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In this article, we familiarize a subclass of Kamali-type starlike functions connected with limacon domain of bean shape. We examine certain initial coefficient bounds and Fekete-Szegö inequalities for the functions in this class. Analogous results have been acquired for the functions f − 1 and ξ / f ξ and also found the upper bound for the second Hankel determinant a 2 a 4 − a 3 2 .

This article exhibits the thermoelastic interactions because of a consistent heat source in an isotropic, homogeneous, unbounded elastic solid with regards to the modified theory of thermoelasticit...

This article has been devoted to investigating the thermoelastic diffusion problem of an infinite medium. The simple and refined single/dual-phase-lag Green–Naghdi models with and without energy di...

Constructing yolk–shell-structured non-noble-metal composites is very important for improving their activity and stability in catalytic performance. Herein, we report a facile strategy for the synt...

Supported non-precious metal nanoparticles (NPs) have attracted considerable interest for their low cost and excellent properties. However, immobilizing them with good dispersion on supports is sti...

The MnO2-based heterogeneous catalyst has been considered as one of the most efficient catalysts for enzyme-like catalysis, however, it usually suffers from low stability and difficulty in recycling and reuse. Herein, MnO2 nanosheets supported on nickel foam (NF@MnO2) have been fabricated, via a facile one-step hydrothermal process, as an artificial oxidase for the detection and quantification of ascorbic acid (AA). NF, as a magnetic support, possesses a three-dimensional (3D) skeleton and excellent conductivity, which greatly facilitate the utilization of active sites, electron transfer, as well as separation from the solution with an external magnet. Owing to this unique architecture and the synergistic effect between NF and MnO2, the designed NF@MnO2 composites show enhanced enzyme-like activity toward the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) as compared to NF or MnO2 alone. By virtue of the reducing ability of ascorbic acid (AA), the AA selectively inhibited this reaction with a detection limit of 0.1 μM. More importantly, this kind of NF-based design can be easily extended to the synthesis of other functional materials for enzyme-like catalytic applications.

We analyze iterative solutions of a split feasibility problem with common fixed point constraints of a family of nonexpansive mappings. We present solution theorems of the feasibility problem under some weak assumptions imposed on different mappings and control sequences.

We present common fixed point results of finite family of set-valued mappings satisfying generalized graphic contractions on set-valued domain endowed with a directed graph. Some examples are presented to support the results proved therein. Consequently, our results unify, improve and generalize various comparable known results.

Fuzzy set is a modern tool for depicting uncertainty. This paper introduces the concept of fuzzy sub e-group as an extension of fuzzy subgroup. The concepts of identity and inverse are generalized in fuzzy sub e-groups. Every fuzzy subgroup is proven to be a fuzzy sub e-group, but the converse is not true. Various properties of fuzzy sub e-groups are established. Moreover, the concepts of proper fuzzy sub e-group and super fuzzy sub e-group are discussed. Further, the concepts of fuzzy e-coset and normal fuzzy sub e-group are presented. Finally, we describe the effect of e-group homomorphism on normal fuzzy sub e-groups.

The aim of this article is to discuss the convergence of iterative sequences of the Prešić type involving new classes of operators satisfying Prešić type Θ -contractive condition in the context of metric spaces. Some examples are also provided to show the significance of the investigation of finding fixed points. Some convergence results for a class of matrix difference equations will be derived as application.

We present the iterated function systems of generalized rational contractive mappings in Hausdorff semi metric spaces. We also study the well-posedness of attractors based problems of generalized rational contractive operator in the framework of semi metric spaces. An example is presented to support the results proved therein. These results extend, improve and generalize many results in the existing literature.

Constructing yolk-shell-structured non-noble-metal composites is very important for improving their activity and stability in catalytic performance. Herein, we report a facile strategy for the synthesis of ternary Cu@SiO

The encapsulation of small non-noble metal nanoparticles (NPs) within an inorganic layer has received considerable attention owing to their enhanced stability and high catalytic activity. Using a combination of emulsion-free polymerization, inner RF-Ni2+ and outer SiO2 coating, and subsequent carbonization treatment, herein, we have fabricated worm-like structured Ni-based composites in which a high density of nickel NPs are embedded in a carbon layer and also entrapped by SiO2 nanocages. We find that the carbonization temperature plays a vital role in adjusting the size of the Ni NPs. A detailed examination of the encapsulated nickel particles synthesized at 700 °C exhibited the best performance on the catalysis of the reduction of 4-NPs. Moreover, owing to the good alloying ability of the Ni NPs with noble metal NPs, the Ni-Pd alloy NPs are also entrapped in the SiO2 nanocages, which exhibit better performance on the catalysis than the Ni-based composites. The encapsulation of Ni-Pd alloys within SiO2 nanocages also improves stability against agglomeration and metal separation during catalytic operation.

In this paper, four thermoelasticity models are applied to investigate the thermo-mechanical waves in an axisymmetric rotating disk. For this purpose, some modifications of Green and Naghdi’s generalized thermoelasticity theory have been made. These novel dual- and triple-phase-lag models are presented. The closed-form solution governing equations of thermomechanical waves in the rotating disk has been presented. Some validation results are tabulated to compare the simple and refined dual- and triple-phase lag models based upon the Green–Naghdi theory. The effects of dimensionless time and angular speed on all variables are investigated. The validity of results is acceptable and benchmark results are tabulated to aid other researchers in their upcoming comparisons.

The aim of this paper is to introduce the concept of a new nonlinear multi-valued mapping so called weakly (α, ψ, ξ)-contractive mapping and prove fixed point results for such mappings in metric spaces. Our results unify, generalize and complement various results from the literature. We give some examples which support our main results while previous results in literature are not applicable. Also, we analyze the existence of fixed points for mappings satisfying a general contractive inequality of integral type. Many fixed point results for multi-valued mappings in metric spaces endowed with an arbitrary binary relation and metric spaces endowed with graph are given here to illustrate the results in this paper.

Heterostructures exhibit excellent performance in catalytic application owing to the synergistic effect of multi-components and unique interface structure. Herein, we develop a facile method to construct multi-element PANI@MoS2@Fe3O4/Ag, Au, Pd composites as catalysts, where polyaniline(PANI) microtubes acts as intimal “core”, wrinkled ultrathin MoS2 nanosheets as the outer “shell”, tiny Fe3O4, Ag, Au, Pd nanoparticles(NPs) as the seeds decorated on the outer MoS2 shell. Benefiting from the synergistic effects among PANI@MoS2, Fe3O4, the noble metal component as well as the unique structure, PANI@MoS2@Fe3O4/Ag, Au, Pd composites show excellent activity in reducing 4-nitrophenol in the presence of NaBH4 and catalyzing the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) with the participation of H2O2. Furthermore, the PANI@MoS2@Fe3O4/Ag, Au, Pd composites can be easily recycled with the help of magnet. Remarkably, the introduction of MoS2 on PANI microtubes enhance the electron transfer, reduce the impedance and thus improve the dispersion of the Fe3O4 and noble metals NPs. Our work offers an advanced surface engineering solution to construct a peroxidase-like and 4-nitrophenol catalyst, with bright future in environmental science and biological technology.

In this paper, we establish some results regarding the existence of the solution to variational inequality, optimization problem and elliptic boundary value problem in Hilbert spaces. Our strategy consists in establishing new best proximity point results in the metric spaces by introducing the concept of cyclic orbital simulative contractions. We also provide nontrivial examples to show that our results are proper generalization. Further, we improve the recent best proximity results for mappings satisfying proximal simulative conditions due to Abbas et al. (2017), Samet (2015), and Tchier et al. (2016) via new class of simulation functions. Our results unify, extend and generalize various existing results.

Best proximity point theorem furnishes sufficient conditions for the existence and computation of an approximate solution x that is optimal in the sense that the error d ( x , T x ) assumes the global minimum value d ( A , B ) . In the present paper, we initiate some new classes of proximal contraction mappings and obtain best proximity point theorems for such fuzzy mappings in a non-Archimedean fuzzy metric space. As outcomes of these theorems, we conclude evident new best proximity and fixed point theorems in non-Archimedean fuzzy metric spaces with partial order. Furthermore, we provide an example to elaborate the usability of the established results.

Grafting functional components onto carbon fibers is important for designing many multifunctional composites. However, this process is often hindered by the low reactivity of carbon fibers. Hence, developing innovative grafting strategies with functional groups or nanomaterials on carbon fibers (CFs) is highly desired. Herein, we proposed a facile method to grow hydrophilic Fe3O4 NPs on non-pretreated CFs using a polyol-assisted hydrothermal method, changing hydrophobic CFs to hydrophilic. Benefiting from the hydrophilic property of CFs@Fe3O4, the resultant CFs@Fe3O4 can be successfully coated by SiO2 layer to form CFs@Fe3O4@SiO2 composites. After a hydrothermal reaction with nickel ions, the CFs@Fe3O4@nickel silicate composites were fabricated. Followed by coating polydopamine (PDA) layer and then carbonizing in N2 atmosphere, CFs@Fe3O4@SiO2-C/Ni hybrids can be finally obtained. Notably, the hydrophilic Fe3O4 NPs play a crucial role in the fabrication process, not only improving the interfacial adhesion of carbon fibers for further modification but also providing the main magnetism resource. Moreover, the density and size of Ni NPs can be tailored by tuning pyrolysis temperature. Experimental results confirm that CFs@Fe3O4@SiO2-C/Ni hybrids synthesized at 700 °C gave the best activity on the reduction in 4-nitrophenol, which are easy to collect and recycle due to their unique structure and good magnetic property.

The linear generalized Green–Naghdi thermoelasticity theory without energy dissipation is employed. The study of thermoelastic interactions in a hollow cylinder under a continuous heat source is carried out. Firstly, Laplace and Hankel transforms are employed to solve the problem without the time domain. Then, the state space approach is employed to get the exact solution of the problem in the space domain. Once again, the inverse Laplace transforms is used to get the solutions in the time domain. Accurate terminologies for the temperature, thermoelastic potential, axial displacement, dilatation, and stresses are derived. Numerical outcomes for field variables are presented with the view of illustrating the theoretical results.

A novel structure of hierarchical SiO2@C-Ni nanoflakes on MnxOy nanowires is designed, in which Ni nanoparticles (NPs) are highly-density embedded in the carbon layer derived from polydopamine(PDA). MnO2 nanowires are started as carriers and SiO2 layer is used as scarifying template coating on the nanowires, which is further chemically reacted with nickel source to forming nickel silicate (NS) nanoflakes on MnO2 nanowires (MnO2@NS). The formed hierarchical nanoflakes of MnO2@NS are further coated by PDA, serving as a reductive agent to form Ni particles in the following N2 carbonization process. The calcination temperature has a great impact on the sizes of reduced Ni NPs, and 500℃ yields samples with ultrafine magnetic Ni NPs, while higher temperatures destroy the layer structure of graphene-like carbon and cause agglomerations of Ni NPs. MnxOy@SiO2@C-Ni/500 shows the best catalytic performance on the reduction of 4-nitrophenol due to the ultrafine and highly dispersed Ni NPs.

An analysis has been carried out for the three dimensional flow of viscous nanofluid in the presence of partial slip and thermal radiation effects. The flow is induced by a permeable stretching surface. Water is treated as a base fluid and alumina as a nanoparticle. Fluid is electrically conducting in the presence of applied magnetic field. Entire different concept of nonlinear thermal radiation is utilized in the heat transfer process. Different from the previous literature, the nonlinear system for temperature distribution is solved and analyzed. Appropriate transformations reduce the nonlinear partial differential system to ordinary differential system. Convergent series solutions are computed for the velocity and temperature. Effects of different parameters on the velocity, temperature, skin friction coefficient and Nusselt number are computed and examined. It is concluded that heat transfer rate increases when temperature and radiation parameters are increased.

We introduce new concepts of anαc-GF-contractive nonself-mapping, a weakαc-GF-contractive nonself-mapping, a generalizedαc-GF-contractive nonself-mapping, and Suzuki typeGF-contractions and establish the existence ofPPFdependent fixed point theorems for such kind of contractive nonself-mappings in the Razumikhin class. As applications of our results, we derive somePPFdependent fixed point theorems forGF-contractive nonself-mappings whenever the range space is endowed with a graph or a partial order. The obtained results generalize, extend, and modify somePPFdependent fixed point results in the literature.