Los contaminantes atmosféricos son con frecuencia responsables
de la aceleración de la degradación de la piedra
en los edificios y monumentos históricos de las zonas
urbanas. Son muchos los factores que influyen de manera
decisiva en el comportamiento de las piedras naturales
ante los contaminantes gaseosos. Dos de esos factores
son la composición de la atmósfera y el tipo de piedra.
Las areniscas en particular son propensas al ataque de
los contaminantes atmosféricos debido a su naturaleza
porosa, pero muchas de las reacciones de las areniscas
no carbonatadas con estos gases no se conocen bien. El
estudio presentado tiene por objeto comprender los procesos
y factores que controlan el distinto comportamiento
de las areniscas respecto al dióxido de azufre. Para el
estudio se investigaron siete areniscas distintas procedentes
del sur y del este de Alemania. Las areniscas mostraban
una diferencia significativa en la composición de
su aglomerado. Por lo que respecta a la absorción de
SO2, las distintas variedades de arenisca mostraron un
comportamiento completamente diferente. Curiosamente,
la cantidad de SO2 depositada no estaba relacionada con
la superficie específica de las areniscas, este parámetro
está relacionado con el contenido en óxidos de hierro.
Air pollutants often accelerate stone deterioration in historical
buildings and monuments in urban areas. Many factors
condition natural stone behaviour with respect to
gaseous pollutants. Two of the more prominent of such
factors are the composition of the atmosphere and the
type of stone. Due to their porosity, sandstones are particularly
vulnerable to air pollutant attack. Many of the reactions
between noncarbonaceous sandstones and these
gases are not well understood, however. The present
study aimed to acquire an understanding of the processes
and factors governing sandstone behaviour when exposed
to sulphur dioxide. Seven different sandstones from southern
and eastern Germany were analyzed for the study.
The binder composition of the stones varied significantly.
They also exhibited completely different behaviour in connection
with SO2 deposition. Interestingly, while the
amount of SO2 deposited was unrelated to the specific surface
area of the sandstones, this parameter was closely
correlated to the iron oxide content.
Laser and plasma processing of materials is a rapidly growing field in fundamental science and materials technology requiring both a multidisciplinary approach and a wide-ranging knowledge. The topical issue Laser and plasma processing for advanced materials of the Journal of Optoelectronics and Advanced Materials covers a number of recent research highlights. The production of thin functionalized films, nanoparticles and nanocomposites using pulsed laser ablation (PLA) and deposition (PLD) or plasma treatment is discussed in a number of papers. Additionally, experiments using matrix assisted pulsed laser evaporation (MAPLE) are described. It is shown in this book that nanoparticles are generated and/or processed by laser or plasma interaction in very different environments ranging from gaseous and liquid to solid phase. Material properties change if the particle size is reduced below a critical limit allowing e.g. optical, electronic, biomedical, and environmental applications. Micro- and nanostructuring of surfaces (2D) and within the bulk of transparent materials (3D) is presented in various articles. In many cases, ultrashort laser pulses were applied. Furthermore, nanoparticles interacting with laser radiation can be used for nanostructuring purposes. Apart from experimental investigations, numerical modeling of the interaction of femtosecond laser pulses with materials has also been performed to understand structure formation theoretically. Especially for bio-functionalization, selective deposition of sensitive materials (e.g. proteins, cells) on surfaces is needed. A sophisticated process used for this purpose is known as laser induced forward transfer (LIFT). Recent findings regarding the LIFT method are depicted in this issue. Laser annealing of implanted dopants and thin films aiming to enhance structural and electrical properties, sensor dicing by laser radiation, and laser or plasma surface modification for the improvement of solar cells or polymer wettability change are but a few of the subjects focusing on applied research. Additionally, hybrid processes combining plasma spraying and laser-induced melting to control microstructure of coatings are introduced. Last but not least, achievements regarding analytical techniques are outlined. Laser induced breakdown spectroscopy (LIBS) make up a large part of this class. Additionally, the contributions to optical emission spectroscopy and mass spectrometry of plasma processes are significant.