Abstract: An alternative pathway to assemble mesoporous molecular sieve silicas is developed using nonionic alkylamines and N,N-dimethylalkylamines (SO) as structure-directing agents in acidic conditions. The synthesized mesostructures possess wormhole-like frameworks with pore sizes and pore volumes in the range of 20-90 Angstrom and 0.5-1.3 cm(3)/g, respectively. The formation of the mesophase is controlled by a counterion-mediated mechanism of the type (S(0)H(+))(X(-)I(+)), where S(0)H(+) are protonated water molecules that are hydrogen bonded to the lone electron pairs on the amine surfactant headgroups (S(0)H(+)), X(-) is the counteranion originating from the acid, and I(+) are the positively charged (protonated) silicate species. We found that the stronger the ion X(-) is bonded to S(0)H(+), the more it catalyzes the silica condensation into (S(0)H(+))(X(-)I(+)). Br(-) is shown to be a strong binding anion and therefore a fast silica polymerization promoter compared to Cl(-) resulting in the formation of a higher quality mesophase for the Br(-) syntheses. We also showed that the polymerization rate of the silica, dictated by the counterion, controls the morphology of the mesostructures from nonuniform agglomerated blocks in the case of Br(-) syntheses to spherical particles for the Cl(-) syntheses. Next to many benefits such as low temperature, short synthesis time, and the use of inexpensive, nontoxic, and easily extractable amine templates, the developed materials have a remarkable higher thermal and hydrothermal stability compared to hexagonal mesoporous silica, which is also prepared with nonionic amines but formed through the S(0)I(0) mechanism.

Abstract: Structural, chemical, and physical properties of whitlockite-type Ca9Bi(VO4)(7) were studied by X-ray powder diffraction (XRD), electron diffraction (ED), second-harmonic generation (SHG), thermogravimetry, differential scanning calorimetry, dielectric, and electrical-conductivity measurements. A new phase-transition of the ferroelectric type was found in Ca9Bi(VO4)(7) with a transition temperature, T-c of 1053 +/- 3 K. The polar phase, beta-Ca9Bi(VO4)(7), is stable below T-c down to at least 160 K. The centrosymmetric beta'-phase is stable above T-c up to 1273 +/- 5 K. Above 1273 K, it decomposes to give BiVO4 and whitlockite-type solid solutions of Ca9+1.5xBi1-x(VO4)(7). The beta<---->beta' phase transition is reversible and of second order. Electrical conductivity of beta'-Ca9Bi(VO4)(7) is rather high (sigma = 0.6 x 10(-3) S/cm at 1200 K) and obeys the Arrhenius law with an activation energy of 1.0 eV. Structure parameters of Ca9Bi(VO4)(7) are refined by the Rietveld method from XRD data measured at room temperature (space group R3c; Z = 6; a = 10.8992(1) Angstrom, c = 38.1192(4) Angstrom, and V = 3921.6(1) Angstrom(3); R-wp = 3.06% and R-p = 2.36%). Bi3+ ions together with Ca2+ ions are statistically distributed among the M1, M2, M3, and M5 sites. Ca9Bi(VO4)(7) has a SHG efficiency of about 140 times that of quartz. Through the powder SHG measurements, we estimated the nonlinear optical susceptibility, Digital, at about 6.1-7.2 pm/V. This value for Ca9Bi(VO4)(7) is comparable with that for known nonlinear optical materials such as LiNbO3 and LiTaO3.

Abstract: A thorough investigation was performed on the physical (mechanical, thermal, and hydrothermal stability) and chemical (ion exchange capacity and silanol number) characteristics of aluminosilicate FSMs, synthesized via a new successful short-time synthesis route using leached saponite and a low concentration of CTAB. Moreover, the influence of an additional Al incorporation, utilizing different aluminum sources, on the structure of the FSM derived from saponite is studied. A mesoporous aluminosilicate with a low Si/Al ratio of 12.8 is synthesized, and still has a very large surface area of 1130 m(2)/g and pore volume of 0.92 cm(3)/g. The aluminum-containing samples all have a high cation exchange capacity of around 1 mmol/9 while they still have a silanol number of about 0.9 OH/nm(2); both characteristics being interesting for high-yield postsynthesis modification reactions. Finally, a study is performed on the transformation of the aluminosilicates into their Bronsted acid form via the exchange with ammonium ions and a consecutive heat treatment.

Abstract: The engineering, construction, performance and running costs of a catalytic flue gas cleaning component in the low dust area of a municipal waste incinerator is discussed. For this purpose, the case study of a Flemish incineration plant is presented, covering the history, the design procedure of the catalyst, relevant process data and the financial aspects. A reliable PCDD/F-destruction by means of oxidation by the catalyst to typical values of 0.001 ng TEQ/Nm3 has been demonstrated. At the same time, NOx− and CO-emissions are reduced by 90% and 20% to about 50 mg/Nm3 and below 10 mg/Nm3, respectively.

Abstract: Many microscopic investigations of materials may benefit from the recording of multiple successive images. This can include techniques common to several types of microscopy such as frame averaging to improve signal-to-noise ratios (SNR) or time series to study dynamic processes or more specific applications. In the scanning transmission electron microscope, this might include focal series for optical sectioning or aberration measurement, beam damage studies or camera-length series to study the effects of strain; whilst in the scanning tunnelling microscope, this might include bias-voltage series to probe local electronic structure. Whatever the application, such investigations must begin with the careful alignment of these data stacks, an operation that is not always trivial. In addition, the presence of low-frequency scanning distortions can introduce intra-image shifts to the data. Here, we describe an improved automated method of performing non-rigid registration customised for the challenges unique to scanned microscope data specifically addressing the issues of low-SNR data, images containing a large proportion of crystalline material and/or local features of interest such as dislocations or edges. Careful attention has been paid to artefact testing of the non-rigid registration method used, and the importance of this registration for the quantitative interpretation of feature intensities and positions is evaluated.