Some problems of precise measurements of heat transfer coefficients in glass melts : Part 1. Measurements of effective conductivity

In the paper the method of measurements of the so-called effective conductivity of glass melts basing on characteristic of temperature gradient in a molten glass inside a refractory tank is analyzed. For this purpose a computer model based on the solution of the radiative transfer equation in a semitransparent medium was used. Among the papers on effective conductivity measurements published so far, only two contained enough numerical information on the details of measurement which permitted to perform the corresponding calculations. The authors of the present paper show what particular defects of experimental procedure could be the reason of surprising results reported in these publications, namely that the measured effective conductivity coefficient of a number of glasses was found to be lower than the radiative conductivity alone

An experimental determination of the scale length of N2O in the soil of a grassland

Concentration profiles of N2O in a grassland soil and dynamic response curves to disturbance of the soil concentration (relaxation curves) were measured with a new membrane tube technique. Diffusive properties of the soil were derived from 222Rn measurements. The mathematical analysis of the relaxation curves yielded N2O uptake rates U soil diffusivities Ds, scale lengths z*, and production rates P at different levels under the surface. The following ranges were found during 2 days of measurements: Ds = (0.4–5) × 10−7 m2 s−1, U = (1–20) × 10−4 s−1, z* = 0.7–2.8 cm, and P = 0.02–4.4 ppb s−1. These values were used to reproduce the measured N2O concentration profiles with a one-dimensional diffusive transport model of N2O in the soil air-filled pore space and to deduce flux profiles. Bidirectional fluxes occurred with small deposition fluxes up to a few ppt ms−1 during intensive growing phases of the grass. Uptake rates were high enough that N2O produced at greater depth did not reach the atmosphere

Radon-220 calibration of near-surface turbulent gas transport

Activity concentration profiles of the short-lived radon isotope 220Rn (half-life 56 seconds) in the lowest 50 cm above the soil are used to study near-surface gas transport processes. The experimental data are compared to profiles calculated by solving the one-dimensional diffusion equation for radioactive atoms with a linear increase of the eddy diffusion coefficient K with altitude according to K(z) = K0 + Kz.Z. The slope KZ in this model and the radon flux from the surface are continuously calculated from the activity measurements in time steps of one hour. Transport times for Rn atoms from an altitude Z1 = 5 cm to an altitude Z2 = 20 cm are typically between one and two minutes in stable meteorological conditions when the friction velocity u* is below 0.1 m/s

Radon-222 monitoring of soil diffusivity

The temporal evolution of activity profiles of the radon isotope 222Rn in the top 50 cm of soil is used to quantify diffusive gas transport in the air-filled pore space. Air is continuously collected from gas-permeable, hydrophobic membrane tubes placed at various depths under the surface and circulated through a high-sensitivity Rn detector. With a micro-processor controlled inlet system an automatic monitoring of several levels is possible for extended periods of time with a typical time resolution of one hour. In addition, a new dynamic approach to measure the in-situ soil diffusivity Ds (m²/s) around the subsurface tubes is presented where the recovery from air injection is evaluated every 3 hours. Within a test period of 3 weeks Ds dropped from 10−6 m²/s to 3 10−7 m²/s at a depth of z=50 cm due to increasing water content of the soil

Constructing Artificial Neural Networks in the E-net Basis

В данной работе предложена методика реализации искусственной нейронной сети, обеспечивающей возможность реконфигурации структуры и параметров сети в процессе ее работы. Результаты работы могут быть использованы в задачах построения многофункциональных компьютерных тренажеров для идентификации объектов управления, что в свою очередь позволит значительно снизить время настройки и калибровки аналитико- имитационной модели компьютерного тренажера, а также отследить и обучить искусственную нейронную сеть действиям оператора.The given article introduces the method of implementation of the artificial neural network. The method gives the possibility of the network structure and parameters reconfiguration during its work. The results can be used in order to construct multifunctional computer simulator identifying control plants. It will significantly reduce the setting and calibration time of the analytical and simulation model. It will also allow monitoring and teaching the artificial neural network to model the operators actions

Constructing Artificial Neural Networks in the E-net Basis

В данной работе предложена методика реализации искусственной нейронной сети, обеспечивающей возможность реконфигурации структуры и параметров сети в процессе ее работы. Результаты работы могут быть использованы в задачах построения многофункциональных компьютерных тренажеров для идентификации объектов управления, что в свою очередь позволит значительно снизить время настройки и калибровки аналитико- имитационной модели компьютерного тренажера, а также отследить и обучить искусственную нейронную сеть действиям оператора.The given article introduces the method of implementation of the artificial neural network. The method gives the possibility of the network structure and parameters reconfiguration during its work. The results can be used in order to construct multifunctional computer simulator identifying control plants. It will significantly reduce the setting and calibration time of the analytical and simulation model. It will also allow monitoring and teaching the artificial neural network to model the operators actions

Phytopathogenic <i>Curtobacterium flaccumfaciens</i> Strains Circulating on Leguminous Plants, Alternative Hosts and Weeds in Russia

Many bacterial plant pathogens have a broad host range important for their life cycle. Alternate hosts from plant families other than the main (primary) host support the survival and dissemination of the pathogen population even in absence of main host plants. Metabolic peculiarities of main and alternative host plants can affect genetic diversity within and between the pathogen populations isolated from those plants. Strains of Gram-positive bacterium Curtobacterium flaccumfaciens were identified as being causal agents of bacterial spot and wilt diseases on leguminous plants, and other crop and weed plants, collected in different regions of Russia. Their biochemical properties and susceptibility to copper compounds have been found to be relatively uniform. According to conventional PCR assays, all of the isolates studied were categorised as pathovar Curtobacterim flaccumfaciens pv. flaccumfaciens, a pathogen of legumes. However, the strains demonstrated a substantial diversity in terms of virulence on several tested host plants and different phylogenetic relationships were revealed by BOX-PCR and alanine synthase gene (alaS) sequencing