Synthesis of a New Class of Materials with a Regular (Periodic) Interconnected Microstructure

The scientific basis for the synthesis of a new class of materials with an regular (periodic) interconnected structure based on triply periodic surfaces of minimum energy is formulated. The analysis of chemical synthesis based on the reaction-diffusion Turing reaction, which allows obtaining periodic microstructures.     

Synthesis of multicomponent nanocomposites containing filamentary carbon nanostructures

Abstract

In this work, the multicomponent nanocomposites containing filamentary carbon nanostructures were synthesized using materials based on iron oxides with a predominant content of the epsilon phase (ε-Fe₂O₃). These iron oxide-based materials were obtained by a direct plasma-dynamic synthesis with supersonic outflow of an iron-containing electric discharge plasma into an oxygen atmosphere. Subsequently, they were used as an initial precursor and placed in the plasma-chemical reactor, where the multicomponent C/Si_xO_y/Fe₂O₃ nanostructures were synthesized under the influence of the pulsed electron beam. This method was based on the volume excitation of the reaction gas by a pulsed electron beam in such a way as to control the uniform process implementation in the entire excitation region. The morphology and phase composition of the synthesized C/Si_xO_y/Fe₂O₃ nanocomposites were studied. A typical morphological feature of the C/Si_xO_y/Fe₂O₃ samples was found to be the formation of filamentary nanostructures. Their diameter does not exceed 10–20?nm, while their length varies up to 1?μm.     

Dealing with Zero Flows in the Simulation of Water Distribution Networks with Low-Resistance Pipes Using the Global Gradient Algorithm

Water Resources Management - This paper shows that the zero flow treatment algorithm and the convergence criteria of EPANET 2.2, the latest version of the EPANET 2 open-source software package, may...     

More than just a plant: cushion plants as biodiversity protectors in high mountains of Siberia

The Siberian cushion plants have been little studied. This research aimed to reveal their morphological and ecological features as enabling them to survive and to protect biodiversity in a changing environment. The research was conducted in the Altai Mountains, Russia, at 1750–4000 m a.s.l. The temperature of cushion plants, the surrounding air and soil were studied. Substrate samples from cushions and topsoil were taken and analysed. Indices of hydrolytic acidity, loss on ignition and percentage of humus, phosphorus and nitrogen were taken into account in soil analysis. Bryophytes and vascular plants inhabiting cushions were studied. Fifty-four cushion plant species were classified into six morphological types based on the cushion skeleton construction and divided into ‘obligate’ and ‘facultative’ cushion plants. The temperature inside the cushions is much more stable, than that of their environment. Accumulation of organic matter within the cushions and in the sphere of their vital functions represents a process of local primary soil formation and makes cushion plant communities indifferent to the ground quality. The functional features of the cushion plants allow them to occupy high-mountain habitats and to be the centres of communities including other plants and animals, which can be found in an extreme environment only within or near the cushions, increasing the biological diversity of the alpine mountain zone.     

Governance in Houston: Growth Theories and Urban Pressures

Abstract: The article explores the political and social forces that have shaped local governance in Houston. This research will present a historical review of the role of local government and then examine two theoretical interpretations, the public choice and political economy perspectives, in explaining Houston's governance and public policy directions. The work will also show that recent events in Houston that might initially appear to contradict the city's historical development practices, such as greater ethnic sensitivity and increasing concern for the environment, have in no way challenged the city's pro‐growth agenda. The new directions in Houston's policy are simply a reflection of a different growth strategy reflecting changing demographics in the city and the new reality of Houston's diversifying economy.     

On the Laplace transform of a matrix of fundamental solutions for thermoelastic plates

The Laplace transform of a matrix D(x,t) of fundamental solutions for the partial differential operator describing the time-dependent bending of thermoelastic plates with transverse shear deformation is constructed, and its asymptotic behavior near the origin is investigated. The differential system is reduced to an algebraic one through the application of the Laplace and then Fourier transformations, and all possible cases of roots of the determinant of the latter system are considered. It is shown that in every case, the asymptotic expansion of near the origin has the same dominant term. This is an important step in the construction of boundary-element methods for the above time-dependent model because it determines the nature of the singularity of the kernel of the boundary-integral-equations associated with various initial-boundary-value problems for the governing system.     

Efficient recovery of CO2 from flue gas by clathrate hydrate formation in porous silica gels

Thermodynamic measurements and NMR spectroscopic analysis were used to show that it is possible to recover CO2 from flue gas by forming a mixed hydrate that removes CO2 preferentially from CO2/N2 gas mixtures using water dispersed in the pores of silica gel. Kinetic studies with 1H NMR microimaging showed that the dispersed water in the silica gel pore system reacts readily with the gas, thus obviating the need for a stirred reactor and excess water. Hydrate phase equilibria for the ternary CO2-N2-water system in silica gel pores were measured, which show that the three-phase hydrate-water-rich liquid-vapor equilibrium curves were shifted to higher pressures at a specific temperature when the concentration of CO2 in the vapor phase decreased. 13C cross-polarization NMR spectral analysis and direct measurement of the CO2 content in the hydrate phase suggested that the mixed hydrate is structure I at gas compositions of more than 10 mol % CO2, and that the CO2 molecules occupy mainly the more abundant 5(12)6(2) cages. This makes it possible to achieve concentrations of more than 96 mol % CO2 gas in the product after three cycles of hydrate formation and dissociation. 1H NMR microimaging showed that hydrate yields of better than 85%, based on the amount of water, could be obtained in 1 h when a steady state was reached, although approximately 90% of this yield was achieved after approximately 20 min of reaction time.     

Computerized segmentation of whole-body bone scintigrams and its use in automated diagnostics

Bone scintigraphy or whole-body bone scan is one of the most common diagnostic procedures in nuclear medicine used in the last 25 years. Pathological conditions, technically poor image resolution and artefacts necessitate that algorithms use sufficient background knowledge of anatomy and spatial relations of bones in order to work satisfactorily. A robust knowledge based methodology for detecting reference points of the main skeletal regions that is simultaneously applied on anterior and posterior whole-body bone scintigrams is presented. Expert knowledge is represented as a set of parameterized rules which are used to support standard image-processing algorithms. Our study includes 467 consecutive, non-selected scintigrams, which is, to our knowledge the largest number of images ever used in such studies. Automatic analysis of whole-body bone scans using our segmentation algorithm gives more accurate and reliable results than previous studies. Obtained reference points are used for automatic segmentation of the skeleton, which is applied to automatic (machine learning) or manual (expert physicians) diagnostics. Preliminary experiments show that an expert system based on machine learning closely mimics the results of expert physicians.     

The IoT Architectural Framework,Design Issues and Application Domains

The challenge raised by the introduction of Internet of Things (IoT) concept will permanently shape the networking and communications landscape and will therefore have a significant social impact. The ongoing IoT research activities are directed towards the definition and design of open architectures and standards, but there are still many issues requiring a global consensus before the final deployment. The paper presents and discusses the IoT architectural frameworks proposed under the ongoing standardization efforts, design issues in terms of IoT hardware and software components, as well as the IoT application domain representatives, such as smart cities, healthcare, agriculture, and nano-scale applications (addressed within the concept of Internet of Nano-Things). In order to obtain the performances related to recently proposed protocols for emerging Industrial Internet of Things applications, the preliminary results for Message Queuing Telemetry Transport and Time-Slotted Channel Hopping protocols are provided. The testing was performed on OpenMote hardware platform and two IoT operating systems: Contiki and OpenWSN.