The Hardy classes for functions in the class MV[α, k]

Suppose that f(z) = z + a₂z² + ··· + a_nz_n + ··· is regular in the unit disc $\text{D}\text{with}\text{[f(z) f′}\text{(z)}\text{z] ≠ 0}\text{in}\text{D}$, and further let α ? 0 and k ? 2. If $\text{∝}{}^{\mathrm{2\pi }}{}_{\mathrm{o}}\text{¦}\text{Re}\text{{(1 ? α)z[}\text{f′(z)}\text{f(z)}\text{] + α(1 + z[}\text{f″(z)}\text{f′(z)}\text{])}¦ dθ ? kπ}\text{for}\text{z ? D}$, then f(z) is said to belong to the class MV[α, k]. This class contains many of the special classes of regular and univalent functions. The authors determine the Hardy classes of which f(z), f′(z) and f″(z) belong and obtain growth estimates of a_n.     

Effect of the molecular weight of the polystyrene matrix on the physicomechanical properties of impact polystyrene

The effect of the molecular weight of the polystyrene on the properties of impact polystyrene obtained by mechanical mixing of polystyrene and rubber has been investigated. As the molecular weight of the polystyrene increases, the physicomechanical properties of the impact polystyrene improve and its rheological properties deteriorate. There is a definite correlation between the physicomechanical properties of the polystyrene and those of the impact polystyrene.Scientific-Research Institute of Synthetic Rubber, Kralupy-on-Vltava, Czechoslovakia. Translated from Mekhanika Polimerov, No. 3, pp. 545–546, May–June, 1971.     

Ordinary p-Laplacian systems with nonlinear boundary conditions

This paper is concerned with the existence of solutions for the boundary value problem

     

Gagliardo–Nirenberg inequalities and non-inequalities: The full story

We investigate the validity of the Gagliardo–Nirenberg type inequality

(1)${6f6}_{W^{s,p}(\mathrm{\Omega })}?{6f6}_{W^{s_1,p_1}(\mathrm{\Omega })}^{\theta }{6f6}_{W^{s_2,p_2}(\mathrm{\Omega })}^{1?\theta },$

with $\mathrm{\Omega }?{\mathbb{R}}^N$. Here, $0\le s_1\le s\le s_2$ are non negative numbers (not necessarily integers), $1\le p_1,p,p_2\le \infty$, and we assume the standard relations

$s=\theta s_1+(1?\theta )s_2,1/p=\theta /p_1+(1?\theta )/p_2\text{ for some }\theta \in (0,1).$

By the seminal contributions of E. Gagliardo and L. Nirenberg, (1) holds when $s_1,s_2,s$ are integers. It turns out that (1) holds for “most” of values of $s_1,\dots ,p_2$, but not for all of them. We present an explicit condition on $s_1,s_2,p_1,p_2$ which allows to decide whether (1) holds or fails.     

Distances between classes in $$W^{1,1}(\Omega ;{\mathbb {S}}^{1})$$

We introduce an equivalence relation on the space \(W^{1,1}(\Omega ;{\mathbb {S}}^1)\) which classifies maps according to their “topological singularities”. We establish sharp bounds for the distances (in the usual sense and in the Hausdorff sense) between the equivalence classes. Similar questions are examined for the space \(W^{1,p}(\Omega ;{\mathbb {S}}^1)\) when \(p>1\).     

On some inequalities of Bourgain,Brezis, Maz'ya,and Shaposhnikova related to L1 vector fields

Bourgain and Brezis established, for maps $f\in L^n({\mathbb{T}}^n)$ with zero average, the existence of a solution $\mathit{Y}\in W^{1,n}\cap L^{\infty }$ of (1) $\mathrm{div}\mathit{Y}=f$. Maz'ya proved that if, in addition, $f\in H^{n/2?1}({\mathbb{T}}^n)$, then (1) can be solved in $H^{n/2}\cap L^{\infty }$. Their arguments are quite different. We present an elementary property of fundamental solutions of the biharmonic operator in two dimensions. This property unifies, in two dimensions, the two approaches, and implies another (apparently unrelated) estimate of Maz'ya and Shaposhnikova. We discuss higher dimensional analogs of the above results.     

Uniqueness of vortexless Ginzburg-Landau type minimizers in two dimensions

In a simply connected two dimensional domain Ω, we consider Ginzburg-Landau minimizers u with zero degree Dirichlet boundary condition ${g \in H^{1/2}(\partial \Omega; \mathbb{S}^1)}$ . We prove uniqueness of u whenever either the energy or the Ginzburg-Landau parameter are small. This generalizes a result of Ye and Zhou requiring smoothness of g. We also obtain uniqueness when Ω is multiply connected and the degrees of the vortexless minimizer u are prescribed on the components of the boundary, generalizing a result of Golovaty and Berlyand for annular domains. The proofs rely on new global estimates connecting the variation of |u| to the Ginzburg-Landau energy of u. These estimates replace the usual global pointwise estimates satisfied by ${\nabla u}$ when g is smooth, and apply to fairly general potentials. In a related direction, we establish new uniqueness results for critical points of the Ginzburg-Landau energy.     

Stable H and O isotope-based investigation of moisture sources and their role in river and groundwater recharge in the NE Carpathian Mountains,East-Central Europe†

The region situated between the mountain area and the lowlands in NE Romania (East-Central Europe) is experiencing increased competition for water resources triggered by a growing population, intensification of agriculture, and industrial development. To better understand hydrological cycling processes in the region, a study was conducted using stable isotopes of water and atmospheric trajectory data to characterize regional precipitation and vapour sources derived from the Atlantic Ocean, Mediterranean and Black Seas, as well as recycled continental moisture, and to assess and partition these contributions to recharge of surface and groundwater. Atmospheric moisture in the lowlands is found to be predominantly delivered along easterly trajectories, while mountainous areas appear to be dominated by North Atlantic Ocean sources, with moisture transported along mid-latitude, westerly storm tracks. Large-scale circulation patterns affect moisture delivery, the North Atlantic Oscillation being particularly influential in winter and the East Atlantic pattern in summer. Winter precipitation is the main contributor to river discharge and aquifer recharge. As winter precipitation amounts are projected to decrease over the next decades, and water abstraction is expected to steadily increase, a general reduction in water availability is projected for the region.     

Review on synthesis methods to obtain LiMn2O4-based cathode materials for Li-ion batteries

Journal of Solid State Electrochemistry - Lithium manganese spinel (LiMn2O4) is considered a promising cathode material for lithium-ion batteries (LIBs). Its structure, morphology, and...