Metamaterials, i.e. artificial materials with properties not found in nature (Caloz & Itoh,
2006; Marqués et al., 2008), have gained a lot of attention in the past decade. The
virtually unlimited freedom in tailoring their constitutive parameters created hopes for
the realization of unique devices, such as subwavelength lenses and invisibility cloaks,
which were essentially impossible to achieve with classical materials.
The results of the survey (see Appendix C) were quantiﬁed in order to deter-
mine how many students objected to a given score, and how many felt that a
given score added to their experience of watching each ﬁlm.
The twentieth century elevated our understanding of the Universe from its early stages to what it is today and what is to become of it. Cosmology is the weapon that utilizes all the scientific tools that we have created to feel less lost in the immensity of our Universe. The standard model is the theory that explains the best what we observe. Even with all the successes that this theory had, two main questions are still to be answered: What is the nature of dark matter and dark energy? This book attempts to understand these questions while giving some of...
Lenses are an important part of most optical systems. Good results in optical measurements often rely on the best selection of lenses. In this chapter we develop the relations governing the passage of light rays through imaging elements on the basis of the paraxial approximation using matrix algebra. We also mention the aberrations occurring when rays deviate from this ideal Gaussian behaviour. Finally we go through some of the standard imaging systems.
All of the types of automatic pyrometers, listed in Section 8.1 and shown in Figure 8 .2 are considered in this chapter. To reach a sufficiently high measurement precision, the radiation emitted by the body under measurement is concentrated on the radiation detector by lenses, light-guides or mirrors . Thus, they also reduce the pyrometer viewing angle and consequently the necessary object diameter . It its also essential that the pyrometer optical system should be able to aim properly at the target .
We also frequently found that even the
best corrective lenses did not improve vi-
sual acuity of the impaired eye to that of
the fellow eye. Through the analysis of
these initial cases, an apparently predomi-
nant common characteristic of these pa-
tients was a work station with papers
angled to the right or to the left of themon-
itor and keyboard. Other reports revealed
the screen was in the frontal position, but
was twisted. Still others reported that their
habitual work pattern was with their