Abstract
Causal models find application in almost all areas of science, and they often support the development of theories that are straightforward and testable. Yet scientists also observe things ...that surprise them. Fascinated by such observations, they learn to admire the playful aspects of life, as well as its creativity and diversity. Under these circumstances, a compelling question arises: Can causal models explain life’s creativity and diversity? Some life scientists say yes. However, other humanities scholars cast doubt, positing that they reached the end of theory. Here, I build on common empirical observations as well as long-accumulated modeling experience, and I develop a unified framework for causal modeling. The framework gives special attention to life’s creativity and diversity, and it applies to all sciences including physics, biology, the sciences of the city, and the humanities.
Ciomadul is the youngest volcano in the Carpathian‐Pannonian Region, Eastern‐Central Europe, which last erupted 30 ka. This volcano is considered to be inactive, however, combined evidence from ...petrologic and magnetotelluric data, as well as seismic tomography studies, suggests the existence of a subvolcanic crystal mush with variable melt content. The volcanic area is characterized by high CO2 gas output rate, with a minimum of 8.7 × 103 t/year. We investigated 31 gas emissions at Ciomadul to constrain the origin of the volatiles. The δ13C–CO2 and 3He/4He compositions suggest the outgassing of a significant component of mantle‐derived fluids. The He isotope signature in the outgassing fluids (up to 3.10 Ra) is lower than the values in the peridotite xenoliths of the nearby alkaline basalt volcanic field (R/Ra 5.95 Ra ± 0.01), which are representative of a continental lithospheric mantle and significantly lower than MORB values. Considering the chemical characteristics of the Ciomadul dacite, including trace element and Sr–Nd and O isotope compositions, an upper crustal contamination is less probable, whereas the primary magmas could have been derived from an enriched mantle source. The low He isotopic ratios could indicate a strongly metasomatized mantle lithosphere. This could be due to infiltration of subduction‐related fluids and postmetasomatic ingrowth of radiogenic He. The metasomatic fluids are inferred to have contained subducted carbonate material resulting in a heavier carbon isotope composition (δ13C is in the range of −1.4‰ to −4.6‰) and an increase of CO2/3He ratio. Our study shows the magmatic contribution to the emitted gases.
Plain Language Summary
Determining the fluxes and composition of gases in active and dormant volcanoes could help to constrain their origin. Ciomadul is the youngest volcano of the Carpathian‐Pannonian Region, Eastern‐Central Europe, where the last eruption occurred 30 ka. Its eruption chronology is punctuated by long quiescence periods (even >100 kyr) separating the active phases; therefore, the long dormancy since the last eruption (30 ka) does not unambiguously indicate inactivity. Knowing if melt‐bearing magma resides in the crust is fundamental to evaluate the nature of the volcano. Isotopic compositions of helium (3He/4He) and carbon (δ13CCO2) are important tools for the study of the origin of the gases. We show that the isotope variation of the emitted gases suggests a metasomatized lithospheric mantle origin for the primary magmas. This is consistent with a degassing deep magma body existing beneath Ciomadul, and this long‐dormant volcano cannot be considered as extinct.
Key Points
CO2 emissions at Ciomadul, Eastern‐Central Europe, suggest a still‐active plumbing system beneath the volcano in spite of long dormancy
The CO2 and He isotope compositions provide evidence for significant contribution of magma‐derived volatiles, up to 80%
Isotopic signatures of gases indicate that primary magmas could have derived from a mantle source modified by subduction‐related fluids
Radon is a radioactive gas with a carcinogenic effect. The malign effect on human health is, however, mostly influenced by the level of exposure. Dangerous exposure occurs predominantly indoors where ...the level of indoor radon concentration (IRC) is, in its turn, influenced by several factors. The current study aims to investigate the combined effects of geology, pedology, and house characteristics on the IRC based on 3132 passive radon measurements conducted in Romania. Several techniques for evaluating the impact of predictors on the dependent variable were used, from univariate statistics to artificial neural network and random forest regressor (RFR). The RFR model outperformed the other investigated models in terms of R2 (0.14) and RMSE (0.83) for the radon concentration, as a dependent continuous variable. Using IRC discretized into two classes, based on the median (115 Bq/m3), an AUC-ROC value of 0.61 was obtained for logistic regression and 0.62 for the random forest classifier. The presence of cellar beneath the investigated room, the construction period, the height above the sea level or the floor type are the main predictors determined by the models used.
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•About 18 % of the radon measurements are higher than 300 Bq/m3.•Using building characteristics, lithology and pedology to assess the impact on IRC•Multiple models from linear regression to random forest regressor (RFR) were applied.•RFR model outperformed the other investigated models.•The construction period and the cellar beneath the investigated room are the main predictors.
In the framework of the last Council Directive 2013/59 (Euratom, 2014) laying down basic safety standards for protection against the dangers arising from exposure to ionizing radiation, the problem ...of radon was assumed in Romania at national level by responsible authorities through the design and development of a National Radon Action Plan and an adequate legislation (HG nr. 526/2018). In order to identify radon risk areas, however, it is necessary to perform systematic radon measurements in different environmental media (soil gas, water, indoor air) and to map the results. This paper presents an atlas of up-to-date radon in soil and water levels for central and western part of Romania. The radon in soil map includes data from 2564 measurements carried out on-site, using Luk3C radon detector. The Luk-VR system was used to measure radon activity concentration from 2452 samples of drinking water. The average radon activity concentration was 29.3 kBq m−3 for soil gas, respectively 9.8 Bq l−1 for water dissolved air. Mapping of radon can be a useful tool to implement radon policies at both the national and local levels, defining priority areas for further study when land-use decisions must be made.
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•Significant difference between the warm months and the cold months was observed.•Low values of radon activity concentration for the sedimentary areas.•A moderate correlation between the radon concentrations in water and soil.•Map of radon in water indicates no significant radiological risk.
Copper-based alloys with the addition of Al present excellent properties and can be considered a proper choice for applications as contact materials based on their good strength and fret resistance. ...Cu-Al alloys are used in different systems parts as bearings, gears and worm gears. The intention is to replace steel materials with new copper-based materials for parts that work in a possible explosive environment to reduce the possibility of spark appearance. Copper-berilyum alloys are known as non-sparking alloys and are used in different tools obtaining for environments with possible explosive gaseous. Results from the obtaining and analysis of a new alloy based on CuAlBe are given. The material was melted in a vacuum induction furnace from CuBe master alloy and high purity aluminium and cast into a metallic die. The alloys obtained were analyzed using EDS – energy dispersive spectroscopy for chemical composition, OM-optical and SEM-electronic microscopy for the microstructure, and the electro-corrosion resistance was tested using linear Tafel diagram and cyclic potentiometry.
Selective Laser Melting is an Additive Manufacturing technology based on 3D scanning of successive layers of metal powder. Three distinct values were determined for each of the three technological ...parameters (P - the power of the laser, Vscan - scanning speed and te - exposure time), therefore resulting nine sets for the "layer by layer" processing. After SLM processing, the samples were sandblasted simply (1S), sandblasted successively (2S), or left unsandblasted (NS). The roughness (Ra) of the outer surfaces was measured for all the samples, and there was found a decrease in the height of the micro-irregularities and the uniformization of the roughness profile along with the intensification of the sandblasting process. For some samples, there were found uncertainties regarding the accuracy of the experimental results' values, determined by the presence of the adherent particles identified by the SEM analysis of the outer surfaces. The number and size of these particles have affected the manner in which the samples were placed on the roughness tester's plate, as well as the accuracy of the measurements. Under these conditions, the tip of the roughness tester's diamond stylus has recorded the specific values of the surface's secondary profile, which is affected by the existence of the formations adhering to the primary profile of the SLM processed samples.
“What is life?” and Erwin Schrödinger's answer, “negative entropy”, inspired researchers in the 20th century to unite physics, chemistry, and physiology into a new synthesis that many believe to be ...an important foundation for life science today. Decades after Schrödinger, life scientists are still fascinated by the riddle that entropy can only accumulate in physical systems, which often leads to biological deterioration and death, but life finds ways to persist and prevail. So to say, life “negates” entropy. Can this fascination and research concept be broadened even further to human culture? Short after Schrödinger's publication, Claude Shannon coined the term “information entropy.” Information entropy accumulates when noise interferes during communication. Eventually, all useful information is lost. Yet, from this observation, something surprising can be inferred. Not only biological life but also cultural life has the ability to persist and prevail in spite of the accumulation of entropy. Does this insight mean that cultural life also negates entropy, in Schrödinger's sense? These questions guided me over several years of research during which I developed and tested a new theory of culture based on variation-selection processes and homeostatic regulation. My contribution is to discover that these two processes not only make statements about biological life. They also explain some of the most important phenomena of culture: returning fashions, polarization, diversification, cycles of growth and reform, and the formation of common ethos across entire bodies of knowledge. With access to big data and supercomputing, I tested my theory against hundreds of thousands of news, magazine articles, books, and TV transcripts as well as textual content collected from the social media. Historical, institutional, and geographical information was extracted from these data using a new method; and new interactive tools were created to interpret the results. What should not be missed when reading this article is that the theory proposed here reveals a striking equivalence between nature and culture. The article states this equivalence in mathematical terms, and contextualizes it in the history of science. The mathematical breakthrough is relevant because it aligns the humanities to science while also allowing for live evaluation of what I call “cultural diversification cycles.”
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•In cultural life, the unit of evolutionary selection is not the isolated idea but the group of interrelated ideas.•Between multiple units of evolutionary selection, there is homeostatic regulation. Within the units, there are variation-selection processes.•Variation-selection processes make the theoretical link between Shannon communication and dimensionality reductions (such as topic modeling).•Homeostatic regulation explains fashions, cultural diversification, as well as the evolution of common ethos across entire bodies of knowledge.•Diversification is a distinct (sixth) type of cooperation, present in both nature and culture.
Modern technologies of Additive Manufacturing type allow for the obtaining of the metal components specific to medical prosthetics in the best conditions. Selective Laser Melting (SLM) method is ...frequently used in dental medicine since there is an obvious trend to replace the classical casting techniques especially for non-noble Co-Cr alloys. According to the values of processing parameters (SLM) there will be parts having different roughness of the exterior surfaces. The conducted studies analysed the influences exercised by three process parameters (laser power - P, scan speed - vscan and exposure time - te) on roughness amplitude expressed by value (Ra). By combining the three distinct values adopted for each parameter we made nine sets of lamellar samples on whose non sandblasted surface, surface sandblasted once and surface sandblasted in two successive stages we carried out roughness measurements. Based on the results obtained for (Ra) parameter we formulated some recommendations for the technological parameter values that may provide surface roughness adequate to the subsequent destination of the processed parts (SLM).
Corrosion consists in the degradation of a material under the chemical or electrochemical action of the environment where it is located. The investigations performed aimed to highlight the structural ...modifications produced within the Ni-Cr-Mo alloy of Ugirex III type (Ugin dentaire, France) subjected to electrochemical corrosion in Fusayama-Mayer artificial saliva. The surfaces of the specimens subjected to experimental tests were analysed structurally by scanning electron microscopy (SEM).
As the first of a series of molecular solenoids, two classes of dithia7helicenes (coil-shaped molecules with sulfur atoms integrated within a helical conjugated system) have been devised and ...synthesized to be used in molecular electronics. We used a modular assembly of fragments using Pd catalyzed coupling reactions and a final photocyclization step for the syntheses; this strategy gave us straightforward access to helicenes bearing thiophene end rings with either exo or endo topologies. Unequivocal structural characterization was carried out by X-ray crystallography. In the solid state, their crystal architectures show little similarities; both can be considered an ensemble of heterochiral dimers ( P / M ) that are themselves very different in nature in light of their main pairing interactions. On a gold surface, the effect of the sulfur atom is to strengthen their binding to the electrodes, as manifested by scanning tunneling microscopy (STM) performed at room temperature. Different coating patterns were observed for each class of molecule, although the most prominent finding is that we could see resolved STM images of a single molecule, with a full display of its inherent chirality under room temperature conditions.
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