Ice slurries phase transition thermodynamics: relations for determining concentration–temperature domains of application

Criteria for calculation of the concentration–temperature domain of use of ice slurries are defined, which allows establishing a temperature–concentration chart relating the temperature and the antifreeze mass fraction. It is shown that the shape of the chart depends only on the thermodynamic properties (heat capacity, ice–liquid equilibrium, etc.) of the diluted substance.     

TES microcalorimeter readout via transformer

Readout configuration for Transition Edge Sensor (TES) electrically coupled to a low noise warm front-end via transformer is studied. The study was aimed at the implementation of the readout involved in imaging with microcalorimeter detector arrays using frequency multiplexing technique (Appl. Phys. Lett. 81(1) (2002) 159). A model describing both TES electrothermal reaction and the readout response is investigated. Contribution of electronic noise to TES energy resolution is calculated. Prospective readout architecture with TES electrical biasing from the warm readout side is introduced. The architecture allows building of large imaging detector arrays with TES. It is shown that an unprecedented combination of imaging and spectrometry features can be achieved with TES readout via transformer.     

Mapping of continuous floristic gradients in grasslands using hyperspectral imagery

Transitions between plant species assemblages are often continuous with the form of the transition dependent on the ‘slope’ of environmental gradients and on the style of self-organization in vegetation. Image segmentation can present misleading or even erroneous results if applied to continuous spatial changes in vegetation. Even methods that allow for multiple-class memberships of pixels presuppose the existence of ideal types of species assemblages that constitute mixtures—an assumption that does not fit the case of continua where any section of a gradient is as ‘pure’ as any other section like in modulations of grassland species composition.Thus, we attempted to spatially model floristic gradients in Bavarian meadows by extrapolating axes of an unconstrained ordination of species data. The models were based on high-resolution hyperspectral airborne imagery. We further modelled the distribution of plant functional response types (Ellenberg indicator values) and the cover values of selected species. The models were made with partial least squares (PLS) regression analyses. The realistic utility of the regression models was evaluated by full leave-one-out cross-validation.The modelled floristic gradients showed a considerable agreement with ground-based observations of floristic gradients (R²=0.71 and 0.66 for the first two axes of ordination). Apart from mapping the most important continuous floristic differences, we mapped gradients in the appearance of plant functional response groups as represented by averaged Ellenberg indicator values for soil pH (R²=0.76), water supply (R²=0.66) and nutrient supply (R²=0.75), while models for the cover of single species were weak.Compared to many other vegetation attributes, plant species composition is difficult to detect with remote sensing techniques. This is partly caused by a lack of compatibility between methods of vegetation ecology and remote sensing. We believe that the present study has the potential to increase compatibility as neither spectral nor vegetation information gets lost by a classifying step.     

A recursive algorithm for generating the equations of motion of spatial mechanical systems with application to the five-point suspension

In this paper, a recursive formulation for generating the equations of motion of spatial mechanical systems is presented. The rigid bodies are replaced by a dynamically equivalent constrained system of particles which avoids introducing any rotational coordinates. For the open-chain system, the equations of motion are generated recursively along the serial chains using the concepts of linear and angular momenta. Closed-chain systems are transformed to open-chain systems by cutting suitable kinematic joints and introducing cut-joint constraints. The formulation is used to carry out the dynamic analysis of multi-link five-point suspension. The results of the simulation demonstrate the generality and simplicity of the proposed dynamic formulation.     

Transition metal oxides on organic semiconductors

Transition metal oxides (TMOs) on organic semiconductors (OSs) structure has been widely used in inverted organic optoelectronic devices, including inverted organic light-emitting diodes (OLEDs) and inverted organic solar cells (OSCs), which can improve the stability of such devices as a result of improved protection of air sensitive cathode. However, most of these reports are focused on the anode modification effect of TMO and the nature of TMO-on-OS is not fully understood. Here we show that the OS on TMO forms a two-layer structure, where the interface mixing is minimized, while for TMO-on-OS, due to the obvious diffusion of TMO into the OS, a doping-layer structure is formed. This is evidenced by a series of optical and electrical studies. By studying the TMO diffusion depth in different OS, we found that this process is governed by the thermal property of the OS. The TMO tends to diffuse deeper into the OS with a lower evaporation temperature. It is shown that the TMO can diffuse more than 20 nm into the OS, depending on the thermal property of the OS. We also show that the TMO-on-OS structure can replace the commonly used OS with TMO doping structure, which is a big step toward in simplifying the fabrication process of the organic optoelectronic devices.     

The effect of transition metal ions (M2+=Mn2+, Ni2+, Co2+, Cu2+) on the chemical synthesis polyaniline as counter electrodes in dye-sensitized solar cells

The effect of transition metal ions(M~(2+)=Mn~(2+),Ni~(2+),Co~(2+),Cu~(2+)) on the chemical synthesis of polyaniline(PANI) used as a platinum-free counter electrode(CE) in dye-sensitized solar cells(DSSCs) was investigated.PANI was synthesized by co-polymerization of aniline in the presence of different transition metal ions by using potassium dichromate in acidic medium. It was found that the ion doping of PANI showed a certain catalytic activity for the regeneration of traditional iodide/triiodide(I~-/I_3~-) redox couples. The power conversion efficiency(η) of PANI CEs doped with Mn~(2+),Ni~(2+),Co~(2+) (4.41%, 2.36% and 2.10%, respectively) were higher than 1.94%, the value measured for PANI CE without doping. Doping with Cu~(2+)decreased the power conversion efficiency of PANI CE(PANI-Cu~(2+) η = 1.41%). The electrical properties of the PANI, PANI-Ni~(2+), PANI-Co~(2+),PANI-Mn~(2+) and PANI-Cu~(2+) were studied by cyclic voltammetry(CV), impedance(EIS), and Tafel polarization curve. The experimental results confirmed that PANI was affected by the doping of different transition metal ions(M~(2+)=Mn~(2+),Ni~(2+),Co~(2+),Cu~(2+)). These results indicate a potential application of ion doped PANI as counter electrode in cost-effective DSSCs.     

Property Restitution and Private Rental Housing in Transition: The Case of the Czech Republic

The objective of this paper is to explain one phenomenon evident in the transformation of post-socialist states that has received insufficient scholarly attention to date: the restitution of the housing stock in terms of its causes and consequences. In this paper, the theory of social constructivism, including Kemeny's advanced application of this theory to the field of housing studies, is used to (a) explain the causes for a particular type of property restitution in the Czech Republic and (b) outline its consequences on the role and long-term social meaning of private rental housing. This research explains how restitution was viewed by the main participants in this discourse, and how the whole process was legitimised and socially constructed in the Czech Republic. The evidence presented stems from a multi-method analysis of discourse that integrates the results of in-depth interviews, content analysis of the press, and an analysis of data from attitude surveys. The paper shows how the initial state of consensus surrounding the image of restitution quickly dissolved. The emergence of divisions combined with the inadequate response of the state generated a biased image of private rental housing among Czech citizens—a pattern that persists to the present.     

An analysis of the transition proportion for binarization in handwritten historical documents

In this paper, we will present a mathematical analysis of the transition proportion for the normal threshold (NorT) based on the transition method. The transition proportion is a parameter of NorT which plays an important role in the theoretical development of NorT. We will study the mathematical forms of the quadratic equation from which NorT is computed. Through this analysis, we will describe how the transition proportion affects NorT. Then, we will prove that NorT is robust to inaccurate estimations of the transition proportion. Furthermore, our analysis extends to thresholding methods that rely on Bayes rule, and it also gives the mathematical bases for potential applications of the transition proportion as a feature to estimate stroke width and detect regions of interest. In the majority of our experiments, we used a database composed of small images that were extracted from DIBCO 2009 and H-DIBCO 2010 benchmarks. However, we also report evaluations using the original (H-)DIBCO?s benchmarks.     

Transition-metal-based NiCoS/C-dot nanoflower as a stable electrocatalyst for hydrogen evolution reaction

Development of highly efficient electrocatalysts to produce hydrogen has been a significant topic over the past few decades. Currently, the platinum metal group shows the best catalytic performance for the hydrogen evolution reaction (HER), but the high cost and low abundance of these materials limit their wider application. Therefore, we synthesized transition-metal-based NiCoS along with carbon dots (C-dots) as a structure-directing agent by a hydrothermal method. We also synthesized sulfur-doped NiCo, where the sulfur enhances the conductivity of the catalysts. Herein, the synthesis temperatures were changed in the range from 120 to 240 °C. Among all, NiCoS synthesized at 150 °C shows the best HER performance capabilities. In more detail, NiCoS prepared at this temperature exhibits an onset potential of 96 mV and an overpotential of 232 mV. Especially, as-prepared NiCoS nanoflower subjects to long-term stability over 20 h at a current density of 10 mA/cm², making it a promising low-cost candidate for hydrogen production.