Flexible conformable hydrophobized surfaces for turbulent flow drag reduction

In recent years extensive work has been focused onto using superhydrophobic surfaces for drag reduction applications. Superhydrophobic surfaces retain a gas layer, called a plastron, when submerged underwater in the Cassie-Baxter state with water in contact with the tops of surface roughness features. In this state the plastron allows slip to occur across the surface which results in a drag reduction. In this work we report flexible and relatively large area superhydrophobic surfaces produced using two different methods: Large roughness features were created by electrodeposition on copper meshes; Small roughness features were created by embedding carbon nanoparticles (soot) into Polydimethylsiloxane (PDMS). Both samples were made into cylinders with a diameter under 12 mm. To characterize the samples, scanning electron microscope (SEM) images and confocal microscope images were taken. The confocal microscope images were taken with each sample submerged in water to show the extent of the plastron. The hydrophobized electrodeposited copper mesh cylinders showed drag reductions of up to 32% when comparing the superhydrophobic state with a wetted out state. The soot covered cylinders achieved a 30% drag reduction when comparing the superhydrophobic state to a plain cylinder. These results were obtained for turbulent flows with Reynolds numbers 10,000 to 32,500

Mapping of QTLs associated with biological nitrogen fixation traits in soybean.

Biological nitrogen fi xation (BNF) is a key process, but despite the economic and environmental importance, few studies about quantitative trait loci (QTL) controlling BNF traits are available, even in the economically important crop soybean Glycine max (L.) Merr. In this study, a population of 157 F 2:7 RILs derived from crossing soybean cultivars Bossier (high BNF capacity) and Embrapa 20 (medium BNF capacity) was genotyped with 105 simple sequence repeat markers (SSRs). The genetic map obtained has 1231.2 cM and covers about 50% of the genome, with an average interval of 18.1 cM. Three traits, nodule number (NN), the ratio nodule dry weight (NDW)/NN and shoot dry weight (SDW) were used to evaluate BNF performance. A composite interval mapping for multiple traits method (mCIM) analysis mapped two QTLs for SDW (LGs E and L), three for NN (LGs B1, E and I), and one for NDW/NN (LG I); all QTLs were of small effect (R 2 -values ranging from 1.7% to 10.0%) and explained 15.4%, 13.8% and 6.5% of total variation for these three traits, respectively

A Manifesto for project management research

Project management research has evolved over the past five decades and is now a mature disciplinary field investigating phenomena of interest to academics, practitioners and policymakers. Studies of projects and project management practices are theoretically rich and scientifically rigorous. They are practically relevant and impactful when addressing the pursuit of operational, tactical and strategic advancements in the world of organisations. We want to broaden the conversation between project management scholars and other scholars from cognate disciplines, particularly business and management, in a true scholarship of integration and cross-fertilisation. This Manifesto invites the latter scholars to join efforts providing a foundation for further creative, theoretical and empirical contributions, including but not limited to tackling grand challenges such as climate change, pandemics, and global poverty. To this end, we identify five theses: Projects are often ‘agents of change’ and hence fundamental to driving the innovation and change required to tackle grand challenges. Much project management research leverages and challenges theories across disciplines, including business, organisation and management studies, contributing to developing new theories, including those specific to projects and temporary organisations. ‘Projects’ are useful units of analysis, project management research is ideal for scientific cross-fertilisation and project management scholars welcome academics from other communities to engage in fruitful conversations. As in many other fields of knowledge, the project management research community embraces diversity, welcoming researchers of different genders and various scientific and social backgrounds. Historically rooted in ‘problem-solving’ and normative studies, project management research has become open to interpretative and emancipatory research, providing opportunities for other business, management and organisational scholars to advance their knowledge communities

Advanced sandwich composite cores for patient support in advanced clinical imaging and oncology treatment

Ongoing advances in both imaging and treatment for oncology purposes have seen a significant rise in the use of not only the individual imaging modalities, but also their combination in single systems such as Positron Emission Tomography combined with Computed Tomography (PET–CT) and PET–MRI (Magnetic Resonance Imaging) when planning for advanced oncology treatment, the most demanding of which is proton therapy. This has identified issues in the availability of suitable materials upon which to support the patient undergoing imaging and treatment owing to the differing requirements for each of the techniques. Sandwich composites are often selected to solve this issue but there is little information regarding optimum materials for their cores. In this paper, we presented a range of materials which are suitable for such purposes and evaluated the performance for use in terms of PET signal attenuation, proton beam stopping, MRI signal shading and X-Ray CT visibility. We found that Extruded Polystyrene offers the best compromise for patient support and positioning structures across all modalities tested, allowing for significant savings in treatment planning time and delivering more efficient treatment with lower margins

Climate-driven impacts of exotic species on marine ecosystems

Aim Temperature is fundamental to the physiological and ecological performance of marine organisms, but its role in modulating the magnitude of ecological impacts by exotic species remains unresolved. Here, we examine the relationship between thermal regimes in the range of origin of marine exotic species and sites of measured impact, after human-induced introduction. We compare this relationship with the magnitude of impact exerted by exotic species on native ecosystems. Location Global. Time period 1977–2017 (meta-analysis). Major taxa studied Marine exotic species. Methods Quantitative impacts of exotic species in marine ecosystems were obtained from a global database. The native range of origin of exotic species was used to estimate the realized thermal niche for each species and compared with the latitude and climatic conditions in recipient sites of recorded impact of exotic species. The difference in median temperatures between recipient sites and the thermal range of origin (i.e., thermal midpoint anomaly) was compared with the magnitude of effect sizes by exotic species on native species, communities and ecosystems. Results Recorded impacts occurred predominantly within the thermal niche of origin of exotic species, albeit with a tendency toward higher latitudes and slightly cooler conditions. The severity of impacts by exotic species on abundance of native taxa displayed a hump-shaped relationship with temperature. Peak impacts were recorded in recipient sites that were 2.2°C cooler than the thermal midpoint of the range of origin of exotic species, and impacts decreased in magnitude toward higher and lower thermal anomalies. Main conclusions Our findings highlight how temperature and climatic context influence ecological impacts by exotic species in marine ecosystems and the implications for existing and novel species interactions under climate change.En prensa5,14

Role of carbonate burial in Blue Carbon budgets

Calcium carbonates (CaCO3) often accumulate in mangrove and seagrass sediments. As CaCO3 production emits CO2, there is concern that this may partially offset the role of Blue Carbon ecosystems as CO2sinks through the burial of organic carbon (Corg). A global collection of data on inorganic carbon burial rates (Cinorg, 12% of CaCO3 mass) revealed global rates of 0.8 TgCinorg yr−1 and 15–62 TgCinorg yr−1 in mangrove and seagrass ecosystems, respectively. In seagrass, CaCO3burial may correspond to an offset of 30% of the net CO2 sequestration. However, a mass balance assessment highlights that the Cinorg burial is mainly supported by inputs from adjacent ecosystems rather than by local calcification, and that Blue Carbon ecosystems are sites of net CaCO3 dissolution. Hence, CaCO3 burial in Blue Carbon ecosystems contribute to seabed elevation and therefore buffers sea-level rise, without undermining their role as CO2 sinks

Projecting coral responses to intensifying marine heatwaves under ocean acidification

Over this century, coral reefs will run the gauntlet of climate change, as marine heatwaves (MHWs) become more intense and frequent, and ocean acidification (OA) progresses. However, we still lack a quantitative assessment of how, and to what degree, OA will moderate the responses of corals to MHWs as they intensify throughout this century. Here, we first projected future MHW intensities for tropical regions under three future greenhouse gas emissions scenario (representative concentration pathways, RCP2.6, RCP4.5 and RCP8.5) for the near-term (2021-2040), mid-century (2041-2060) and late-century (2081-2100). We then combined these MHW intensity projections with a global data set of 1,788 experiments to assess coral attribute performance and survival under the three emissions scenarios for the near-term, mid-century and late-century in the presence and absence of OA. Although warming and OA had predominately additive impacts on the coral responses, the contribution of OA in affecting most coral attributes was minor relative to the dominant role of intensifying MHWs. However, the addition of OA led to greater decreases in photosynthesis and survival under intermediate and unrestricted emissions scenario for the mid- and late-century than if intensifying MHWs were considered as the only driver. These results show that role of OA in modulating coral responses to intensifying MHWs depended on the focal coral attribute and extremity of the scenario examined. Specifically, intensifying MHWs and OA will cause increasing instances of coral bleaching and substantial declines in coral productivity, calcification and survival within the next two decades under the low and intermediate emissions scenario. These projections suggest that corals must rapidly adapt or acclimatize to projected ocean conditions to persist, which is far more likely under a low emissions scenario and with increasing efforts to manage reefs to enhance resilience

Estimates for energy expenditure in free‐living animals using acceleration proxies; a reappraisal

It is fundamentally important for many animal ecologists to quantify the costs of animal activities, although it is not straightforward to do so. The recording of triaxial acceleration by animal-attached devices has been proposed as a way forward for this, with the specific suggestion that dynamic body acceleration (DBA) be used as a proxy for movement-based power. Dynamic body acceleration has now been validated frequently, both in the laboratory and in the field, although the literature still shows that some aspects of DBA theory and practice are misunderstood. Here, we examine the theory behind DBA and employ modelling approaches to assess factors that affect the link between DBA and energy expenditure, from the deployment of the tag, through to the calibration of DBA with energy use in laboratory and field settings. Using data from a range of species and movement modes, we illustrate that vectorial and additive DBA metrics are proportional to each other. Either can be used as a proxy for energy and summed to estimate total energy expended over a given period, or divided by time to give a proxy for movement-related metabolic power. Nonetheless, we highlight how the ability of DBA to predict metabolic rate declines as the contribution of non-movement-related factors, such as heat production, increases. Overall, DBA seems to be a substantive proxy for movement-based power but consideration of other movement-related metrics, such as the static body acceleration and the rate of change of body pitch and roll, may enable researchers to refine movement-based metabolic costs, particularly in animals where movement is not characterized by marked changes in body acceleration

Fixação de fósforo por um latossolo vermelho escuro-orto

This paper deals with an experiment carried out in pots with the aim of studying the fixation of P in a Dark Red Latosol, from the Municipality of Piracicaba, State of Sao Paulo, Brazil. The main conclusions were as follows: a) about 90% of the fixed P remained soluble in 0,05N H2SO4 solution; b) Fe and Al contributed to increase the quantities of fixed P; c) the pre-treatment of the soil with Ca(H2PO4)2. H2O decreased its capacity for fixing P.Este trabalho relata os resultados de um ensaio realizado com o objetivo de estudar a fixação de P por um Latossolo Vermelho Escuro-Orto, serie Iracema, de Piracicaba, Estado de São Paulo. O ensaio foi realizado em vasos de plástico, cada um recebendo 500 g de terra e os tratamentos, correspondentes a 0, 100, 200, 400, 600 e 1.200 kg/ha de P2O5 na forma de Ca (H2PO4)2. H2O. Houve 4 repetições de cada tratamento. Seguiu-se um período de incubação de 3 semanas, durante o qual as parcelas permaneceram umidecidas, entre 40 e 70% do poder de retenção de umidade. Depois foram feitos trabalhos necessários do que se concluiu que: a) grande proporção do P fixado permaneceu solúvel em H2SO4 0,05 N; b) o Fe e o Al foram importantes na fixação do P; c) o pré-tratamento do solo com Ca (H2P0(4))2· H2O reduziu-lhe a capacidade de fixação de fosfato