Romanian River Basins Lag Time Analysis. The SCS-CN Versus RNS Comparative Approach Developed for Small Watersheds

Romanian policy makers have to perceive that human intervention on river basins land cover is influencing rainfall-runoff relation and the used methodology cannot accurately estimate watershed surface flow transformations. Global water cycles and energy fluxes understanding is leading to better predictions of land atmosphere interaction and local hydro-climates evolution. The water transfer time determination from rainfall to runoff needs accurate measurements of river basins hydrological parameters. Here, we analyzed and compared the lag time value results of two different methodologies (curve number and rational methodology) used for 54 Romanian small catchment areas study. The focus of this paper is the lag time evaluation and interpretation for an effective implementation of the best methodology approach in the Romanian geographical space. Our research in small river basins was developed using remote sensing technology maps, GIS and environmental datasets in combination with field work on every drainage basin in order to assess the specific morphological features and validate the land cover typology. We found that Soil Conservation Service - Curve Number (SCS-CN) method is widely used according to USA landscape features classification, but not necessarily applicable to Romanian river basins characteristics. Our results show how the official Romanian rational methodology national standard (RNS) can be improved and the limits of SCS-CN method.

     

Analytical method of calculating preheating temperature in order to avoid cold cracking

Summary

The IIW method is shown to be one of the most precise and that it may be programmed to advantage.     

Crystal growth of rare-earth-doped ternary potassium lead chloride single crystals by the Bridgman method

High optical quality pure and rare-earth-doped ternary-potassium-lead-chloride (KPb₂Cl₅) single crystals have been grown using the Bridgman technique in a two-zone transparent vertical furnace. Combining the chlorination of the melt, to eliminate oxygen impurities, with a horizontal zone-refining, followed by the Bridgman growth itself using sealed silica ampoules, we successfully grew non-moisture-sensitive crystals of a high optical quality. The moisture content in the raw materials determines the quality of the resulting crystals.     

Ice crystal interspacing in frozen foods

In this paper we show that the ice crystal growth in food and biomaterials is a function of the freezing rate. Our experimental data and literature data on other biomaterials collapse to a single curve, if plotted against the freezing rate. The fitted correlation is compared to scaling rules developed for dendrite interspacing during directional solidification of alloys. We argue that the food freezing process is reasonably comparable to the solidification process in alloys, as is apparent in the comparable exponent in our fitted scaling rule with the one commonly used in alloy solidification.     

Optical spectroscopy of Dy ions in LiNbO3

A systematic spectroscopic study of Dy³⁺ doped LiNbO₃ is presented. The energy position of the Stark levels and their symmetry character is given for most of the multiplets. Luminescence of this system has been investigated in the visible and infrared. The only emitting state in this region is the metastable 4F_9/2 multiplet whose life time is temperature independent and with a value of 186 μs. Evidence about Dy³⁺ multicentres is also discussed.     

The autocalibration of PI controllers based on two frequency measurements

A generalization of the previously presented KLV method for the autocalibration of PI controllers (based on one frequency experiment) is realized so as to extend its validity domain. The underlying process models and PI designs are given. The new autocalibration procedure includes two frequency experiments on the plant (closed-loop relay experiments) to extract the process dynamics. Comparisons with other tuning methods are presented. Simulations and experiments on a real plant illustrate the feasibility of the proposed approach.     

Robust digital control approach for high performance tunneling current measurement system

This paper is devoted to the digital control system design for high performance measurement of tunneling current. A common approach for such applications is to use a conventional Proportional Integral (PI) control. In this paper, a robust digital design method is instead considered, based on combined pole placement with sensitivity function shaping, and allowing for better performance tuning in terms of precision, robustness and disturbance rejection. The resulting control scheme looks like some enhanced PID controller, and is validated over an experimental setup, developed in GIPSA-lab (Grenoble Image Parole Signal Automatique) research center. The corresponding simulation and experimental results show improved performances with respect to those obtained with the more conventional PI control technique.