Improving age-depth correlations by using the LANDO model ensemble

Age-depth correlations are the key elements in paleoenvironmental studies to place proxy measurements into a temporal context. However, potential influencing factors of the available radiocarbon data and the associated modeling process can cause serious divergences of age-depth correlations from true chronologies, which is particularly challenging for paleolimnological studies in Arctic regions. This paper provides geoscientists with a tool-assisted approach to compare outputs from age-depth modeling systems and to strengthen the robustness of age-depth correlations. We primarily focused in the development on age determination data from a data collection of high latitude lake systems (50° N to 90° N, 62 sediment cores, and a total of 661 dating points). Our approach used five age-depth modeling systems (Bacon, Bchron, clam, hamstr, Undatable) that we linked through a multi-language Jupyter Notebook called LANDO (“Linked age and depth modeling”). Within LANDO we have implemented a pipeline from data integration to model comparison to allow users to investigate the outputs of the modeling systems. In this paper, we focused on highlighting three different case studies: comparing multiple modeling systems for one sediment core with a continuous, undisturbed succession of dating points (CS1 - “Undisturbed sequence”), for one sediment core with scattered dating points (CS2 - “Inconsistent sequence”), and for multiple sediment cores (CS3 - “Multiple cores”). For the first case study (CS1), we showed how we facilitate the output data from all modeling systems to create an ensemble age-depth model. In the special case of scattered dating points (CS2), we introduced an adapted method that uses independent proxy data to assess the performance of each modeling system in representing lithological changes. Based on this evaluation, we reproduced the characteristics of an existing age-depth model (Lake Ilirney, EN18208) without removing age determination data. For the multiple sediment core (CS3) we found that when considering the Pleistocene-Holocene transition, the main regime changes in sedimentation rates do not occur synchronously for all lakes. We linked this behavior to the uncertainty within the modeling process as well as the local variability of the sediment cores within the collection.

A Magnetospheric Dichotomy for Pulsars with Extreme Inclinations

In this work, we expand on a comment by Lyne et al. (2017), that intermittent pulsars tend to congregate near a stripe in the logarithmic period versus period-derivative diagram. Such a stripe represents a small range of polar cap electric potential. Taking into account also the fact (already apparent in their Figure 7, but not explicitly stated there) that high-fraction nulling pulsars also tend to reside within this and an additional stripe, we make the observation that the two stripes further match the “death lines” for double- and single-pole interpulses, associated with nearly orthogonal and aligned rotators, respectively. These extreme inclinations are known to suffer from pair production deficiencies, so we propose to explain intermittency and high-fraction nulling by reinvigorating some older quiescent (no pulsar wind or radio emission) “electrosphere” solutions. Specifically, as the polar potential drops below the two threshold bands (i.e., the two stripes), corresponding to the aligned and orthogonal rotators, their respective magnetospheres transition from being of the active pair-production-sustained-type into becoming the electrospheres, in which charges are only lifted from the star. The borderline cases sitting in the gap outside of the stable regime of either case manifest as high-fraction nullers. Hall evolution of the magnetic field inside orthogonally rotating neutron stars can furthermore drive secular regime changes, resulting in intermittent pulsars.

Exploring the Thickness-Dependence of the Properties of Layered Gallium Sulfide

Group III layered monochalcogenide gallium sulfide, GaS, is one of the latest additions to the two-dimensional (2D) materials family, and of particular interest for visible-UV optoelectronic applications due to its wide bandgap energy in the range 2.35–3.05 eV going from bulk to monolayer. Interestingly, when going to the few-layer regime, changes in the electronic structure occur, resulting in a change in the properties of the material. Therefore, a systematic study on the thickness dependence of the different properties of GaS is needed. Here, we analyze mechanically exfoliated GaS layers transferred to glass substrates. Specifically, we report the dependence of the Raman spectra, photoluminescence, optical transmittance, resistivity, and work function on the thickness of GaS. Those findings can be used as guidance in designing devices based on GaS.

Amazon fire regimes under climate change scenarios

Fire is one of the most important disturbances of the earth-system, shaping the biodiversity of ecosystems and particularly forests. Anthropogenic drivers such as climatic change and other human activities could produce potentially abrupt changes in fire regimes, triggering more profound transformations like the transition from forests to savannah or grasslands ecosystems. Large biodiversity loss could be produced if these transitions occur. Climatic change could cause conditions that enhance fire ignition and spread, which may potentially produce more extensive, intense, and frequent fires. In this work, by considering climate projections for the 21st century, we evaluate the possible changes in the Amazon region's fire regime. We parametrize a fire model using remote sensing data on fire extension and temperature. In the context of our model, there are two possible regime changes: the critical regime that implies high variability in fire extension and mega-fires, and an absorbing phase transition which would produce the extinction of the forest and transition to a different vegetation state. The fitted model and the projections suggest that the Amazon region is not close to any of these regime changes, but other factors not included in the model could result crucial in determining such critical transitions.

Distributional effects of technological regime changes: hysteresis, concentration and inequality dynamics

In this paper, we study the effect of different types of technological regime changes on the evolution of industry concentration and wage inequality. Using a calibrated agent-based macroeconomic framework, the Eurace@Unibi model, we consider scenarios where the new regime is characterized by a finite time period of more frequent respectively more substantial changes in the frontier technology compared to the old regime. We show that under both scenarios, the regime change leads to an increase in the heterogeneity of productivity in the firm population and to increased market concentration, where effects are much less pronounced if the new regime differs from the old one with respect to the frequency of innovations. If the new regime is characterized by an increase of the size of the frontier jumps along the technological trajectory, the evolution of the wage inequality has an inverted U-shape with a large fraction of workers profiting in the very long run from high wages offered by dominant high-tech firms. Finally, it is shown that (observable) heterogeneity of worker skills plays an important role in generating these dynamic effects of technological regime changes.

Specific standards of energy consumption in the problem of controlling its use efficiency

Purpose. Analysis of the existing methods of specific energy consumption standardization and determination of the method acceptable for the standardization in conditions of transient structural and regime changes in energy consumption at a modern industrial enterprise. Methodology. Analysis of the existing methods of specific energy consumption standardization, identification of their disadvantages and advantages. Comparison of the possibilities of these methods with the requirements for the specific energy consumption standardization in modern production. Findings. Emphasis is focused on the significant dependence between reliability of the results of energy efficiency control of the production process (savings or overconsumption of energy) and the accuracy of the calculation of specific norms of energy consumption. The dependence between the assessments of the enterprise’s staff energy saving activity and the achieved accuracy of energy consumption standardization is determined. It is highlighted that in energy efficiency standardization practice, the existing methods are focused on the production conditions, where their benefits are fully revealed. It is proved that due to the increased accuracy of the standardization, efficiency of obtaining and processing information, the statistical method is the most acceptable for the conditions of transient structural and regime changes in the power consumption of the object. Prospects for improving the method of energy efficiency control are described. Originality. For the first time, the use of the statistical method of specific energy consumption standardization in the system of energy efficiency control of production processes with rapid structural and regime changes in energy consumption of the object is proposed. Practical value is to determine an acceptable method of specific energy consumption standardization in the conditions of modern industrial production, as well as ways to improve it.