Northumbria University

About: Northumbria University is a education organization based out in Newcastle upon Tyne, United Kingdom. It is known for research contribution in the topics: Context (language use) & Population. The organization has 5624 authors who have published 17423 publications receiving 381949 citations. The organization is also known as: University of Northumbria at Newcastle.

Cyclometalated Ir(III) Complexes for High-Efficiency Solution-Processable Blue PhOLEDs

Abstract: This article reports the systematic functionalization of FIrpic (1) with solubilizing alkyl groups (complexes 2–4) or mesityl groups (complexes 5 and 6). Complex 5 is shown to offer significant advantages over FIrpic (1) in terms of performance of sky-blue polymer-based phosphorescent organic light-emitting diodes (PhOLEDs) with a solution-processed emitting layer (λmaxEL 477 nm for 5). Devices with 5 doped into poly(vinylcarbazole) (PVK):OXD-7 gave a maximum luminous efficiency of 19.1 cd A–1 at a brightness of 5455 cd m2 with EQE 8.7%. Optimized multilayer devices with additional TPBi and LiF layers gave 23.7 cd A–1 and EQE 10.4%. These data compare favorably with leading literature values for sky-blue polymer-based PhOLEDs. The enhanced performance of 5 is ascribed to three main reasons: (i) reduced concentration quenching of 5; (ii) the higher radiative yield of 5; and (iii) improved solubility of 5 in organic solvents. Complex 5 should find widespread use as a soluble blue phosphor for displays and l...

Static behaviour of functionally graded sandwich beams using a quasi-3D theory

Abstract: This paper presents static behaviour of functionally graded (FG) sandwich beams by using a quasi-3D theory, which includes both shear deformation and thickness stretching effects. Various symmetric and non-symmetric sandwich beams with FG material in the core or skins under the uniformly distributed load are considered. Finite element model (FEM) and Navier solutions are developed to determine the displacement and stresses of FG sandwich beams for various power-law index, skin-core-skin thickness ratios and boundary conditions. Numerical results are compared with those predicted by other theories to show the effects of shear deformation and thickness stretching on displacement and stresses.

Two-Dimensional van der Waals Materials with Aligned In-Plane Polarization and Large Piezoelectric Effect for Self-Powered Piezoelectric Sensors

Abstract: Piezoelectric two-dimensional (2D) van der Waals (vdWs) materials are highly desirable for applications in miniaturized and flexible/wearable devices. However, the reverse-polarization between adjacent layers in current 2D layered materials results in decreasing their in-plane piezoelectric coefficients with layer number, which limits their practical applications. Here, we report a class of 2D layered materials with an identical orientation of in-plane polarization. Their piezoelectric coefficients (e22) increase with layer number, thereby allowing for the fabrication of flexible piezotronic devices with large piezoelectric responsivity and excellent mechanical durability. The piezoelectric outputs can reach up to 0.363 V for a 7-layer α-In2Se3 device, with a current responsivity of 598.1 pA for 1% strain, which is 1 order of magnitude higher than the values of the reported 2D piezoelectrics. The self-powered piezoelectric sensors made of these newly developed 2D layered materials have been successfully used for real-time health monitoring, proving their suitability for the fabrication of flexible piezotronic devices due to their large piezoelectric responses and excellent mechanical durability.

ICT adoption in developing countries : perspectives from small-scale agribusinesses

Abstract: Purpose – The purpose of this paper is to critically examine how social augmented parameters impact on the effective adoption of information and communication technology (ICT) by small‐scale agribusinesses operating in Southeast Nigeria. The relevance of incorporating social imperatives in scholarship focused on technology adoption is due to its role in sustaining the process of adoption and diffusion.Design/methodology/approach – Data were gathered from a focus group made up of 27 agribusiness proprietors affiliated with a state cooperative based in the south‐eastern Nigerian state of Ebonyi.Findings – This paper puts forward an argument that to ensure successful diffusion of innovation, a balance must be maintained between the amount of effort expended in the design of ICT and social factors such as language and traditional life. The paper finds that a willingness of indigenous ICT users is particularly influenced by the recognition and incorporation of visible social imperatives during the adoption pro...

Managing for local resilience: towards a strategic approach:

Abstract: The term resilience is increasingly being used to capture the challenges involved in managing in ‘hard times’. This article aims to provide one of the first empirical studies of the term’s applicat...