azide, any of a class of chemical compounds containing three nitrogen atoms as a group, represented as (-N3). Azides are considered as derived from hydrazoic acid (HN3), an inorganic salt such as sodium azide (NaN3), or an organic derivative in which the hydrogen atom of hydrazoic acid is replaced by a hy…
a cappella (Italian: "in the church style"), performance ofa polyphonic (multipart) musical work by unaccompanied voices. Originally referring to sacred choral music, the term now refers to secular music as well.The a cappella style arose about the time of the composer Josquin des Prez, in the late 15th century, and reached preemine…
Infrared and nonresonant Raman spectroscopies are based on the excitation of specific vibrational modes of the system under study. The frequency, intensity and width of the measured signals are highly sensitive to the local structure, composition and microstructure of the investigated samples, leading to a wide range of applications in mineralogy …
A direct means of indicating the presence of concealed mineralization would be the ultimate in exploration. In many ways the.induced-polarization (IP) technique comes close to achieving this goal. it has been remarkably successful in locating concealed bodies containing even small percentages of metallic-luster minerals.
I…
When I put pen to paper in the summer of 1982, uppermost in my mind was the need to provide new practitioners with an introduction to the theory and practice of thermoluminescence (TL) dating, particularly those without a strong background in physics. Assimilating the corpus of specialist papers which at present define the theory and practi…
There are few places in the developed world particularly where the coal industry does not feel that it faces major challenges. Climate change, safety and a variety of other environmental.issues are just some of the concerns. In many cases these concerns are justified, and certainly in the developing world much more needs to be d…
A century has passed since the first X-ray diffraction experiment (Friedrich et al.1912). During this time, X-ray diffraction has become a commonly .used technique for the identification and characterization of materials and the field has seen continuous development. Advances in the theory ofdiffraction, in the generation o…
Archaeological geophysics is not the kind of research one can do alone. Every project I have worked on, whether field research, data processing, or software development, has involved someone in a crucial capacity towhom.I owe a great deal. My great thanks go to Ieffrey Lucius at the U.S. Geological Survey in Denver, Colorado, who first held my…