Titanium metal (Ti) with antibacterial function was successfully developed in the present study by electrodeposition of biomimetic Ca-P coat in simple supersaturated calcium and phosphate solution (SCPS).The electrochemical behavior and corrosion resistance of Ca-P deposited on anodized titanium (AT) has been investigated in SCPS by using electrochemical impedance spectroscopy (EIS). The plate-counting method was used to evaluate the antibacterial performance against Staphylococcus aureus (ATCC6538). In vitro antibacterial activity study indicated a significantly reduced number of bacteria S- aureus on Ca-P/AT plate surface when compared with that on Ti or AT surfaces and the corresponding antibacterial mechanism is discussed. The morphology and chemical structure of different titanium samples were systematically investigated by scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX). The study confirmed that the antibacterialproperties of the samples were related to chemical composition of sample surface.

The study aims to present new information and illustrations about sulfidic sedimentary rocks in
order to provide a better understanding of how the sulfide minerals might have been formed. It also
presents detailed information on the major and trace element contents of various sulfide phases
hosted within the sediments.
The K/T sediments at Gabal Gifata (Weina and Birbaya sections), hold different morphologic
patterns of sulfides including tubular burrow fills, flat sulfidic thin bands and films, fossil
replacement and fills, as well as disseminated grains and framboids. The sulfide minerals are
composed of pyrite, sphalerite and galena with minor greenockite set in a groundmass composed of
gypsum and clays with celestite.
These sulfide minerals are believed to have originated in reduced bottom-water conditions via
sulfate reducing bacteria after rapid burial of organic matter. The sulfide minerals seam to develop
through successive stages by segregation, filling and replacement processes in early and
intermediate diagenesis. The framboidal pyrite and its associations of fine pyrite crystals were
formed in early diagenesis by rapid growth. The sulfide minerals are arranged within the burrow
fills in concentric shells. The outer shells are composed of pyrite while the cores are composed
mostly of large sphalerite and in some cases with galena. The grain size and crystallinity of the
mineral crystals increase inwards through the shells suggesting progressive formation of the
sulfides from the margins to the centers. The minerals were crystallized in a sequence: pyrite,
sphalerite-galena in early (pyrite) and intermediate (sphalerite-galena) diagenetic stages. The
sulfidic thin bands are composed mostly of pyrite with subordinate sphalerite. The preservation of
biogenic cells by pyrite within these bands and the survival of pyrite within sphalerite suggest
earlier formation of pyrite by replacement of organic matter (in early diagenesis) followed by
sphalerite through cavity filling (in intermediate diagenesis).
The microprobe analyses of sulfides showed that the pyrite, which occurs close to the sphalerite,
displays much higher concentrations of the trace elements Zn and Ni than the pyrite in the outer
shells. Distinct chemical differences exist among the different colors of sphalerite.
Several observations suggest that benthic conditions during the deposition of black shales were
sufficiently O2-depleted as to exclude benthic organisms (anoxic/euxinic), and that a possibly sharp
rise in dissolved O2 levels coincided with the onset of the overlying sediments deposition, crossing a
critical threshold to dysoxic levels that allowed benthic rise.

This study deals wi th the mineralogy and geochemistry of the mineralogical phases found in the
Beida Shale Member belonging to the Dakhla Formation and exposed at G. Duwi section, Red Sea, Egypt.
The sediments of the upper Dakhla Formation (85 m thick) are composed mainly of grey, dark greyto
black shales as well as grey marly shales and pink marl. These sediments are intercalated by many
thin layers (30-50 cm thick) of brown and reddish brown marl. The marl and marly shale are slightly to
moderately dolomitic.
The stereoscopic microscopy and the SEM survey of the insoluble residues of these sediments have
revealed the presence of Mn-oxides (mainly manganite), dolomite, goethite pseudomorphs (after pyrite
and pyrite framboids), goethite, few Fe-Ti oxides and organic carbon particles. The mineralogical and
geochemical investigations indicate that the manganese oxides, dolomite, goethite and goethite
pseudomorphs are of diagenetic origin. However, the Fe-Ti oxides are of detrital origin. These
mineralogical contents suggest that the Beida Shale Member is a normal marine sediment deposited in
oxygen- containing bottom waters, except for the middle part which is composed of dark grey shale and
contains pyrite and pyrite framboids. This part reflects an euxinic marine environment and deposition in
anoxic, H2S- containing bottom water.
X-ray diffraction analysis of the clay fraction revealed that the sediments under investigation are
composed of detrital kaolinite, smectite and illite. The fluctuation in frequencies of these minerals
within the sediments indicates a warm / humid climate with high rain falls at the K/T boundary and
during the Danian periods as indicated by the abundance of kaolinite. This is followed by a temperate or
cool and dry climatic conditions during the Selandian-lowermost Thanetian and a sea level rise in the
early Thanetian as indicated by the low kaolinite content and the relative abundance of smectite.

The upper Maastrichtian organic-rich sediments studied at Gabal Oweina, Egypt, are moderately enriched in syngenetic
and diagenetic pyrite. Pyrite occurs mostly as layers or bands, group of lamina, lenses, diagenetic intercalated pockets, burrow
fills and disseminated individual pyrite framboids and crystals within the host sediments. The pyritic thin bands and lamina
consist mostly of unconsolidated to compact-oriented pyrite (oriented along the bedding planes) in gypsiferous–clayey matrix
and less common as poorly oriented pyrite crystallites. In several cases, pyrite crystals of the latter type depict zoning, fracturing
and micro-concretions. Pyritic burrow fills are composed mainly of pyrite, phosphatic ooids, microfossils, glauconitic
grains, poorly graphitized carbon and native sulfur. Pyrite replaces minerals other than gypsum, sulfur or carbon. It also
replaces microfossils thus turning some of the phosphatic ooids and microfossils to pyritized pseudomorphs. None of the
studied phosphate ooids or framboids contains any mackinawite, pyrrhotite or greigite. Based on the microscopic and
SEM observations of the micro-textures of disseminated pyrite found at Gabal Oweina section, four morphological forms
of primary pyrite could be identified: (1) Grouped multiple-framboids; (2) Individual framboids; (3) Pyrite idiomorphic crystal
overgrowths on framboids and (4) Single and aggregates of euhedral pyrite crystals. The multiple-framboid formation may
have emerged from three successive processes: nucleation and growth of individual aggregates of the microcrystals to form
combined micro-framboids (the growth of framboids); and followed by grouping of the several pyrite framboids. Direct pyrite
nucleation (shell formation), crystallization, and aggregation processes might complete a single framboid. The disseminated
single and aggregated euhedral pyrite crystals bear evidence indicating that their formation was via nucleation and growth of
pyrite crystallites and their aggregation (to individual framboids), infilling (in the interstices by additional pyritic material),
compaction and homogenization (of all these materials). Furthermore, we encounter for the first time in nature idiomorphic
pyrite crystals that integrated numerous framboids, using them as their nucleation and growth sites without erasing or modifying
their pristine morphology. Elemental sulfur contains minor concentration of Sb, Ni, Cd and Cu strongly suggesting
their presence as submicron sulfide crystallite inclusions. SEM and microprobe investigations revealed that goethite is present
as a weathering product in all morphological types of pyrite however; only an iron-sulfate (presumably melanterite) was
encountered as oxidation product of the multi-framboids and the euhedral aggregate crystals. The upper Maastrichtian sediments
not only contain a menagerie of pyrite morphologies but probably a complete record of the formation process and the
geochemical conditions of the growth of framboids, single pyrite crystals, pyrite burrows, pyritized Mn–Fe-oxide framboids
and finally their weathered products. The various pyrite forms strongly suggest a multistage process that led to their formation
without any evidence for mackinawite, pyrrhotite or greigite, precursors. There is also no evidence in the Oweina sediments
for post pyrite formation of mackinawite, pyrrhotite or greigite. The presence of elemental sulfur containing minor

A thermophilic Bacillus strain ASU7 was isolated from soil sample collected from Assiut governorate in Upper Egypt on latex rubber-containing medium at 45 °C. Genetically, the 16S bacterial ribosomal RNA gene of the strain ASU7 was amplified by the polymerase chain reaction (PCR) and sequenced. The sequence of the PCR product was compared with known 16S rRNA gene sequences in the GenBank database. Based on phylogenetic analyses, strain ASU7 was identified as Bacillus amyloliquefaciens. The strain was able to utilize Ficus elastica rubber latex as a sole source for carbon and energy. The ability for degradation was determined by measuring the increase in protein content of bacterium (mg/g dry wt), reduction in molecular weight (g/mol), and inherent viscosity (dl/g) of the latex. Moreover, the degradation was also confirmed by observing the growth of bacterium and formation of aldehyde or keto group using scanning electron microscopy (SEM) and shiff's reagent, respectively.

A thermophilic Bacillus strain ASU7 was isolated from soil sample collected from Assiut governorate in Upper Egypt on latex rubber-containing medium at 45 °C. Genetically, the 16S bacterial ribosomal RNA gene of the strain ASU7 was amplified by the polymerase chain reaction (PCR) and sequenced. The sequence of the PCR product was compared with known 16S rRNA gene sequences in the GenBank database. Based on phylogenetic analyses, strain ASU7 was identified as Bacillus amyloliquefaciens. The strain was able to utilize Ficus elastica rubber latex as a sole source for carbon and energy. The ability for degradation was determined by measuring the increase in protein content of bacterium (mg/g dry wt), reduction in molecular weight (g/mol), and inherent viscosity (dl/g) of the latex. Moreover, the degradation was also confirmed by observing the growth of bacterium and formation of aldehyde or keto group using scanning electron microscopy (SEM) and shiff's reagent, respectively.