The role of Brønsted acid site strength on the catalytic performance of phosphotungstic acid supported on nano γ-alumina catalysts for the dehydration of ethanol to diethyl ether

CaMoO4 catalyst was synthesized by a facile and direct co-precipitation method. The original and calcined catalysts were characterized by a variety of techniques. The acidity of the catalysts was studied and correlated with the catalytic activity. The obtained results clearly revealed that CaMoO4 was an active and selective catalyst towards the formation of anhydrous formaldehyde. The highest conversion of methanol and yield of formaldehyde obtained were 100 and 98%, respectively. In addition, the moderate strength of Brønsted acid sites created on the surface of catalyst plays the main role in the formation of formaldehyde. Finally, the CaMoO4 catalyst exhibited a remarkable stability towards anhydrous formaldehyde production up to 120 h.

CaMoO4 catalyst was synthesized by a facile and direct co-precipitation method. The original and calcined catalysts were characterized by a variety of techniques. The acidity of the catalysts was studied and correlated with the catalytic activity. The obtained results clearly revealed that CaMoO4 was an active and selective catalyst towards the formation of anhydrous formaldehyde. The highest conversion of methanol and yield of formaldehyde obtained were 100 and 98%, respectively. In addition, the moderate strength of Brønsted acid sites created on the surface of catalyst plays the main role in the formation of formaldehyde. Finally, the CaMoO4 catalyst exhibited a remarkable stability towards anhydrous formaldehyde production up to 120 h.

In this paper we introduce and study semi closed and semi open sets in bitopological spaces and then we introduce and study the notions of sets and sets in bitopological spaces. Also, we define a new closure operator and associated topology on the bitopological space .

In this paper we introduce new two types of generalized closed sets in bitopological spaces and study some of it's properties and it's relations with other kinds of generalized closed sets. Using these sets we obtain a characterization of some separation axioms in bitopological spaces.

In this manuscript, the concept of a generalized fuzzy soft point is introduced and some of its basic properties were studied. Also, the concepts of a generalized fuzzy soft base (subbase) and a generalized fuzzy soft subspace were introduced and some important theorems were established. Finally, the relationship between fuzzy soft set, intuitionistic fuzzy soft set, generalized fuzzy soft set and generalized intuitionistic fuzzy soft set were investigated.

In this manuscript, the concept of a generalized fuzzy soft point is introduced and some of its basic properties were studied. Also, the concepts of a generalized fuzzy soft base (subbase) and a generalized fuzzy soft subspace were introduced and some important theorems were established. Finally, the relationship between fuzzy soft set, intuitionistic fuzzy soft set, generalized fuzzy soft set and generalized intuitionistic fuzzy soft set were investigated.

This study attempts to carry out a critical revision for the genus Ephedra in Egypt based on morphological characters for leaf, stem and flower. DNA sequencing data used for the first time for DNA barcoding of the family Ephedraceae in Egypt. One chloroplast marker -intergenic spacer trn-H/psb-A and another nuclear Internal Transcribed Spacer (ITS) were sequenced to authenticate the identification and to reconstruct the phylogenetic relationships of the Egyptian Ephedra species. The results revealed that, the name of Ephedra ciliata Fischer & C. A. Mey. was illegitimate and became a synonym to Ephedra foliata Boiss., which reported here as accepted name. The current work recommends using the DNA barcode as a tool for species identification of Ephedra species as well as other gymnosperms in Egypt.

Trichomes, epidermal cell features, and seed coat sculpturing of 12 Lotus taxa from Egypt were studied using scanning electron microscopy. In addition, statistical analysis for the taxa under investigation was carried out. The results revealed that trichomes have high taxonomic significances between studied taxa. Anticlinal and periclinal cell walls and epidermal cell shape for the stem, leaf, and calyx for each taxon were examined. Seed coat sculpturing exhibited 4 main different surface patterns categories: rugose, reticulate, sulcate, and verrucate. These features can serve as good diagnostic characters at the species level of the genus Lotus.

Trichomes, epidermal cell features, and seed coat sculpturing of 12 Lotus taxa from Egypt were studied using scanning electron microscopy. In addition, statistical analysis for the taxa under investigation was carried out. The results revealed that trichomes have high taxonomic significances between studied taxa. Anticlinal and periclinal cell walls and epidermal cell shape for the stem, leaf, and calyx for each taxon were examined. Seed coat sculpturing exhibited 4 main different surface patterns categories: rugose, reticulate, sulcate, and verrucate. These features can serve as good diagnostic characters at the species level of the genus Lotus.