Surveying energy efficiency in housing and transport using a Priority Evaluator

This paper presents a survey combining a stated choice experiment and a priority evaluator. The survey addresses ways that people would invest in energy efficiency and differences between energy efficiency in housing and private transport. The survey sample consists of 500 homeowners (owner occupiers) owning at least one car and is divided in two parts: a paper and pen questionnaire with Stated Preference experiments followed by an Internet-based Priority Evaluator. Both choice experiments are personalized to present the candidates with meaningful choice sets. In the stated preference experiments, respondents are asked to choose between four alternatives as a reaction to hypothetically increasing fuel prices: insulating the house, buying a heat pump, buying a new, more efficient car and selling the car and switching to public transport. In the second part of the survey, the Priority Evaluator, respondents interactively optimize their CO2 output in an Internet application, selecting among long-term investments as well as short-term measures. Data collected in the survey will be processed using statistical models, such as multinomial logit models, to derive parameters for different efficiency measures used to predict long-term investment behavior of homeowners

Combination Service for Time-variable Gravity Fields: operational GRACE-FO combination and validation of Chinese GRACE time-series

The Combination Service for Time-variable Gravity Fields (COST-G) of the International Association of Geodesy (IAG) provides combined monthly gravity fields of its associated and partner Analysis Centers (ACs). In November 2020, the combination of monthly GRACE-FO gravity fields started its operational mode, providing consolidated L2 (spherical harmonics) and L3 (gridded and post-processed) products with a latency of currently 3 months. We present an overview and quality assessment of the available products. COST-G aims at the extension of its service to include further GRACE and GRACE-FO analysis centers. In January 2020 a collaboration with representatives of five Chinese ACs was initiated, who provided GRACE time-series according to the COST-G requirements. We present the results of a test combination with the Chinese AC models, including comparison and quality assessment of all contributing time-series and validation of the combined gravity fields

Combination Service for Time-variable Gravity Fields (COST-G): operations and new developments

Since its start of operations in July 2019, IAGâ?Ts Combination Service for Time-variable Gravity fields (COST-G) is providing a complete time-series of combined monthly GRACE gravity fields and a regularly updated time-series of monthly gravity fields derived from kinematic Swarm orbits. Starting from October 2020, the COST-G product line is complemented by a time-series of operationally combined and monthly updated GRACE-FO gravity fields. All these combinations are performed by variance component estimation on the solution level. We report on new developments, i.e., a planned extension of COST-G to include Chinese analysis centers of GRACE and GRACE-FO data, a re-consideration of the combination strategy to better focus on the range of spherical harmonic coefficients most relevant for the users, and the potential application of COST-G products for orbit determination of altimeter satellites

Nanoscale stiffness topography reveals structure and mechanics of the transport barrier in intact nuclear pore complexes

The nuclear pore complex (NPC) is the gate for transport between the cell nucleus and the cytoplasm. Small molecules cross the NPC by passive diffusion, but molecules larger than ∼5 nm must bind to nuclear transport receptors to overcome a selective barrier within the NPC1. Although the structure and shape of the cytoplasmic ring of the NPC are relatively well characterized2, 3, 4, 5, the selective barrier is situated deep within the central channel of the NPC and depends critically on unstructured nuclear pore proteins5, 6, and is therefore not well understood. Here, we show that stiffness topography7 with sharp atomic force microscopy tips can generate nanoscale cross-sections of the NPC. The cross-sections reveal two distinct structures, a cytoplasmic ring and a central plug structure, which are consistent with the three-dimensional NPC structure derived from electron microscopy2, 3, 4, 5. The central plug persists after reactivation of the transport cycle and resultant cargo release, indicating that the plug is an intrinsic part of the NPC barrier. Added nuclear transport receptors accumulate on the intact transport barrier and lead to a homogenization of the barrier stiffness. The observed nanomechanical properties in the NPC indicate the presence of a cohesive barrier to transport and are quantitatively consistent with the presence of a central condensate of nuclear pore proteins in the NPC channel

Influence of Low Europa Orbit design on gravity field recovery

The characterization of Europa's surface and interior ocean and ice shell is key to explore the habitability of the fourth largest moon of Jupiter. Europa Clipper will largely contribute to our knowledge of Europa with multiple dedicated flybys. However, global mapping can only be significantly improved by means of an orbiter with high inclination and low altitude, as it will be done in the case of Ganymede by JUICE. This was the strategy of several mission proposals (Joint Europa Mission, Jupiter Europa Orbiter, HADES). A specific difficulty in designing suitable orbits in the Jovian system is related to the orbit stability, which is highly impacted by the influence of Jupiter as a third body exerting strong perturbations on a Europa orbiter. This results in constraints for potential science orbits which would allow, e.g., for the determination of Europa's gravity field using radio tracking to the probe. In this presentation, we will analyze a set of different low Europa orbits and compare their scientific value for gravity field recovery. We will explore different orbital characteristics, with the possibility to use repetitive ground track orbits. The analysis will be performed based on closed-loop simulations using the planetary extension of the Bernese GNSS Software. We simulate realistic Doppler tracking data (2-way X-band Doppler range rate) from the Deep Space Network. These observations are then used to reconstruct the orbit as well as geodetic parameters, such as Europa gravity field parameters and the tidal Love number k2. We will discuss the quality of the retrieved solutions

Modeling long term investment decisions in housing and transportation

This paper for the first time addresses trade-offs between long-term energy efficiency investments in two major areas: housing and transport, e.g., retrofitting the house versus purchasing a more efficient car. The main question is whether homeowners treat their energy consumption and related expenses as one single budget or as two separate ones. A survey of homeowners (owner-occupiers) was conducted to study this issue. It comprised questions about their households, houses and car fleets as well as a relevant series of nine Stated Preference experiments with various listed energy prices. The resulting (personalized) energy costs were shown to the respondents along with the following optional ways to lower them: insulate the house (1), install a heat pump (2), buy a more efficient car (3), and switch to public transport (4). The alternatives differed with regard to the investment sum, the expected savings, the expected CO2 reduction and the expected annual mileage. The data were used to estimate a Multinomial Logit to predict the homeowners investment decisions regarding energy efficiency and private transport mobility tools. The model included socioeconomic variables, variables pertaining to the condition of the houses, the composition of the private transport fleets and energy prices