Impact of interstitial impurities on the trapping of dislocation loops in tungsten

AbstractAb initio simulations are employed to assess the interaction of typical interstitial impurities with self-interstitial atoms, dislocation loops and edge dislocation lines in tungsten. These impurities are present in commercial tungsten grades and are also created as a result of neutron transmutation or the plasma in-take process. The relevance of the study is determined by the application of tungsten as first wall material in fusion reactors. For the defects with dislocation character, the following ordering of the interaction strength was established: H < N < C < O < He. The magnitude of the interaction energy was rationalized by decomposing it into elastic (related to the lattice strain) and chemical (related to local electron density) contributions. To account for the combined effect of impurity concentration and pinning strength, the impact of the presence of these impurities on the mobility of isolated dislocation loops was studied for DEMO relevant conditions in the non-elastic and dilute limit.

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Anthropogenic perturbation modifies interactions between mammals and fruits in a tropical forest of southern Mexico

Animal Biology ◽

10.1163/15707563-bja10056 ◽

2021 ◽

Vol 71 (3) ◽

pp. 311-327

Author(s):

Mayra Zamora-Espinoza ◽

Juan Carlos López-Acosta ◽

Eduardo Mendoza

Keyword(s):

Daily Activity ◽

Interaction Strength ◽

Biotic Interactions ◽

Camera Traps ◽

Canis Lupus Familiaris ◽

Mammalian Fauna ◽

Mammal Species ◽

Southern Mexico ◽

Field Station ◽

The Impact

Abstract Studies of tropical mammal defaunation highlight the loss of species as well as their reduction in abundance and diversity; however, there is a complex series of effects associated with this anthropogenic disruption, including increases in the relative abundance of disturbance-tolerant mammals and the arrival of alien mammals whose effects on biotic interactions have been poorly studied. We compared the species richness, composition, interaction strength, and patterns of daily activity of mammals that consume the fruits of Pouteria sapota on the forest floor, both inside and outside of the Los Tuxtlas Field Station (LTFS) in Veracruz, southern Mexico. Using camera traps, we recorded eight mammal species interacting with the fruits inside the LTFS ( trees) and nine species interacting outside ( trees). Alien species such as Canis lupus familiaris were recorded both inside and outside of the LTFS, whereas Bos taurus was only recorded outside. Medium-sized generalist mammals were overrepresented both inside and outside of the LTFS, evidencing an impoverishment of the fauna, when compared to the mammal assemblage reported to interact with P. sapota fruits in a more intact forest. The daily activity patterns of the mammals that interacted strongly with P. sapota fruits were different inside and outside the LTFS, particularly in the case of Cuniculus paca. Our results show that the impact of human activity is highly pervasive, directly affecting the mammalian fauna at different levels and indirectly affecting the biotic interactions in which these animals are involved.

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Analysis of the Impact of the Construction of a Trombe Wall on the Thermal Comfort in a Building Located in Wrocław, Poland

Atmosphere ◽

10.3390/atmos10120761 ◽

2019 ◽

Vol 10 (12) ◽

pp. 761 ◽

Cited By ~ 1

Author(s):

Jagoda Błotny ◽

Magdalena Nemś

Keyword(s):

Temperature Increase ◽

Cooling System ◽

Renewable Energy Sources ◽

Heating System ◽

Wall Material ◽

Ansys Fluent ◽

Cooling Period ◽

Heating And Cooling ◽

Trombe Wall ◽

The Impact

Changes in climate, which in recent years have become more and more visible all over the world, have forced scientists to think about technologies that use renewable energy sources. This paper proposes a passive solar heating and cooling system, which is a Trombe wall located on the southern facade of a room measuring 4.2 m × 5.2 m × 2.6 m in Wrocław, Poland. The studies were carried out by conducting a series of numerical simulations in the Ansys Fluent 16.0 environment in order to examine the temperature distribution and air circulation in the room for two representative days during the heating and cooling period, i.e., 16 January and 15 August (for a Typical Meteorological Year). A temperature increase of 1.11 °C and a temperature decrease in the morning and afternoon hours of 2.27 °C was obtained. Two options for optimizing the passive heating system were also considered. The first involved the use of triple glazing filled with argon in order to reduce heat losses to the environment, and for this solution, a temperature level that was higher by 8.50 °C next to the storage layer and an increase in the average room temperature by 1.52 °C were achieved. In turn, the second solution involved changing the wall material from concrete to brick, which resulted in a temperature increase of 0.40 °C next to the storage layer.

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The Electronic Properties of Extended Defects in SrTiO3—A Case Study of a Real Bicrystal Boundary

Crystals ◽

10.3390/cryst10080665 ◽

2020 ◽

Vol 10 (8) ◽

pp. 665 ◽

Cited By ~ 1

Author(s):

Christian Rodenbücher ◽

Dominik Wrana ◽

Thomas Gensch ◽

Franciszek Krok ◽

Carsten Korte ◽

...

Keyword(s):

Electronic Properties ◽

Boundary Region ◽

Thermal Reduction ◽

Fluorescence Lifetime Imaging ◽

Extended Defects ◽

Force Microscopy ◽

Ab Initio Simulations ◽

Complementary Method ◽

Inhomogeneous Properties ◽

The Impact

This study investigates the impact of extended defects such as dislocations on the electronic properties of SrTiO3 by using a 36.8° bicrystal as a model system. In order to evaluate the hypothesis that dislocations can serve as preferential reduction sites, which has been proposed in the literature on the basis of ab initio simulations, as well as on experiments employing local-conductivity atomic force microscopy (LC-AFM), detailed investigations of the bicrystal boundary are conducted. In addition to LC-AFM, fluorescence lifetime imaging microscopy (FLIM) is applied herein as a complementary method for mapping the local electronic properties on the microscale. Both techniques confirm that the electronic structure and electronic transport in dislocation-rich regions significantly differ from those of undistorted SrTiO3. Upon thermal reduction, a further confinement of conductivity to the bicrystal boundary region was found, indicating that extended defects can indeed be regarded as the origin of filament formation. This leads to the evolution of inhomogeneous properties of defective SrTiO3 on the nano- and microscales.

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The impact of chemical structure on polyphenol bioaccessibility, as a function of processing, cell wall material and pH: A model system

Journal of Food Engineering ◽

10.1016/j.jfoodeng.2020.110304 ◽

2021 ◽

Vol 289 ◽

pp. 110304 ◽

Cited By ~ 2

Author(s):

Eden Eran Nagar ◽

Liora Berenshtein ◽

Inbal Hanuka Katz ◽

Uri Lesmes ◽

Zoya Okun ◽

...

Keyword(s):

Cell Wall ◽

Chemical Structure ◽

Model System ◽

Wall Material ◽

Cell Wall Material ◽

The Impact

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Molecular Dynamics of the Properties of Fluid Film Induced by Fluid-Solid Interaction Potential Strength in Wedge Nanochannel

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.574.133 ◽

2014 ◽

Vol 574 ◽

pp. 133-137

Author(s):

Yan Jia ◽

Ping Ge Qu

Keyword(s):

Molecular Dynamics ◽

Interaction Potential ◽

Interaction Strength ◽

Potential Interaction ◽

Molecular Dynamics Method ◽

Fluid Film ◽

Potential Strength ◽

The Impact ◽

Fluid Solid Interaction ◽

Dynamics Method

Molecular dynamics method is applied to study the influence of fluid-solid interaction potential on the properties of fluid film in wedge nanochannel. The pressure and density are studied for a variety of potential interaction strength between the liquid and the solid. The impact of potential interaction strength between the liquid and the solid on the pressure is limitation. The density alongydirection is affected by the potential interaction strength. As the potential interaction strength is weak, the density of liquids can be affected easily.

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Exploring the Impact of Dockless Bikeshare on Docked Bikeshare—A Case Study in London

Sustainability ◽

10.3390/su12156110 ◽

2020 ◽

Vol 12 (15) ◽

pp. 6110

Author(s):

Dongdong Feng ◽

Lin Cheng ◽

Mingyang Du

Keyword(s):

Network Analysis ◽

Complex Network ◽

Interaction Strength ◽

Network Connectivity ◽

Temporal Analysis ◽

Complex Network Analysis ◽

Last Mile ◽

Considerable Impact ◽

The Impact ◽

Spatial Temporal Analysis

As a green and sustainable travel mode, the bikeshare plays an important role in solving the “last-mile” problem. The new dockless bikeshare system (DBS) is widely favored by travelers, and the traditional docked bikeshare system (BS) is affected to a certain extent, but the specific circumstances of this impact are not yet known. To fill the knowledge gap, the objective of this study is to measure the impacts of DBS on London cycle hire, which is a type of BS. In this study, the travel data of 707 docking stations in two periods, i.e., March 2018 and March 2017, are included. A spatial-temporal analysis is first conducted to investigate the mobility pattern changes. A complex network analysis is then developed to explore the impact of DBS on network connectivity. The results suggest a significant decrease of 64% in the average trip amounts, with both origins and destinations in the affected area, and the trips with short and medium duration and short and medium distances are mainly replaced by DBS. DBS also has a considerable impact on the structure and properties of the mobility network. The connectivity and interaction strength between stations decrease after DBS appears. We also concluded that the observed changes are heterogeneously distributed in space, especially on weekends. The applied spatial-temporal analysis and complex network analysis provide a better understanding of the relationships between DBS and BS.

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Ion Implantation Defect Characterization by High-Resolution X-Ray Diffraction

MRS Proceedings ◽

10.1557/proc-262-1121 ◽

1992 ◽

Vol 262 ◽

Author(s):

Jos G.E. Klappe ◽

István Bársony ◽

Tom W. Ryan

Keyword(s):

High Resolution ◽

Ion Implantation ◽

Lattice Strain ◽

Crystalline Silicon ◽

High Energy ◽

Silicon Sample ◽

Dislocation Loops ◽

X Ray Diffraction ◽

X Ray ◽

Residual Defect

ABSTRACTHigh-energy ion-implantation is one of the roost critical processing steps regarding the formation of defects in mono-crystalline silicon. High- as well as low-doses implanted at various energies can result in relatively high residual defect concentrations after post-implantation annealing.Before annealing, the crystal lattice strain is mainly caused by the point defects. After annealing, the accommodation of substitutional impurities is the main origin of the residual lattice strain. High-Resolution X-ray Diffraction (HRXD) has been frequently used for the characterization of these structures. Dislocation loops formed during the high temperature step, however, cause enhanced diffuse X-ray scattering, which can dominate the measured X-ray intensity in conventional HRXD.Triple axis diffractometry is used in this study to analyze the size, type and location of defects in a boron implanted and rapid thermally annealed silicon sample.

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A discussion on deformation of solids by the impact of liquids, and its relation to rain damage in aircraft and missiles, to blade erosion in steam turbines, and to cavitation erosion - The application of dislocation etching techniques to the study of liquid impacts

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1966.0035 ◽

1966 ◽

Vol 260 (1110) ◽

pp. 101-120 ◽

Cited By ~ 8

Keyword(s):

Liquid Droplet ◽

Effective Area ◽

Optical Microscope ◽

Dislocation Loops ◽

Steam Turbines ◽

Liquid Drops ◽

Dislocation Etching ◽

Chemical Etch ◽

The Impact ◽

Droplet Impacts

Erosion damage is very often the cumulative result of a series of liquid droplet impacts which individually do not produce any deformation visible under the optical microscope. Such collisions do, however, produce dislocations in the crystalline structure surrounding the area of impact, and in suitable materials these dislocations can be revealed by chemical etch pitting. The technique is particularly easy to apply to freshly cleaved lithium fluoride crystals, and it has been used to study several types of impact. The impact of solid balls produces symmetrical rosettes of dislocations lying on {110} planes, and the dimensions of the rosettes can be related to the area of contact and stress distribution calculated from the theory of the collision of elastic/plastic bodies. Similar, but less symmetrical, rosettes are produced by liquid impacts and, by comparison of the extent and distribution of the dislocation loops in the two cases, it has been possible to make an estimate of the pressure and effective area of contact for liquid drops of various sizes, quantities which are otherwise difficult to measure. The behaviour of liquids other than water has also been investigated.

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Mutations in a single signaling pathway allow growth on a different solvent than water

10.1101/692889 ◽

2019 ◽

Author(s):

Caroline Kampmeyer ◽

Jens V. Johansen ◽

Christian Holmberg ◽

Magnus Karlson ◽

Sarah K. Gersing ◽

...

Keyword(s):

Cell Wall ◽

Morphological Changes ◽

Biological Effects ◽

Control Cell ◽

Wall Material ◽

Cell Integrity ◽

Prolonged Incubation ◽

Altered Glucose ◽

Wide Range ◽

The Impact

AbstractSince life is completely dependent on water, it is difficult to gauge the impact of solvent change. To analyze the role of water as a solvent in biology, we replaced water with heavy water (D2O), and investigated the biological effects by a wide range of techniques, using the fission yeast Schizosaccharomyces pombe as model organism. We show that high concentrations of D2O lead to altered glucose metabolism, growth retardation, and inhibition of meiosis. However, mitosis and overall cell viability were only slightly affected. After prolonged incubation in D2O, cells displayed gross morphological changes, thickened cell walls as well as aberrant septa and cytoskeletal organization. RNA sequencing revealed that D2O causes a strong downregulation of most tRNAs and triggers activation of the general stress response pathway. Genetic screens identified several D2O sensitive mutants, while mutants compromised in the cell integrity pathway, including the protein kinase genes pmk1, mkh1, pek1 and pck2, that control cell wall biogenesis, were more tolerant to D2O. We speculate that D2O affects the phospholipid membrane or cell wall glycans causing an activation of the cell integrity pathway. In conclusion, the effects of solvent replacement are pleiotropic but the D2O-triggered activation of the cell integrity pathway and subsequent increased deposition of cell wall material and septation problems appear most critical for the cell growth defects.

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A comparison of H2 formation models at high redshift

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2313 ◽

2020 ◽

Vol 497 (4) ◽

pp. 5008-5023 ◽

Cited By ~ 1

Author(s):

Alexander Schäbe ◽

Emilio Romano-Díaz ◽

Cristiano Porciani ◽

Aaron D Ludlow ◽

Matteo Tomassetti

Keyword(s):

Galaxy Formation ◽

High Redshift ◽

Empirical Method ◽

High Mass ◽

Rate Equations ◽

Approximate Methods ◽

Ab Initio Simulations ◽

H2 Formation ◽

Semi Empirical ◽

The Impact

ABSTRACT Modelling the molecular gas that is routinely detected through CO observations of high-redshift galaxies constitutes a major challenge for ab initio simulations of galaxy formation. We carry out a suite of cosmological hydrodynamic simulations to compare three approximate methods that have been used in the literature to track the formation and evolution of the simplest and most abundant molecule, H2. Namely, we consider (i) a semi-empirical procedure that associates H2 to dark-matter haloes based on a series of scaling relations inferred from observations, (ii) a model that assumes chemical equilibrium between the H2 formation and destruction rates, and (iii) a model that fully solves the out-of-equilibrium rate equations and accounts for the unresolved structure of molecular clouds. We study the impact of finite spatial resolution and show that robust H2 masses at redshift $z$ ≈ 4 can only be obtained for galaxies that are sufficiently metal enriched in which H2 formation is fast. This corresponds to H2 reservoirs with masses $M_{\mathrm{H_2}}\gtrsim 6\times 10^9$ M⊙. In this range, equilibrium and non-equilibrium models predict similar molecular masses (but different galaxy morphologies) while the semi-empirical method produces less H2. The star formation rates as well as the stellar and H2 masses of the simulated galaxies are in line with those observed in actual galaxies at similar redshifts that are not massive starbursts. The H2 mass functions extracted from the simulations at $z$ ≈ 4 agree well with recent observations that only sample the high-mass end. However, our results indicate that most molecular material at high $z$ lies yet undetected in reservoirs with $10^9\lt M_{\mathrm{H}_2}\lt 10^{10}$ M⊙.

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