Abstract Every year, smoke is still a significant problem and challenge in Indonesia. Forest land fires cause vast amounts of smoke, negatively affecting society, such as health by decreased air quality index transportation through reduced visibility. Factors that affect the spread from fire source include wind, injection height, atmospheric conditions. This study examines dispersion occurred o...

Currently, the research on inversion of wave height by using shadow statistical method attracts more attention, due to benefit without external calibration equipment. Under assumption sea satisfying ideal first-order dispersion relation, period is used describe relationship between slope and significant height. However, influence surface current ignored during process extracting height, since r...

Today, the cement industry is one of the major air polluting industries in the world. Hence, in this study, owing to the importance and role of contaminants from the plant, an appraisal of the emission contributions in addition to other factors have been discussed. There are several reasons behind the importance of modeling air pollutants. First, the assessment of standards for air pollution, a...

Visualization of disaster dispersion prediction enables decision makers and civilian to prepare disaster and to reduce the damage by showing the realistic simulation results. With advances of GIS technology and the theory of volcanic disaster prediction algorithm, the predicted disaster dispersions are displayed in spatial information. However, most of volcanic ash dispersion predictions are di...

In this study, a numerical solution for degenerate space–time fractional advection–dispersion equations is proposed to simulate atmospheric dispersion in vertically inhomogeneous planetary boundary layers. The derivative exists Caputo sense. We establish the maximum principle and priori estimates solutions. Then, we construct positivity-preserving finite-difference scheme, using monotone discre...

This article is the second in a two-paper series presenting results from wind tunnel and computational fluid dynamics (CFD) simulations of flow and dispersion in an idealized model urban neighborhood. Pollutant dispersion results are presented and discussed for a model neighborhood that was characterized by regular city blocks of three-story row houses with a single 12-story tower located at th...

A recent development of a parabolic equation method for wave propagation in a non-orthogonal coordinate system is reviewed. A transformation of the full governing equation prior to development of any approximation leads to a model whose results stand in closer agreement to laboratory data for a case of waves propagating into a breakwater harbor. The effect of amplitude dispersion on predicted w...

Different materials with different phase changes on reflection affect the surface-height measurement when interferometric techniques are employed for testing objects constructed of different materials that are adjacent to one another. We test the influence of this phase change on reflection when vertical scanning interferometry with a broadband source is used. We show theoretically and experime...

In a sample of 94 planetary nebulae of the Galactic disk we find a systematic decrease of the abundances of He, N, O, S, and Ar with height above the Galactic plane, and also with radial velocity. Over an interval of 3 kpc the abundance of O, S, and Ar decrease by 0.1 ... 0.2 dex. This value is in good agreement with the predictions of an empirical model for the chemical and kinematical evoluti...