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Based on two cases of ecclesiastical book censorship from the 1950s, the article deals with the Holy Office's handling of Catholic biblical exegesis during the late phase of the pontificate of Pius XII (1939-58). On the one hand, the inner-Vatican conflicts between the Suprema Congregazione and the Pontifical Biblical Commission in the years 1956-58 are examined. Secondly, the case of the German New Testament scholar Karl Hermann Schelkle shows the specific situation of Catholic biblical scholarship between the centre and the periphery a good decade after the biblical encyclical "Divino afflante Spiritu" (1943).

High Froude-number open-channel flows can entrain significant volumes of air, a phenomenon that occurs continuously in spillways, in free-falling jets and in hydraulic jumps, or as localized events, notably at the toe of hydraulic jumps or in plunging jets. Within these flows, turbulence generates millions of bubbles and droplets as well as highly distorted wavy air–water interfaces. This phenomenon is crucial from a design perspective, as it influences the behaviour of high-velocity flows, potentially impairing the safety of dam operations. This review examines recent scientific and engineering progress, highlighting foundational studies and emerging developments. Notable advances have been achieved in the past decades through improved sampling of flows and the development of physics-based models. Current challenges are also identified for instrumentation, numerical modelling and (up)scaling that hinder the formulation of fundamental theories, which are instrumental for improving predictive models, able to offer robust support for the design of large hydraulic structures at prototype scale. [ABSTRACT FROM AUTHOR]

Large wood (LW) elements are often transported by rivers into reservoirs during heavy rainfall events. Large wood has important environmental attributes that benefit the diversification of riverine ecosystems. There are several studies dealing with the transport and behaviour of LW inside streams. However, during flood events, LW tends to create jams or blockages at diverse hydraulic structures inside streams, creating significant problems such as discharge limitations and increased water levels. Even though knowledge on the effect of LW at bridges in rivers with relatively high flow velocities starts to be available, the latter is hardly applicable for reservoir approach flow conditions. Understanding LW blockage processes at a reservoir spillway is essential regarding the safety evaluation of a dam and the surrounding areas. The geomorphologic benefits of wood for stream restoration depends also on our present ability to manage jams and the risk they imply for civil structures when blocked. Therefore, series of systematic laboratory experiments were conducted to analyse blockage of floating stems at an ogee crested spillway equipped with piers. Different LW characteristics were represented in a physical model with cylindrical stems. Results associate the size of stem groups to blockage probabilities and the effect blockages can have on the discharge capacity of a spillway.

In recent decades, stepped chutes followed by a stilling basin became a standard for spillways of dams. The comprehensive knowledge of stepped chute approach flows on internal air–water flow properties of the hydraulic jump is still too limited for an appropriate design of stilling basins. Therefore, an experimental campaign was performed on a large-scale physical model of a plain stilling basin preceded by a 30° sloping smooth or stepped chute. Stepped chute approach flows induce lower deaeration rates along the jump roller as compared to smooth chute approach flows, indicating longer dimensionless jump lengths, normalized by the tailwater depth. Pronounced bottom air concentrations were observed within the first 40% of the jump length in the stilling basin downstream of the stepped chute. Thus, despite the significantly higher pressure fluctuations, this zone seems better protected against cavitation damage than in stilling basins following a smooth chute. [ABSTRACT FROM AUTHOR]

Chutes with flow velocities in excess of some 20 to 30 m/s are usually prone to cavitation damage. Therefore, these flows are aerated using chute aerators. The current literature describes the aerator efficiency mainly in terms of the air entrainment coefficient as the ratio of the entrained air and the water discharges. However, this global coefficient neither specifies the air distribution nor its detrainment rate. The present investigation focuses on the flow structure and the air transport downstream of chute aerators. Systematic hydraulic model tests were conducted including a data analysis of the spatial air concentration distribution in both the near and the far aerator fields. Based on these, three flow zones were introduced, namely: (1)jet zone; (2) reattachment and spray zone; and (3) far-field zone. It was further found that aerators have primarily an effect on the average air concentration, whereas the increase of the bottom air concentration is typically small. DOI: 10.1061/(ASCE)HY.1943-7900.0000189 CE Database subject headings: Aeration; Cavitation; Spillways; Velocity. Author keywords: Aerator; Cavitation; Chute; Deflector; Offset; Spillway.

Chute aerators are applied if cavitation damage on spillways is expected or observed. The aerator efficiency is usually described with the ratio of the air discharge entrained through the air supply ducts and the water discharge, which does however not account for the resulting air concentration distribution within the flow or for air detrainment. The present study investigates the streamwise development of the air transport along the flow downstream of chute aerators. Based on an extensive test program in which six governing parameters were systematically varied, the development of the average and the bottom air concentrations is provided up to the self-aeration point. Based on this information, an optimization of aerators in terms of increased air entrainment and reduced detrainment rates is possible, by assuming minimum required air concentrations. The main parameters influencing the air transport downstream of aerators are the approach flow Froude number, the deflector angle and the chute bottom angle. DOI: 10.1061/(ASCE)HY.1943-7900.0000201 CE Database subject headings: Aeration; Cavitation; Entrainment; Spillways. Author keywords: Air; Aerator; Cavitation; Chute; Deflector; Detrainment; Entrainment; Offset.