MRS Energy & Sustainability

The following footnote should be included in this article [1]: This paper was commissioned for publication by Elizabeth Kocs, who served as Editor-in-Chief of this journal from 2015-2018.

The following footnote should be included in this article [1]: This paper was commissioned and accepted for publication by Elizabeth Kocs, who served as Editor-in-Chief of this journal from 2015-2018.

We report a significant advance in thermally insulating transparent materials: silica-based monoliths with controlled porosity which exhibit the transparency of windows in combination with a thermal conductivity comparable to aerogels. The lack of transparent, thermally insulating windows leads to substantial heat loss in commercial and residential buildings, which accounts for ~4.2% of primary US energy consumption annually. The present study provides a potential solution to this problem by demonstrating that ambiently dried silica aerogel monoliths, i.e., ambigels, can simultaneously achieve high optical transparency and low thermal conductivity without supercritical drying. A combination of tetraethoxysilane, methyltriethoxysilane, and post-gelation surface modification precursors were used to synthesize ambiently dried materials with varying pore fractions and pore sizes. By controlling the synthesis and processing conditions, 0.5–3 mm thick mesoporous monoliths with transmittance >95% and a thermal conductivity of 0.04 W/(m K) were produced. A narrow pore size distribution, <15 nm, led to the excellent transparency and low haze, while porosity in excess of 80% resulted in low thermal conductivity. A thermal transport model considering fractal dimension and phonon-boundary scattering is proposed to explain the low effective thermal conductivity measured. This work offers new insights into the design of transparent, energy saving windows.

A smart city is an efficient and resilient urban center that, by leveraging its resources, provides its inhabitants with a good standard of living. Many countries worldwide have it as a mission to create citizen-friendly, eco-friendly, and sustainable smart cities. Power generation and power management are also integral parts of this mission. Power generation through renewable energy sources will be a crucial factor in a smart city environment. Renewable energy sources like solar and winds are the most used renewable energy and are more suited for urban applications. The present manuscript focuses on wind power generation using wind turbines in urban environments like smart cities. Most of the urban applications use Vertical axis Wind Turbine (VWT) for power generation. Compared with the Horizontal axis Wind Turbine (HWT), the low efficiency and dynamic instability problems are the main drawbacks of VWT. But the HWT does not have any such issues. Instead, it has its own disadvantages when it is used in smart cities like urban environments. The main shortfalls of conventional HWT are weighing heavily and creating more vibration and acoustic noise. An aramid fiber-based wind blade is proposed in this work to solve the shortcomings of conventional HWT and make it more suited for smart cities such as the urban environment. The CATIA modeling software suite is used to model and design wind blades. To examine the behaviour of the proposed wind turbine, structural, modal, and harmonic analyses are performed using ANSYS. The numerical results indicated that the proposed aramid fiber-based wind turbine is light in weight, creates low acoustic noises, free from vibration, and has a lower chance of resonance occurrence. Thus, it is better suited for urban environments such as smart cities.

This article [1] was published in the incorrect volume and has since been corrected. The publisher apologizes for the error.

There are few feasible options for sorbents, which can be quickly manufactured and deployed in the event of a major oil spill and so every oil spill is an ecological disaster. This paper aims to provide an understanding of what a realistic, full-scale crude oil spill solution would look like based on the performance of the best sorbents currently available, their costs, and their advantages. Adsorbent materials or “sorbents” described here have been a recent target for research toward applications in environmental cleanup, remediation, and hazardous material containment. These materials contain many compositions, syntheses, and practical manufacturing parameters that make most of them practically and logistically unfit to tackle quantities much larger than a single barrel of oil. Different properties of crude oil and nonpolar materials, such as their viscosity, density, and weathering, can also make these materials seem attractive on a lab scale but underperform in field testing and in practical applications. This review addresses the challenges, advantages, and disadvantages of different technical applications of the superior sorbent materials and material types in the literature. In addition, we discuss the different costs and manufacturing challenges of sorbent materials in real oil spills and what a feasible containment sorbent material might look like.

This perspective article summarizes the operational principles of dual-ion batteries and highlights the main issues in the interpretation and reporting of their electrochemical performance. Secondary dual-ion batteries (DIBs) are emerging stationary energy storage systems that have been actively explored in view of their low cost, high energy efficiency, power density, and long cycling life. Nevertheless, a critical assessment of the literature in this field points to numerous inaccuracies and inconsistencies in reported performance, primarily caused by the exclusion of the capacity of used electrolytes and the use of non-charge-balanced batteries. Ultimately, these omissions have a direct impact on the assessment of the energy and power density of DIBs. Aiming to secure further advancement of DIBs, in this work, we critically review current research pursuits and summarize the operational mechanisms of such batteries. The particular focus of this perspective is put on highlighting the main issues in the interpretation and reporting of the electrochemical performance of DIBs. To this end, we survey the prospects of these stationary storage systems, emphasizing the practical hurdles that remain to be addressed.

The hybrid solar heating systems help in increasing energy savings. However, an optimal configuration along with suitable control strategies will be required to enhance the thermal performance of the system. In the present work, a hybrid solar-gas heating system is built up in Algiers, Algeria, to investigate its thermal performances and thus highlight the annual solar coverage rate. The system consists essentially of two flat plate solar collectors, a gas boiler, and a hot water storage tank. The operation of the installation is controlled by data acquisition card through LabVIEW software. For this purpose, experiment tests have been conducted for different weather conditions on which the hybrid system was operating under three different scenarios simulating working days and weekends. It has been found that temperatures of the storage tank water can reach 36, 34 and 27 °C for days with a global horizontal irradiation of 390, 400 and 533 W/m2, respectively. These preliminary results showed that temperatures of the tank under the steady state operating modes might contribute to the reduction of energy consumption for a given space heating application.