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• A CsPbI 2 Br, CsPbIBr 2 and MAPbI 3 based triple layer perovskite solar cell simulated using SCAPS-1D. • A remarkable efficiency of 29.92% has been achieved in all perovskite triple layer solar cell. • The efficiency of the bilayer and single-junction solar cells was also 20.62% and 7.0%, respectively. • Effect of absorber layer thickness, defect density and interface defect density has been observed on the performance of perovskite solar cell. The perovskite solar cells are attaining maximum efficiency but lagging in stability as compared with other solar cells. The consistent use of hybrid organic–inorganic materials in PSC poses greatest hurdle in the path of stability. To overcome this problem the attention of research community, is diverted from methyl ammonium based perovskite solar cells to cesium (Cs) based perovskite solar cell. To enhance the efficiency of PSCs further, effective absorption of solar-spectrum by the multi-layer will allow the maximum utilization of spectrum and in turn it will increase the efficiency of the resulting Perovskite Solar Cell (PSC). Here, we have analyzed the efficiencies of single, double and triple absorber layers PSCs. Initially we have simulated and studied the performance of two CsPbI 2 Br and CsPbIBr 2 based single-junction perovskite solar cell. Then we have simulated a PSC with CsPbI 2 Br and CsPbIBr 2 as the two absorber layers and have optimized the performance of bilayer solar cell. Finally, we simulated a triple layer PSC have used the combination of CsPbI 2 Br, CsPbIBr 2 and MAPbI 3 as absorber layers. The bilayer and triple layer PSCs are optimized with respect to different variables i.e., absorber layer thickness, defect density and interface defect density in all three PSCs. In this study we achieved a remarkable efficiency of 29.92%, 20.62% and 7% efficiency in case of triple layer solar cell, in case of bilayer solar cell and in case of single-junction PSC respectively. Thus, well aligned multiple absorber layers in PSC will provide the future pathways for highly efficient PSCs. [ABSTRACT FROM AUTHOR]

The influence of ion type at constant ionic strength on the surfactant layer present between a polar and a non-polar liquid has been investigated. The investigated systems are composed of sodium bis(2-ethylhexyl) sulfosuccinate (AOT), dodecane and brines with different electrolyte compositions. Parallel and coordinated sampling have been performed via molecular dynamics simulation and experiments. By varying the molar ratio between calcium and sodium ions at constant ionic strength, we determined the relative influence of the bivalent ion. In the present work, firstly, we provide an atomistic description via molecular dynamics (MD) simulations of the surfactant and electrolyte distributions in respect to the dodecane-water interface. Secondly, we report the interfacial tension (IFT) and the estimated Debye length based on the theory of the electric double layer, comparing the simulation results with a classical interface description. [ABSTRACT FROM AUTHOR]

Abstract Early fuel spray development and subsequent autoignition are investigated using our turbulent atomization model that has enabled physically-closed primary atomization modeling. Thanks to its modeling methodology, no parameter tuning or adjustment is needed to simulate a turbulent spray. Due to turbulent atomization, a dense droplet layer is formed over the injected liquid core. With evaporation, this region has a triple layer structure, which is composed of the inner layer with many droplets, the vaporization layer and the outer layer exposed to the hot air. With combustion, hot spots are generated in the outer layer, while the inner layer is too cold and hinders the hot gas to penetrate inside. The group combustion number indicates that this is sheath evaporation/combustion mode and its structure is preserved down to the liquid core length. The liquid core thinning is determined by atomization characteristics and under evaporative/reactive conditions where the outer gas temperature is high and thus the kinematic viscosity is also high, the flow motion is larger and the core is unsteadily affected by this motion. Due to this, the Rayleigh–Taylor (RT) atomization mode is further excited and core breakup occurs relatively faster. It is also observed that the unsteady core head flapping motion leads to non-uniform distributions of droplets and vapor. Due to this non-uniformity, the initial autoignition in the outer layer does not occur uniformly. After core breakup, the droplet layer rolls up in the front region and the group combustion number becomes lower, where external group combustion behavior is observed. Multistep chemistry improves the ignition delay estimation compared with the global chemistry, but the spray dynamics is mostly determined by the above fluid dynamic effects. Therefore, the present study indicates that the accurate simulation capability of fluid dynamics, i.e. primary atomization and early spray development, is important in predicting spray combustion behavior. [ABSTRACT FROM AUTHOR]

Highlights • 5-Ammonium valeric acid iodide cation was synthesized and used as an additive. • Linear hydrogen bonding between 5-AVAI and Perovskite could enhance the shelf-life. • Carbon based perovskite solar cell performance remains ∼90% over 75 days. Abstract Perovskite solar cell (PSC) was fabricated in ambient atmospheric conditions with carbon as counter electrode (CE). 5-Ammonium valeric acid iodide (5-AVAI) cation was synthesized and used as an additive in the perovskite precursor. The light absorber, perovskite precursor was infiltrated on to the TiO 2 /ZrO 2 /Carbon layer and annealed at 60 °C for 30 min. The perovskite layer was characterized by Ultraviolet–visible spectroscopy, Photoluminescence (PL) spectroscopy, and optical microscope analysis. The carbon perovskite solar cell was characterized by Photocurrent-Voltage (J-V) measurement and Incident Photon to Current Conversion Efficiency (IPCE) measurement. The device power conversion efficiency of the perovskite solar cell was found to be 6.6% with an active area of 0.25 cm2. The lifetime of electron injection is found to be 2.5 ms, which is noticed from, bode plot. From electrochemical impedance spectrum, lower charge transport resistance (R ct) is observed at the interface of perovskite/carbon CE. The shelf-life of the device was investigated under ambient condition and its performance remains over ∼90% even after 75 days. This triple layer device architecture shows a hopeful photovoltaic technology towards commercialization. [ABSTRACT FROM AUTHOR]

Highlights • An ultrasonic motor with a PPS/alumina/PZT triple-layered vibrator has been proposed. • The force factor of the triple-layered vibrator reaches its maximal value when the neutral axis locates on the boundary between the alumina and PZT disks. • The output torques and power have been markedly enhanced after the triple-layered vibrators were used. Abstract Our previously reported ultrasonic motors with poly phenylene sulfide (PPS)/lead zirconate titanate (PZT) double-layered vibrators were capable of providing high rotation speeds and light weight, but their output torques and power were limited owing to the low stiffness of PPS vibrating bodies. In this study, we constructed a triple-layered vibrator by sandwiching a thin alumina disk between the PPS vibrating body and PZT disk to compensate the stiffness. First, their fundamental vibration characteristics were investigated as some of key dimensions were varied. The force factor of the PPS/alumina/PZT triple-layered vibrator reached the maximal value when the neutral axis located at the boundary between the PZT and alumina disks. In contrast, the neutral axes existed in the PZT disks for the PPS/PZT double-layered vibrators; this caused the relatively low force factors compared to the triple-layered vibrators. Subsequently, the load characteristics of the PPS/alumina/PZT triple-layered motors were experimentally assessed. The maximum output torque and power of the triple-layered motors were 5 and 13 times the values of the double-layered motors, respectively, owing to the enhanced force factor and electromechanical coupling factor. Besides, the optimal thickness was lower for the triple- than for the double-layered motor. These advantages indicate the potential of our newly designed triple-layered motors for practical applications. [ABSTRACT FROM AUTHOR]

In the context of more electrical aircraft and reduction of fuel consumption, aircraft manufacturers are moving towards more complex and transient ice protection systems. The operating of these systems involves several unsteady heat and mass transfer phenomena. Modelling and numerical simulation play an important role in the investigation of these unsteady phenomena. In this paper, a model for unsteady ice build-up and melting is presented. The model is based on a triple layer assumption. In addition, a tailored numerical methodology for solving the governing partial differential equations is also described. It is based on a Galerkin finite element method and a Gauss-Seidel like implicit time marching scheme. The global method is validated and its capabilities are demonstrated on several cases. [ABSTRACT FROM AUTHOR]

Abstract: Bacterial surface adsorption reactions are influenced by electric field effects caused by changes in ionic strength; however, existing datasets are too sparse to definitively constrain these differences or to determine the best way to account for them using thermodynamic models. In this study, we examine the ionic strength dependence of proton and metal adsorption onto the surfaces of Pseudomonas mendocina and Pseudomonas putida by conducting proton, Cd(II), Pb(II), and Sr(II) adsorption experiments over the ionic strength range of 0.001 to 0.6 M. Chosen experimental results are thermodynamically modeled using a non-electrostatic approach, a diffuse layer model (DLM), and a triple-layer model (TLM). The results demonstrate that bacterial surface electric field effects are negligible for proton, Cd, and Pb adsorption onto P. putida and P. mendocina, and that the discrete site non-electrostatic model developed in this study is adequate for describing these reactions. The extent of Sr adsorption is influenced by changes in the bacterial surface electric field; however, the non-electrostatic model better describes Sr adsorption behavior than the DLM or TLM. The DLM and TLM greatly overpredict the effect of the electric field for all adsorption reactions at all ionic strengths tested. [Copyright &y& Elsevier]