Specular Reflection Detection for Early Prediction of Cervix Cancer

1992 ◽

Vol 50 (2) ◽

pp. 1528-1529

Author(s):

Edward G. Bartick ◽

John A. Reffner

Keyword(s):

Specular Reflection ◽

Forensic Analysis ◽

Attenuated Total Reflection ◽

Internal Reflection ◽

Standard Size ◽

Ir Microscopy ◽

Ir Analysis ◽

Plastic Explosives ◽

Internal Reflection Spectroscopy ◽

Reflectance Measurements

Since the introduction of commercial Fourier transform infrared (FTIR) microscopic systems in 1983, IR microscopy has developed as an important analytical tool in research, industry and forensic analysis. Because of the frequent encounter of small quantities of physical evidence found at crime scenes, spectroscopic IR microscopes have proven particularly valuable for forensic applications. Transmittance and reflectance measurements have proven very useful. Reflection-absorption, specular reflection, and diffuse reflection have all been applied. However, it has been only very recently that an internal reflection (IRS) objective has been commercially introduced.The IRS method, also known as attenuated total reflection (ATR), has proven very useful for IR analysis of standard size samples. The method has been applied to adhesive tapes, plastic explosives, and general applications in the analysis of opaque materials found as evidence. The small quantities or uncontaminated areas of specimens frequently found requiring forensic analysis will often be directly applicable to microscopic IRS analysis.

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Valence electron energy loss spectroscopy in reflection geometry

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100153865 ◽

1989 ◽

Vol 47 ◽

pp. 378-379

Author(s):

J. Liu ◽

J. M. Cowley

Keyword(s):

Energy Loss ◽

Valence Electron ◽

Interband Transition ◽

Specular Reflection ◽

Three Dimensional ◽

Electron Excitation ◽

Transmission Electron ◽

Yield Information ◽

Valence Bands ◽

Excitation Processes

The low energy loss region of a EELS spectrum carries information about the valence electron excitation processes (e.g., collective excitations for free electron like materials and interband transitions for insulators). The relative intensities and the positions of the interband transition energy loss peaks observed in EELS spectra are determined by the joint density of states (DOS) of the initial and final states of the excitation processes. Thus it is expected that EELS in reflection mode could yield information about the perturbation of the DOS of the conduction and valence bands of the bulk crystals caused by the termination of the three dimensional periodicity at the crystal surfaces. The experiments were performed in a Philipps 400T transmission electron microscope operated at 120 kV. The reflection EELS spectra were obtained by a Gatan 607 EELS spectrometer together with a Tracor data acquisition system and the resolution of the spectrometer was about 0.8 eV. All the reflection spectra are obtained from the specular reflection spots satisfying surface resonance conditions.

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