In this article, we present two new families of anisotropic solutions for static spherically symmetric stellar systems by taking into account the implications of complexity factor proposed by Herrera ...(Phys. Rev. D 97:044010, 2018) in the framework of gravitational decoupling. We start by taking minimal geometric deformation approach as a useful solution generating tool for the new physically viable models of anisotropic matter distributions, and utilize the Durgapal IV and Durgapal V perfect fluid stellar models as seed solutions in the mechanism under consideration. We consider a complexity factor which corresponds to a polynomial of order
N
, and use it as an axillary condition in order to determine the deformation function. We explore the scenarios, in which polynomial type complexity factors leads to stable stellar configurations. In all cases, both solutions produce similar results with an inappreciable changes in their magnitudes.
In this work, we have adopted gravitational decoupling by minimal geometric deformation (MGD) approach and have developed an anisotropic version of well-known Tolman VII isotropic solution in the ...framework of
f
(
R
,
T
) gravity, where
R
is Ricci scalar and
T
is trace of energy momentum tensor. The set of field equations has been developed with respect to total energy momentum tensor, which combines effective energy momentum tensor in
f
(
R
,
T
) gravity and additional source
ϕ
ij
. Following MGD approach, the set of field equations has been separated into two sections. One section represents
f
(
R
,
T
) field equations, while the other is related to the source
ϕ
ij
. The matching conditions for inner and outer geometry have also been discussed, and an anisotropic solution has been developed using mimic constraint for radial pressure. In order to check viability of the solution, we have considered observation data of three different compact star models, named PSR J1614-2230, PSR 1937+21 and SAX J1808.4-3658, and have discussed thermodynamical properties analytically and graphically. The energy conditions are found to be satisfied for the three compact stars. The stability analysis has been presented through causality condition and Herrera’s cracking concept, which ensures physical acceptability of the solution.
We discuss the dynamical analysis in
f
(
R
,
T
) gravity (where
R
is the Ricci scalar and
T
is the trace of the energy momentum tensor) for gravitating sources carrying axial symmetry. The ...self-gravitating system is taken to be anisotropic and the line element describes an axially symmetric geometry avoiding rotation about the symmetry axis and meridional motions (zero vorticity case). The modified field equations for axial symmetry in
f
(
R
,
T
) theory are formulated, together with the dynamical equations. Linearly perturbed dynamical equations lead to the evolution equation carrying the adiabatic index
Γ
, which defines the impact of a non-minimal matter to geometry coupling on the range of instability for Newtonian and post-Newtonian approximations.
A dynamical analysis of a spherically symmetric collapsing star surrounded by a locally anisotropic environment under an expansion-free condition is presented in
f
(
R
,
T
)
gravity, where
R
...corresponds to the Ricci scalar and
T
stands for the trace of the energy momentum tensor. The modified field equations and evolution equations are reconstructed in the framework of
f
(
R
,
T
)
gravity. In order to acquire the collapse equation we implement the perturbation on all matter variables and dark source components comprising the viable
f
(
R
,
T
)
model. The instability range is described in the Newtonian and post-Newtonian approximation. It is observed that the unequal stresses and density profile define the instability range rather than the adiabatic index. However, the physical quantities are constrained to maintain positivity of the energy density and a stable stellar configuration.
In this work, we explore wormhole solutions in
f
(
R
,
T
) theory of gravity, where
R
is the scalar curvature and
T
is the trace of stress-energy tensor of matter. To investigate this, we consider a ...static spherically symmetric geometry with matter contents as anisotropic, isotropic, and barotropic fluids in three separate cases. By taking into account the Starobinsky
f
(
R
) model, we analyze the behavior of energy conditions for these different kinds of fluids. It is shown that the wormhole solutions can be constructed without exotic matter in few regions of space-time. We also give the graphical illustration of the results obtained and discuss the equilibrium picture for the anisotropic case only. It is concluded that the wormhole solutions with anisotropic matter are realistic and stable in this theory of gravity.
This article investigates Casimir wormhole solutions in Einstein Gauss–Bonnet (EGB) gravity. We are familiar that Null energy conditions (NEC) need not be satisfied for a stable wormhole due to the ...existence of exotic matter. As the Casimir effect acts as a negative energy source, it can be treated as a classical applicant for the exotic matter to discuss the stable dynamics of the wormhole. This work explores the Casimir effects with the Generalized Uncertainty Principle (GUP) on wormhole geometry in EGB gravity by confining our results for
D
=
5
. We have examined two GUP procedures, e.g., Kempf, Mangano, Mann (KMM) and Dentournay, Gabriel, and Spindel (DGS). We have developed shape functions for Casimir wormholes, and GUP corrected Casimir wormholes and studied their existence. In addition, we investigate the behavior of the Gauss–Bonnet (GB) Coupled parameter and minimal uncertainty (MU) parameter on the Equation of state (EOS) parameter. The active gravitational mass and embedding diagrams for all developed shape functions are analysed. Moreover, the violation of the NEC by an exotic matter, the equilibrium forces, and the complexity factor of Casimir wormholes and GUP-corrected Casimir wormholes have also been explored.
The International Agency for Research on Cancer (IARC) has recently reported a 66% increase in the global number of cancer deaths since 1960. In the US alone, about one in eight women is expected to ...develop invasive breast cancer(s) (breast cancer) at some point in their lifetime. Traditionally, a BC diagnosis includes mammography, ultrasound, and some high-end molecular bioimaging. Unfortunately, these techniques detect BC at a later stage. So early and advanced molecular diagnostic tools are still in demand. In the past decade, various histological and immuno-molecular studies have demonstrated that BC is highly heterogeneous in nature. Its growth pattern, cytological features, and expression of key biomarkers in BC cells including hormonal receptor markers can be utilized to develop advanced diagnostic and therapeutic tools. A cancer cell's progression to malignancy exhibits various vital biomarkers, many of which are still underrepresented in BC diagnosis and treatment. Advances in genetics have also enabled the development of multigene assays to detect genetic heterogeneity in BC. However, thus far, the FDA has approved only four such biomarkers-cancer antigens (CA); CA 15-3, CA 27-29, Human epidermal growth factor receptor 2 (HER2), and circulating tumor cells (CTC) in assessing BC in body fluids. An adequately structured portable-biosensor with its non-invasive and inexpensive point-of-care analysis can quickly detect such biomarkers without significantly compromising its specificity and selectivity. Such advanced techniques are likely to discriminate between BC and a healthy patient by accurately measuring the cell shape, structure, depth, intracellular and extracellular environment, and lipid membrane compositions. Presently, BC treatments include surgery and systemic chemo- and targeted radiation therapy. A biopsied sample is then subjected to various multigene assays to predict the heterogeneity and recurrence score, thus guiding a specific treatment by providing complete information on the BC subtype involved. Thus far, we have seven prognostic multigene signature tests for BC providing a risk profile that can avoid unnecessary treatments in low-risk patients. Many comparative studies on multigene analysis projected the importance of integrating clinicopathological information with genomic-imprint analysis. Current cohort studies such as MINDACT, TAILORx, Trans-aTTOM, and many more, are likely to provide positive impact on long-term patient outcome. This review offers consolidated information on currently available BC diagnosis and treatment options. It further describes advanced biomarkers for the development of state-of-the-art early screening and diagnostic technologies.
Reverse osmosis is becoming popular for the purification of water resources e.g. sea and brackish water. However, one of the major limitations in efficient operation are the fouling of membranes and ...relevant technique used to inhibit scaling due to the presence of sparingly soluble salts. The occurrence of this type of fouling results in a significant increase in both operation and maintenance. This review begins by providing a general overview of membrane fouling by minerals usually found in sea and inland water resources. The paper then discusses some important aspects of the phenomena itself: different mechanisms; concentration polarization; the major types of mineral scales including their prevalence and characteristics; and consequences of fouling on membrane performance. This is followed by a discussion of the major strategies currently considered for the control and prevention of scale formation. The penultimate section discusses the drawbacks and deficiencies of current systems in operation and highlights potential future directions that need to be pursued in order to achieve overall process improvements in terms of sustainability. In particular, the need for evaluation under more realistic conditions, studying the interactions between membrane and spacer surface and foulants, and the development of environmentally benign antiscalants are stressed.
•Membrane fouling in RO plants is examined both from scientific and technological standpoint.•Membrane fouling by minerals found in sea and inland water resources is examined•Major strategies currently considered for the control and prevention of scale formation are discussed•The drawbacks and deficiencies of current systems in operation and monitoring are highlighted.•Development of environmentally benign antiscalants is discussed and key directions highlighted.
This article presents a study on the process of isotropization and properties of stellar models with different complexity factors, which was introduced by Herrera (Phys Rev D 97:044010, 2018). We ...consider gravitational decoupling via MGD (Minimal Geometric Deformation) approach for spherically symmetric systems with static background and explore the scenarios where the isotropization of an anisotropic solution of Einstein field equations is possible. Moreover, we work on generating the new analogues of Durgapal–Fuloria model under different conditions associated with complexity factor. The physical existence and stability of the new stellar models have been discussed in details with the help of different potent tools.
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