Anodization of some valve metals such as titanium (Ti), leads to the self-organized nanostructured. In
this work we present a systematic study of the formation, characterization, and refractive index of
titanium dioxide (TiO2) nanotubes. The anodizing of Ti foil was performed in ethanol-H2O
electrolyte (50%) mixture containing 0.3 wt% HFat different voltages and durations. It was found that
the current density, measured during preparing the samples, is controlled by the variation of the
anodizing voltage. In addition, increasing the applied voltage used in the anodizing process resulted in
an increase of the calculated refractive index of nanostructured samples. The results also revealed that
the nanotube diameter, wall thickness, center-to-center nano-tube, and porosity, refractive index are
affected by changing the anodizing parameters.

Anodization of some valve metals such as titanium (Ti), leads to the self-organized nanostructured. In
this work we present a systematic study of the formation, characterization, and refractive index of
titanium dioxide (TiO2) nanotubes. The anodizing of Ti foil was performed in ethanol-H2O
electrolyte (50%) mixture containing 0.3 wt% HFat different voltages and durations. It was found that
the current density, measured during preparing the samples, is controlled by the variation of the
anodizing voltage. In addition, increasing the applied voltage used in the anodizing process resulted in
an increase of the calculated refractive index of nanostructured samples. The results also revealed that
the nanotube diameter, wall thickness, center-to-center nano-tube, and porosity, refractive index are
affected by changing the anodizing parameters.

The present study provides an analysis of the floristic composition, habitat types, vegetation structure and species diversity,
elucidating the role of the environmental factors that affect species distribution in Kharga Oasis, Western Desert, Egypt. The
vegetation was sampled from 89 permanently visited stands in 12 sites situated along N - S line transect across the oasis, and
extending for about 185 km to cover as much as possible the physiognomic variation in habitats. Four main habitats were
recognized and forming concentric zones (from inside to outside): farmlands and date-palm orchards represent the inner zone,
the waste-salinized lands (not saltmarshes) in the middle zone, and the surrounding (bounding) desert in the outer zone. A
total of 122 species from 35 families and 102 genera represented the flora of the study area. Poaceae, Asteraceae and Fabaceae
were the major families, which constituted 47% of the total flora. Classification using Bray-Curtis cluster analysis produced 4
vegetation groups (A - D); each can be linked to a certain habitat. The arrangement of habitat zones along the first DCA axis
can be noticed: outer zone (bounding desert), middle zone (waste-salinized lands) and inner zone (arable lands). On the other
hand, farmlands and date-palm orchard groups were separated from each other along the second DCA axis. The relationship
between the vegetation and soil variables was studied using Canonical Correspondence Analysis (CCA); it was indicated the
most important environmental gradients those control the vegetation composition and the distribution pattern of species in
Kharga Oasis, which were mainly related to gradients in soil moisture content and fine fractions. The present situation of
Kharga Oasis urges the conservation of some old historic wells and the naturally growing open dom-palm forests before
vanishing due to high human activities in the area.

The present study provides an analysis of the floristic composition, habitat types, vegetation structure and species diversity,
elucidating the role of the environmental factors that affect species distribution in Kharga Oasis, Western Desert, Egypt. The
vegetation was sampled from 89 permanently visited stands in 12 sites situated along N - S line transect across the oasis, and
extending for about 185 km to cover as much as possible the physiognomic variation in habitats. Four main habitats were
recognized and forming concentric zones (from inside to outside): farmlands and date-palm orchards represent the inner zone,
the waste-salinized lands (not saltmarshes) in the middle zone, and the surrounding (bounding) desert in the outer zone. A
total of 122 species from 35 families and 102 genera represented the flora of the study area. Poaceae, Asteraceae and Fabaceae
were the major families, which constituted 47% of the total flora. Classification using Bray-Curtis cluster analysis produced 4
vegetation groups (A - D); each can be linked to a certain habitat. The arrangement of habitat zones along the first DCA axis
can be noticed: outer zone (bounding desert), middle zone (waste-salinized lands) and inner zone (arable lands). On the other
hand, farmlands and date-palm orchard groups were separated from each other along the second DCA axis. The relationship
between the vegetation and soil variables was studied using Canonical Correspondence Analysis (CCA); it was indicated the
most important environmental gradients those control the vegetation composition and the distribution pattern of species in
Kharga Oasis, which were mainly related to gradients in soil moisture content and fine fractions. The present situation of
Kharga Oasis urges the conservation of some old historic wells and the naturally growing open dom-palm forests before
vanishing due to high human activities in the area.

The present study provided an investigation of the floristic analysis, vegetation composition and species
distribution along 100 m intervals of the elevation gradient (<1500 m a.s.l.- >2000 m a.s.l.) on Jabal
Musa (south Sinai, Egypt), and assessed the role of elevation and other soil parameters controlling plant
diversity. It is a study on altitudinal variation in vegetation in a very dry climate. The vegetation
structure, growth forms, and species diversity were analyzed within the 7 elevation belts on Jabal Musa
area, 44 sample plots, 81 species (including one bryophyte), and 17 examined environmental factors
including altitude. Asteraceae, Lamiaceae, Zygophyllaceae and Brassicaceae contributed about 41% of
the species, represented in all belts. Based on the Bray-Curtis dissimilarity coefficients, it exhibited
floristically homogeneous higher belts than the lower belts. Along moisture gradient, the Non Metric
Multidimensional Scaling (NMDS) ordination was able to distinguish the different vegetation belts along
the altitudinal gradient. The vegetation groups of the lower elevations occupied the negative side of Axis
1 while those of elaqsaa higher elevations occupied the positive end. CCA was applied to assess the
relationships between soil parameters, species composition and vegetation groups. Altitude, coarse and
fine sand fractions, magnesium and bicarbonates had significant correlations with diversity indices more
than the others.

The present study provided an investigation of the floristic analysis, vegetation composition and species
distribution along 100 m intervals of the elevation gradient (<1500 m a.s.l.- >2000 m a.s.l.) on Jabal
Musa (south Sinai, Egypt), and assessed the role of elevation and other soil parameters controlling plant
diversity. It is a study on altitudinal variation in vegetation in a very dry climate. The vegetation
structure, growth forms, and species diversity were analyzed within the 7 elevation belts on Jabal Musa
area, 44 sample plots, 81 species (including one bryophyte), and 17 examined environmental factors
including altitude. Asteraceae, Lamiaceae, Zygophyllaceae and Brassicaceae contributed about 41% of
the species, represented in all belts. Based on the Bray-Curtis dissimilarity coefficients, it exhibited
floristically homogeneous higher belts than the lower belts. Along moisture gradient, the Non Metric
Multidimensional Scaling (NMDS) ordination was able to distinguish the different vegetation belts along
the altitudinal gradient. The vegetation groups of the lower elevations occupied the negative side of Axis
1 while those of elaqsaa higher elevations occupied the positive end. CCA was applied to assess the
relationships between soil parameters, species composition and vegetation groups. Altitude, coarse and
fine sand fractions, magnesium and bicarbonates had significant correlations with diversity indices more
than the others.

The present study provided an investigation of the floristic analysis, vegetation composition and species
distribution along 100 m intervals of the elevation gradient (<1500 m a.s.l.- >2000 m a.s.l.) on Jabal
Musa (south Sinai, Egypt), and assessed the role of elevation and other soil parameters controlling plant
diversity. It is a study on altitudinal variation in vegetation in a very dry climate. The vegetation
structure, growth forms, and species diversity were analyzed within the 7 elevation belts on Jabal Musa
area, 44 sample plots, 81 species (including one bryophyte), and 17 examined environmental factors
including altitude. Asteraceae, Lamiaceae, Zygophyllaceae and Brassicaceae contributed about 41% of
the species, represented in all belts. Based on the Bray-Curtis dissimilarity coefficients, it exhibited
floristically homogeneous higher belts than the lower belts. Along moisture gradient, the Non Metric
Multidimensional Scaling (NMDS) ordination was able to distinguish the different vegetation belts along
the altitudinal gradient. The vegetation groups of the lower elevations occupied the negative side of Axis
1 while those of elaqsaa higher elevations occupied the positive end. CCA was applied to assess the
relationships between soil parameters, species composition and vegetation groups. Altitude, coarse and
fine sand fractions, magnesium and bicarbonates had significant correlations with diversity indices more
than the others.

The present study provided an investigation of the floristic analysis, vegetation composition and species
distribution along 100 m intervals of the elevation gradient (<1500 m a.s.l.- >2000 m a.s.l.) on Jabal
Musa (south Sinai, Egypt), and assessed the role of elevation and other soil parameters controlling plant
diversity. It is a study on altitudinal variation in vegetation in a very dry climate. The vegetation
structure, growth forms, and species diversity were analyzed within the 7 elevation belts on Jabal Musa
area, 44 sample plots, 81 species (including one bryophyte), and 17 examined environmental factors
including altitude. Asteraceae, Lamiaceae, Zygophyllaceae and Brassicaceae contributed about 41% of
the species, represented in all belts. Based on the Bray-Curtis dissimilarity coefficients, it exhibited
floristically homogeneous higher belts than the lower belts. Along moisture gradient, the Non Metric
Multidimensional Scaling (NMDS) ordination was able to distinguish the different vegetation belts along
the altitudinal gradient. The vegetation groups of the lower elevations occupied the negative side of Axis
1 while those of elaqsaa higher elevations occupied the positive end. CCA was applied to assess the
relationships between soil parameters, species composition and vegetation groups. Altitude, coarse and
fine sand fractions, magnesium and bicarbonates had significant correlations with diversity indices more
than the others.

Abstract
Samples of Citrullus colocynthis shoots were collected from nine stands during two seasons (winter and summer
2015) in two tributaries of Wadi Qena (W. El-Atrash and W. El-Ghuza) in the Eastern Desert of Egypt. Soil of
these stands was characterized by slight alkalinity and low soil moisture and organic matter percentages. Soil
macronutrients were arranged as Ca>K> Na>Cl>SO4>Mg>PO4. However, in C. colocynthis tissues, these nutrients
accumulated in the following order: SO4 >K > Ca > Mg > Na> Cl > PO4. The plant chlorophyll contents (Chl. a
and b), their ratio and their stability index (CSI) increased drastically during summer. Shoot accumulated SO4,
PO4 and all cations during summer more than winter, except Cl that was higher during winter. Soluble sugars
(SS) and soluble proteins (SP) increased during summer while total free amino acids were higher during winter.
Data revealed that there were close relationships between the high SO4, K and Ca contents and the hot-dry
conditions and the accumulation of SS and SP on the relatively hot-dry season However, this may be primarily
related to metabolism of drought resistance in such desert plants. Correlations between plant and soil variables
showed important positive relations between soil Ca, Mg and plant Mg and between soil SO4 with Ca and Mg of
plant. Spatial distribution of C. colocynthis was the most important factor that controls WC, Na, K, Ca, Mg, Cl,
PO4, CSI a, CSI b , Chl. a and b, Chl. a/b ratio, TAA, , SS and SP. While, the interaction between both factors,
spatial and temporal, could be the promoter.

Abstract
Samples of Citrullus colocynthis shoots were collected from nine stands during two seasons (winter and summer
2015) in two tributaries of Wadi Qena (W. El-Atrash and W. El-Ghuza) in the Eastern Desert of Egypt. Soil of
these stands was characterized by slight alkalinity and low soil moisture and organic matter percentages. Soil
macronutrients were arranged as Ca>K> Na>Cl>SO4>Mg>PO4. However, in C. colocynthis tissues, these nutrients
accumulated in the following order: SO4 >K > Ca > Mg > Na> Cl > PO4. The plant chlorophyll contents (Chl. a
and b), their ratio and their stability index (CSI) increased drastically during summer. Shoot accumulated SO4,
PO4 and all cations during summer more than winter, except Cl that was higher during winter. Soluble sugars
(SS) and soluble proteins (SP) increased during summer while total free amino acids were higher during winter.
Data revealed that there were close relationships between the high SO4, K and Ca contents and the hot-dry
conditions and the accumulation of SS and SP on the relatively hot-dry season However, this may be primarily
related to metabolism of drought resistance in such desert plants. Correlations between plant and soil variables
showed important positive relations between soil Ca, Mg and plant Mg and between soil SO4 with Ca and Mg of
plant. Spatial distribution of C. colocynthis was the most important factor that controls WC, Na, K, Ca, Mg, Cl,
PO4, CSI a, CSI b , Chl. a and b, Chl. a/b ratio, TAA, , SS and SP. While, the interaction between both factors,
spatial and temporal, could be the promoter.