Self-organized nanotemplating on misfit dislocation networks investigated by scanning tunneling microscopy

Self-ordering growth of nanoarrays on strained metallic interfaces is an attractive option for preparing highly ordered nanotemplates. The great potential of this natural templating approach is that symmetry, feature sizes, and density are predicted to depend on the interfacial stress in these strained layers, which can be adjusted by changing the substrate-thin film composition, temperature, and adlayer coverage. This bottom-up approach of growing nanostructured two-dimensional ordered arrays of clusters on the misfit dislocation networks of strained metallic thin films and surfaces requires a detailed understanding of the nucleation and film-adsorbate interaction processes. Here we show how high resolution, large scale, variable temperature scanning tunneling microscopy imaging can improve our understanding of these self-assembly processes.     

Cold War atmosphere: Distorted information and facts in the case of Free Europe balloons

Radio Free Europe used balloons to drop leaflets in an attempt to supplement radio with printed words in the 1950s—a historical moment when closing borders, censoring the press, jamming foreign radios, tapping telephone lines, and tracking letters from abroad created an almost hermetically sealed space without many means for exchanging information across the Iron Curtain. This article traces how distorted and limited information shaped Cold War propaganda and practices of information‐gathering. The article further examines unpredictable environmental factors that were transformed into persuasive political rhetoric. A comparative analysis of communist media shows similarities of imagination in a visual propaganda campaign across five communist countries. Fantasies evolved into an object of public interest when propaganda strategies embraced a language of facts.     

Particle size and support effects on the complete benzene oxidation by Co and Co–Pt catalysts

Monometallic cobalt and bimetallic Co–Pt samples of various particle sizes have been prepared using SiO₂ and synthetic kenyaite (layered silicate) as a support. They are characterized by elemental analysis, XRD, TPR, and XPS. Cobalt is introduced by two methods—classical impregnation and ammonia method. The ammonia method of preparation leads to the formation of finely dispersed Co₃O₄ on both supports. Besides, hardly reducible cobalt silicate phases appear predominantly on the SiO₂ support. The Co₃O₄ particle size varies between 5 and 20 nm, depending on the support. The monometallic Co samples prepared by ammonia method on both supports are more active in benzene combustion than the impregnated ones due to the finer dispersion of the easily reducible Co₃O₄. Addition of Pt improves the activity and the promoting effect is more evident for the impregnated sample. This is explained with the synergy effect of cobalt oxide species and Pt. The less promoting effect of Pt on the catalytic activity of the bimetallic kenyaite-supported samples is attributed to the stronger interaction between the Co oxide phase and Pt during the preparation process.     

Desulphurization of damped battery paste by sodium carbonate and sodium hydroxide

The paper treats investigation of the desulphurization process of damped Pb-paste by Na₂CO₃ or NaOH. There is determined the effect of Na₂CO₃ (NaOH) concentration and the liquid–solid phase ratio on the process parameters (degree of desulphurization and degree of Na₂CO₃ (NaOH) utilization in function of the temperature and process duration). The optimum conditions for carrying out desulphurization of Pb-pastes by Na₂CO₃ or NaOH are determined in dependence of the used reactors (common reactor with laboratory agitator and rotary reactor of drum type). The content of inclusions in the solutions is examined with the purpose of producing sufficiently pure crystalline Na₂SO₄ for the industry.     

Smart polymer recycling: Synthesis of novel rigid polyurethanes using phosphorus‐containing oligomers formed by controlled degradation of microporous polyurethane elastomer

This article describes a new approach for the recycling of microporous polyurethane elastomers by Tris(1‐methyl‐2‐chloroethyl) phosphate‐induced degradation. The phosphorus‐containing degradation products formed are transformed into reactive intermediates by reaction with propylene oxide and are used for the preparation of rigid polyurethane foams. These new phosphorus‐containing materials have higher density and better mechanical properties compared to the standard rigid polyurethane foams. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Numerical study of the atmospheric composition in Bulgaria

The present work aims at studying the local to regional atmospheric pollution transport and transformation processes over Bulgaria and at tracking and characterizing the main pathways and processes that lead to atmospheric composition formation in the region.The US EPA Models-3 system is chosen as a modeling tool. As the NCEP Global Analysis Data with 1 degree resolution is used as meteorological background, the MM5 and CMAQ nesting capabilities are applied for downscaling the simulations to a 9 km resolution over Balkans and 3 km over Bulgaria. The TNO emission inventory is used as emission input. Special pre-processing procedures are created for introducing temporal profiles and speciation of the emissions.The study is based on a large number of numerical simulations carried out day by day for the years 2000–2007 and four emission scenarios—with all the emissions and with biogenic emissions, emissions from energetics and road transport excluded. Results from the numerical simulations concerning the main features of the atmospheric composition in Bulgaria and the contribution of the different emission categories are demonstrated in the paper. Some results from the CMAQ “Integrated Process Rate Analysis” are also given.     

More on the microstructural characterization of dense particle gels

A systematic study of the microstructure of densely packed coagulated colloidal particle gels is important for understanding their macroscopic, in particular, mechanical properties. It was previously shown that heterogeneous gels exhibit higher elastic properties and yield strengths than their homogeneous counterparts at the same solids loading. This was explained by the newly developed straight path method.¹ However, this macroscopic behaviour can be also explained by classical and conceptually simpler methods of spatial statistics, in particular, the pair-correlation function and the related K-function. Additionally, the structural differences of homogeneous and heterogeneous gels can be described by the contact distributions, which characterize the pore space and are of relevance for certain transport properties. The understanding of the structural differences is completed by presenting a benchmark model, which is in some sense ‘between’ the homogeneous and heterogeneous case.