Minimizing diurnal variation of downstream flow in hydroelectric projects to reduce environmental impact

Hydroelectric projects are generally operated as peaking power plant, particularly during lean period; consequently, diurnal variation of flow in the downstream of the dam is induced even in a run-of-the-river scheme. Although such deviation from the natural flow may have significant impact downstream, it generally goes unnoticed. Lower Subansiri Hydroelectric project, located on the Subansiri River of Assam, India, is one of the major hydroelectric projects proposed in the Northeastern part of India. Reservoir Simulation Model has been developed with the objective of assessing the extent of flow variation in the downstream due to operation of the Lower Subansiri Reservoir. Simulation has been carried out using a Standard Operating Policy proposed for the project. The study has revealed that during the peaking hour, the discharge downstream increases about eight times of the normal flow in the lean period and becomes almost zero during the non-operating period. While the high discharge poses erosion and flood threats, the low discharge may lead to adverse environmental impacts such as increase in pollutant concentrations. The possibility of adopting structural and non-structural measures for minimizing the deviation of flow from its normal condition is investigated and performance of these measures is compared based on seven performance criteria. The comparisons have revealed that the structural measure provide the best solution. As an alternative, the non-structural measure also promises notable improvement over the baseline standard operation scenario.     

Arrays of discrete atomic beams for sub-λ/2 lithography via dipole force

We present a novel experiment of generating multiple, pulsed indium atomic beams with sub-micron periodicity via rear side ablation of thin film by multiple beam interferometer using high power Q-switched Nd:YAG laser under high vacuum (∼10⁻⁵ Torr) for the first time. The applications of these atomic beams in atom lithography using dipole force as well as in direct deposition lithographic technique are discussed.     

Effects of privatization: A case study from Cayirhan coal district,Turkey

Privatization of lignite coal-fired power plants in Turkey began in the middle of 1990 and is still an ongoing process. Among the 10 power plants offered to bidders in 1996, only Cayirhan power plant bundled with the coal mine was privatized. Considerable improvements have been obtained following the privatization of both the power plant and the coal mine. In view of its success, it is considered that Cayirhan experience could serve as a model for further privatization in energy sector, planned to be completed by the end of 2006 according to the agenda issued by government. This paper deals with the overall improvements following the privatization of both the power plant and the coal mine. In particular, mechanized roadway drivage performances before and after privatization are compared in order to highlight the specific effects of privatization in this area. It is found that competition, organizational and operational changes are the main causes of improvements attained in the post-privatization period.     

Changing landscape in biotechnology patenting

Trade regime of the world has brought into focus the ability to generate and secure IPR. The transformation has been rapid and recent decades have seen an increase in intellectual property protection worldwide. The Patent Cooperation Treaty (PCT) has, since it began in 1978, seen continuous growth with a record 156,100 application filed in 2007, representing a 4.7% growth over the previous year. Most academic patents applied for are in biotechnology or related fields. The paper identifies the effect of the changing landscape in biotechnology patents. Changes in specific areas like transgenic crops, nanotechnology, pharmaceuticals etc. are also discussed along with trends like the increase in patent applications by educational institutes across the globe. Certain problems pertaining to patenting of biotechnological innovations that have arisen in recent times are also discussed.     

Industrial production of light metal hydrides for hydrogen storage

Light metal hydrides show a high potential for reversible hydrogen storage applications. In view of the potential future storage of large amounts of hydrogen, an economic tonnage scale production will be required. This viewpoint set introduces production methods and discusses the potential for simplifying processing routes and reducing costs in view of an industrial mass production. For this purpose, sodium alanate, for which cost-competitive large-scale production is already considered feasible, is used as an example for future promising hydrides, like complex hydrides or reactive hydride composites.     

Polyaniline-sulfate salt as an efficient and reusable catalyst for the synthesis of 1,5-benzodiazepines and 2-phenyl benzimidazoles

Polyaniline-sulfate salt was used as an efficient catalyst for the preparation of benzodiazepines and 2-phenyl benzimidazoles in excellent yields. This method is applicable for the reaction of phenylenediamine with cyclic or acyclic ketones or aromatic aldehydes. The salient features of the present methodology are cheaper process, easy synthesis of stable catalyst, versatility and in addition, the catalyst can be easily recovered after completion of the reaction and reusable without affecting its activity.     

Variation in growth and resource utilisation among eight poplar clones grown under different irrigation and fertilisation regimes in Sweden

Growth, biomass allocation and nutrient economy of eight clones of poplar (Populus balsamifera L., P. trichocarpa Hook.) and hybrid poplar (P. trichocarpa Hook. × P. deltoides Bartr.) of north-American origin were studied in a full-factorial pot experiment in Sweden, using the approach of classical growth analysis. The clones were compared in terms of relative growth rate (RGR), biomass production, biomass allocation, nitrogen accumulation and productivity, and ability to withdraw nitrogen from senescing leaves (leaf nitrogen proficiency). The clones differed significantly among treatments by means of several variables, and for some of them also clone × treatment interaction effects were significant. The components of RGR, i.e., leaf area ratio (LAR) and unit leaf rate (ULR), shifted in their importance to explain differences between treatments and genotypes. The results are discussed in the context of growth characteristics particularly important for the selection of clones for multi-purpose poplar plantations grown under the cool-temperate, high-latitude climatic conditions typical for large parts of Sweden.     

Amine catalysed silicon–oxygen bond formation

Catalytic amount of triethylenetetramine causes dehydration of diphenylsilanediol to form octaphenyltetrasiloxane, whereas, catalytic reaction of triethylenetetramine leads to dehydrogenative polymerisation of phenylsilane with various diols.     

Multilevel network characterization using regular topologies

Multilevel networks have been a good solution in large-scale networks scenarios. The implementation of a network into different levels or sub-layers improves the performance and reduces the investment against plain topologies. This paper tries to characterize important parameters on multilevel networks such as diameter, average distance and gateway location to be able to optimize the global network topology with no need for additional path calculations. The study focuses on the lower level of the network formed by subnetworks with regular structures such as Single Ring, Double Ring and Torus Grid. The achieved results will ease and improve the network planning of large-scale networks.     

Statistical behavior of carbon monoxide from vehicular exhausts in urban environments

Air pollutant concentrations are essentially random variables and can be well described by statistical distribution models. The statistical distribution models are, therefore, useful tools in predicting the distribution of air pollutant concentrations. The statistical distributional form, fitting to the concentrations data, is based upon several factors, i.e. source types, pollutant types, emission patterns, meteorological conditions, and averaging times [Taylor, J.A., Jakeman, A.J., Simpson, R.W., 1986. Modeling distributions of air pollutant concentrations – I: identification of statistical models. Atmospheric Environment 20 (9), 1781–1789]. The statistical characteristics of dispersion of air pollutants in the atmosphere are represented by successive random dilution process [Ott, W.R., 1995. Environmental Statistics and Data Analysis. Lewis publishers]. This process may, however, differ depending upon the location of pollutant dispersion, i.e. near roadways, at intersections or in street canyons. Further, the distributional form may also differ. Several investigators, in the past, presumed lognormal distribution (LND) for the air quality data. While, a few found other distributional form when carried out the actual data analysis.The present paper develops the statistical distribution model fitting to carbon monoxide (CO) concentrations for the heterogeneous traffic pattern at the urban hotspots in Delhi, India. Three years of 1-h average CO concentration data (from 1997 to 1999), at the traffic intersection and near a roadway, are examined using goodness-of-fit tests for the suitable statistical distributional form. The results showed that the log logistic distribution model (LLD) best fit the CO concentration data at both the intersection and the roadway. It can therefore be deduced that ‘heterogeneity in traffic’ and ‘emission patterns’ may be affecting the statistical distributional form significantly.