Since the late 1990s, more than 25 U.S. shared-use vehicle programs—including carsharing and station cars—have been launched. Given the presumed social and environmental benefits, the majority of these programs received some governmental support, primarily in the form of start-up grants and subsidized parking. As of July 2003, 15 shared-use vehicle programs were in existence, including 11 carsharing organizations, 2 carsharing research pilots, and 2 station car programs. Over the past 5 years, membership in U.S. carsharing programs has experienced exponential growth. Despite this expansion, the social and environmental impacts and long-term sustainability of these services remain unclear. As part of a U.S. shared-use vehicle survey (August 2002 to July 2003), market growth and trends as well as limited, systematic evaluation of program impacts were documented. Although 80% of shared-use programs implement internal customer surveys (initially or as follow-up), few independent studies have been conducted to date. Across organizations, participant use and program benefits are measured with various study tools and metrics. Given current shared-use vehicle growth and the ongoing interest of policymakers and governmental agencies in this concept, a longitudinal monitoring approach to better understand market developments, social and environmental impacts, and targeted policy strategies is recommended. Furthermore, it is concluded that coordinated, programwide data collection (consistent survey instruments and performance measures) could enhance overall market awareness and the credibility of shared-use vehicle organizations in leveraging additional public support.

Research on advanced thermal barrier coating (TBC) materials capable of operating beyond 1200°C has primarily focused on the rare earth zirconate pyrochlores, particularly gadolinium zirconate (Gd 2 Zr 2 O 7 -GZO). The drawback of this material is a significant reduction in durability due to a low fracture toughness. This study investigates utilization of a thermodynamically compatible gadolinia alumina perovskite (GdAlO 3 -GAP) toughening phase to improve the durability of GZO. Dense pellets were fabricated to assess the material properties with minimal microstructural influence. Thermal stability, elastic modulus, hardness, indentation fracture resistance and erosion durability were evaluated for GZO, GAP, and composite pellets containing 10, 30, and 50 wt.% GAP. It was demonstrated that GAP and GZO are thermodynamically compatible through 1600°C and thus capable of operating well beyond the limits of traditional 7 wt.% yttria stabilized zirconia (YSZ). Grain sizes are maintained due to a lack of diffusion, and thus microstructural stability is enhanced. The GAP fracture toughness was shown to be over 2X that of GZO while exhibiting a lower elastic modulus and similar hardness. The 50:50 GZO-GAP composite exhibited a 63% reduction in the absolute erosion rate, demonstrating the immense toughening capabilities of this system. The implications for composite TBCs utilizing this system are discussed, along with future work. K E Y W O R D Saluminates, composites, durability, gadolinium zirconate, thermal barrier coatings

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Significant innovation has been made in the development of public-key cryptography that is able to withstand quantum attacks, known as post-quantum cryptography (PQC). This paper focuses on the development of an efficient PQC hardware implementation. Specifically, an implementation of the binary Ring-learning-with-errors (BRLWE)-based encryption scheme, a promising lightweight PQC suitable for resource-constrained applications, is proposed. The paper first develops the mathematical formulation to present the proposed algorithmic process. The corresponding hardware accelerators are then described in detail. Finally, comparisons with previous implementations are provided to demonstrate the superior performance of the proposed design. For instance, the proposed low-complexity accelerator has 34.7% less area-delay product (ADP) than the state-of-the-art design for n ¼ 256 in the field-programmable gate array (FPGA) platform. Apart from the efficiency of the hardware architectures, the proposed design also has a complete input/output processing setup, and thus is feasible for emerging lightweight applications.

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