Face Mask: A Novel Material for Protection against Bacteria/Virus

Facemask is defined as a loose-fitting device which creates a physical barrier between the mouth and nose of the individual wearing mask and likely pollutants in the immediate environment. Evolution of severe viral respiratory infectious agents such as pandemic COVID-19, severe acute respiratory syndrome, pandemic influenza and avian influenza has driven the use of protective face masks by public and health workers. In this chapter, characteristics features and uses of different types of masks are discussed. Characteristics of various nonwoven technologies for manufacturing face masks are also discussed. Test methods and recent developments in face masks are briefly covered.

On the connection between microscopic description and memory effects in open quantum system dynamics

The exchange of information between an open quantum system and its environment allows us to discriminate among different kinds of dynamics, in particular detecting memory effects to characterize non-Markovianity. Here, we investigate the role played by the system-environment correlations and the environmental evolution in the flow of information. First, we derive general conditions ensuring that two generalized dephasing microscopic models of the global system-environment evolution result exactly in the same open-system dynamics, for any initial state of the system. Then, we use the trace distance to quantify the distinct contributions to the information inside and outside the open system in the two models. Our analysis clarifies how the interplay between system-environment correlations and environmental-state distinguishability can lead to the same information flow from and toward the open system, despite significant qualitative and quantitative differences at the level of the global evolution.

Appraisal for the environment, weathering and provenance of Upper Cretaceous-Lower Tertiary shales, Western Desert, Egypt

The combination of the mineralogical and geochemical composition of shales is considered a key to decipher their environment evolution, weathering, climatic conditions, and provenance. The Upper Cretaceous-Lower Tertiary succession is extensively dispersed in Egypt. The present work is devoted to studying the Dakhla shales of (Maastrichtian- Danian), Duwi (Campanian) and Quseir (pre-Campanian) formations. Chemical and mineralogical analyses were conducted by using seven representative surface sections from Dakhla Oasis. Dakhla shales are dominates by Smectite and kaolinite. The average percentages of SiO2, Al2O3, CaO, MgO, Na2O and K2O are subordinate values. In contrast, Al2O3 contents of Dakhla shale, TiO2, P2O5 and Fe2O3, contents are relatively higher than common shale composition. The CIA and CIW high values due to clay minerals and the absence of feldspars. This is also confirmed by the smectite domination and subordinate kaolinite in these formations. The ICV values for Dakhla and Duwi shales are 0.59 and 0.74 (ICV < 1). The shale is mature and deposited in a quiescent environment. Whereas the ICV for Quseir shale is 1.24, it can be incidental that it is immature. The shale is wholly detrital and a product of moderate to intensive weathering. The provenance was constituted of granitic and basaltic source rocks, and the parent provenance is basalt. Consequently, the shale is deposited under fluvio-marine environments, and the prevailed condition was of alkaline chemical affinity probably passed through different environments varying from a fluvial, eolian and shallow marine.