Revisiting Salvucci’s Semi-analytical Solution for Bare Soil Evaporation with New Consideration of Vapour Diffusion and Film Flow

Bare soil evaporation is controlled by a combination of capillary flow, vapour diffusion and film flow. Relevant analytical solutions mostly assume horizontal flow conditions and ignore gravitational effects. Salvucci (1997) provided a rare example of a semi-analytical solution for vertical bare soil evaporation. However, they did not explicitly represent vapour diffusion and film flow, which are likely to account for a significant proportion of total flow during vertical evaporation from soils. Vapour diffusion and film flow can be incorporated via Salvucci’s desorptivity parameter, which represents the proportionality constant relating Stage 2 cumulative evaporation to the square root of time under horizontal flow conditions. The objective of this article is to implement vapour diffusion and film flow within Salvucci’s semi-analytical solution and test its performance by comparison with isothermal numerical simulation and relevant experimental data. The following important conclusions are drawn. Analytical solutions that assume horizontal flow conditions are inadequate for understanding vertical evaporation problems because they overestimate evaporation rates and mostly predict vapour diffusion and film flow to be of negligible influence. Salvucci’s semi-analytical solution is effective at predicting the order-of-magnitude reduction in evaporation caused by gravitational effects. However, it is unable to identify the correct importance of vapour diffusion and film flow because these processes can only be represented through its desorptivity parameter

Visibility of age restriction warnings, harm reduction messages, and terms and conditions::A content analysis of paid-for gambling advertising in the United Kingdom.

Objective: The inclusion and design of age restriction warnings, harm reduction messages, and terms and conditions (T&Cs) in gambling advertising is self-regulated in the United Kingdom. Our study examines the visibility and nature of this information in a sample of paid-for gambling adverts. Study design: Content analysis of a stratified random sample of gambling adverts (n=300) in the United Kingdom from eight paid-for advertising channels (March 2018). Methods: For each advert, we assessed whether any age restriction warnings, harm reduction messages, and T&Cs were present. If so, visibility was scored on a five-point scale ranging from Very poor (25% of advert), which had high inter-rater reliability. Descriptive information on position, design, and tone of language was recorded. Results: One-in-seven adverts (14%) did not feature an age restriction warning or harm reduction message. In adverts that did, 84% of age restriction warnings and 54% of harm reduction messages had very poor visibility. At least one-in-ten adverts did not contain T&Cs. In adverts that did, 73% had very poor visibility. For age restriction warnings, harm reduction messages, and T&Cs, most appeared in small fonts and outside the main advert frame. Most harm reduction messages did not actually reference gambling-related harms. Conclusion: Age restriction warnings, harm reduction messages, and T&Cs do not always appear in paid-for gambling advertising. When they do, visibility is often very poor and the messaging not clear. The findings do not support a self-regulatory approach to managing this information in gambling adverts

Artificial neural network analysis of factors controling ecosystem metabolism in coastal systems

Knowing the metabolic balance of an ecosystem is of utmost importance in determining whether the system is a net source or net sink of carbon dioxide to the atmosphere. However, obtaining these estimates often demands significant amounts of time and manpower. Here we present a simplified way to obtain an estimation of ecosystem metabolism. We used artificial neural networks (ANNs) to develop a mathematical model of the gross primary production to community respiration ratio (GPP:CR) based on input variables derived from three widely contrasting European coastal ecosystems (Scheldt Estuary, Randers Fjord, and Bay of Palma). Although very large gradients of nutrient concentration, light penetration, and organic-matter concentration exist across the sites, the factors that best predict the GPP:CR ratio are sampling depth, dissolved organic carbon (DOC) concentration, and temperature. We propose that, at least in coastal ecosystems, metabolic balance can be predicted relatively easily from these three predictive factors. An important conclusion of this work is that ANNs can provide a robust tool for the determination of ecosystem metabolism in coastal ecosystems

Atmospheric sampling of Supertyphoon Mireille with NASA DC-8 aircraft on September 27,1991, during PEM-West A

The DC-8 mission of September 27, 1991, was designed to sample air flowing into Typhoon Mireille in the boundary layer, air in the upper tropospheric eye region, and air emerging from the typhoon and ahead of the system, also in the upper troposphere. The objective was to find how a typhoon redistributes trace constituents in the West Pacific region and whether any such redistribution is important on the global scale. The boundary layer air (300 m), in a region to the SE of the eye, contained low mixing ratios of the tracer species O3, CO, C2H6, C2H2, C3H8, C6H6and CS2 but high values of dimethylsulfide (DMS). The eye region relative to the boundary layer, showed somewhat elevated levels of CO, substantially increased levels of O3, CS2 and all nonmethane hydrocarbons (NMHCs), and somewhat reduced levels of DMS. Ahead of the eye, CO and the NMHCs remained unchanged, O3 and CS2 showed a modest decrease, and DMS showed a substantial decrease. There was no evidence from lidar cross sections of ozone for the downward entrainment of stratospheric air into the eye region; these sections show that low ozone values were measured in the troposphere. The DMS data suggest substantial entrainment of boundary layer air into the system, particularly into the eye wall region. Estimates of the DMS sulphur flux between the boundary layer and the free troposphere, based on computations of velocity potential and divergent winds, gave values of about 69 μg S m−2 d−1 averaged over a 17.5° grid square encompassing the typhoon. A few hours after sampling with the DC-8, Mireille passed over Oki Island, just to the north of Japan, producing surface values of ozone of 5.5 ppbv. These O3 levels are consistent with the low tropospheric values found by lidar and are more typical of equatorial regions. We suggest that the central eye region may act like a Taylor column which has moved poleward from low latitudes. The high-altitude photochemical environment within Typhoon Mireille was found to be quite active as evidenced by significant levels of measured gas phase H2O2 and CH3OOH and model-computed levels of OH

Ice surface changes during recent glacial cycles along the Jutulstraumen and Penck Trough ice streams in western Dronning Maud Land, East Antarctica

Reconstructing past ice-sheet surface changes is key to testing and improving ice-sheet models. Data constraining the past behaviour of the East Antarctic Ice Sheet are sparse, limiting our understanding of its response to past, present and future climate change. Here, we report the first cosmogenic multi-nuclide (10Be, 26Al, 36Cl) data from bedrock and erratics on nunataks along the Jutulstraumen and Penck Trough ice streams in western Dronning Maud Land, East Antarctica. Spanning elevations between 741 and 2394 m above sea level, the samples have apparent exposure ages between 2 ka and 5 Ma. The highest-elevation bedrock sample indicates (near-) continuous minimum exposure since the Pliocene, with a low apparent erosion rate of 0.15 ± 0.03 m Ma−1, which is similar to results from eastern Dronning Maud Land. In contrast to studies in eastern Dronning Maud Land, however, our data show clear indications of a thicker-than-present ice sheet within the last glacial cycle, with a thinning of ∼35–120 m during the Holocene (∼2–11 ka). Difficulties in separating suitable amounts of quartz from the often quartz-poor rock-types in the area, and cosmogenic nuclides inherited from exposure prior to the last deglaciation, prevented robust thinning estimates from elevational profiles. Nevertheless, the results clearly demonstrate ice-surface fluctuations of several hundred meters between the current grounding line and the edge of the polar plateau for the last glacial cycle, a constraint that should be considered in future ice-sheet model simulations

Interdisciplinary medication decision making by pharmacists in pediatric hospital settings: An ethnographic study

OBJECTIVE: Children are particularly vulnerable to experiencing medication incidents in hospitals. Making sound medication decisions is therefore of paramount importance. Prior research has principally described pharmacists' role in reducing medication errors. There is a dearth of information about pharmacists' interactions with pediatric hospital staff across disciplines in resolving medication issues. The aim of this study was to examine interdisciplinary medication decision making by pharmacists in pediatric hospital settings. DESIGN: An ethnographic design was undertaken comprising observations, semi-structured interviews and focus groups. Audio-recorded data were analyzed thematically. SETTING: The study was conducted in three wards of an Australian pediatric tertiary teaching hospital, comprising general surgical, gastroenterology, endocrinology, neurology, adolescent and rehabilitation settings. PARTICIPANTS: Pharmacists, registered nurses and doctors were recruited from diverse clinical wards following information sessions. RESULTS: Pharmacists were central to complex pediatric medication decision making, intervening about dosage, administration, drug interactions and authorities. Pharmacists proactively contacted doctors and nurses about prescribing issues; conversely, staff routinely approached pharmacists for medication advice. Pharmacists were perceived as medication experts, their extensive knowledge valued in resolving complex issues: when off-label medications were prescribed, when protocols were absent or ambiguous, where tension existed between protocol adherence and patient safety, and where patients on multiple medications were at risk of medication error. Pharmacists had strong relationships with doctors and nurses, which had a bearing on pharmacists' input in interventions. Furthermore, pharmacists identified prescribing errors through strategies, such as case note review and medication reconciliation, although the lack of emergency department pharmacists and limited after-hours staffing posed challenges to both strategies. CONCLUSIONS: Pharmacists made a substantial and highly valued contribution to pediatric inter-professional medication decision making. These results provide new knowledge that informs theoretical developments of pharmacists' role in decision making

Geographically touring the eastern bloc: British geography, travel cultures and the Cold War

This paper considers the role of travel in the generation of geographical knowledge of the eastern bloc by British geographers. Based on oral history and surveys of published work, the paper examines the roles of three kinds of travel experience: individual private travels, tours via state tourist agencies, and tours by academic delegations. Examples are drawn from across the eastern bloc, including the USSR, Poland, Romania, East Germany and Albania. The relationship between travel and publication is addressed, notably within textbooks, and in the Geographical Magazine. The study argues for the extension of accounts of cultures of geographical travel, and seeks to supplement the existing historiography of Cold War geography

Detecting the start of an influenza outbreak using exponentially weighted moving average charts

Background. Influenza viruses cause seasonal outbreaks in temperate climates, usually during winter and early spring, and are endemic in tropical climates. The severity and length of influenza outbreaks vary from year to year. Quick and reliable detection of the start of an outbreak is needed to promote public health measures. Methods. We propose the use of an exponentially weighted moving average (EWMA) control chart of laboratory confirmed influenza counts to detect the start and end of influenza outbreaks. Results. The chart is shown to provide timely signals in an example application with seven years of data from Victoria, Australia. Conclusions. The EWMA control chart could be applied in other applications to quickly detect influenza outbreaks