On the gap-opening criterion of migrating planets in protoplanetary disks

We perform two-dimensional hydrodynamical simulations to quantitatively explore the torque balance criterion for gap-opening (as formulated by Crida et al. 2006) in a variety of disks when considering a migrating planet. We find that even when the criterion is satisfied, there are instances when planets still do not open gaps. We stress that gap-opening is not only dependent on whether a planet has the ability to open a gap, but whether it can do so quickly enough. This can be expressed as an additional condition on the gap-opening timescale versus the crossing time, i.e. the time it takes the planet to cross the region which it is carving out. While this point has been briefly made in the previous literature, our results quantify it for a range of protoplanetary disk properties and planetary masses, demonstrating how crucial it is for gap-opening. This additional condition has important implications for the survival of planets formed by core accretion in low mass disks as well as giant planets or brown dwarfs formed by gravitational instability in massive disks. It is particularly important for planets with intermediate masses susceptible to Type III-like migration. For some observed transition disks or disks with gaps, we expect that estimates on the potential planet masses based on the torque balance gap-opening criterion alone may not be sufficient. With consideration of this additional timescale criterion theoretical studies may find a reduced planet survivability or that planets may migrate further inwards before opening a gap.Comment: Accepted by ApJ, 22 pages, 13 figures, 6 table

Computer Simulation of Ion Beam Analysis: Possibilities and Limitations

Quantitative application of ion beam analysis methods, such as Rutherford backscat- tering, elastic recoil detection analysis, and nuclear reaction analysis, requires the use of computer simulation codes. The different types of available codes are pre- sented, and their advantages and weaknesses with respect to underlying physics and computing time requirements are discussed. Differences between different codes of the same type are smaller by about one order of magnitude than the uncertainty of basic input data, especially stopping power and cross section data. Even very com- plex sample structures with elemental concentration variations with depth or lat- erally varying structures can be simulated quantitatively. Laterally inhomogeneous samples generally result in an ambiguity with depth profiles. The optimization of ion beam analysis measurements is discussed, and available tools are presented

Greenhouse gas implications of mobilizing agricultural biomass for energy: a reassessment of global potentials in 2050 under different food-system pathways

Global bioenergy potentials have been the subject of extensive research and continued controversy. Due to vast uncertainties regarding future yields, diets and other influencing parameters, estimates of future agricultural biomass potentials vary widely. Most scenarios compatible with ambitious climate targets foresee a large expansion of bioenergy, mainly from energy crops that needs to be kept consistent with projections of agriculture and food production. Using the global biomass balance model BioBaM, we here present an assessment of agricultural bioenergy potentials compatible with the Food and Agriculture Organization's (2018) 'Alternative pathways to 2050' projections. Mobilizing biomass at larger scales may be associated with systemic feedbacks causing greenhouse gas (GHG) emissions, e.g. crop residue removal resulting in loss of soil carbon stocks and increased emissions from fertilization. To assess these effects, we derive 'GHG cost supply-curves', i.e. integrated representations of biomass potentials and their systemic GHG costs. Livestock manure is most favourable in terms of GHG costs, as anaerobic digestion yields reductions of GHG emissions from manure management. Global potentials from intensive livestock systems are about 5 EJ/yr. Crop residues can provide up to 20 EJ/yr at moderate GHG costs. For energy crops, we find that the medium range of literature estimates (~40 to 90 EJ/yr) is only compatible with FAO yield and human diet projections if energy plantations expand into grazing areas (~4–5 million km2) and grazing land is intensified globally. Direct carbon stock changes associated with perennial energy crops are beneficial for climate mitigation, yet there are—sometimes considerable—'opportunity GHG costs' if one accounts the foregone opportunity of afforestation. Our results indicate that the large potentials of energy crops foreseen in many energy scenarios are not freely and unconditionally available. Disregarding systemic effects in agriculture can result in misjudgement of GHG saving potentials and flawed climate mitigation strategies

AFLATOXIN CONTAMINATION IN EDIBLE NUTS IN CROATIA

Cilj ovog istraživanja bio je utvrditi prisutnost te količinu prisutnih ukupnih aflatoksina u različitim vrstama koštunjičavog voća koje se konzumira na području Republike Hrvatske. Tijekom 2007. godine s hrvatskog je tržišta prikupljeno ukupno 106 uzoraka različitog koštunjičavog voća (badema, lješnjaka, pistacija i oraha). U svim je uzorcima pomoću imunoenzimskog testa (ELISA testa) utvrđena prisutnost te količina prisutnih ukupnih aflatoksina. Istraživanje je pokazalo da su u 91,5% (97/106) analiziranih uzoraka koštunjičavog voća utvrđene razine ukupnih aflatoksina bile unutar, dok su u 8,5% (9/106) analiziranih uzoraka koštunjičavog voća utvrđene razine ukupnih aflatoksina bile iznad, maksimalno dopuštenih vrijednosti u Europskoj Uniji od 4,0 μgkg-1. Sukladno preporukama nutricionista, posljednjih je godina zamijećena povećana konzumacija koštunjičavog voća u svakodnevnoj prehrani opće populacije u Republici Hrvatskoj zbog čega kontinuirano praćenje te nadzor nad prisutnosti aflatoksina u spomenutim namirnicama ima veliko javnozdravstveno značenje.The aim of the study was to analyze the presence and the quantity of aflatoxin levels in various types of commonly consumed nuts in Croatia. The total amount of 106 nut samples (almonds, hazelnuts, pistachios and walnuts) were collected on the Croatian market during the year 2007, after which the total aflatoxin content was determined using the enzyme linked immunosorbent assay (ELISA) test. The results showed that 91.5% (97/106) of the analyzed samples contained the total aflatoxin levels within the permitted range, while in 8.5% (9/106) of nut samples the aflatoxin levels were above the maximum permitted level of 4.0 μgkg-1, set by the European Union. Following nutritionists\u27 recommendation, the nut consumption in daily nutrition in the Croatian general population has recently increased, thus continuous monitoring and control of aflatoxin levels in nuts is of great public health importance

AFLATOXIN CONTAMINATION IN EDIBLE NUTS IN CROATIA

Cilj ovog istraživanja bio je utvrditi prisutnost te količinu prisutnih ukupnih aflatoksina u različitim vrstama koštunjičavog voća koje se konzumira na području Republike Hrvatske. Tijekom 2007. godine s hrvatskog je tržišta prikupljeno ukupno 106 uzoraka različitog koštunjičavog voća (badema, lješnjaka, pistacija i oraha). U svim je uzorcima pomoću imunoenzimskog testa (ELISA testa) utvrđena prisutnost te količina prisutnih ukupnih aflatoksina. Istraživanje je pokazalo da su u 91,5% (97/106) analiziranih uzoraka koštunjičavog voća utvrđene razine ukupnih aflatoksina bile unutar, dok su u 8,5% (9/106) analiziranih uzoraka koštunjičavog voća utvrđene razine ukupnih aflatoksina bile iznad, maksimalno dopuštenih vrijednosti u Europskoj Uniji od 4,0 μgkg-1. Sukladno preporukama nutricionista, posljednjih je godina zamijećena povećana konzumacija koštunjičavog voća u svakodnevnoj prehrani opće populacije u Republici Hrvatskoj zbog čega kontinuirano praćenje te nadzor nad prisutnosti aflatoksina u spomenutim namirnicama ima veliko javnozdravstveno značenje.The aim of the study was to analyze the presence and the quantity of aflatoxin levels in various types of commonly consumed nuts in Croatia. The total amount of 106 nut samples (almonds, hazelnuts, pistachios and walnuts) were collected on the Croatian market during the year 2007, after which the total aflatoxin content was determined using the enzyme linked immunosorbent assay (ELISA) test. The results showed that 91.5% (97/106) of the analyzed samples contained the total aflatoxin levels within the permitted range, while in 8.5% (9/106) of nut samples the aflatoxin levels were above the maximum permitted level of 4.0 μgkg-1, set by the European Union. Following nutritionists\u27 recommendation, the nut consumption in daily nutrition in the Croatian general population has recently increased, thus continuous monitoring and control of aflatoxin levels in nuts is of great public health importance

Deposition of 13C tracer and impurity elements on the divertor of Wendelstein 7-X

Carbon impurity transport and deposition were investigated in the Wendelstein 7-X stellarator by injecting isotopically labelled methane ((CH4)-C-13) into the edge plasma during the last plasma operations of its Operational Phase (OP) 1.2B experimental campaign. C-13 deposition was measured by secondary ion mass spectrometry (SIMS) on three upper divertor tiles located on the opposite side of the vessel to the(13)CH(4) inlet. The highest C-13 inventories were found as stripe-like patterns on both sides of the different strike lines. These high deposition areas were also analysed for their impurity contents and the depth profiles of the main elements in the layers. Layered deposition of different impurity elements such as Cr, Ni, Mo and B was found to reflect various events such as high metallic impurities during the OP1.2A and three boronizations carried out during OP1.2B.Peer reviewe

Deposition of impurity metals during campaigns with the JET ITER-like Wall

Post mortem analysis shows that mid and high atomic number metallic impurities are present in deposits on JET plasma facing components with the highest amount of Ni and W, and therefore the largest sink, being found at the top of the inner divertor. Sources are defined as “continuous” or “specific”, in that “continuous” sources arise from ongoing erosion from plasma facing surfaces and “specific” are linked with specific events which decrease over time until they no longer act as a source. This contribution evaluates the sinks and estimates sources, and the balance gives an indication of the dominating processes. Charge exchange neutral erosion is found to be the main source of nickel, whereas erosion of divertor plasma facing components is the main source of tungsten. Specific sources are shown to have little influence over the global mid- and high-Z impurity concentrations in deposits.Peer reviewe

Impacts of Scaling up Agroecology on the Sustainability of European Agriculture in 2050

The European Commission recently embraced the concept of agroecology as a pathway to reduce negative impacts from agri-food systems on the environment. So far, it remains unclear whether agroecology can deliver on these high hopes if implemented on a large scale. We here assess socio-economic and environmental implications of multiple agroecological futures in the European Union in 2050, based on a novel diagnostic scenario approach, i.e. the biomass balancing model BioBaM-GHG 2.0. We find that agroecological measures from the plot to the food systems level can indeed reduce environmental pressures while maintaining domestic food availability within the EU. Such measures are, for example, more hedgerows on croplands or reduced biomass harvest on high natural value – HNV grasslands. However, a key prerequisite is an overall reduction of the food system's size (based on the reduction of animal production, food wastes, and export production) and an optimised crop-livestock integration. Only then does the transformation towards an agroecological agri-food system in the EU not risk overstretching domestic land availability or produce insufficient agricultural commodities. Mitigating the accompanied trade-off of reduced farm income is a central mandate for policy development aimed at re-designing agriculture in Europe to align with the Green Deal goals

Impacts of Scaling up Agroecology on the Sustainability of European Agriculture in 2050

The European Commission recently embraced the concept of agroecology as a pathway to reduce negative impacts from agri-food systems on the environment. So far, it remains unclear whether agroecology can deliver on these high hopes if implemented on a large scale. We here assess socio-economic and environmental implications of multiple agroecological futures in the European Union in 2050, based on a novel diagnostic scenario approach, i.e. the biomass balancing model BioBaM-GHG 2.0. We find that agroecological measures from the plot to the food systems level can indeed reduce environmental pressures while maintaining domestic food availability within the EU. Such measures are, for example, more hedgerows on croplands or reduced biomass harvest on high natural value – HNV grasslands. However, a key prerequisite is an overall reduction of the food system's size (based on the reduction of animal production, food wastes, and export production) and an optimised crop-livestock integration. Only then does the transformation towards an agroecological agri-food system in the EU not risk overstretching domestic land availability or produce insufficient agricultural commodities. Mitigating the accompanied trade-off of reduced farm income is a central mandate for policy development aimed at re-designing agriculture in Europe to align with the Green Deal goals