Compress sensing algorithm for estimation of signals in sensor networks

Wireless Networks - In this research, we present a data recovery scheme for wireless sensor networks. In some sensor networks, each node must be able to recover the complete information of the...     

Investigating the quantity–quality relationship in scientific creativity: an empirical examination of expected residual variance and the tilted funnel hypothesis

Scientometrics - Among scientists who study scientific production, the relationship between the quantity of a scientist’s production and the quality of their work has long been a topic of...     

Location Planning for the Production of CO2-Based Chemicals Using the Example of Olefin Production

A methodology for identifying suitable locations for the CO₂-based production of olefins in Germany is presented. Based on electricity and CO₂ requirements, locations are identified that can provide sufficient CO₂ and renewable energy for the conversion of CO₂ to olefins. In addition, the use of existing infrastructures is taken into account. The regional, technical renewable energy potential in Germany is sufficient to produce ∼ 800 kt of olefins from CO₂-based methanol per year in one plant. But the currently available CO₂ point sources with high CO₂ concentrations of around 100 % are not sufficient to meet the CO₂ requirement of an 800 kt a⁻¹ methanol-to-olefins plant. If existing refineries are preferred due to existing infrastructure services, locations in the north of Cologne, in Lower Saxony, and in Brandenburg are particularly suitable. A full substitution of fossil olefins by CO₂-based olefins is possible in Germany. The challenge is to provide sufficient renewable electricity for the production of H₂ with a low CO₂ intensity.     

From MCDA to Fuzzy MCDA: violation of basic axiom and how to fix it

Neural Computing and Applications - The use of fuzzy numbers (FNs) for managing uncertainty in multi-criteria decision analysis (MCDA) demands a thorough exploring multi-criteria decision problem...     

Separating the reaction and spark plasma sintering effects during the formation of TiC–Cu composites from mechanically milled Ti–C–3Cu mixtures

The goal of this work was to separate the reaction and spark plasma sintering (SPS) effects during the in-situ synthesis of TiC in mechanically milled Ti–C–3Cu powder mixtures. The powders were milled for 3–10 min in a high-energy planetary ball mill. Structural changes occurring in the reaction mixtures during thermal explosion (TE) in a furnace and SPS in a graphite die were compared. Although the maximum temperature of TE reached the melting point of copper in some samples, no evidence of extensive melting was observed in the microstructure of the products of TE. The ignition and maximum temperatures of TE were found to decrease with increasing milling time of the mixture. In the mixture milled for 10 min, the maximum temperature of TE was only 820 °C. Melting of copper at the inter-particle contacts during SPS was observed in samples milled for 5–10 min (SPS at 900–980 °C) and caused the formation of TiC-depleted regions in the microstructure. Those regions were the re-solidified melt partially filling the pores between the agglomerates. Based on the analysis of the TE parameters in the mixtures and microstructures of the products of TE and SPS, melting during SPS was attributed to the effect of electric current (a high electric current density at the inter-particle contacts) and not to the heat of reaction. The hardness, compressive strength and Young's modulus of the sintered composites are reported. A TiC–Cu composite (milling time 5 min, SPS at 980 °C, relative density 93%) shows a compressive yield strength of 890 MPa and an ultimate compressive strength of 920 MPa.     

Metal hydride hydrogen storage and compression systems for energy storage technologies

Along with a brief overview of literature data on energy storage technologies utilising hydrogen and metal hydrides, this article presents results of the related R&D activities carried out by the authors. The focus is put on proper selection of metal hydride materials on the basis of AB₅- and AB₂-type intermetallic compounds for hydrogen storage and compression applications, based on the analysis of PCT properties of the materials in systems with H₂ gas. The article also presents features of integrated energy storage systems utilising metal hydride hydrogen storage and compression, as well as their metal hydride based components developed at IPCP and HySA Systems.     

Integration of peroxide delignification and sulfamic acid sulfation methods for obtaining cellulose sulfates from aspen wood

A new method to obtain cellulose sulfates from available and inexpensive raw material—aspen wood was developed. This method integrates catalytic peroxide delignification and sulfamic acid sulfation stages. Solvents such as acetic acid and water were used for isolation of pure cellulose by wood peroxide delignification with TiO₂ catalyst. Low-aggressive and less-toxic sulfating agent—sulfamic acid–urea mixture was used to obtain cellulose sulfates.     

Removal of Zinc Ions from Acid Aqueous Solutions and Acid Mine Drainage Using Zeolite-Bearing Tuff

Mine Water and the Environment - Zeolite-bearing tuff (stilbite) was shown to be an effective and efficient adsorbent for treating acid mine drainage (AMD). We tested the adsorption of zinc ions...