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A partial cooling supercritical carbon dioxide cycle is used in this study for the application of a solar power tower. Additionally, the organic Rankine cycle (ORC) is considered as a bottoming cycle in the process of recovering wasted heat. Moreover, fluids with zero ozone depletion potential and low global warming potential are considered as operating fluids for bottoming ORC. Exergy, energy and exergoenvironmental analyses were performed in order to evaluate the usefulness of the proposed system to generate electrical power and driven by solar energy. The effect of various independent parameters on system performance is investigated. It is concluded that as direct normal irradiation (DNI) changes from 0.4 to 0.95 kW m−2, the combined cycle's thermal efficiency, exergy efficiency, and power output increase from 35.16% to 55.43%, 37.73% to 59.42%, and 188 kW to 298.5 kW, respectively for R1224yd(Z) fluid. However, exergoenvironmental impact index falls by 58.79% as DNI rises, while the exergetic stability factor rises by 57.79%. The system's optimized thermal efficiency is found to be 53.45%. Furthermore, the performance of the combined system can be improved by decreasing the incidence angle of the sun while simultaneously increasing the concentration ratio. The fluid R1224yd(Z) is recommended as the best-performing fluid as compared to the other fluids due to its superior thermal performance. [ABSTRACT FROM AUTHOR]

Flexible electronics have recently gained considerable attention due to their potential to provide new and innovative solutions to a wide range of challenges in various electronic fields. These electronics require specific material properties and performance because they need to be integrated into a variety of surfaces or folded and rolled for newly formatted electronics. Two-dimensional (2D) materials have emerged as promising candidates for flexible electronics due to their unique mechanical, electrical, and optical properties, as well as their compatibility with other materials, enabling the creation of various flexible electronic devices. This article provides a comprehensive review of the progress made in developing flexible electronic devices using 2D materials. In addition, it highlights the key aspects of materials, scalable material production, and device fabrication processes for flexible applications, along with important examples of demonstrations that achieved breakthroughs in various flexible and wearable electronic applications. Finally, we discuss the opportunities, current challenges, potential solutions, and future investigative directions about this field. [ABSTRACT FROM AUTHOR]

P‐values that are derived from continuously distributed test statistics are typically uniformly distributed on (0,1) under least favorable parameter configurations (LFCs) in the null hypothesis. Conservativeness of a p‐value P (meaning that P is under the null hypothesis stochastically larger than uniform on (0,1)) can occur if the test statistic from which P is derived is discrete, or if the true parameter value under the null is not an LFC. To deal with both of these sources of conservativeness, we present two approaches utilizing randomized p‐values. We illustrate their effectiveness for testing a composite null hypothesis under a binomial model. We also give an example of how the proposed p‐values can be used to test a composite null in group testing designs. We find that the proposed randomized p‐values are less conservative compared to nonrandomized p‐values under the null hypothesis, but that they are stochastically not smaller under the alternative. The problem of establishing the validity of randomized p‐values has received attention in previous literature. We show that our proposed randomized p‐values are valid under various discrete statistical models, which are such that the distribution of the corresponding test statistic belongs to an exponential family. The behavior of the power function for the tests based on the proposed randomized p‐values as a function of the sample size is also investigated. Simulations and a real data example are used to compare the different considered p‐values. [ABSTRACT FROM AUTHOR]

This research encompasses the numerical analysis of trioxymethylene dimethyl ether (OME3) e-fuel on an industrial compression ignition engine, as a viable replacement for diesel fuel. The performed simulations examined single injection and multi-injection operating conditions of OME3, varying injection rates and timing. The combustion process is modeled employing two approaches: three-dimensional extended coherent flame model (ECFM-3Z) and general gas phase reactions (GGPR) with a reduced chemical kinetic mechanism. ECFM-3Z gives a faster convergence, where pretabulated autoignition and laminar flame speed databases are integrated into the model to decrease computational time. The GGPR approach is validated on the experimental values for mean pressure, temperature, and rate of released heat in the same engine with diesel fuel and then again employed on an OME3. Both approaches confirmed that a higher amount of OME3 and a prolonged injection time is needed to achieve the same released heat per cycle as diesel fuel since OME3 has a lower net calorific value. It is established that combusting OME3, a 15% higher mean pressure peak can be achieved in multi-injection case compared to the diesel fuel, by adapting the injection timing. Additionally, nitrogen oxides emissions for OME3 are also compared to the diesel case for both combustion modeling approaches. Under the context of multi-injection, the OME3 fuel results show equivalent or lesser nitrogen oxides emissions than those of diesel fuel. The outcomes yielded by the GGPR model utilizing the Lin mechanism revealed decreased temperatures, leading to correspondingly diminished concentrations of nitrogen oxide emissions in comparison with the ECFM-3Z model. [ABSTRACT FROM AUTHOR]

Titanium dioxide (Titania) nanoparticle-coated biochar derived through co-pyrolysis of COVID-19 waste face mask (WFM) and Moringa oleifera seed cake (MO) provides an effective way to alleviate toxic metal in wastewater. This study investigates the effects of Biochar/titania photocatalyst preparation, characterization, and its photoreduction of Cr(VI). The morphological and functional modifications in the catalyst were identified using X-Ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet spectrophotometer, surface area analysis, and Raman spectrophotometer, respectively. The influencing parameters, namely, pH, photocatalyst dosage, initial pollutant concentration, and visible light irradiation time, have been investigated. The findings reveal that the Cr(VI) reduction by the photocatalyst was highly facilitated by photocatalytic process. The prepared photocatalyst shows higher and faster reduction rate of Cr(VI) and also improves the catalyst stability. The photoreduction of Cr(VI) ensembles well with pseudo-first order kinetics. At 180 min of reaction time, maximum Cr(VI) reduction of 98.65% was achieved at pH 2, 0.3 g/L catalyst dosage, and 10 ppm initial concentration, respectively. The synthesized photocatalyst shows excellent recycling performance up to 7 times, and these studies proved that the prepared catalyst is cost-effective and efficiently employed for removing pollutants. [ABSTRACT FROM AUTHOR]