Photocatalytic Property and Electronic Structure of Lanthanide-based Oxysulfides

Lanthanide-based oxysulfides and sulfide, LnTaO_3.5S_0.5, Ln₁₀OS₁₄ (Ln = La, Pr, Nd, Sm) and La₄In₅S₁₃, were successively synthesized by sulfurization in a flowing H₂S. The sulfurization decreased the band-gap energies from >4 eV to <3eV, because of the formation of occupied S3p orbitals on the top of valence band. In accordance with the small band gap, the H₂ evolution from a 0.01 M Na₂S and 0.01 M Na₂SO₃ solution system was observed under irradiation of light up to >500 nm. The rate of H₂ evolution under light irradiation of >500 nm increased in the order of Ni/LaTaO_3.5S_0.5 < Ru/La₁₀OS₁₄ < Pt/La₄In₅S₁₃.     

A Convenient Synthesis of Some Coumarin Derivatives Using SnCl2 · 2H2O as Catalyst

Some substituted coumarins have been synthesized by von-Pechmann condensation using SnCl₂ · 2H₂O (10 mol %) as catalyst in ethanolic medium. The reactions are simple, easy in handling and environmentally benign.     

The relationship between photo-catalytic performance and optical property over Si-incorporated TiO2

This study focuses on the relationship between photo-catalytic performance and optical property over Si-incorporated TiO₂. The Si-incorporated TiO₂ particles exhibited a pure structure of anatase having a particle size of less than 20 nm and surface area of more than 190 m²/g. The absorbance did not shift to a higher wavelength in spite of the incorporation of the Si ions, but the intensity of the photoluminescence (PL) curve was the smallest in the case of the 2.0 mol% Si-TiO₂, which was related to the recombination between the excited electrons and holes. Based on these results, the photodecomposition of methyl orange in the liquid reaction was enhanced over the 2.0 mol% Si-incorporated TiO₂ compared with that over pure TiO₂: Methyl orange at 10.0 ppm was completely decomposed after 100 min when 1.0 g of the 2.0 mol% Si-incorporated TiO₂ was used.     

Novel electro-optic properties of epitaxially grown (Pb, La)(Zr, Ti)O3 (PLZT) thin films derived by advanced sol–gel methods

Advanced sol–gel methods using a secondary solvent addition into (Pb, La)(Zr, Ti)O₃ (PLZT) sol–gel solution and a methanol pre-treatment of sapphire substrates are demonstrated. For the secondary solvent addition, the additive affected the crystallinity and electro-optic (EO) property of PLZT films and only methanol addition can improve them. In addition, the methanol pre-treatment is also appeared to be effective to improve film characteristics.

Through these optimizations, epitaxially grown PLZT thin films on r-cut sapphire are obtained and a high Pockels coefficient which is comparable to those of bulk PLZTs is achieved. It is believed that these PLZT thin films are applicable for integrated EO devices and open the door for the future data communication systems.     

Power sector development in India with CO2 emission targets: Effects of regional grid integration and the role of clean technologies

The power sector in India at present comprises of five separate regional electricity grids having practically no integrated operation in between them. This study analyses the utility planning, environmental and economical effects of integrated power sector development at the national level in which the regional electric grids are developed and operated as one integrated system. It also examines the effects of selected CO₂ emission reduction targets in the power sector and the role of renewable power generation technologies in India. The study shows that the integrated development and operation of the power system at the national level would reduce the total cost including fuel cost by 4912 million $, total capacity addition by 2784 MW, while the emission of CO₂, SO₂ and NO_x would be reduced by 231.6 (1.9%), 0.8 (0.9%), 0.4 (1.2%) million tons, respectively, during the planning horizon. Furthermore, the study shows that the expected unserved energy, one of the indices of generation system reliability, would decrease to 26 GWh under integrated national power system from 5158 GWh. As different levels of CO₂ emission reduction targets were imposed, there is a switching of generation from conventional coal plants to gas fired plants, clean coal technologies and nuclear based plants. As a result the capacity expansion cost has increased. It was found that wind power plant is most attractive and economical in the Indian perspective among the renewable options considered (Solar, wind and biomass). Copyright © 2003 John Wiley & Sons, Ltd.     

Amtshaftung bei Bauführung im Hochwassergebiet; fehlerhafter Flächenwidmungsplan; Nachforschungspflichten der Gemeinde

Bestehen ausreichende Anhaltspunkte für die Hochwassergef?hrdung, ist die Gemeinde verpflichtet, sich durch Nachforschungen Gewissheit über das Vorliegen oder Nichtvorliegen eines Hochwasserabflussgebietes gem § 38 Abs 3 WRG zu verschaffen. Liegt ein solches vor, hat sie gem § 12 Abs 1 Z 2 krnt GplG dieses im Fl?chenwidmungsplan ersichtlich zu machen. Erteilt die Gemeinde eine Baubewilligung ohne diese von der Erteilung einer wasserrechtlichen Bewilligung abh?ngig zu machen, haftet sie für die Kosten der Bauführung, die bei gesetzes-konformer Vorgangsweise unterlassen worden w?re.     

3D velocity from 3D Doppler radial velocity

We present local least squares and regularization frameworks for computing 3D velocity (3D optical flow) from 3D radial velocity measured by a Doppler radar. We demonstrate the performance of our algorithms quantitatively on synthetic radial velocity data and qualitatively on real radial velocity data, obtained from the Doppler radar at Kurnell Radar station, Botany Bay, New South Wales, Australia. Radial velocity can be used to predict the future positions of storms in sequences of Doppler radar datasets.© 2005 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 189–198, 2005     

Ring‐opening polymerization of D,L‐lactide by rare earth 2,6‐dimethylaryloxide

Ring‐opening polymerization of D,L ‐lactide (LA) has been successfully carried out by using rare earth 2,6‐dimethylaryloxide (Ln(ODMP)₃) as single component catalyst or initiator for the first time. The effects of different rare earth elements, solvents, monomers and catalyst concentration as well as polymerization temperature and time on the polymerization were investigated. The results show that La(ODMP)₃ exhibits higher activity to prepare poly(D,L ‐lactide) (PLA) with a viscosity molecular weight of 4.5 × 10⁴ g mol^?1 and the conversion of 97 % at 100 °C in 45 min. The catalytic activity of Ln(ODMP)₃ has following sequence: La > Nd > Sm > Gd > Er > Y. A kinetic study has indicated that the polymerization is first order with respect to both monomer and catalyst concentration. The apparent activation energy of the polymerization of LA with La(ODMP)₃ is 69.6 kJ mol^?1. The analyses of polymer ends indicate that the LA polymerization proceeds according to ‘coordination–insertion’ mechanism with selective cleavage of the acyl–oxygen bond of the monomer. Copyright © 2004 Society of Chemical Industry     

Innovation in construction: a sociology of technology approach

An alternative approach to understanding innovation is made using two intersecting ideas. The first is that successful innovation requires consideration of the social and organizational contexts in which it is located. The complex context of construction work is characterized by inter-organizational collaboration, a project-based approach and power distributed amongst collaborating organizations. The second is that innovations can be divided into two modes: 'bounded', where the implications of innovation are restricted within a single, coherent sphere of influence, and 'unbounded', where the effects of implementation spill over beyond this. Bounded innovations are adequately explained within the construction literature. However, less discussed are unbounded innovations, where many firms' collaboration is required for successful implementation, even though many innovations can be considered unbounded within construction's inter-organizational context. It is argued that unbounded innovations require an approach to understand and facilitate the interactions both within a range of actors and between the actors and technological artefacts. The insights from a sociology of technology approach can be applied to the multiplicity of negotiations and alignments that constitute the implementation of unbounded innovation. The utility of concepts from the sociology of technology, including 'system building' and 'heterogeneous engineering', is demonstrated by applying them to an empirical study of an unbounded innovation on a major construction project (the new terminal at Heathrow Airport, London, UK). This study suggests that 'system building' contains outcomes that are not only transformations of practices, processes and systems, but also the potential transformation of technologies themselves.     

CO2 emissions in Greece for 1990–2002: A decomposition analysis and comparison of results using the Arithmetic Mean Divisia Index and Logarithmic Mean Divisia Index techniques

This paper deals with the decomposition analysis of energy-related CO₂ emissions in Greece from 1990 to 2002. The Arithmetic Mean Divisia Index (AMDI) and the Logarithmic Mean Divisia Index (LMDI) techniques are applied and changes in CO₂ emissions are decomposed into four factors: income effect, energy intensity effect, fuel share effect and population effect. The period-wise and time series analyses show that the biggest contributor to the rise in CO₂ emissions in Greece is the income effect; on the contrary, the energy intensity effect is mainly responsible for the decrease in CO₂ emissions. A comparison of the results of the two techniques gave an insight in the intricacies of energy decomposition. Finally, conclusions and future areas of research are presented.