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This article studies the effects of Brownian motion and thermophoresis on unsteady mixed convection flow near the stagnation-point region of a heated vertical plate embedded in a porous medium saturated by a nanofluid. The plate is maintained at a variable wall temperature and nanoparticle volume fraction. The presence of a solid matrix, which exerts first and second resistance parameters, is considered in this study. A suitable coordinate transformation is introduced and the resulting governing equations are transformed and then solved numerically using the local nonsimilarity method and the Runge-Kutta shooting quadrature. The effects of various governing parameters on the flow and heat and mass transfer on the dimensionless velocity, temperature, and nanoparticle volume fraction profiles as well as the skin-friction coefficient, Nusselt number, and the Sherwood number are displayed graphically and discussed to illustrate interesting features of the solutions. The results indicate that as the values of the thermophoresis and Brownian motion parameters increase, the local skin-friction coefficient increases whereas the Nusselt number decreases. Moreover, the Sherwood number increases as the thermophoresis parameter increases, and decreases as the Brownian motion parameter increases. On the other hand, the unsteadiness parameter and the resistance parameters enhance the local skin-friction coefficient, local Nusselt number, and the local Sherwood number.

The unsteady mixed convection flow near the stagnation point region of a heated vertical plate in a porous medium saturated with a nanofluid is studied analytically and numerically using Buongiorno’s model. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. An appropriate similarity transforms are used and the resultant equations are solved using the fourth-fifth order Runge-Kutta method with shooting technique for different values of the parameters governing the problem. The effects of the governing parameters on fluid velocity, temperature, nanoparticle volume fraction, skin friction, Nusselt number and Sherwood number are discussed.

Thirty-eight cutting samples from the Lower Jurassic to the Upper Cretaceous succession of the Abu Tunis-1X well, north Western Desert of Egypt, were processed palynologically to extract their psilate sporomorphs. This designated practice was made to assess the digitally-quantified progressive changes in the triple Red-Green-Blue (RGB) coloration of sporomorph exine with depth. Stabilization and calibration of the illumination system was applied. Certain precautions were also implemented prior to such digital RGB measurements; forexample, some exceptionally lighter (caved) or darker (reworked) specimens were excluded from RGB coloration population samples to avoid misleading results. A minimum of three and up to ten spore grains were studied according to the sample richness and two RGB readings were taken for each selected specimen. The average, standard deviation, and confidence level values for each sample were calculated due to the variable palynological productivity of the samples. In the present study, an attempt was made to monitor and distinguish which of the color components and/or parameters is the most sensitive detector of the progressive maturation changes with depth. By investigating the trends of different parameters of the RGB (i.e. total RGB, R, G, B, R/G) with depth, we were able to distinguish and deduce a linear maturation index from the triple RGB readings. Such a linear maturation index was based on the R component and was successfully correlated and calibrated with other conventional, linear maturity indices (T⁠max⁠°C, vitrinite reflectance-VRo%, and thermal alteration index-TAI). The newly modified, RGB-based maturation index called the Kerogen Maturity Index (KMI) can confidently and effectively detect the subtle and progressive changes in kerogen maturation with depth. Such correlation and calibration practices presented herein enabled us to present a modern, reliable, easy to use, and inexpensive measuring technique to assess the thermal maturity of organic matter. The KMI covers the immature and most of the mature phases (early-upper mature) of kerogen and it has its own vitrinite-calibrated cut-offs, which can be correlated with both the T⁠max and TAI parameters. This undoubtedly allows the KMI to be easily correlated and complement other classical, expensive maturity indices. This opens the door widely for the palynologists and organic petrologists to use the KMI with good confidence and high reliability for its proven good maturity appraisal.

This paper discusses the hydrocarbon potential of the Jurassic succession in a mature basin in Egypt as an
important element of a larger petroleum system study. Prior to any organic petrographic and organic geochemical
analyses, a palynological age dating of the originally undifferentiated Jurassic sequence was carried
out to identify different formations under investigation. This was based on key bioevents of some recovered
dinoflagellate cysts and the identified lithology. Palynological, TOC/Rock Eval pyrolysis (including modified
Rock-Eval methods), and vitrinite reflectance (VRo%) data from a total of 14 samples taken from the uppermost
lower-upper Jurassic sequence represented by the Wadi Natrun (Toarcian-Aalenian), Khatatba (late Bathonian-
Callovian), and Masajid (Oxfordian) formations in the Abu Tunis-1× well, are presented. In addition, two
samples from the Abu Tunis-1× well and the proximal (~32 km to the east) Siqueifa-1× well, having the
highest remaining hydrocarbon potential (S2 yields), were analyzed and their results were compared using
modified pyrolysis programs. Although the data showed a good correlation between the TAI of the palynomorph
assemblage, vitrinite reflectance, and Tmax from Rock-Eval pyrolysis in the shallower intervals, the correlation
between VRo and Tmax was poor in the lower half of the studied succession (middle Khatatba and Wadi Natrun
formations). The very low Tmax values indicate immature OM while VRo and TAI indicated middle stage of oil
window to past peak oil generation. The reason for this discrepancy is that the deeper samples are reservoir
rocks, not source rocks, and the majority of the organic matter is not composed of reactive kerogen but consists
of migrated hydrocarbons and NSO compounds. Contamination due to oil-based mud (OBM) was eliminated
because the Abu Tunis-1× well was drilled in 1969, prior to the extensive use of OBM in drilling. This study
showed that a multi-proxy approach is the best way to screen the hydrocarbon potential in a thick succession
that contains interbedded source and reservoir rocks.

Sixteen samples from the “E” to “B” members of the Abu Roash Formation encountered in the Beni Suef Basin, Eastern Desert of Egypt were palynologically analyzed for palaeoenvironmental and sequence stratigraphic investigations. The integrated palynofacies and lithofacies analysis of the studied section indicates deposition of five alternating regressive and transgressive sequences in well-oxygenated,
proximal shelf settings. The Abu Roash “E” and the upper “D” to the lower “C” members were deposited during pronounced regressive phases in oxic, shallow marginal marine settings. The upper “B” Member was deposited during a recurring regressive phase but of a lower magnitude in oxic, shallow inner neritic conditions. The lower “D” Member was deposited during a minor transgression phase in dysoxic, shallow inner neritic settings. While the upper “C” to the lower “B” section was deposited during
a stronger transgressive episode in a relatively deep, inner neritic environment of prominent dysoxic conditions. This interchange in the depositional setting was documented by the pronounced and concurrent, cyclic nature of the freshwater algae, peridinioid dinoflagellate cysts, pteridophyte spores, and reworked sporomorphs with variable intensities. Their increasing and conversely their diminishing trends clearly reflect alternating regressive-transgressive periods of reduced and relatively normal salinity conditions, respectively. Overall, sedimentation of the studied Abu Roash section indicates a recurring rise in sea level, which accentuated during the earliest Santonian time.
The analogous peaking in the Pediastrum signals with those of the pteridophyte spores and reworked taxa indicate a good connection between these Pediastrum signals and the pronounced fluviatile influxes of terrigenous sediments during regressive phases. Accordingly, this can be used to identify regressive sequence boundaries and hence the clastic reservoirs. Even with the small counts recorded herein, we believe high ratios of peridinioid/gonyalulacoid dinocysts are significantly paralleled by peaking signals of freshwater algae and regressive sedimentation phases. This must be preliminary documented here. Probably future palynological studies will be able to fully interpret and address this important Pediastrum rhythmic event in different sequence stratigraphic settings. The palynological parameters, age controlled sporomorph marker taxa, lithology, and gamma ray data were used to differentiate the Abu Roash members into three distinctive 3rd order depositional sequences
(AR SQ1, AR SQ2, and AR SQ3). These sequences match well with the global stratigraphic sequences Tu 3, Tu 4, and Co 1 and connect the local rise in sea level to the global eustatic sea level rise.

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