[en] Most of the CFD simulations of spray dryers reported in the literature utilizes a fixed air inlet temperature numerical framework. In this paper, a numerical framework was introduced to model spray drying as an outlet air temperature controlled process. A P-controller numerical framework was introduced which allows the inlet temperature to be automatically adjusted based on the required outlet temperature set point. This numerical framework was evaluated with a simulation of a two-stage pilot scale spray drying system at the Davis Dairy Plant (South Dakota State University) which is used for commercial contract spray drying operation. (Author)

[en] Coincidence measurements of the absolute cross section for the production of bremsstrahlung by electrons in the field of gold atoms are reported. The incident electron energy T₀ was 300 keV. Measurements were made for four different combinations of electron scattering angle and photon emission angle over a wide range of the relative photon energy k/T₀ up to k/T₀ = 0.83. The measured cross sections are compared with results of Bethe-Heitler and Elwert-Haug calculations. (orig.)

[en] Experiments were performed to calibrate a recently developed pulsed field gel electrophoresis assay, the asymmetric field inversion gel electrophoresis (AFIGE), for the measurement of double-strand breaks (dsb) in the DNA of mammalian cells. Calibration was carried out by means of ¹²⁵I decay accumulation, under conditions preventing repair, based on the observation that each ¹²⁵I decay in the DNA produces approximately one dsb. Results suggest that that observed fluctuations in the fraction of DNA activity released (FAR) per Gy throughout the cycle reflect cell-cycle-associated differences in the physicochemical properties of the DNA molecules that alter their electrophoretic mobility, rather than variations in the induction of dsb per Gy, i.e. the sensitivity of the assay fluctuates throughout the cycle. (author)

[en] Full text: During the months of December to March, Peru is affected by intense precipitations which generate every year land slides and floods mainly in low and middle river basins of the western and Eastern of the Andes, places that exhibit the greatest number of population and productive activities. These extreme events are favored by the steep slopes that characterize the Peruvian topography. For this reason at the end of year 2000, SENAMHI began the design of a monitoring, analysis and forecast system, that had the capacity to predict the occurrence of adverse events on the low and middle river basins of the main rivers such as Piura river in the north of Peru and the Rimac river in the capital of the country. The success of this system opened the possibilities of developing similar systems throughout the country and extend to different users or sectors such as: energy, water management, river transport, etc. An example of a solution prepared for a user (the gas extraction company Pluspetrol) was the implementation of a river level forecasting system in the Urubamba river to support river navigation in this amazonic river where water level variability turns risky the navigation during the dry season. The Urubamba catchment higher altitudes are famous because of the presence of the Machupicchu ancient city, downslope this city is characterized by the Amazon rainforest with scarce observation stations for water level and rainfall. A very challenging modelling and operational hydrology enterprise was developed. The system implemented for the Urubamba river consist on running the atmospheric part of the global climate model CCM3, this model inputs Sea Surface Temperature forecasts from NCEP-NOAA. The global model was set on a T42 (300 km) grid resolution, this information was used as initial and boundary conditions for the regional model RAMS which provided a downscaled 20 Km grid resolution having as results daily precipitation forecasts. Besides the global climate model a statistical forecast was developed using Empirical Orthogonal Functions (EOF), this methodology uses the Long Wave Radiation as a predictor for the precipitation occurrence in the study area. This model is based on an atmospheric-ocean teleconnection El Nino 3 region in the central tropical pacific and the observed rainfall over the Andes. The information generated by the atmospheric model was used as input for the Sacramento hydrologic model originally developed by the National Weather Service River Forecast System (NWSRFS) which considers all the historical data (precipitation, flows and evapotranspiration), the model considers a perturbation in the form of a random variable which depends on the standard deviation and the mean, this algorithm allows to have not only one precipitation time series but the double or triple. This is the basis on the hydrologic ensemble forecasting where each precipitation time series generates a flow time series and then using post processing codes we find the probabilistic forecasts of non excedance for different percentage of probability. Finally the hydraulic model used was the HEC-RAS V.3.1 developed by the U.S Army Corps of Engineering which used all the cross sections available in the zone, manning values, contraction and expansion coefficients to convert the forecasted flow data into water level of the Urubamba river in four check points requested by the user: Malvinas, Nuevo Mundo, Sepahua and Maldonadillo. SENAMHI provided of useful information for 2 years and was the result of a multidisciplinary systemic work that joined meteorologists, hydrologists, climatologists and system engineers. The information used by the Regional numerical model RAMS was assimilated from geostationary satellite GOES 8 and automatic stations located in strategic points considering the topography, accessibility, security, extreme rainfall conditions and consequent variability in the levels of the Urubamba river. As a conclusion the work developed in the Urubamba river involves the ocean-atmospherehydrosphere interaction for gener ating precipitations and water levels in a virgin jungle basin in which has been established a hydrologic and hydraulic modelling system to give support and information to the river navigation in Amazonia. (author)

[en] Repair of DNA double-strand breaks (dsb) was measured in exponentially growing, plateau-phase and synchronized G₁, G₁/S, early S, mid-S, late S, G₂ + M amd mitotic CHO cells. Results suggest that the state of chromatin condensation has only a limited impact on the ability of the cells to rejoin dsb, and indicate that the cell cycle-dependent fluctuations in radiosensitivity cannot be explained by alterations in the rate of rejoining of dsb. Repair half-times of the slow component of dsb rejoining were similar to the half-times of rejoining of chromosome breaks as visualized by the technique of premature chromosome condensation, suggesting a cause-effect relationship between rejoining of this subject of dsb and rejoining of chromosome breaks. (author)

[en] Since 1980, the site of the Hanau nuclear enterprises has been subject to a radiological monitoring programme. The measured results and the experience gained so far have been taken as a basis for a revision of this programme. The revision was intended to finally yield a programme which satisfies the principle requirements of the currently applicable directive for radiological monitoring and which in terms of procedure and formal aspects is as close as possible to the pattern applied to nuclear power plants. The measured results are listed in detail. (orig./DG)

[en] The two units of the Biblis reactor station are monitored by the system of the KFUeHessen. The main functions of the KFUeare to assist the nuclear inspectorate in the case of normal operation as well as in the case of accidents, to give immediated alarm in case of radioactivity release exceeding normal, to calculate radiological loads in the environment, and to measure ambient doses. Furthermore, the data measured by the KFUeHessen are available to the radiation protection experts who belong to the emergency management services in Hessen and in Rhineland-Palatinate. (orig.)

[en] Full text: During the months of December to March, Peru is affected by intense precipitations which generate every year land slides and floods mainly in low and middle river basins of the western and Eastern of the Andes, places that exhibit the greatest number of population and productive activities. These extreme events are favored by the steep slopes that characterize the Peruvian topography. For this reason at the end of year 2000, SENAMHI began the design of a monitoring, analysis and forecast system, that had the capacity to predict the occurrence of adverse events on the low and middle river basins of the main rivers such as Piura river in the north of Peru and the Rimac river in the capital of the country. The success of this system opened the possibilities of developing similar systems throughout the country and extend to different users or sectors such as: energy, water management, river transport, etc. An example of a solution prepared for a user (the gas extraction company Pluspetrol) was the implementation of a river level forecasting system in the Urubamba river to support river navigation in this amazonic river where water level variability turns risky the navigation during the dry season. The Urubamba catchment higher altitudes are famous because of the presence of the Machupicchu ancient city, downslope this city is characterized by the Amazon rainforest with scarce observation stations for water level and rainfall. A very challenging modelling and operational hydrology enterprise was developed. The system implemented for the Urubamba river consist on running the atmospheric part of the global climate model CCM3, this model inputs Sea Surface Temperature forecasts from NCEP-NOAA. The global model was set on a T42 (300 km) grid resolution, this information was used as initial and boundary conditions for the regional model RAMS which provided a downscaled 20 Km grid resolution having as results daily precipitation forecasts. Besides the global climate model a statistical forecast was developed using Empirical Orthogonal Functions (EOF), this methodology uses the Long Wave Radiation as a predictor for the precipitation occurrence in the study area. This model is based on an atmospheric-ocean teleconnection El NINO 3 region in the central tropical pacific and the observed rainfall over the Andes. The information generated by the atmospheric model was used as input for the Sacramento hydrologic model originally developed by the National Weather Service River Forecast System (NWSRFS) which considers all the historical data (precipitation, flows and evapotranspiration), the model considers a perturbation in the form of a random variable which depends on the standard deviation and the mean, this algorithm allows to have not only one precipitation time series but the double or triple. This is the basis on the hydrologic ensemble forecasting where each precipitation time series generates a flow time series and then using post processing codes we find the probabilistic forecasts of non excedance for different percentage of probability. Finally the hydraulic model used was the HEC-RAS V.3.1 developed by the U.S Army Corps of Engineering which used all the cross sections available in the zone, manning values, contraction and expansion coefficients to convert the forecasted flow data into water level of the Urubamba river in four check points requested by the user: Malvinas, Nuevo Mundo, Sepahua and Maldonadillo. SENAMHI provided of useful information for 2 years and was the result of a multidisciplinary systemic work that joined meteorologists, hydrologists, climatologists and system engineers. The information used by the Regional numerical model RAMS was assimilated from geostationary satellite GOES 8 and automatic stations located in strategic points considering the topography, accessibility, security, extreme rainfall conditions and consequent variability in the levels of the Urubamba river. As a conclusion the work developed in the Urubamba river involves the ocean-atmosphere-hydrosphere interaction for gene rating precipitations and water levels in a virgin jungle basin in which has been established a hydrologic and hydraulic modelling system to give support and information to the river navigation in Amazonia. (author)

[en] The initial (up to 30 min) rate of DNA double-strand break (dsb) rejoining was measured in irradiated plateau-phase CHO cells, in a set of parallel experiments using the same cell suspension, by means of non-unwinding filter elution, neutral sucrose gradient centrifugation, and two pulsed-field gel electrophoresis assays: asymmetric field inversion gel electrophoresis (AFIGE) and clamped homogeneous electric field (CHEF) gel electrophoresis. The rate of DNA dsb rejoining was compared to the rate of rejoining of chromatin breaks measured, also in the same cell population, using the technique of premature chromosome condensation (PCC). Two radiation exposures, 25 Gy and/or 50 Gy, were used and applied to the individual parts of the experiments according to the sensitivity of the assay under investigation. The results suggest all major techniques currently used for assaying rejoining of DNA dsb give similar results, and indicate that more information is required before a direct correlation between rejoining of DNA dsb and rejoining of chromatin breaks can be established. (author)

[en] A pulsed field gel electrophoresis technique, asymmetric field inversion gel electrophoresis (AFIGE), was used to evaluate induction by X-rays of DNA damage in CHO cells. The fraction of DNA activity released from the plug (FAR) was used as a measure for the amount of radiation-induced DNA damage, predominantly DNA double-strand breaks (dsb) (Stamato and Denko 1990), and was determined at various stages of growth and phases of the cell cycle in a range of doses between zero and 70 Gy. It is concluded that caution needs to be exercised before differences observed in the FAR between different cell lines or between various phases of the cell cycle after exposure to a given dose of radiation are interpreted as suggesting differences in the induction of DNA dsb. (author)