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Articles 181 - 193 of 193

Full-Text Articles in Physical Sciences and Mathematics

A Handheld Polarimeter For Aerosol Remote Sensing, James W. Frost, Fouad Nasraddine, J. Rodriguez, I. Andino, Brian Cairns Sep 2005

A Handheld Polarimeter For Aerosol Remote Sensing, James W. Frost, Fouad Nasraddine, J. Rodriguez, I. Andino, Brian Cairns

Publications and Research

In this paper we show how measurements made by a simple handheld polarimeter in conjunction with automated sunsky radiometers can be used to effectively constrain the real part of the complex refractive index of aerosols. We find that even measurements over a limited angular range near 90° scattering angle are sufficient for this purpose. We also note that because of the effect of surface reflectance on the observed degree of linear polarization (DOLP) it is sensible to select spectral bands for these measurements for which the surface is relatively dark and homogeneous (i.e. wavelengths shorter than 700 nm are to …


Biospeleologists, Aldemaro Romero Jr. Jan 2004

Biospeleologists, Aldemaro Romero Jr.

Publications and Research

No abstract provided.


The Unsung Heroes Of Speleology, Aldemaro Romero Jr., Kathryn Benz Jan 2000

The Unsung Heroes Of Speleology, Aldemaro Romero Jr., Kathryn Benz

Publications and Research

No abstract provided.


Microanalytical Investigations Of Gold-Bearing Rocks From The An Najadi Region In Saudi Arabia, Nazrul I. Khandaker, M. Ahmed, M. M. Hariri, M. A. Garwan, K. R. Khan, M. M. Al-Ohali Jul 1997

Microanalytical Investigations Of Gold-Bearing Rocks From The An Najadi Region In Saudi Arabia, Nazrul I. Khandaker, M. Ahmed, M. M. Hariri, M. A. Garwan, K. R. Khan, M. M. Al-Ohali

Publications and Research

The Proton Induced X-ray Emission technique with a scanning microbeam (micro-PIXE) and Scanning Electron Microscopy (SEM) were employed to study gold-bearing rocks from the An Najadi and adjacent regions situated within the exposed northeastern part of the Arabian Shield. These microanalytical investigations, together with routine petrological and ore microscopic studies, demonstrated the presence of important partitioning of major minerals and trace elements in several samples. These measurements also revealed microstructural features including brecciation within quartz grains and metal concentrations within these fracture-controlled micro-conduits. Results showed promise in terms of using distinctive geochemical signatures for ore body recognition. Of particular interest …


Study Of Volcanic Sediments By Microbeam-Pixe Technique, Nazrul I. Khandaker, M. Ahmed, M. A. Garwan Apr 1996

Study Of Volcanic Sediments By Microbeam-Pixe Technique, Nazrul I. Khandaker, M. Ahmed, M. A. Garwan

Publications and Research

Single mineral grains in a suite of Cretaceous (85–90 Ma) volcanic sedimentary rocks were analyzed using the microbeam-PIXE technique to understand fundamental geological processes responsible for micro-scale variation in elemental composition across mineral zones, twinning, cleavage planes, fractures and grain boundaries. Distributions of major and trace elements show distinct geochemical features indicative of a specific geological setting and a subsequent diagenetic process in these volcanic sediments. Examples of mineral zoning, microstructures of variable chemistry and post-depositional fluid flow are discussed using the data on feldspar group of minerals.


Natural And Technological Disasters: Causes, Effects And Preventive Measures, Nazrul I. Khandaker Jan 1992

Natural And Technological Disasters: Causes, Effects And Preventive Measures, Nazrul I. Khandaker

Publications and Research

No abstract provided.


El Hombre Comenzó A Extinguir Especies Hace 11.000 Años, Aldemaro Romero Jr. Jan 1989

El Hombre Comenzó A Extinguir Especies Hace 11.000 Años, Aldemaro Romero Jr.

Publications and Research

No abstract provided.


Que La Luz De La Sabiduría Ilumine Nuestras Cuevas, Aldemaro Romero Jr. Jan 1985

Que La Luz De La Sabiduría Ilumine Nuestras Cuevas, Aldemaro Romero Jr.

Publications and Research

No abstract provided.


Tarracolimulus Rieki, Nov. Gen., Nov. Sp., Nuevo Limúlido Del Triásico De Montreal – Alcover (Tarragona), Aldemaro Romero Jr., L. Vía Boada Jan 1977

Tarracolimulus Rieki, Nov. Gen., Nov. Sp., Nuevo Limúlido Del Triásico De Montreal – Alcover (Tarragona), Aldemaro Romero Jr., L. Vía Boada

Publications and Research

No abstract provided.


Predicción De Terremotos: ¿Cuándo?, Aldemaro Romero Jr. Jan 1976

Predicción De Terremotos: ¿Cuándo?, Aldemaro Romero Jr.

Publications and Research

No abstract provided.


Descubiertos Restos Recientes De Un Megaterio, Aldemaro Romero Jr. Jan 1975

Descubiertos Restos Recientes De Un Megaterio, Aldemaro Romero Jr.

Publications and Research

No abstract provided.


La Deriva De Los Continentes, Aldemaro Romero Jr. Jan 1974

La Deriva De Los Continentes, Aldemaro Romero Jr.

Publications and Research

No abstract provided.


Los Cañones Submarinos, Aldemaro Romero Jr. Jan 1973

Los Cañones Submarinos, Aldemaro Romero Jr.

Publications and Research

No abstract provided.