A permanent electric dipole moment (EDM) of a particle or system is a separation of charge along its angular momentum axis and is a direct signal of T violation and, assuming CPT symmetry, CP ...violation. For over 60 years EDMs have been studied, first as a signal of a parity-symmetry violation and then as a signal of CP violation that would clarify its role in nature and in theory. Contemporary motivations include the role that CP violation plays in explaining the cosmological matter-antimatter asymmetry and the search for new physics. Experiments on a variety of systems have become ever-more sensitive, but provide only upper limits on EDMs, and theory at several scales is crucial to interpret these limits. Nuclear theory provides connections from standard-model and beyond-standard-model physics to the observable EDMs, and atomic and molecular theory reveal how CP violation is manifest in these systems. EDM results in hadronic systems require that the standard-model QCD parameter of θ¯ must be exceptionally small, which could be explained by the existence of axions, also a candidate dark-matter particle. Theoretical results on electroweak baryogenesis show that new physics is needed to explain the dominance of matter in the Universe. Experimental and theoretical efforts continue to expand with new ideas and new questions, and this review provides a broad overview of theoretical motivations and interpretations as well as details about experimental techniques, experiments, and prospects. The intent is to provide specifics and context as this exciting field moves forward.
The rapid industrial growth has led to the large production of oily wastewater. Treatment of oily wastewater is an inevitable challenge to manage the greater demand of clean water for the rapidly ...growing population and economy. In the present work, we have developed a smart surface mesh with reversible wetting properties via a simple, ecofriendly, and scalable approach for on-demand oil–water separation. ZnO nanowires (NWs) obtained from the chemical vapor deposition method were coated on a stainless steel (SS) mesh. The as-synthesized ZnO-NWs-coated mesh shows superhydrophilic/underwater superoleophobic behavior. This mesh works in “water-removing” mode, where the superhydrophilic as well as underwater superoleophobic nature allows the water to permeate easily through the mesh while preventing oil. The wetting property of ZnO-NWs-coated mesh can be switched easily from superhydrophilic to superhydrophobic state and vice versa by simply annealing it at 300 °C alternatively under hydrogen and oxygen environment. The separation is solely driven by gravity. Thus, the reversible wettability of ZnO NWs provides a smart surface mesh which can be switched between “oil-removing” and “water-removing” modes. It was found that for more than 10 cycles of mesh reutilization in both modes alternatively, the separation efficiency of 99.9% stayed relatively invariant, indicating a prolonged antifouling property and excellent recyclability. This work provides a simple, fast, cost-effective, and on-demand solution for oily wastewater treatment and opens up new perspectives in the field of controllable oil–water separation.
A cosmological model with a specific form of the Hubble parameter is constructed in a flat homogeneous, and isotropic background in the framework of f(R,T) gravity, where R is the scalar curvature ...and T is the trace of the stress-energy-momentum tensor. The proposed functional form of the Hubble parameter is taken in such a way that it fulfills the successful bouncing criteria to find the solution of the gravitational field equations provided the Universe is free from initial singularity. The various constraints on the parameters are involved in the functional form of the Hubble parameter which are analyzed in detail. In addition, we explore physical and geometrical consequences of the model based on the imposed constraints. Furthermore, we demonstrate the bouncing scenario which is realized in our model with some particular values of the model parameters. As a result, we find that all of the necessary conditions are satisfied for a successful bouncing model.
Hypercalcemia occurs in up to 4% of the population in association with malignancy, primary hyperparathyroidism, ingestion of excessive calcium and/or vitamin D, ectopic production of ...1,25-dihydroxyvitamin D 1,25(OH)2D, and impaired degradation of 1,25(OH)2D. The ingestion of excessive amounts of vitamin D3 (or vitamin D2) results in hypercalcemia and hypercalciuria due to the formation of supraphysiological amounts of 25-hydroxyvitamin D 25(OH)D that bind to the vitamin D receptor, albeit with lower affinity than the active form of the vitamin, 1,25(OH)2D, and the formation of 5,6-trans 25(OH)D, which binds to the vitamin D receptor more tightly than 25(OH)D. In patients with granulomatous disease such as sarcoidosis or tuberculosis and tumors such as lymphomas, hypercalcemia occurs as a result of the activity of ectopic 25(OH)D-1-hydroxylase (CYP27B1) expressed in macrophages or tumor cells and the formation of excessive amounts of 1,25(OH)2D. Recent work has identified a novel cause of non-PTH-mediated hypercalcemia that occurs when the degradation of 1,25(OH)2D is impaired as a result of mutations of the 1,25(OH)2D-24-hydroxylase cytochrome P450 (CYP24A1). Patients with biallelic and, in some instances, monoallelic mutations of the CYP24A1 gene have elevated serum calcium concentrations associated with elevated serum 1,25(OH)2D, suppressed PTH concentrations, hypercalciuria, nephrocalcinosis, nephrolithiasis, and on occasion, reduced bone density. Of interest, first-time calcium renal stone formers have elevated 1,25(OH)2D and evidence of impaired 24-hydroxylase-mediated 1,25(OH)2D degradation. We will describe the biochemical processes associated with the synthesis and degradation of various vitamin D metabolites, the clinical features of the vitamin D-mediated hypercalcemia, their biochemical diagnosis, and treatment.
► LAS rebars corrode 2–3 times slower than PCS in concrete pore solution and mortars. ► Raman and XRD studies show that goethite and maghemite phases of rusts formed on LAS. ► On PCS unstable phases ...of lepidocrocite and akaganite are formed. ► EIS confirms more stable rust on LAS than on PCS. ► A model is proposed to explain formation of passive film on surface of steels.
Correlation of corrosion characteristics and nature of rusts on low alloy (LA) and plain carbon (PC) steels exposed in simulated concrete pore solution of different pH is studied. Rusts formed under wet/dry conditions are examined by Raman spectroscopy and X-ray diffraction. LA rust is more adherent compared to PC as confirmed by measurement of weight in gain and electrochemical studies. EIS results show improvement in protective properties of steels with passage of time. Both steels are found prone to pitting attack in chloride contaminated pore solution. Rebars embedded in concrete exhibit same trend as recorded in solution exposure tests.
Structural and optical properties of several high light output halide scintillators and closely related materials are presented based on first-principles calculations. The optical properties are ...based on the Engel-Vosko generalized gradient approximation and the recently developed density functional of Tran and Blaha. The materials investigated are BaBr{sub 2}, BaIBr, BaCl{sub 2}, BaF{sub 2}, BaI{sub 2}, BiI{sub 3}, CaI{sub 2}, Cs{sub 2}LiYCl{sub 6}, CsBa{sub 2}Br{sub 5}, CsBa{sub 2}I{sub 5}, K{sub 2}LaBr{sub 5}, K{sub 2}LaCl{sub 5}, K{sub 2}LaI{sub 5}, LaBr{sub 3}, LaCl{sub 3}, SrBr{sub 2}, and YI{sub 3}. For comparison results are presented for the oxide CdWO{sub 4}. We find that the Tran Blaha functional gives greatly improved band gaps and optical properties in this class of materials. Furthermore, we find that unlike CdWO{sub 4}, most of these halides are highly isotropic from an optical point of view even though in many cases the crystal structures and other properties are not. This general result is rationalized in terms of halide chemistry. Implications for the development of ceramic halide scintillators are discussed.
FLRW cosmology with EDSFD parametrization Singh, J. K.; Nagpal, Ritika
The European physical journal. C, Particles and fields,
04/2020, Letnik:
80, Številka:
4
Journal Article
Recenzirano
Odprti dostop
In this paper, we study a cosmological model in the background of Friedmann–Lemaitre–Robertson–Walker (FLRW) space time by assuming an appropriate parametrization in the form of a differential ...equation in terms of energy density of scalar field
ρ
ϕ
, which is defined as Energy Density Scalar Field Differential equation (EDSFD) parametrization. The EDSFD parametrization leads to a required phase transition from early deceleration to present cosmic acceleration. This parametrization is used to reconstruct the equation of state parameter
ω
ϕ
in terms of redshift
z
i.e.
ω
ϕ
(
z
)
to examine the evolutionary history of the universe in a flat FLRW space time. Here, we constrain the model parameter using the various observational datasets of Hubble parameter
H
(
z
) , latest Union 2.1 compilation dataset
SNeIa
,
BAO
, joint dataset
H
(
z
)
+
S
N
e
I
a
and
H
(
z
)
+
S
N
e
I
a
+
B
A
O
for detail analysis of the behavior of physical parameters and we find its best fit present value. Also, we discuss the dynamics of reheating phase after inflation, analyse the behaviors of the physical features using some diagnostic tools, and examine the viability of our parametric model.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We report a theoretical investigation of the electronic structure and transport properties of eleven Zintl compounds including nine 122 phases (AMg2X2, AZn2Sb2 (A = Ca, Sr, Ba; X = Sb, Bi)) and two ...212 phases (Ba2ZnX2 (X = Sb, Bi)). The electronic structures and electrical transport properties are studied using ab initio calculations and semi-classical Boltzmann theory within the constant relaxation time approximation. All the compounds are semiconducting. We find that the n-type 122 phases with the CaAl2Si2 structure type show better performance than p-type materials due to the multi-valley degeneracy with anisotropic carrier pockets at and near the conduction band minimum. The pocket anisotropy is beneficial in achieving high conductivity and Seebeck coefficient simultaneously. This mechanism yields substantial improvement in the power factor. The general performance of 212 phases is inferior to that of the 122 phases, with the Ba2ZnSb2 compound showing better performance.
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