Medline, Web of Science, Cochrane Embase and CNKI for relevant studies. CT imaging signs of bubble lucency, speculation, lobulated margin, and pleural indentat...

We describe a new mechanism for the generation of the baryon asymmetry of the universe during a first order electroweak phase transition. The mechanism requires the existence of two (or more) baryon number carrying scalar fields with masses and CP violating mixing which vary with the Higgs field expectation value. This mechanism can be implemented using squarks in supersymmetric theories or usi...

Foamed surfactant solutions can clean surfaces! We hypothesise that the cleaning efficiency depends on liquid fraction and stability of foam. also is better smaller average bubble size is. The double syringe technique was used to generate foams with varying fractions but same, very small sizes without perfluorohexane in gas phase. performed tests which were applied glass substrates contaminated...

Measuring the volume of a bubble, especially at its detachment, is a basic subject in gas-liquid two-phase flow research. A new indirect method for this measurement under constant flow conditions is presented. An electronic device is designed and constructed based on laser beam intensity. This device calculates the frequency of the bubble formation by measuring the total time of the formation p...

In this paper, we build an empirical specification that helps to explain bitcoin volatility and characterize phases of the bubble using information derived from investors’ emotions sentiment captures investment intentions aversion risk. To end, investigated bilateral relations between investor 2018 2021, a period characterized by significant changes in prices as well wide disparities emotions, ...

Numerical simulation of bubble growth during pool boiling under the influence of low frequency vibration was performed to understand the influence of common vibrations such as those induced by wind, highway transportation, and nearby mechanical devices on the performance of thermal systems that rely on boiling. The simulations were done for saturated R123 boiling at 277.6 K with a 15 K wall sup...

Air bubbles are used in chemical, biochemical, environmental, and food process for improving the heat and mass transfer. Due to the dominance of non-Newtonian liquids used in various process industries, an understanding of bubble rise in rheologically complex liquids has grown to be important. An experimental study of the bubble rise velocity and drag co-efficient at high Reynolds number in non...