Interaction of water with montmorillonite exchanged with Na+, K+, Co2+, and Cu2+ cations as a function of water content was examined using an FTIR/gravimetric cell designed to collect spectroscopic and sorption data simultaneously. Correlation of water desorption isotherms with infrared spectra of the clay-water complex showed that the position of the HOH bending band of water decreased as a function of water content. The largest decreases in frequency were observed for Cu2+ and Co2+; smaller decreases were found for Na+ and K+. In addition, the molar absorptivity of sorbed water increased upon decreasing the water content. The decrease in frequency and the concomitant increase in molar absorptivity were attributed to polarization effects on the sorbed water molecules by exchangeable cations. The interference fringes of a self supporting clay film permitted d-spacings to be determined optically and, therefore, changes in frequency, molar absorptivity, and water sorption behavior to be related directly to changes in interlayer spacing. The d-spacings obtained from the interference fringes were consistently larger by approximately 0.5 Å than those determined using powder XRD.

Civil aircraft that fly long ranges consume a large fraction of civil aviation fuel, injecting an important amount of aviation carbon into the atmosphere. Decarbonising solutions must consider this sector. A philosophical-analytical feasibility of an airliner family to assist in the elimination of carbon dioxide emissions from civil aviation is proposed. It comprises four models based on the integration of the body of a large two-deck airliner with the engines, wings and flight surfaces of a long-range twin widebody jet. The objective of the investigation presented here is to evaluate the impact of liquid hydrogen tank technology in terms of gravimetric efficiency. A range of hydrogen storage gravimetric efficiencies was evaluated; from a pessimistic value of 0.30 to a futuristic value of 0.85. This parameter has a profound influence on the overall fuel system weight and an impact on the integrated performance. The resulting impact is relatively small for the short-range aircraft; it increases with range and is important for the longer-range aircraft. For shorter-range aircraft variants, the tanks needed to store the hydrogen are relatively small, so the impact of tank weight is not significant. Longer range aircraft are weight constrained and the influence of tank weight is important. In the case of the longest range, the deliverable distance increases from slightly over 4,000 nautical miles, with a gravimetric efficiency of 0.3, to nearly 7,000 with a gravimetric efficiency of 0.85.

Deception Island is an active volcano located in Bransfield Strait. Its volcanic activity is linked to the presence of gravity anomalies that influence the definition of the geoid. In this paper, a precise undulation geoid model (GeoiDEC14) has been computed from GPS, gravimetric and levelling measurements. GeoiDEC14 highlights local anomalies of the island that match with hot spots, such as the minimum values shown in Fumarole Bay and Whalers Bay (fumarole areas), or the maximum values found in the remains of lava at Colatinas, Black Glacier and Murature Point. Comparison of GeoiDEC14 with global models always shows negative values due to an average of 18.80 m for our model compared to 19.80–20.60 m for models such as ITSG-Grace2014s, EGM08, AIUG-Grace03s or EGM96. This difference is due to the lack of resolution of global models and to the volcanic activity on the island. To confirm the results, the same measurements were taken on nearby Livingston Island. The values of geoid undulation on this island reaffirm the lack of detail in the global geoid in the area, presenting an average of 18.90 m, similar to the average value of GeoiDEC14.