Roadmap on Photovoltaic Absorber Materials for Sustainable Energy Conversion

Photovoltaics (PVs) are a critical technology for curbing growing levels of anthropogenic greenhouse gas emissions, and meeting increases in future demand for low-carbon electricity. In order to fulfil ambitions for net-zero carbon dioxide equivalent (CO2eq) emissions worldwide, the global cumulative capacity of solar PVs must increase by an order of magnitude from 0.9 TWp in 2021 to 8.5 TWp by 2050 according to the International Renewable Energy Agency, which is considered to be a highly conservative estimate. In 2020, the Henry Royce Institute brought together the UK PV community to discuss the critical technological and infrastructure challenges that need to be overcome to address the vast challenges in accelerating PV deployment. Herein, we examine the key developments in the global community, especially the progress made in the field since this earlier roadmap, bringing together experts primarily from the UK across the breadth of the photovoltaics community. The focus is both on the challenges in improving the efficiency, stability and levelized cost of electricity of current technologies for utility-scale PVs, as well as the fundamental questions in novel technologies that can have a significant impact on emerging markets, such as indoor PVs, space PVs, and agrivoltaics. We discuss challenges in advanced metrology and computational tools, as well as the growing synergies between PVs and solar fuels, and offer a perspective on the environmental sustainability of the PV industry. Through this roadmap, we emphasize promising pathways forward in both the short- and long-term, and for communities working on technologies across a range of maturity levels to learn from each other.Comment: 160 pages, 21 figure

Marshall Space Flight Center Research and Technology Report 2019

Today, our calling to explore is greater than ever before, and here at Marshall Space Flight Centerwe make human deep space exploration possible. A key goal for Artemis is demonstrating and perfecting capabilities on the Moon for technologies needed for humans to get to Mars. This years report features 10 of the Agencys 16 Technology Areas, and I am proud of Marshalls role in creating solutions for so many of these daunting technical challenges. Many of these projects will lead to sustainable in-space architecture for human space exploration that will allow us to travel to the Moon, on to Mars, and beyond. Others are developing new scientific instruments capable of providing an unprecedented glimpse into our universe. NASA has led the charge in space exploration for more than six decades, and through the Artemis program we will help build on our work in low Earth orbit and pave the way to the Moon and Mars. At Marshall, we leverage the skills and interest of the international community to conduct scientific research, develop and demonstrate technology, and train international crews to operate further from Earth for longer periods of time than ever before first at the lunar surface, then on to our next giant leap, human exploration of Mars. While each project in this report seeks to advance new technology and challenge conventions, it is important to recognize the diversity of activities and people supporting our mission. This report not only showcases the Centers capabilities and our partnerships, it also highlights the progress our people have achieved in the past year. These scientists, researchers and innovators are why Marshall and NASA will continue to be a leader in innovation, exploration, and discovery for years to come

Comparative analysis of new configurations of aircraft aimed at competitiveness, environmental compatibility and safety

This Ph.D. Thesis aims at suggesting a proper integrated and multidisciplinary design methodology to improve the current conceptual and preliminary design phases of breakthrough innovative aerospace products. The methodology, based on a Systems Engineering approach, is presented together with an envisaged toolchain, consisting of both commercial and ad-hoc developed software, integrated in a Model-Based Systems Engineering perspective. In addition, for the sake of clarity and for validation purposes, a specific case study has been selected and developed all along the document. The reference case-study is inspired to a real pre-feasibility study in which the research group of Politecnico di Torino, which the author of this Thesis belongs to, has been involved. The project aims at developing a suborbital vehicle able to perform parabolic flights for both scientific and touristic purposes. This kind of initiatives paves the way for the future hypersonic vehicles, because it allows to crucial enabling technologies to be tested and validated in relevant environment but with lower performances’ requirements. The Thesis is articulated in seven Chapters with an introduction and conclusion sections and in each Chapter a balanced mix between theoretical investigation, mathematical model development, tool selection or development and application to the selected case study is guaranteed. This document starts reporting the major reasons why an innovative design methodology should be envisaged to deal with the increasing level of complexity in the aerospace domain. In particular, in the first Chapter, a brief overview of existing or underdevelopment initiatives related to hypersonic is reported, together with the description of the different types of mission in which the new hypersonic vehicles will be exploited. Moreover, the major issues related to the infrastructures required to operate these transportation systems are summarized. As far as operations are concerned, a short section makes the readers aware of the current under-development regulatory framework. Then, the integrated multidisciplinary design methodology is presented starting from the very high level analyses up to the sizing of the different components of the transportation system. All along the document, crucial role is played by requirements, whose management can allow a complete traceability of the different design characteristics during the overall product life-cycle. Furthermore, proper algorithms allowing to move from purely qualitative to quantitative trade-offs, are presented, with a noticeable advantage in terms of traceability and reproducibility. Eventually, further improvements of both the tool-chain and the reference case studies are envisaged for future developments

Active thermography for the investigation of corrosion in steel surfaces

The present work aims at developing an experimental methodology for the analysis of corrosion phenomena of steel surfaces by means of Active Thermography (AT), in reflexion configuration (RC). The peculiarity of this AT approach consists in exciting by means of a laser source the sound surface of the specimens and acquiring the thermal signal on the same surface, instead of the corroded one: the thermal signal is then composed by the reflection of the thermal wave reflected by the corroded surface. This procedure aims at investigating internal corroded surfaces like in vessels, piping, carters etc. Thermal tests were performed in Step Heating and Lock-In conditions, by varying excitation parameters (power, time, number of pulse, ….) to improve the experimental set up. Surface thermal profiles were acquired by an IR thermocamera and means of salt spray testing; at set time intervals the specimens were investigated by means of AT. Each duration corresponded to a surface damage entity and to a variation in the thermal response. Thermal responses of corroded specimens were related to the corresponding corrosion level, referring to a reference specimen without corrosion. The entity of corrosion was also verified by a metallographic optical microscope to measure the thickness variation of the specimens

1-D broadside-radiating leaky-wave antenna based on a numerically synthesized impedance surface

A newly-developed deterministic numerical technique for the automated design of metasurface antennas is applied here for the first time to the design of a 1-D printed Leaky-Wave Antenna (LWA) for broadside radiation. The surface impedance synthesis process does not require any a priori knowledge on the impedance pattern, and starts from a mask constraint on the desired far-field and practical bounds on the unit cell impedance values. The designed reactance surface for broadside radiation exhibits a non conventional patterning; this highlights the merit of using an automated design process for a design well known to be challenging for analytical methods. The antenna is physically implemented with an array of metal strips with varying gap widths and simulation results show very good agreement with the predicted performance