Reconstruction of the friction units of turbine guide vanes

Conclusions After the almost 2-yr operation of the gate apparatus since the start of reconstruction of friction units of the vanes, we can make a preliminary evaluation of the effectiveness of the works:There is practically no leakage of water through the gate vanes to the turbine cover, which led to a complete unloading of the drainage pumps on the turbine cover and the efficiency of operating the gate apparatus increased considerably.Repair of the gate apparatus is not required during maintenance.There is no vibration of the gate vanes, since the gaps in the friction units of the journals of the gate vanes are minimum and stable.The operating personnel objectively evaluate highly the work of the gate apparatus of the turbine after reconstruction and will continue this work on the remaining turbines.Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 12–14, September, 1985.     

An air curtain for Protecting Hydraulic Structures from seismic and blast effects

Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 1–6, October, 1992.     

Structural vibrations of hydraulic structures at the boundary with fluid regions with a complex shape (three-dimensional problem)

Translated from Gidrotehnicheskoe Stroitel'stvo, No. 3, pp. 27–31, March, 1992.     

Quantification and genotyping of Cryptosporidium spp. in river water by quenching probe PCR and denaturing gradient gel electrophoresis.

A new detection method was developed for the simultaneous quantification and genotyping of Cryptosporidium spp. in river water. Several modifications made to the US EPA Method 1623 enabled high and stable recovery of Cryptosporidium from 40 L of river water (geometric mean = 35%, standard deviation = 8.7%). Quenching probe PCR (QProbe PCR) was used to quantify the 18S rRNA gene of Cryptosporidium spp. This method could successfully detect single oocysts in a sample, and the lower quantitation limit was as low as 2.5 oocysts/sample. In addition, denaturing gradient gel electrophoresis (DGGE) followed by DNA sequencing was used to identify the genotypes. These methods were applied to detect Cryptosporidium spp. in the Koyama River, Japan. The positive ratio was 69% (11/16) with the maximum concentration of 59 oocysts/100 L. Seven genotypes including two novel ones were identified. These results showed that this detection method could provide valuable information on Cryptosporidium in river water, both in the concentration and in the genotypes, which is essential for the precise assessment of waterborne risk to human health.     

The characteristics and measuring technique of refractory dissolved organic substances in urban runoff.

It is considered that refractory dissolved organic substances have caused an increase in the COD concentration in Lake Biwa in recent years. We investigated the organic matter in the first flush of stormwater runoff from a road in the watershed area of the lake, and studied the possibility of improvement in the water environment from that aspect. After percolating the stormwater through soil, we analyzed organic substances fractionated by using GPC-TC. And we examined the effect of removal of organic substances by comparing the peak height before and after percolation. In the result of the experiments, we found that soil infiltration reduced the refractory dissolved organic substance and we successfully designed a system for a simple and easy experimental facility to treat urban runoff.     

Fuzzy control of nitrogen removal in predenitrification process using ORP.

In order to meet increasingly stringent discharge standards, new applications and control strategies for the sustainable removal of nitrogen from wastewater have to be implemented. In the past years, numerous studies have been carried out dealing with the application of fuzzy logic to improve the control of the activated sludge process. In this paper, fuzzy control strategies of predenitrification systems are presented that could lead to better effluent quality and, in parallel, to a reduction of chemicals consumption. Extensive experimental investigations on lab scale plant studies have shown that there was excellent correlation between nitrate concentration and ORP value at the end of the anoxic zone. Results indicated that ORP could be used as an on-line fuzzy control parameter of nitrate recirculation and external carbon addition. The optimal value of ORP to control nitrate recirculation and external carbon addition was - 86 +/- 2 mV and - 90 +/- 2 mV, respectively. The results obtained with real wastewater also showed the good performance and stability of the fuzzy controllers independently from external disturbances. The integrated control structure of nitrate recirculation and external carbon addition in the predenitrification system is also presented.     

Nitrogen management in reservoir catchments through constructed wetland systems.

In this study, nitrogen removal was investigated in pilot-scale subsurface flow (SSF) and in free water surface flow (FWS) constructed wetlands installed in the campus of TUBITAK-Marmara Research Center, Gebze, near Istanbul, Turkey. The main purposes of this study are to apply constructed wetlands for the protection of water reservoirs and to reuse wastewater. Experiments were carried out at continuous flow reactors. The effects of the type of plants on the removal were investigated by using emergent (Canna, Cyperus, Typhia spp., Phragmites spp., Juncus, Poaceae, Paspalum and Iris.), submerged (Elodea, Egeria) and floating (Pistia, Salvina and Lemna) marsh plants at different conditions. During the study period HLRs were 30, 50, 70, 80 and 120 L m(2)d(-1) respectively. The average annual NH4-N, NO(3)-N, organic N and TN treatment efficiencies in SSF and FWS wetlands are 81% and 68%, 37% and 49%, 75% and 68%, 47% and 53%, respectively. Nitrification, denitrification and ammonification rate constant (k20) values in SSF and FNS systems have been found as 0.898 d(-1) and 0.541 d(-1), 0.488 d(-1) and 0.502 d(-1), 0.986 d(-1) and 0.908 respectively. Two types of the models (first-order plug flow and multiple regression) were tried to estimate the system performances.     

Do Gold Market Returns Have Long Memory?

This study examines the long memory behavior in gold returns during the post-Bretton Woods period using a new rescaled range technique. Unlike the conventional rescaled range analysis, the new rescaled range analysis is robust to short-term dependence and conditional heteroscedasticity found in the gold data. Statistical results suggest that the long memory behavior in gold returns is rather unstable. When only few observations corresponding to major political events in the Middle East, together with the Hunts event, in late 1979 are omitted, little evidence of long memory can be found.     

Are differences in firm size transitory or permanent?

An Erratum for this article has been published in Journal of Applied Econometrics 18(2) 2003, 249 Previous empirical work on corporate growth rates using cross‐section or short‐panel econometric techniques suggests that growth rates are random but that some degree of mean reversion exists. This means that size differences between firms are transitory. Another, more natural way to explore the long‐run distribution of firm sizes is to examine data on the growth of particular firms over long periods of time. Using a sample of 147 UK firms observed continually for more than 30 years, our conclusions are that growth rates are highly variable over time and that differences in growth rates between firms do not persist for very long. Further, firms show no tendency to converge to either a common size or to a pattern of stable size differences over time. These results are compared and contrasted with standard approaches that suggest that firms reach and maintain stable positions in a skewed size distribution. Copyright © 2002 John Wiley & Sons, Ltd.     

Bayesian MCMC Mapping of Quantitative Trait Loci in a Half-sib Design: a Graphical Model Perspective

Graphical models provide a powerful and flexible approach to the analysis of complex problems in genetics. While task-specific software may be extremely efficient for any particular analysis, it is often difficult to adapt to new computational challenges. By viewing these genetic applications in a more general framework, many problems can be handled by essentially the same software. This is advantageous in an area where fast methodological development is essential. Once a method has been fully developed and tested, problem-specific software may then be required. The aim of this paper is to illustrate the potential use of a graphical model approach to genetic analyses by taking a very simple and well-understood problem by way of example.