New Type Of Diagram Research Articles

Variation partitioning in double-constrained multivariate analyses: linking communities, environment, space, functional traits, and ecological niches

Constrained multivariate analysis is a common tool for linking ecological communities to environment. The follow-up is the development of the double-constrained correspondence analysis (dc-CA), integrating traits as species-related predictors. Further, methods have been proposed to integrate information on phylogenetic relationships and space variability. We expand this framework, proposing a dc-CA-based algorithm for decomposing variation in community structure and testing the simple and conditional effects of four sets of predictors: environment characteristics and space configuration as predictors related to sites, while traits and niche (dis)similarities as species-related predictors. In our approach, ecological niches differ from traits in that the latter are distinguished by and characterize the individual level, while niches are measured on the species level, and when compared, they are characteristics of communities and should be used as separate predictors. The novelties of this approach are the introduction of new niche parameters, niche dissimilarities, synthetic niche-based diversity which we related to environmental features, the development of an algorithm for the full variation decomposition and testing of the community–environment–niche–traits–space (CENTS) space by dc-CAs with and without covariates, and new types of diagrams for the results. Applying these methods to a dataset on freshwater mollusks, we learned that niche predictors may be as important as traits in explaining community structure and are not redundant, overweighting the environmental and spatial predictors. Our algorithm opens new pathways for developing integrative methods linking life, environment, and other predictors, both in theoretical and practical applications, including assessment of human impact on habitats and ecological systems.

Routine uncertainty propagation for the marine carbon dioxide system

Pairs of marine carbonate system variables are often used to calculate others, but those results are seldom reported with estimates of uncertainties. Although the procedure to propagate these uncertainties is well known, it has not been offered in public packages that compute marine carbonate chemistry, fundamental tools that are relied on by the community. To remedy this shortcoming, four of these packages were expanded to calculate sensitivities of computed variables with respect to each input variable and to use those sensitivities along with user-specified estimates of input uncertainties (standard uncertainties) to propagate uncertainties of calculated variables (combined standard uncertainties). Sensitivities from these packages agree with one another and with analytical solutions to within 0.01%; similar agreement among packages was found for the combined standard uncertainties. One package was used to quantify how propagated uncertainties vary among computed variables, seawater conditions, and the chosen pair of carbonate system variables that is used as input. The relative contributions to propagated uncertainties from the standard uncertainties of the input pair of measurements and various other input data (equilibrium constants etc) were explored with a new type of diagram. These error-space diagrams illustrate that further improvement beyond today's state-of-the-art measurement uncertainties for the input pair would generally be ineffective at reducing the combined standard uncertainties because the contribution from the constants is larger. Likewise, using much more uncertain measurements of the input pair does not always substantially worsen combined standard uncertainty. The constants that contribute most to combined standard uncertainties are generally K1 and K2, as expected. Yet more of the propagated uncertainty in the computed saturation states of aragonite and calcite comes from their solubility products. Thus percent relative combined standard uncertainties for the saturation states are larger than for the carbonate ion concentration. Routine propagation of these uncertainties should become standard practice.

Nonequilibrium gas-liquid transition in the driven-dissipative photonic lattice

We study the nonequilibrium steady state of the driven-dissipative Bose-Hubbard model with Kerr nonlinearity. Employing a mean-field decoupling for the intercavity hopping $J$, we find that the steep crossover between low and high photon-density states inherited from the single cavity transforms into a gas$-$liquid bistability at large cavity-coupling $J$. We formulate a van der Waals like gas$-$liquid phenomenology for this nonequilibrium situation and determine the relevant phase diagrams, including a new type of diagram where a lobe-shaped boundary separates smooth crossovers from sharp, hysteretic transitions. Calculating quantum trajectories for a one-dimensional system, we provide insights into the microscopic origin of the bistability.

Continuous Representation of the Proton and Electron Kinetic Parameters in the pH–Potential Space for Water Oxidation on Hematite

Understanding the mechanisms of multielectron and multiproton electrochemical reactions, particularly in the context of solar-to-fuel water splitting, is an outstanding challenge. Historically, Pourbaix diagrams are used to show the influence of potential and pH on the thermodynamic stability of electrode–electrolyte systems. These diagrams do not carry kinetic or mechanistic information, which often restricts their use to cases in which the thermodynamic limit can be assumed. We introduce and construct from experimental data two new types of diagrams that demonstrate the kinetic variations of electrochemical reactions as a function of pH and potential. These diagrams show the variation of the electron-transfer parameter (α) and the proton reaction order (ρ) in a wide range of potential and pH. We present α(pH, E) and ρ(pH, E) for water electrolysis on an iron oxide electrode in the range of pH 7 to 13. In these plots, regions of acidic and basic mechanisms, relationship to surface protonation equilibria,...

The role of hydroxy aluminium sulfate minerals in controlling Al3+ concentration and speciation in acidic soils

Abstract A thermodynamic approach for the complex chemical equilibria investigation of two-phase systems containing hydroxy aluminium sulfate (HAS) minerals in soils has been developed. This approach utilizes thermodynamic relationships combined with original mass balance constraints, where the HAS mineral phases are explicitly expressed. The factors influencing the distribution and concentrations of various soluble aluminium species have been taken into account. The new type of diagrams, based on thermodynamic, graphical and computerized methods, which quantitatively describe the distribution of soluble and insoluble inorganic, and organic, monomeric and polymeric aluminium species in acidic soil solutions in a large range of pH values has been used. The thermodynamics of equilibria of different natural HAS in soils, the conditions under which solids involving common ions can coexist at equilibrium, the acid-base and mineral equilibria and complex formation have been examined. It has been proved that the presence of sulfate ion dramatically alters the HAS mineral solubility under acidic conditions. The obtained data regarding the factors influencing Al speciation, based on the constructed diagrams of heterogeneous chemical equilibria, are in good agreement with the current experimental and theoretical evidence. The proposed approach is intended to determine the dominant processes that are responsible for the Al3+ concentration levels and its speciation in acidic soils.

Tunnel Design and Sensitivity Analysis

Sensitivity analysis should be employed to examine the effect of the variability of selected parameters on critical response of a construction, using credible upper and lower bounds. This investigation performs such an analysis for an actual tunnel design case by means of numerical modeling. A local method, which is a partial derivative of the output with respect to several input factors, is used so as to ensure ease of use for the designer. In this way, the effect of varying geotechnical parameters over their possible values with respect to internal forces and displacements of the tunnel temporary lining is evaluated. The analysis includes not only assessment of the greatest influence on the item under observation by use of new types of diagrams that provide better comprehension but also a first order reliability evaluation on the effect of input parameters with respect to the reinforcement requirements of the temporary lining.

Aluminium heterogeneous speciation in natural waters

The presence of aluminium in natural waters is of major concern at present because of the potential threat for the health of a number of species, including humans. In natural water, aluminium exists in different forms depending on the concentrations of various other species, organic matter, the types of minerals, the pH, etc. The aluminium species in the natural water – gibbsite system is considered in this work. The main approaches for estimating of the individual concentrations of the aluminium species involve the use of reliable thermodynamic data, together with experimental measurements of free or total concentrations of major components. The new type of diagrams based on graphical and computerized methods, which quantitatively describe the distribution of soluble and insoluble, inorganic, and organic, and monomeric and polymeric aluminium species in heterogeneous aquatic systems is presented. This approach utilizes thermodynamic relationships coupled with original mass balance constraints, where the mineral phases are explicitly expressed. The factors influencing the distribution of soluble and insoluble aluminium species in aquatic systems were analyzed. The new type of developed diagrams may be used to interpret data obtained within the framework of water-quality monitoring programs.

Characterization and Prediction of Flow Behavior in High-Manganese Twinning Induced Plasticity Steels: Part II. Jerky Flow and Instantaneous Strain Rate

The jerky and smooth flow curves in high-manganese twinning induced plasticity (TWIP) steels were investigated by comparing Fe-Mn-C and Fe-Mn-Al-C systems. The pronounced serrations on the flow curves of Fe-Mn-C TWIP steel, produced during tensile testing at 300 K (27 °C) and 373 K (100 °C), were shown to be the result of localized high-temperature Portevin Le-Chatelier (PLC) bands moving across the gage length throughout the deformation. The speed of the PLC bands and their temperature effects were found to be strongly dependent on the applied strain rate, which was controlled by adjusting the cross-head speed of the tensile testing machine. The localized temperature-dependent stacking fault energy (SFE) variations resulting from the PLC effect and adiabatic heating were analyzed and compared for both slow and fast deformation rates. The instabilities in the measured logarithmic strain values caused by jerky flow could cause the local strain rate to deviate systematically from the targeted (applied) strain rate. These instabilities are better observed by calculating the instantaneous strain rate (ISR) values for each instant of deformation along the entire gage length. Finally, a new type of diagram was developed by plotting the true stress against the ISR values. From the diagram, the onset of different mechanisms, such as deformation twinning, nonpronounced, and pronounced serrations, could be marked precisely.

Development of Corrosion Assessment Diagrams for High Temperature Chlorine Corrosion Part II: Development of “Dynamic” Quasi-stability Diagrams

The corrosion of metals at high temperatures in halogen containing environments differs from most other types of high temperature corrosion in that in addition to solid and liquid corrosion products volatile phases are also formed. The latter are not covered by the usual thermodynamic stability diagrams, which are often used for prediction of the corrosion products formed, and indirectly on whether corrosion has to be regarded as critical or not. The present paper aims at including the situation where gas phase corrosion products determine the extent of corrosion and a new type of diagram is developed and discussed for the example of chlorine containing environments. Part I of this paper (Latreche et al. Oxid Met 2009) was dedicated to the establishment of the basis for a new extended approach to a corrosion risk assessment diagram called the “dynamic” quasi-stability diagram. The present part deals with the principles of the new type of diagram and the establishment of specific diagrams for the most common alloying elements, i.e. Fe, Ni, Mo, Cr, Si, Al. For the development of the specific diagrams, the calculation of gas viscosities and gas diffusion coefficients of all relevant volatile potential corrosion products was conducted, with methods specified in the paper. The new “dynamic” quasi-stability diagrams were then compared to experimental results from kinetics investigations of pure metals, which showed quite good agreement with the experimental observations. Furthermore, the diagrams were used to assess the behaviour of the metallic elements in alloys. Again, in this case good agreement between prediction and experimental results was observed if the specific role of the different elements in the corrosion behaviour of the alloys was taken into account.

Development of Corrosion Assessment Diagrams for High Temperature Chlorine Corrosion. Part I: State of the Art and Development of the Basis for a New Extended Approach

As in many other areas of material science there is an increasing need for computational tools predicting materials behaviour, also in high temperature corrosion. In many cases stability diagrams have been developed for the assessment of high temperature corrosion resistance of metallic materials where the potentially formed corrosion products are plotted as fields of stability as a function of the activities or partial pressures of the species in the reaction environment. One major drawback of these diagrams is that they only contain solid or liquid phases as reaction products, but in halogen induced high temperature corrosion volatile metal halides are also formed. In order to overcome this drawback, the present paper deals with the development of a new type of diagram for high temperature halogen corrosion which will be developed and discussed for the example of oxygen/chlorine environments and which will be named “dynamic” quasi-stability diagram. In part I of the paper, the basis for this new approach to the corrosion resistance assessment of metals under chlorine environments is established using the present understanding described in the literature. A comparison is made between the concept of the conventional stability diagram and the recently developed “static” quasi-stability diagram, where in the latter case the evaporation of the gaseous metal chloride phases is taken into account through the use of a critical metal chloride partial pressure of 10−4 bar, as a criterion distinguishing critical and non-critical corrosion conditions. Concluding from the existing knowledge, the fundamentals for the new improved approach are developed in the form of a “dynamic” quasi-stability diagram. This new type of diagram is based not only on thermodynamic considerations (as for the diagrams existing so far) but also on the products and reactants flow through a gas boundary layer formed on the material surface. As a consequence, in this approach the criterion for corrosion resistance is given in terms of a metal recession rate for dynamic conditions as encountered in most industrial applications. In part II diagrams of the new type will be established for the most common alloying elements, i.e. Fe, Ni, Mo, Cr, Si and Al, and a comparison with experimental data will be performed.

Proposal and validation of a new type of flame stability diagram for partially premixed flames

A flame stability diagrams in a partially premixed flame are typically expressed using the axis coordinates of heat input rate and equivalence ratio. These diagrams are inadequate for identifying changes in combustion conditions and flame stability when a reference fuel is substituted with other fuels under identical operating conditions. To improve the usefulness of the flame stability diagram for estimating this interchangeability, this study proposes a new type of diagram and validates it experimentally. In this new diagram, the axis coordinates are air flow rate and Wobbe fuel flow rate, defined as the fuel flow rate multiplied by the square root of the relative density. The diagram was validated in trials using various fuels, including CH 4, C 3H 8, and LFG–C 3H 8 mixed fuels, in a domestic gas-range and an interchangeability test burner. The results of these trials show that the new diagram can provide useful information for assessing interchangeability of combustion conditions and flame stability when one fuel is substituted with another under identical operating conditions.

Locating air quality monitoring station using wind impact area diagram

In this study a new methodology is suggested to approximate the impact area downwind of an air pollution source, where air quality monitoring can be carried out to capture the maximum pollutant concentration. Hourly wind speed for a given month is grouped in to different wind speed ranges and the distance of pollutant travel is approximated from the average wind speed of that wind speed range. Since change in wind direction causes the impact distance to rotate, its rotation is approximated by the SD of wind direction change. Using this approach, area or region down wind of a source is determined and plotted. The pattern of monthly change of wind is better represented by the new type of diagram as compared to the wind rose diagram.

Covering points with a polygon

We consider problems in which we try to cover a given set of points (or a maximum number of them) with a given polygon. To solve these problems we use a new type of diagram that captures point-containment information for scalable, rotated, and/or translated versions of convex polygons. For a given polygon P and a contact point q in a point set S, the diagram parameterizes possible translations, rotations, and scales of P in order to represent containment regions for every other point v ∈ S . We present geometric and combinatorial properties of this diagram, and describe how it can be computed and used in the solution of several geometric matching problems. The latter have direct applications to object recognition and tolerancing problems in manufacturing.

The visibility–Voronoi complex and its applications

We introduce a new type of diagram called the VV ( c ) -diagram (the visibility–Voronoi diagram for clearance c), which is a hybrid between the visibility graph and the Voronoi diagram of polygons in the plane. It evolves from the visibility graph to the Voronoi diagram as the parameter c grows from 0 to ∞. This diagram can be used for planning natural-looking paths for a robot translating amidst polygonal obstacles in the plane. A natural-looking path is short, smooth, and keeps—where possible—an amount of clearance c from the obstacles. The VV ( c ) -diagram contains such paths. We also propose an algorithm that is capable of preprocessing a scene of configuration-space polygonal obstacles and constructs a data structure called the VV-complex. The VV-complex can be used to efficiently plan motion paths for any start and goal configuration and any clearance value c, without having to explicitly construct the VV ( c ) -diagram for that c-value. The preprocessing time is O ( n 2 log n ) , where n is the total number of obstacle vertices, and the data structure can be queried directly for any c-value by merely performing a Dijkstra search. We have implemented a Cgal-based software package for computing the VV ( c ) -diagram in an exact manner for a given clearance value and used it to plan natural-looking paths in various applications.

Modified predominance diagrams for gas-solid reactions

A new type of diagram is proposed to describe gas-solid reactions. These diagrams, called modified predominance diagrams, unite thermodynamics and kinetics into a new tool that should prove useful in many metallurgical and chemical systems. They are created from predominance diagrams by applying a mathematical transformation derived from basic transport and chemical rate phenomena. The diagrams predict the reaction product for given kinetic conditions and bulk atmospheric compositions. They consider the reaction from a single solid reactant to any solid product contained in the corresponding predominance diagram. The diagrams are similar to predominance diagrams except that some lines are curved and binary regions are created to satisfy both the equilibrium and kinetic requirements. The curvature results from the presence of gaseous reaction products at the solid reactant surface. The diagrams are developed in this article using the oxidation of a metal sulfide as an example. They show that the reaction path can be influenced even if the system is rate-limited by chemical kinetics. For a fixed bulk oxygen concentration, another diagram can be created, which can predict kinetic conditions under which mass transport no longer influences the reaction path predicted by thermodynamics.

Two-loop QCD corrections to top quark width

We present O( α s 2) corrections to the decay t → bW in the limit of a very large top quark mass, m t ⪢ m W . We find that the O( α s 2) effects decrease the top quark decay width Γ t by about 2%: Γ t = Γ 0 (1 − 0.8 α t ( m t ) − 1.7 α s 2). The complete corrections are smaller by about 24% than their estimate based on the BLM effects O( α s 2). We explain how to compute a new type of diagrams which contribute to Γ( t → bW) at the O( α s 2) level.

Drying Potential Of Humid Air - A Thermodynamical Anlysis

ABSTRACT Theoretical analysis of thermodynamical potentials relevant for water vapour transfer processes in the system: wet material - moist air, pertormed in the paper. leads to the conclusion that masimal possible isothermal decrease of chemical potential of water vapour in the moist air might be considered as the measure of humid air afinity to unbound water vapour. The concept developed provides better estimation of the drying ability of humid air of different states, as well as tracing Lines of equal values of humid air drying potential into psychrometric charts and constructing several new types of diagrams for convective drying processes in which air is used as the drying medium.

Epsilon -type contribution to baryon asymmetry from colored Higgs triplets.

In scenarios where the cosmological baryon asymmetry is generated in the decay of heavy colored Higgs triplets at the one-loop level (at least two triplets are needed), it is shown that in addition to the conventional triangle loop (\ensuremath{\epsilon}'-type effect), a new kind of diagram must be considered. This new type of diagram has its origin in the mixing of the two Higgs fields (\ensuremath{\epsilon}-type effect). The mixing of the two Higgs fields violates CP provided they have at least two common decay channels. For small mixing angles, the new contribution can be bigger than the conventional one.

A diagram for interpreting orientation data for planar features in core

A new type of diagram depicts orientation data for planar structures found in drill core. Strike and dip of fractures intersected by a borehole are plotted independently, side by side, as a function of borehole length. These companion plots show variations in distribution and orientation of fractures. The diagram is used to establish boundaries between fracture domains and to interpret a sequence of fracturing based on the spatial relationship between domains comprising different fracture patterns.

Method for extracting kinetic parameters from measured impedance spectra

The necessity for extracting faradaic impedances from measured ac impedance spectra is discussed. A straightforward extrapolation methods is described which allows the separation of faradaic impedances from measured spectra. Perturbations like solution resistances, inductivities and double-layer capacitances are extracted step by step to obtain the frequency dependence of the purely faradaic part of the impedance, which can now be analysed separately, for example, by using the same method again. This approach provides electrolyte and polarization resistances as well as charge transfer resistances and other important values of electrode kinetics. The method can be applied to systems exhibiting two or more time constants. A new type of diagram to depicting impedance spectra is introduced. Examples are presented to illustrate the use of separating faradaic impedances for the analysis of ac impedance spectra.