Analysis of the fluidization behaviour and application of a novel spouted bed\ud apparatus for spray granulation and coating

Spouted beds are well known for their good mixing of the solid phase and for their intensive heat\ud and mass transfers between the fluid phase and the solid phase. Nearly isothermal conditions are\ud enabled which is of advantage for the treatment of granular solid materials in granulation,\ud agglomeration or coating processes. In this work the hydrodynamic behaviour of a novel spouted\ud bed apparatus with two horizontal and slit-shaped gas inlets is investigated by high-frequency\ud recordings of the gas phase pressure fluctuations over the entire bed. The hydrodynamic stable\ud operation domain, which is of importance for operating the apparatus, will be identified and\ud depicted in the Re-G-Ar-diagram by Mitev [1]. Another focus of this work is the simulation of the\ud spouting process by application of a continuum approach in FLUENT 6.2. The effect of the\ud frictional stresses on the hydrodynamic behaviour is examined by performing simulations with and\ud without consideration of friction. The angle of internal friction fi in Schaeffer`s [10] model will be\ud varied and the simulation results will be compared with experiments. It was found that the influence\ud of friction is not very big by application of the quite simple and empirical frictional viscosity model\ud by Schaeffer [10] basing on soil mechanical principles. Also the simulation results under negligence\ud of friction were similar to those under consideration of friction. Another part of this work is the\ud industrial application of the novel spouted bed in granulation and coating processes. Compared to\ud classical fluidized beds, a much narrower particle size distribution, a higher yield and a higher\ud product quality was obtained in the novel spouted be

In Vivo Retinal Pigment Epithelium Imaging using Transscleral Optical Imaging in Healthy Eyes.

To image healthy retinal pigment epithelial (RPE) cells in vivo using Transscleral OPtical Imaging (TOPI) and to analyze statistics of RPE cell features as a function of age, axial length (AL), and eccentricity. Single-center, exploratory, prospective, and descriptive clinical study. Forty-nine eyes (AL: 24.03 ± 0.93 mm; range: 21.9-26.7 mm) from 29 participants aged 21 to 70 years (37.1 ± 13.3 years; 19 men, 10 women). Retinal images, including fundus photography and spectral-domain OCT, AL, and refractive error measurements were collected at baseline. For each eye, 6 high-resolution RPE images were acquired using TOPI at different locations, one of them being imaged 5 times to evaluate the repeatability of the method. Follow-up ophthalmic examination was repeated 1 to 3 weeks after TOPI to assess safety. Retinal pigment epithelial images were analyzed with a custom automated software to extract cell parameters. Statistical analysis of the selected high-contrast images included calculation of coefficient of variation (CoV) for each feature at each repetition and Spearman and Mann-Whitney tests to investigate the relationship between cell features and eye and subject characteristics. Retinal pigment epithelial cell features: density, area, center-to-center spacing, number of neighbors, circularity, elongation, solidity, and border distance CoV. Macular RPE cell features were extracted from TOPI images at an eccentricity of 1.6° to 16.3° from the fovea. For each feature, the mean CoV was < 4%. Spearman test showed correlation within RPE cell features. In the perifovea, the region in which images were selected for all participants, longer AL significantly correlated with decreased RPE cell density (R Spearman, Rs = -0.746; P < 0.0001) and increased cell area (Rs = 0.668; P < 0.0001), without morphologic changes. Aging was also significantly correlated with decreased RPE density (Rs = -0.391; P = 0.036) and increased cell area (Rs = 0.454; P = 0.013). Lower circular, less symmetric, more elongated, and larger cells were observed in those > 50 years. The TOPI technology imaged RPE cells in vivo with a repeatability of < 4% for the CoV and was used to analyze the influence of physiologic factors on RPE cell morphometry in the perifovea of healthy volunteers. Proprietary or commercial disclosure may be found after the references

Application of electron beam irradiation for inhibition of Fusarium oxysporum f. sp. dianthi activity

Electron beam irradiation was tested against Fusarium oxysporum f. sp. dianthi (Fod) a pathogen causing Fusarium wilt of carnation. Efficiency of the different radiation doses on in vitro survival and development of Fod culture on potato-dextrose agar (PDA) medium was tested. A dose of 6 kGy completely inhibited the pathogen growth. Application of radiation for microbiological decontamination of four substrates used for carnation production demonstrated that, depending on the type of substrate, doses of 10 or 25 kGy were effective in Fod elimination. All carnation plants cultivated on radiation decontaminated substrates were healthy

Effectiveness of electron beam irradiation in the control of some soilborne pathogens

Electron beam (EB) irradiation was tested against Botrytis cinerea, Pythium ultimum and Phytophthora citricola the most dangerous pathogens causing stem and root rot of seedlings, cuttings and older plants. In the laboratory trials cultures of 3 species were irradiated with doses 0 (control), 1.5, 3.0, 4.5 and 6.0 kGy whereas peat was treated with 10,15 and 25 kGy. P. citricola was the most sensitive species for irradiation. In greenhouse trials 15 kGy irradiation of peat protected chrysanthemum cuttings against B. cinerea and P. ultimum as well as rhododendron young plants against P. citricola. Irradiation of peat did not influence the growth and development of the tested plants

Effectiveness of electron beam irradiation in the control of Rhizoctonia solani

Effectiveness of electron beam irradiation was evaluated against Rhizoctonia solani, which is one of the most dangerous soil-borne pathogen, causing stem base and root rot of many horticultural plants. Treatment of in vitro cultures with 0.5 kGy significantly inhibited the pathogen's growth and the spread of necrosis on chrysanthemum leaf blades inoculated with the irradiated cultures. Application of e-beam irradiation for peat disinfection resulted in a two-fold decrease rot development in chrysanthemum stem at a dose of 5 kGy and complete inhibition at 10 kGy. For the elimination of R. solani from composted pine bark and its mixture with peat, irradiation of both substrates with 15 kGy was necessary

E-beam irradiation for the control of Phytophthora nicotianae var. nicotianae in stonewool cubes

Effectiveness of electron beam irradiation was evaluated against Phytophthora nicotianae var. nicotianae, the causal agent of stem base and root rot of tomato. In laboratory trials, irradiation of 7-day-old Phytophthora cultures growing on potato-dextrose-agar (PDA) medium with 1 kGy resulted in the disintegration of the pathogen’s hyphae. Increasing the irradiation dose to 3 kGy caused decay of the hyphae. Irradiation of infested stonewool with 5 kGy caused decrease of the pathogen population about 5 times. Application of 20 kGy completely eliminated the pathogen from stonewool. Irradiation of substratum resulted in significant increase of tomato seedlings healthiness, especially when the dose 20 kGy was applied

Analysis of the fluidization behavior and application of a novel spouted bed apparatus for spray granulation and coating

Spouted beds are well known for their good mixing of the solid phase and for their intensive heat and mass transfers between the fluid phase and the solid phase. Nearly isothermal conditions are enabled which is of advantage for the treatment of granular solid materials in granulation, agglomeration or coating processes. In this work the hydrodynamic behaviour of a novel spouted bed apparatus with two horizontal and slit-shaped gas inlets is investigated by high-frequency recordings of the gas phase pressure fluctuations over the entire bed. The hydrodynamic stable operation domain, which is of importance for operating the apparatus, will be identified and depicted in the Re-G-Ar-diagram by Mitev [1]. Another focus of this work is the simulation of the spouting process by application of a continuum approach in FLUENT 6.2. The effect of the frictional stresses on the hydrodynamic behaviour is examined by performing simulations with and without consideration of friction. The angle of internal friction fi in Schaeffer`s [10] model will be varied and the simulation results will be compared with experiments. It was found that the influence of friction is not very big by application of the quite simple and empirical frictional viscosity model by Schaeffer [10] basing on soil mechanical principles. Also the simulation results under negligence of friction were similar to those under consideration of friction. Another part of this work is the industrial application of the novel spouted bed in granulation and coating processes. Compared to classical fluidized beds, a much narrower particle size distribution, a higher yield and a higher product quality was obtained in the novel spouted bed