scholarly journals A New Approach to Quantifying Bioaccumulation of Elements in Biological Processes

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 345
Author(s):  
Kinga Proc ◽  
Piotr Bulak ◽  
Monika Kaczor ◽  
Andrzej Bieganowski

Bioaccumulation, expressed as the bioaccumulation factor (BAF), is a phenomenon widely investigated in the natural environment and at laboratory scale. However, the BAF is more suitable for ecological studies, while in small-scale experiments it has limitations, which are discussed in this article. We propose a new indicator, the bioaccumulation index (BAI). The BAI takes into account the initial load of test elements, which are added to the experimental system together with the biomass of the organism. This offers the opportunity to explore the phenomena related to the bioaccumulation and, contrary to the BAF, can also reveal the dilution of element concentration in the organism. The BAF can overestimate bioaccumulation, and in an extremal situation, when the dilution of element concentration during organism growth occurs, the BAF may produce completely opposite results to the BAI. In one of the examples presented in this work (Tschirner and Simon, 2015), the concentration of phosphorous in fly larvae was lower after the experiment than in the younger larvae before the experiment. Because the phosphorous concentration in the feed was low, the BAF indicated a high bioaccumulation of this element (BAF = 14.85). In contrast, the BAI showed element dilution, which is a more realistic situation (BAI = −0.32). By taking more data into account, the BAI seems to be more valid in determining bioaccumulation, especially in the context of entomoremediation research.

2014 ◽  
Vol 915-916 ◽  
pp. 668-672 ◽  
Author(s):  
Li Jun Wu ◽  
Chang Cai Zhao ◽  
Guo Jiang Dong

According to the GH3044 nickel-based superalloy with high yield strength, a new approach for superalloy tube named Tube Solid Granules Medium Forming (SGMF) was present, and tube SGMF process principle and the mechanical model of solid granules were designed. The superalloy tube SGMF process was investigated numerically by using User subroutine of Abaqus software, the deforming simulations of two groups of tube products were performed separately, and the elongation rate and thickness distributions of the products were analyzed. An experimental system was designed and developed for tube SGMF, typical GH3044 superalloy tubes were deformed, good correlation was observed between the simulation results and experimental data.


Geophysics ◽  
2020 ◽  
Vol 85 (1) ◽  
pp. R11-R28 ◽  
Author(s):  
Kun Xiang ◽  
Evgeny Landa

Seismic diffraction waveform energy contains important information about small-scale subsurface elements, and it is complementary to specular reflection information about subsurface properties. Diffraction imaging has been used for fault, pinchout, and fracture detection. Very little research, however, has been carried out taking diffraction into account in the impedance inversion. Usually, in the standard inversion scheme, the input is the migrated data and the assumption is taken that the diffraction energy is optimally focused. This assumption is true only for a perfectly known velocity model and accurate true amplitude migration algorithm, which are rare in practice. We have developed a new approach for impedance inversion, which takes into account diffractive components of the total wavefield and uses the unmigrated input data. Forward modeling, designed for impedance inversion, includes the classical specular reflection plus asymptotic diffraction modeling schemes. The output model is composed of impedance perturbation and the low-frequency model. The impedance perturbation is estimated using the Bayesian approach and remapped to the migrated domain by the kinematic ray tracing. Our method is demonstrated using synthetic and field data in comparison with the standard inversion. Results indicate that inversion with taking into account diffraction can improve the acoustic impedance prediction in the vicinity of local reflector discontinuities.


2018 ◽  
Vol 76 (1) ◽  
pp. 113-133 ◽  
Author(s):  
Fabian Hoffmann ◽  
Takanobu Yamaguchi ◽  
Graham Feingold

Abstract Although small-scale turbulent mixing at cloud edge has substantial effects on the microphysics of clouds, most models do not represent these processes explicitly, or parameterize them rather crudely. This study presents a first use of the linear eddy model (LEM) to represent unresolved turbulent mixing at the subgrid scale (SGS) of large-eddy simulations (LESs) with a coupled Lagrangian cloud model (LCM). The method utilizes Lagrangian particles to provide the trajectory of air masses within LES grid boxes, while the LEM is used to redistribute these air masses among the Lagrangian particles based on the local features of turbulence, allowing for the appropriate representation of inhomogeneous to homogeneous SGS mixing. The new approach has the salutary effect of mitigating spurious supersaturations. At low turbulence intensities, as found in the early stages of an idealized bubble cloud simulation, cloud-edge SGS mixing tends to be inhomogeneous and the new approach is shown to be essential for the production of raindrop embryos. At higher turbulence intensities, as found in a field of shallow cumulus, SGS mixing tends to be more homogeneous and the new approach does not significantly alter the results, indicating that a grid spacing of 20 m may be sufficient to resolve all relevant scales of inhomogeneous mixing. In both cases, droplet in-cloud residence times are important for the production of precipitation embryos in the absence of small-scale inhomogeneous mixing, either naturally due to strong turbulence or artificially as a result of coarse resolution or by not using the LEM as an SGS model.


Languages ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 198
Author(s):  
Bettina Leitner

This paper reevaluates the ground on which the division into urban and rural gələt dialects, as spoken in Iraq and Khuzestan (south-western Iran), is built on. Its primary aim is to describe which features found in this dialect group can be described as rural and which features tend to be modified or to emerge in urban contexts, and which tend to be retained. The author uses various methodical approaches to describe these phenomena: (i) a comparative analysis of potentially rural features; (ii) a case study of Ahvazi Arabic, a gələt dialect in an emerging urban space; and (iii) a small-scale sociolinguistic survey on overt rural features in Iraqi Arabic as perceived by native speakers themselves. In addition, previously used descriptions of urban gələt features as described for Muslim Baghdad Arabic are reevaluated and a new approach and an alternative analysis based on comparison with new data from other gәlәt dialects are proposed. The comparative analysis yields an overview of what has been previously defined as rural features and additionally discusses further features and their association with rural dialects. This contributes to our general understanding of the linguistic profile of the rural dialects in this geographic context.


ACS Omega ◽  
2018 ◽  
Vol 3 (9) ◽  
pp. 10449-10459 ◽  
Author(s):  
Sandrine Duong ◽  
Nora Lamharess-Chlaft ◽  
Mickaël Sicard ◽  
Bruno Raepsaet ◽  
Maria Elena Galvez ◽  
...  

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 737
Author(s):  
Christopher Jung ◽  
Dirk Schindler

A new approach for modeling daily precipitation (RR) at very high spatial resolution (25 m × 25 m) was introduced. It was used to develop the Precipitation Atlas for Germany (GePrA). GePrA is based on 2357 RR time series measured in the period 1981–2018. It provides monthly percentiles (p) of the large-scale RR patterns which were mapped by a thin plate spline interpolation (TPS). A least-squares boosting (LSBoost) approach and orographic predictor variables (PV) were applied to integrate the small-scale precipitation variability in GePrA. Then, a Weibull distribution (Wei) was fitted to RRp. It was found that the mean monthly sum of RR ( R R ¯ s u m ) is highest in July (84 mm) and lowest in April (49 mm). A great dependency of RR on the elevation (ε) was found and quantified. Model validation at 425 stations showed a mean coefficient of determination (R2) of 0.80 and a mean absolute error (MAE) of less than 10 mm in all months. The high spatial resolution, including the effects of the local orography, make GePrA a valuable tool for various applications. Since GePrA does not only describe R R ¯ s u m , but also the entire monthly precipitation distributions, the results of this study enable the seasonal differentiation between dry and wet period at small scales.


Author(s):  
Andrew Kurzawski ◽  
Ofodike A. Ezekoye

A fire contained within a room can spread into void spaces in the walls and ceiling through penetrations in the material that lines the compartment. Few studies have looked at how a room and contents fire transitions to a structural fire. One of the active areas of fire research is the coupling of the fire to the structure. Lightweight wood frame construction represents the majority of residential construction in the U.S. The construction details and choice of materials will affect the overall fire resistance of the structure. Because of the relative lack of knowledge on the fire penetration into wall spaces, this research examined how fire might penetrate into the void spaces of wood framed structures. In the U.S.A., a critical barrier to the penetration of hot gas products into void spaces is provided by the gypsum-board skin of the compartment. For most compartments, there are many penetrations within the compartment’s gypsum-board skin. Common potential access points include security system wiring (e.q. smoke detectors and cameras), ventilation fixtures, light switches, and electrical outlets among others. A hole in the gypsum may create opportunities for void space ignition. One of the purposes of this work is to develop a small scale testing system to characterize fire driven flow and heat transfer into a void space. With such an apparatus, one can rapidly identify materials that are prone to igniting for a given leakage geometry and fire size. Common materials found in void spaces include wooden structural members, plywood/oriented strand board, a variety of insulation types, and vapor barriers. This study discusses the characteristics of the small scale experimental system and preliminary tests on a range of void space construction materials.


Author(s):  
Justin Leidwanger

This book offers an archaeological analysis of maritime economy and connectivity in the Roman east. That seafaring was fundamental to prosperity under Rome is beyond doubt, but a tendency to view the grandest long-distance movements among major cities against a background noise of small-scale, short-haul activity has tended to flatten the finer and varied contours of maritime interaction and coastal life into a featureless blue Mediterranean. Drawing together maritime landscape studies and network analysis, this work takes a bottom-up view of the diverse socioeconomic conditions and seafaring logistics that generated multiple structures and scales of interaction. The material record of shipwrecks and ports along a vital corridor from the southeast Aegean across the northeast Mediterranean provides a case study of regional exchange and communication based on routine sails between simple coastal facilities. Rather than a single well-integrated and persistent Mediterranean network, multiple discrete and evolving regional and interregional systems emerge. This analysis sheds light on the cadence of economic life along the coast, the development of market institutions, and the regional continuities that underpinned integration—despite certain interregional disintegration—into Late Antiquity. Through this model of seaborne interaction, the study advances a new approach to the synthesis of shipwreck and other maritime archaeological and historical economic data, as well as a path through the stark dichotomies that inform most paradigms of Roman connectivity and trade.


2010 ◽  
Vol 14 (03) ◽  
pp. 435-448 ◽  
Author(s):  
ALEX GOFMAN ◽  
HOWARD R. MOSKOWITZ

The proposed consumer-driven innovation approach allows for the creation of individual communications with heterogeneous customers. It utilizes Rule Developing Experimentation (a modified conjoint analysis-based approach) to create a database of messages specific to the product and to segment consumers based on the patterns of individual utilities assigned to the different test elements. The paper introduces a new approach to identify a small subset of classification messages that allows for an actionable and parsimonious classification of any new population into pattern-based segments to achieve better targeting. The approach is demonstrated by a case study of identifying segment membership for better messages targeting prospective customers of a KIA car dealership.


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