•The physics of droplet in shear is accurately captured.•Mass of the droplet is fully conserved.•The vorticity magnitude inside of the droplet decreases as viscosity ratio increases.•Highly confined ...droplet exposed to shear flow exhibits fluctuations in deformation.•Two critical viscosity ratios exists for each confinement ratio.
This paper is concerned with a numerical study on the behavior of a single Newtonian droplet suspended in another Newtonian fluid, all subjected to a simple shear flow. Conservative finite-volume approximation on a collocated three-dimensional grid along with a conservative Level-set method are used to solve the governing equations. Four parameters of capillary number (Ca), Viscosity ratio (λ), Reynolds number (Re) and walls confinement ratio are used to physically define the problem. The main focus of the current study is to investigate the effect of viscosity on walls critical confinement ratio. In this paper, the phrase critical is used to specify a state of governing parameters in which divides the parameter space into the subcritical and supercritical regions where droplets attain a steady shape or breakup, respectively. To do so, first, we validate the ability of proposed method on capturing the physics of droplet deformation including: steady-state subcritical deformation of non-confined droplet, breakup of supercritical conditioned droplet, steady-state deformation of moderate confined droplet, subcritical oscillation of highly-confined droplet, and the effect of viscosity ratio on deformation of the droplet. The extracted results are compared with available experimental, analytical and numerical data from the literature. Afterward, for a constant capillary number of 0.3 and a low Reynolds number of 1.0, subcritical (steady-state) and supercritical (breakup) deformations of the droplet for a wide range of walls confinement in different viscosity ratios are studied. The results indicate the existence of two steady-state regions in a viscosity ratio-walls confinement ratio graph which are separated by a breakup region.
Background and aims
Following the recognition of ‘internet gaming disorder’ (IGD) as a condition requiring further study by the DSM‐5, ‘gaming disorder’ (GD) was officially included as a diagnostic ...entity by the World Health Organization (WHO) in the 11th revision of the International Classification of Diseases (ICD‐11). However, the proposed diagnostic criteria for gaming disorder remain the subject of debate, and there has been no systematic attempt to integrate the views of different groups of experts. To achieve a more systematic agreement on this new disorder, this study employed the Delphi expert consensus method to obtain expert agreement on the diagnostic validity, clinical utility and prognostic value of the DSM‐5 criteria and ICD‐11 clinical guidelines for GD.
Methods
A total of 29 international experts with clinical and/or research experience in GD completed three iterative rounds of a Delphi survey. Experts rated proposed criteria in progressive rounds until a pre‐determined level of agreement was achieved.
Results
For DSM‐5 IGD criteria, there was an agreement both that a subset had high diagnostic validity, clinical utility and prognostic value and that some (e.g. tolerance, deception) had low diagnostic validity, clinical utility and prognostic value. Crucially, some DSM‐5 criteria (e.g. escapism/mood regulation, tolerance) were regarded as incapable of distinguishing between problematic and non‐problematic gaming. In contrast, ICD‐11 diagnostic guidelines for GD (except for the criterion relating to diminished non‐gaming interests) were judged as presenting high diagnostic validity, clinical utility and prognostic value.
Conclusions
This Delphi survey provides a foundation for identifying the most diagnostically valid and clinically useful criteria for GD. There was expert agreement that some DSM‐5 criteria were not clinically relevant and may pathologize non‐problematic patterns of gaming, whereas ICD‐11 diagnostic guidelines are likely to diagnose GD adequately and avoid pathologizing.
The homoleptic cationic complex formed by reacting suitable manganese(II) salts with 2,2′-bipyridine-1,1′-dioxide (bipyO2) has been subjected to several studies in the past because of its peculiar ...absorption and electrochemical features. Here, the first single-crystal X-ray structure determination of a Mn(bipyO2)32+ salt is reported, where the charge of the cation is balanced by perchlorate anions. The hydrated salt Mn(bipyO2)3(ClO4)2 crystallizes in the monoclinic system (P21/n space group) and the asymmetric unit contains three cationic complexes and six perchlorate anions. The environment of the manganese(II) ions is best described as octahedral, with scarce variations among the three cations in the asymmetric unit. The bipyO2 ligands exhibit κ2 coordination mode, forming seven-membered metallacycles. The X-ray outcomes have been used as the starting point for DFT and TDDFT calculations, aimed to elucidate the charge transfer origin of the noticeable absorption in the visible range. The MLCT nature is confirmed by the hole and electron distributions associated with the spin-allowed transitions. DFT calculations on the related manganese(III) complex indicate that the geometry of Mn(bipyO2)32+ changes only slightly upon oxidation, in agreement with the reversible electrochemical behaviour experimentally observed.
Summary
Background
In Crohn's disease, it is essential to distinguish between persistent damage and abnormalities that can heal with anti‐inflammatory therapy.
Aim
To assess magnetic resonance ...enterography (MRE) lesions that persist in patients in long‐standing endoscopic remission, analyse their relationship with baseline characteristics, and determine their prognostic implications.
Methods
We systematically reviewed pre‐ and post‐treatment MRE findings in patients with Crohn's disease and severe inflammation (segmental CDEIS ≥ 7 or ulcers in at least one segment) who achieved endoscopic remission (CDEIS < 2) after 1 year of treatment with TNF‐inhibitors or autologous haematopoietic stem‐cell transplantation. Logistic regression analysis was used to identify predictors of persistent abnormalities.
Results
Endoscopic remission was achieved in 73 intestinal segments in 28 patients (69% females; 9.95 years disease duration, 67.9% inflammatory phenotype; 39.3% ileal location). Creeping fat and intestinal wall fat deposits were unchanged on pre‐ and post‐treatment MRE despite the endoscopic remission. Luminal strictures persisted in 6 out of the 8 segments with baseline strictures, and wall thickening in 23 out of the 72 of segments with thickening at baseline. Predictors of persistent mural thickening were pre‐treatment wall thickness > 5.9 mm (OR = 4.38, P = 0.027) and refractory disease prior to baseline (OR = 2.35, P = 0.001). Creeping fat was the only predictor for persistence of creeping fat (OR = 36.43, P < 0.001). Persistence of strictures at MRE is associated with earlier recurrence (P = 0.014).
Conclusions
Persistent MRE abnormalities are frequent in patients with Crohn's disease despite achieving endoscopic remission. Significant wall thickening, intestinal fat deposition, strictures, and creeping fat at baseline MRE are signs of established damage.
The tetrafluoroborate salt of the cationic Cu(I) complex Cu(CHpz3)(PPh3)+, where CHpz3 is the tridentate N-donor ligand tris(pyrazol-1-yl)methane and PPh3 is triphenylphosphine, was synthesized ...through a displacement reaction on the acetonitrile complex Cu(NCCH3)4BF4. The compound crystallizes in the monoclinic P21/c space group. The single-crystal X-ray diffraction revealed that the copper(I) centre is tetracoordinated, with a disposition of the donor atoms surrounding the metal centre quite far from the ideal tetrahedral geometry, as confirmed by continuous shape measures and by the τ4 parameter. The intermolecular interactions at the solid state were investigated through the Hirshfeld surface analysis, which highlighted the presence of several non-classical hydrogen bonds involving the tetrafluoroborate anion. The electronic structure of the crystal was modelled using plane-wave DFT methods. The computed band gap is around 2.8 eV and separates a metal-centred valence band from a ligand-centred conduction band. NMR spectroscopy indicated the fluxional behaviour of the complex in CDCl3 solution. The geometry of the compound in the presence of chloroform as implicit solvent was simulated by means of DFT calculations, together with possible mechanisms related to the fluxionality. The reversible dissociation of one of the pyrazole rings from the Cu(I) coordination sphere resulted in an accessible process.
•4-amino-2,1,3-benzothiadiazole and pyridine-2-carboxaldehyde were reacted.•Palladium(II) complexes with the polydentate N-donor ligand were synthesized.•The metal centre interacts with the pyridine ...and imine nitrogen atoms.•The methyl-complex reacted with CO under mild conditions to form an acyl derivative.•The complexes revealed active towards the methoxycarbonylation of iodobenzene.
Palladium(II) chloro‑ and methyl-complexes with N-((pyridin-2-yl)methylene)-4-amino-2,1,3-benzothiadiazole in the coordination sphere were synthesized from 4-amino-2,1,3-benzothiadiazole, pyridine-2-carboxaldehyde and suitable metal precursors. According to experimental outcomes and DFT calculations, the ligand interacts with the metal centre through the pyridine and imine nitrogen atoms, while the benzothiadiazole heterocycle remains as a free pendant. The methyl-complex was reacted with CO in mild conditions affording the related acyl-complex, whose structure was unambiguously determined by X-ray diffraction. All the complexes revealed to be catalytically active towards the methoxycarbonylation of iodobenzene to methyl benzoate.
Palladium(II) complexes with N-((pyridin-2-yl)methylene)-4-amino-2,1,3-benzothiadiazole were synthesized from 4-amino-2,1,3-benzothiadiazole, pyridine-2-carboxaldehyde and suitable metal precursors. The ligand interacts with the metal centre through the pyridine and imine nitrogen atoms. The methyl-complex reacted with CO under mild conditions affording the related acyl-complex. The complexes revealed active towards the methoxycarbonylation of iodobenzene. Display omitted
Diazoalkane complexes Os(η
5
-C
5
Me
5
)(N
2
CAr1Ar2)(PPh
3
){P(OR)
3
}BPh
4
(
1
,
2
) R = Me (
1
), Et (
2
); Ar1 = Ar2 = Ph (
a
); Ar1 = Ph, Ar2 =
p
-tolyl (
b
); Ar1Ar2 = C
12
H
8
(fluorenyl) (
c
...) were prepared by reacting bromo-compounds OsBr(η
5
-C
5
Me
5
)(PPh
3
){P(OR)
3
} with an excess of diazoalkane in ethanol. The treatment of diazoalkane complexes
1
and
2
with acetylene under mild conditions (1 atm, RT) led to dipolar (3 + 2) cycloaddition affording 3
H
-pyrazole derivatives Os(η
5
-C
5
Me
5
)(η
1
-&z.ub1s;N&z.dbd;NC(C
12
H
8
)CH&z.dbd;C&z.ub1e;H)(PPh
3
){P(OR)
3
}BPh
4
(
6
,
7
) R = Me (
6
), Et (
7
) whereas reactions with terminal alkynes R1C&z.tbd;CH (R1 = Ph,
p
-tolyl, COOMe) gave vinylidene derivatives Os(η
5
-C
5
Me
5
){&z.dbd;C&z.dbd;C(H)R1}(PPh
3
){P(OR)
3
}BPh
4
(
8b-d
,
9b-d
) R = Me (
8
), Et (
9
); R1 = Ph (
b
),
p
-tolyl (
c
), COOMe (
d
). Exposure to air of dichloromethane solutions of complexes
1
and
2
produced dioxygen derivatives Os(η
5
-C
5
Me
5
)(η
2
-O
2
)(PPh
3
){P(OR)
3
}BPh
4
(
10
,
11
) R = Me (
10
), Et (
11
). Allenylidene Os&z.dbd;C&z.dbd;C&z.dbd;CR1R2 (
12-14
) R1 = R2 = Ph (
12
,
13
); R1 = Ph, R2 = Me (
14
), vinylvinylidene Os&z.dbd;C&z.dbd;C(H)C(Ph)&z.dbd;CH
2
(
15
) and 3-hydroxyvinylidene Os&z.dbd;C&z.dbd;C(H)C(H)R2(OH) (
16
,
17
) R2 = Ph (
16
), H (
17
) derivatives were also prepared. The vinylidene complex Os(η
5
-C
5
Me
5
)(&z.dbd;C&z.dbd;CH
2
)(PPh
3
){P(OMe)
3
}BPh
4
(
8a
) reacted with PPh
3
to afford the alkenylphosphonium derivative Os(η
5
-C
5
Me
5
){η
1
-C(H)&z.dbd;C(H)PPh
3
}(PPh
3
){P(OMe)
3
}BPh
4
(
18
) whereas vinylidene complexes
8
and
9
reacted with water leading to the hydrolysis of the alkyne and the formation of carbonyl complexes Os(η
5
-C
5
Me
5
)(CO)(PPh
3
){P(OR)
3
}BPh
4
(
19
,
20
). The complexes were characterised by spectroscopic data (IR and NMR) and by X-ray crystal structure determination of Os(η
5
-C
5
Me
5
){&z.dbd;C&z.dbd;C(H)
p
-tolyl}(PPh
3
){P(OEt)
3
}BPh
4
(
9c
), Os(η
5
-C
5
Me
5
)(η
2
-O
2
)(PPh
3
){P(OMe)
3
}BPh
4
(
10
) and Os(η
5
-C
5
Me
5
)(CO)(PPh
3
){P(OMe)
3
}BPh
4
(
19
).
The preparation and reactivity of a series of half-sandwich pentamethylcyclopentadienyl complexes of osmium containing diazoalkane, alkene, dioxygen, vinylidene and allenylidene ligands are described.
Manganese(
ii
) tetrahedral complexes having general formula MnX
2
L
2
(X = Cl, Br, I; L = 1,3-dimethyl-2-phenyl-1,3-diazaphospholidine-2-oxide) were isolated and characterized. The structures of ...the chloro- and bromo-derivatives were ascertained by single-crystal X-ray diffraction. The three species are appreciably luminescent in the green region upon excitation with UV light. The luminescence lifetimes are strongly dependent upon the choice of the coordinated halide. The rigid 1,3-diazaphospholidine-2-oxide moiety improved the photoluminescence features with respect to comparable phenylphosphonic diamide Mn(
ii
) derivatives.
Photoluminescent Mn(
ii
) tetrahedral complexes characterized by intense emission in the green region were isolated from the reaction of MnX
2
(X = Cl, Br, I) and the ligand 1,3-dimethyl-2-phenyl-1,3-diazaphospholidine-2-oxide.
Diazoalkane complexes Ru(η5-C5Me5)(N2CAr1Ar2)(PPh3){P(OR)3}BPh4 R = Me (1), Et (2); Ar1 = Ar2 = Ph (a); Ar1 = Ph, Ar2 = p-tolyl (b); Ar1Ar2 = C12H8 (c) were prepared by allowing chloro complexes ...RuCl(η5-C5Me5)(PPh3)P(OR)3 to react with diazoalkane Ar1Ar2CN2 in ethanol. The treatment of compounds 1 and 2 with H2O afforded 1,2-diazene derivatives Ru(η5-C5Me5)(η2-NHNH)(PPh3){P(OR)3}BPh4 (3 and 4) and ketone Ar1Ar2CO. A reaction path involving nucleophilic attack by H2O on the coordinated diazoalkane is proposed. The complexes were characterized spectroscopically (IR and NMR) and by X-ray crystal structure determination of Ru(η5-C5Me5)(η2-NHNH)(PPh3){P(OMe)3}BPh4 (3).
•Volume-of-Fluid method for 3D unstructured meshes.•Volume-of-Fluid advection method based on cell-vertex velocities.•The new implementation minimizes over/underlapping.•One of the first attempts to ...report results for unstructured grids.•Results for cartesian meshes are also reported.
A new geometrical Volume-of-Fluid (VOF) method for capturing interfaces on three-dimensional (3-D) Cartesian and unstructured meshes is introduced. The method reconstructs interfaces as first- and second-order piecewise planar approximations (PLIC), and advects volumes in a single unsplit Lagrangian–Eulerian (LE) geometrical algorithm based on constructing flux polyhedrons by tracing back the Lagrangian trajectories of the cell-vertex velocities. In this way, the situations of overlapping between flux polyhedrons are minimized, consequently, the accuracy in the solution of the advection equation is improved by minimizing the creation of overshoots (volume fractions over one), undershoots (volume fractions below zero) and wisps (fluid in void regions or vice versa). However, if not treated carefully, the use of cell-vertex velocities may result in the construction of flux polyhedrons that contain nonplanar faces and that do not conserve volume. Therefore, this work explains in detail a set of geometric algorithms necessary to overcome these two drawbacks. In addition, the new VOF method is analyzed numerically on 3-D Cartesian and unstructured meshes, first, by reconstructing the interface of spherical geometries and, second, by evaluating the final advection result of a sphere placed in a rotation, shear and deformation field.
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