A global coating quality model for top-spray fluidized beds: spray sub model

Fluidized beds are amongst others used in industrial applications for coating particles. Little research has been performed in developing a quality model for a coating process. A quality model is able to predict the quality of the process in terms of coating thickness and uniformity and the occurrence of unwanted side-effects, including agglomeration, attrition and spray loss. The quality of the coating process in a fluidized bed is largely determined by the spray characteristics and the particle motion. A new quality model was developed for the coating process in a top-spray fluidized bed. The first step in the development of the new model was the creation of an accurate spray sub-model that describes the movement and the heat and mass balances of the droplets in the coating process. The second step was the creation of a particle sub-model that describes the movement and the heat and mass balances of the particles in the fluidized bed. The third and final step will be the development of the global coating quality model by combining the spray and the particle sub model. Experimental validation of the spray sub-model has already been carried out and is presented in this paper

Development of a stereovision-based technique to measure the spread patterns of granular fertilizer spreaders

Centrifugal fertilizer spreaders are by far the most commonly used granular fertilizer spreader type in Europe. Their spread pattern however is error-prone, potentially leading to an undesired distribution of particles in the field and losses out of the field, which is often caused by poor calibration of the spreader for the specific fertilizer used. Due to the large environmental impact of fertilizer use, it is important to optimize the spreading process and minimize these errors. Spreader calibrations can be performed by using collection trays to determine the (field) spread pattern, but this is very time-consuming and expensive for the farmer and hence not common practice. Therefore, we developed an innovative multi-camera system to predict the spread pattern in a fast and accurate way, independent of the spreader configuration. Using high-speed stereovision, ejection parameters of particles leaving the spreader vanes were determined relative to a coordinate system associated with the spreader. The landing positions and subsequent spread patterns were determined using a ballistic model incorporating the effect of tractor motion and wind. Experiments were conducted with a commercial spreader and showed a high repeatability. The results were transformed to one spatial dimension to enable comparison with transverse spread patterns determined in the field and showed similar results

Exchanging Medieval Material Culture. Studies on archaeology and history presented to Frans Verhaeghe

This volume, the result of a collaboration between the Flemish Heritage Institute (Vlaams Instituut voor het Onroerend Erfgoed) and the Brussels Free University (Vrije Universiteit Brussel), consists of a collection of twenty-two papers on material culture offered to prof. em. Frans Verhaeghe by his friends and colleagues from Belgium, Britain, The Netherlands, France and Denmark. Grouped in three sections material culture, landscape and settlement, theory these contributions represent Frans Verhaeghes fields of interest and work, in recognition of his contributions to the study of all aspects of material culture in a broad sense. Besides writing articles about the exchange of material culture, he also exchanged his knowledge with researchers and scholars throughout Europe. The first section of this volume covers the field of material culture stricto sensu, and mainly contains contributions about pottery studies. These range from specific find groups, a classification system or special contexts to studies on individual production sites of Antwerp maiolica and s-Hertogenbosch red and white ware. But non-pottery finds are also represented, both specific studies on individual finds, such as a lead urinal and a carved netting needle made from wood and surveys on particular find categories, such as cloth seals from Belgium or metal tripod ewers from Europe. Most papers in the second section, about landscape and settlement, combine the study of archaeological data with written sources. The early medieval period is represented by contributions on such subjects as the Merovingian cemetery of Broechem, the tombs of chiefs in northwestern Gaul, the role of Ename in the pagus Bracbatensis, and the formation processes of a small town in Flanders. Other papers discuss the meaning of moated sites in coastal Flanders and the issue of waste disposal in medieval towns. The third section consists of a massive paper on social theory and post-medieval archaeology. The volume begins with a comprehensive overview of the career of Frans Verhaeghe and ends with a complete bibliography

Disintegration of sedimentary rocks used as building material: evaluation and quantification in 4D

C

Grow - store - steam - re-peat : reuse of spent growing media for circular cultivation of Chrysanthemum

Substantially extending the life span of peat- and perlite-based growing media is a measure to increase the sustainability of soilless cultivation. The extraction of peat from pristine peatlands threatens these sensitive ecosystems and carbon sinks, meanwhile resulting in increased emissions of greenhouse gasses. Each batch of peat that is reused, results in a clear reduction in CO2 emissions and a lower impact on the climate. After using growing media for one cultivation, we aim at reusing the spent material as growing medium for another crop. Spent peat and perlite-based growing media from strawberry and cucumber cultivation were upcycled after steam treatment. We tested the effectiveness of steaming to reduce phytosanitary risks. The hygienisation efficiency of the steam treatment was confirmed: plant pathogenic fungi, larvae of vine weevils and weed seeds added or already present before the process were killed by the steam treatment. As the upcycled spent growing medium already contained high nutrient levels, the fertilizer application in the reused growing medium should be reduced, especially for P and K. Five indicators for assessing stability of the materials were used: CO2 flux measurements, oxygen uptake rate (OUR), biodegradation potential, mineral N content and risk for N immobilization. The spent growing media had a low decomposition rate and the release of nutrients in a leaching experiment was lower than for a fertilized peat-based growing medium, being a reference blend for open field cultivated Chrysanthemum. N mineralisation and P uptake were tested in an incubation and pot trial, respectively, and the upcycled spent growing medium was found to be an important source of plant-available K and P. Steam treatment did not severely affect the microbial biomass and diversity of the spent growing media. Blending the steam-treated spent media with other materials or inoculating by a commercially available biocontrol fungus also had a limited effect, indicating that newly introduced microorganisms do not easily establish in steamed-treated spent growing media (SSGM). Acidification of the SSGM was achieved by a low dose of elemental S. The steam-treated growing medium was tested for growing Chrysanthemum cuttings and plantlets. Spent growing media were not able to supply sufficient mineral N, but the stored amounts of P and K in the media were sufficiently plant available for optimal crop growth

Simplified Iohexol-Based Method for Measurement of Glomerular Filtration Rate in Goats and Pigs

SIMPLE SUMMARY: To improve the treatment of patients with kidney disease, new therapies are being developed. Before being used on humans, such therapies need to be tested on animals with kidney disease because reduced kidney function may influence the safety and efficacy of the treatment. Using large animals for this purpose is important because they tolerate frequent blood sampling, which allows for repeated monitoring. Goats seem particularly suitable for the evaluation of novel hemodialysis therapies since they are docile, have easily accessible neck veins to obtain blood access and body weights comparable with humans. Currently, no simple method is available to measure kidney function in goats (with or without impaired kidney function). Therefore, we developed a simple method to measure the kidney function in goats and pigs, which is based on a single injection of iohexol and requires three blood samples. Subsequently, kidney function can be calculated using a formula derived from pharmacokinetic modelling. The measurement of kidney function using our simplified method is relatively easy to perform, reduces total blood sampling and eliminates the need for an indwelling bladder catheter as compared to existing methods that require continuous infusion of a substance and timed urine collection. ABSTRACT: The preclinical evaluation of novel therapies for chronic kidney disease requires a simple method for the assessment of kidney function in a uremic large animal model. An intravenous bolus of iohexol was administered to goats (13 measurements in n = 3 goats) and pigs (23 measurements in n = 5 pigs) before and after induction of kidney failure, followed by frequent blood sampling up to 1440 min. Plasma clearance (CL) was estimated by a nonlinear mixed-effects model (CL(NLME)) and by a one-compartmental pharmacokinetic disposition model using iohexol plasma concentrations during the terminal elimination phase (CL(1CMT)). A simple method (CL(SM)) for the calculation of plasma clearance was developed based on the most appropriate relationship between CL(NLME) and CL(1CMT). CL(SM) and CL(NLME) showed good agreement (CL(NLME)/CL(SM) ratio: 1.00 ± 0.07; bias: 0.03 ± 1.64 mL/min; precision CL(SM) and CL(NLME): 80.9% and 80.7%, respectively; the percentage of CL(SM) estimates falling within ±30% (P30) or ±10% (P10) of CL(NLME): 53% and 12%, respectively). For mGFR(NLME) vs. mGFR(SM), bias was −0.25 ± 2.24 and precision was 49.2% and 53.6%, respectively, P30 and P10 for mGFR based on CL(SM) were 71% and 24%, respectively. A simple method for measurement of GFR in healthy and uremic goats and pigs was successfully developed, which eliminates the need for continuous infusion of an exogenous marker, urine collection and frequent blood sampling