Mahmoud Abd El Hafez M. Adam

n/a

Protolytic equilibria often have profound effects on chemical activity, since protolytic species usually behave quite differently. It is therefore important to characterize the protolytic properties of important chemicals. Here we present a new approach to study protolytic equilibria of fluorescent species that is extremely accurate and relies on minimum assumptions. We show that by measuring 2-dimensional excitation/emission scans of samples at different pH. the 3-dimensional experimental data set, I(lambda(ex), lambda(em), C(pH)), can be unambiguously decomposed into the spectral responses of the protolytic species present as well as their concentration. The approach is demonstrated on the protolytic equilibrium of fluorescein. Although the fluorescein monoanion cannot be obtained in pure form, the spectra and concentrations of both fluorescein species, as well as the protolytic constant, are determined with excellent accuracy. The proposed method is general and can be applied not only for studies of protolytic equilibria, but on any chemical equilibria and chemical reactions involving fluorescent species

To understand traditional Islamic architecture or any other form of ideological based architecture, it is necessary to be aware of the way traditional man viewed his being, his relation to the macrocosms, or his sacred vision. This paper is an attempt to comprehend the representation of Islamic sacred beliefs through geometric compositions with special concern to geometric patterns. The paper runs three successive lines of inquiry in addition to an introduction to the concept of sacredness between cosmology and ontology. The first inquiry is an investigation of the distinctive characteristics of sacredness in the Islamic vision. The second is a revision of the concept of sacred geometry and representation in Islamic arts and architecture, while the third is a close examination of the usage of geometric patterns and their metaphysical dimensions as have been understood in the traditional Islamic philosophy. Finally the paper set forth its notes on the sacredness of Islamic geometric patterns between abstraction and substitution.

The subject of beauty is as old as philosophy; it was a matter of both interest and contradiction, however the most remarkable characteristic of the sense of beauty remains undefined. In relation, studies of aesthetic in architecture have many difficulties, due to the shortage of applied aesthetic studies in addition to the lack of clear philosophical bases.
"The sense of beauty" by G. Santayana (1896) is one of the distinguished philosophical studies that tackled the subject of beauty in a clear, simple and comprehensive way; based on the naturalistic psychology. The objective of the paper is to examine the applicability and validity of Santayana's aesthetic theory as a critical and analytical frame work in architecture. The methodology of the study depends on rereading and reviewing the main frame of Santayana's theory from the point of view of selected architectural writings such as Rasmussen (1959), Schulz (1965) and Lang (1987). In addition the study presents some recent local architectural examples that clarify the discussed philosophical and architectural concepts.
The paper runs three lines of inquiry. First is an introduction that outlines Santayana's vision to the nature of beauty and the main frame of his theory, second comes the analysis of the main categories of beauty; (material, form and expression). Finally the paper concludes and assesses some guidelines to approach the sense of architectural beauty within the borders of Santayana's aesthetic theory.