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This paper reports on how the observation of the morphology development and growth by in situ optical methods as well as the determination of substrate temperature can be employed to tailor the characteristics of GaN and to control growth in MOVPE (metalorganic vapor phase epitaxy). Furthermore for the first time a method will be demonstrated that allows the difficult determination of an alloy composition – here (AlxGa1-x)N – independent on the perfection and roughness of the developing layer.

This paper reports on the in situ determination of the Al-content in AlxGa1–xN layers deposited by MOVPE on sapphire and silicon substrates by means of optical reflectance. The accuracy of the conventional in situ method which utilizes the dependence of the refractive index and the extinction coefficient on Al-content is compared to that of the new dispersion approach. The limits and possibilities of the new approach will be discussed. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

This paper reports on how the observation of the morphology development and growth by in situ optical methods as well as the determination of substrate temperature can be employed to tailor the characteristics of GaN and to control growth in MOVPE (metalorganic vapor phase epitaxy). Furthermore for the first time a method will be demonstrated that allows the difficult determination of an alloy composition?? here (AlxGa1-x)N ? independent on the perfection and roughness of the developing layer.

Experiments were carried out to evaluate the performance of various types of drip irrigation emitters, widely used in Israel, using waste water from a storage reservoir. Fine particulate matter agglomerated by microbial by-products and in-line developed biomass were the principal clogging agents. Clogging fluctuated, increased as water quality deteriorated and decreased when it improved. There were definable differences between emitters of various types as to their clogging susceptibility which were not directly correlated with differences in emitter flow-rate, although, for any particular type, the emitter with smaller discharge was always more sensitive to clogging. The clogging process generally started with emitters located at the far end of the lateral and partial emitter clogging was more common than complete plugging. Overflow was also found in most emitter types and was more common in regulated emitters. Reliable long term operation of most emitter types was achieved with filtration at 80 mesh (180 µm opening) combined with daily chlorination and bimonthly lateral flushing. Regular lateral discharge monitoring was found to be a convenient way to detect the initiation of the clogging process. Chlorination was most efficient when applied before the emitters became massively clogged.

Sorption of aniline by montmorillonite was studied by infra‐red, X‐ray diffraction and differential thermal analysis methods. The amount of aniline sorbed and the type of bonding depend upon the interlayer cations: anilinium, H+‐ and Al3+‐ give anilinium aniline ions, NH44‐ammonium aniline ions, alkalis and alkaline earths except Cs are bonded to aniline through water bridges and transition metal cations are coordinated to aniline partly directly and partly through water bridges. Sorption does not occur in the complete absence of water.

Infra‐red spectra supported by chemical, differential thermal and X‐ray analyses indicate that indole and methylated indoles are sorbed by variously substituted montmorillonites in seven different configurations. The type of configuration formed depends upon the indoles and the interlayer cations. It affects the layer separation and the thermal stability of the assemblages.

Freestanding electrodes for lithium ion batteries are considered as a promising option to increase the total gravimetric energy density of the cells due to a decreased weight of electrochemically inactive materials. We report a simple procedure for the fabrication of freestanding LiFe0.2Mn0.8PO4(LFMP)/rGO electrodes with a very high loading of active material of 83 wt%, high total loading of up to 8 mg cm−2, high energy density, excellent cycling stability and at the same time very fast charging rate, with a total performance significantly exceeding the values reported in the literature. The keys to the improved electrode performance are optimization of LFMP nanoparticles via nanoscaling and doping; the use of graphene oxide (GO) with its high concentration of surface functional groups favoring the adhesion of high amounts of LFMP nanoparticles, and freeze-casting of the GO-based nanocomposites to prevent the morphology collapse and provide a unique fluffy open microstructure of the freestanding electrodes. The rate and the cycling performance of the obtained freestanding electrodes are superior compared to their Al-foil coated equivalents, especially when calculated for the entire weight of the electrode, due to the extremely reduced content of electrochemically inactive material (17 wt% of electrochemically inactive material in case of the freestanding compared to 90 wt% for the Al-foil based electrode), resulting in 120 mAh g−1electrodein contrast to 10 mAh g−1electrodeat 0.2 C. The electrochemical performance of the freestanding LFMP/rGO electrodes is also considerably better than the values reported in literature for freestanding LFMP and LMP composites, and can even keep up with those of LFP-based analogues. The freestanding LFMP/rGO reported in this work is additionally attractive due to its high gravimetric energy density (604 Wh kg−1LFMPat 0.2C). The obtained results demonstrate the advantage of freestanding LiFe0.2Mn0.8PO4/rGO electrodes and their great potential for applications in lithium ion batteries.

Establishing a relationship between hydrocarbon migration and the precipitation of authigenic magnetite in sedimentary rocks is of significant interest with respect to (1) elucidating mechanisms for remagnetization and establishing the origin of secondary magnetizations residing in magnetite, (2) developing a method to date hydrocarbon migration events by determining the time of remanence acquisition by palaeomagnetic methods, and (3) evaluating whether searching for anomalous concentrations of diagenetic magnetic minerals and/or aeromagnetic anomalies is justified as a relatively inexpensive exploration tool. The direct association of hydrocarbon migration and the precipitation of authigenic magnetite has, however, not been established. In this paper we report palaeomagnetic, rock magnetic, petrographic and geochemical results of a study of samples from Permian spelebthems and gilsonite found in the Ordovician Arbuckle Group in southern Oklahoma. The results indicate that there is a genetic relationship between hydrocarbon migration and the precipitation of authigenic magnetite.

Bi4Ta2O11, Bi7Ta3O18, and Bi3TaO7