Basrah Journal of Science

The effect of the slip boundary condition on the Newtonian die-swell free surface issue is the main objective of this study. The major aspect of this article is the determination of the free surface position using the free surface location methodology under the slip boundary condition. A Taylor Galerkin/pressure-correction (TG/PC) finite element method is used to solve this issue numerically. Furthermore, the system of equations that governs such a problem includes a time-dependent momentum equation and a continuity equation for mass conservation. These equations are shown here in an axisymmetric frame with Newtonian flow. The free-surface location is calculated using the Phan-Thien (dh/dt) approach in conjunction with slip boundary impact. This work focuses on the effect of slip boundary condition on swelling ratio for Newtonian representation. The current findings reveal that the slip boundary condition has a considerable impact on the swelling ratio of the fluid, causing a decrease in the fluid swell. Furthermore, the behaviors of solution components are presented.

This study deals with the class of locally conformal ????12−manifolds in
such a way that the characterization identity for the aforementioned
class is produced. Furthermore, the first clan of Cartan's structure
equations is determined when the components of Kirichenko's tensors
on associated G-structures for locally conformal ????12−manifolds are
determined. The second clan of Cartan's structural equations for locally
conformal ????12−manifolds was also completed.

This work investigates the problem of a periodic hyperbolic equation
formulated in a bounded domain with a convection term and weakly
sourced nonlinear functions. The purpose of this work is to analyze the
existence of solutions to the control initial problem using ideas of
hyperbolic and periodicity of first derivatives and control starting
conditions, as well as some properties of some inequalities offered to
investigate this topic.

A hybrid procedure combining the homotopy perturbation method and
the Fourier transform has been proposed, and it was used to find an
approximate analytical solution to the problem of two-dimensional
transient natural convection in a horizontal cylindrical concentric
annulus bounded by two isothermal surfaces. The effect of varying
values of the Grashof number, Prandtl number, and radius ratio on fluid
flow (air) and heat transfer is explored. Furthermore, the velocity
distributions and the average Nusselt number are investigated, with
Nusselt numbers utilized to express local and global heat transfer rates.
Finally, the convergence of the new algorithm was theoretically
checked by proving several theorems, which were then applied to the
findings of the new solutions provided by the suggested approach.

This study introduced and investigated a modification of the Szasz
sequence in double sums with one variable. This sequence's recurrence
relation for the m-th order moment, convergence theorem, and
Voronovskaya-type asymptotic theorem in ordinary approximation are
investigated. A numerical example is also provided to demonstrate the
approximation of the chosen test function by this modification
sequence, and the numerical results are compared to the numerical
results of the classical Szasz sequence. It turns out that the results
achieved from the modification sequence are superior to those
obtained from the classical sequence.

This study aims to investigate some physical parameters in presence
of an oblique shock wave numerically. Computational fluid
dynamics has been used to analyze fluid behavior upstream and
downstream of the shock wave. To obtain a good resolution, the
computational domain is constructed by fine meshing. Due to its
wide use in engineering applications, Air has been used as fluid
material. A wedge of half-angle  = 22 has been used to intercept
the airflow path and founding the oblique shock wave of angle. For
gathering comprehensive information, the air flows have been tested
for three Mach numbers, namely slightly higher than 1, slightly
higher than two, and slightly higher than three (M1~=1, M2~=2, and
M3~=3) and represented as a case (a), (b) and (c) respectively. The
continuity equation, momentum equation, and energy equation have
been solved numerically. Velocity, turbulent viscosity, total
pressure, and total enthalpy have been investigated upstream and
downstream of the shockwave for the three different Mach numbers.
The results showed that the total pressure downstream of the shock
wave was less than that of the upstream shock wave. In addition, the
turbulent viscosity area around the object becomes thicker as the
Mach numbers become bigger. Also, the total pressure was slightly
different for the three different Mach numbers. These behaviors of
the above-mentioned parameters are attributed to the shock wave
effects. In addition, the oblique shock wave angle  is appeared to
be decreased as the Mach number increased.

The influence of an external static electric field on the chemisorption of
a single Cu atom on perfect graphene (Cu/graphene) is explored and
investigated using magnetic moment and electronic structure
calculations based on the Anderson model, which is characterized by
various model parameters. The Cu atom on top of a carbon atom site
configuration is taken into account in our research. The effects of an
electric field on Cu chemisorption on graphene were examined. The
changes in charge accumulation on the adatom Cu confirm the potential
of altering the magnetic characteristics of Cu/graphene via the
perpendicular electric field direction. The magnetic moment on
Cu/graphene was measured as a function of the electric field. Metallic
state is observed for multiple electric field values on a single Cu
adatom/graphene with variable electronic structure. It has been
discovered that the bonding between Cu atoms and graphene can be
tuned using an electric field. The dependence of adatom/graphene
electronic and magnetic properties on the density of states indicates the
importance of the microscopic details for graphene functionalization
towards spintronics applications. Our findings could be quite interesting
since they imply that the magnetic moment and spin dependent
electronic structure on the Cu atom site can be modified by the electric
field action .

This work presents the synthesis of silica sol, gel, and aerogel. To
achieve a hydrophobic silica gel infused with copper chloride, a surface
modification was performed on the sample. Furthermore, The present
study focused on the examination of the evolutionary patterns of
composition profiles in sol, gel, and aerogel materials. This
investigation aimed to analyze the spectral properties of fluorescence,
absorption, Raman spectroscopy, and FTIR spectrum. Additionally,
the surface morphology, topography, and square of the surface
roughness were evaluated using advanced imaging techniques such as
scanning electron microscopy with a field-emission source (FE-SEM)
and Atomic Force Microscope (AFM) images. The results indicate that
there are notable distinctions in peak regions and distribution between
the fluorescence and absorption spectra. This distinction is particularly
evident in the Raman spectrum of sol, gel, and aerogel samples, where
variations in peak regions and distribution are observed. Furthermore,
the dominance of homogeneity and nano-structure, as well as the
presence of surface roughness and increased surface area, are clearly
discernible in the AFM topography.

In fundamental neuroscience and cell biology, gadgets for studying
living cells have been of great interest. Recent research has expanded
cell-based sensors to pharmacological screening, environmental
monitoring, and toxicological detection. Among the many
measurement methods, optical sensors make bioactivity and cell
population analysis easy. This research is part of a larger effort to
develop microorganism-based heavy metal (toxin) sensing methods. A
correlation was established to examine how heavy metals affect E. Coli
and Deinococcus radiodurans bacteria's optical density. CdCl2 and
NiCl2 were used for this study. In this study, Escherichia coli (E. coli)
and Deinococcus radiodurans (D. radiodurans) were exposed to heavy
metal solutions. Dissolving the compounds in de-ionized water
generated 0.1, 1, 10, 100, and 1 M CdCl2 and NiCl2. This study used
fluorescence microscopy, spectrophotometers, and fluorescence
spectroscopy .

In the present study, two fungal species, Didymella glomerata and
Penicillium polonicum, were isolated from seeds of four wheat
cultivars, named Mahmoodia (MHD), Adena (ADN), Eba 99 (EBA),
and Wefia (WAF), and determined by using phenotypic characteristics
and molecular sequencing. Molecular diagnosis for both fungi was
applied based on internal transcribed spacer primers (ITS1 and ITS4).
This is the first record of D. glomerata and P. polonicum as wheat
seed-borne fungi in Iraq.

The deacetylated form of chitin found in the cell walls of Aspergillus
niger is called chitosan. The United States Food and Drug
Administration classifies chitosan, which has many uses, as GRAS.
Using three Aspergillus niger isolates, chitosan was produced, and the
isolates' capacity to manufacture mycotoxin was determined using
polymerase chain reaction (PCR).
By using infrared FTIR,
manufactured chitosan could be distinguished from commercial
chitosan acquired from Sigma. The antibacterial activity of chitosan
was investigated using the disk diffusion method and the Minimum
Inhibitory Concentration (MIC) assay was conducted against the
following bacteria: Salmonella entrica sub entritica ATCC 14028,
Clostridium perfrigens ATCC 13124, Escherichia coli, and
Streptococcus pneumonia ATCC 49616.It was discovered that
Salmonella entrica sub entritica ATCC 14028 was more sensitive than
chitosan. Samples of salmon fish were dipped in a 2% chitosan
solution, and the samples' shelf life and microbiological quality were
assessed. The findings indicated that while pH and moisture loss were
tolerable during refrigerated storage, the number of psychrophilic cells
was decreased, resulting in a near 12-day storage life.

Ion exchange resins, which are essential for water purification, have
seen a major increase in use over the past 20 years due to industrial
expansion. They are used to remove heavy metals, which are one of
the most widespread pollutants, considering that these notoriously
toxic metals can end up in ecosystems via several pathways. The
chemical structure of chitosan extracted from the shrimp shell was
confirmed by Fourier transform infrared (FTIR) and Proton nuclear
magnetic resonance (1H-NMR) characterization. It was used as an ion
exchange material for the removal of heavy metal ions Fe(III), Cd(II),
and Pb(II) from their aqueous solutions in polluted water treatment,
and the samples were tested by flame atomic absorption. The analytical
study started by exploring the influence of pH (2, 4, 6, and 8) on the
removal process by chitosan resin in a batch system. The obtained
results revealed that as the pH of the analyzed ion solution increased,
the removal efficiency for ions also increased. The highest removal
efficiencies were obtained at pH 8 for the investigated Pb(II) and
Fe(III) ions, ranging from 94.62 to 96.0, respectively, and 99.98% for
Cd(II) ions at pH 6.