190 research outputs found
The inspection of soil-disinfection equipment in Belgium.
In Belgium, the mandatory inspection of field and orchard sprayers was already started up in 1995. At that time, there were only inspection protocols available for those two types of sprayers. From 2008 on, two new inspection protocols were developed: one for greenhouse sprayers and one for soil-disinfection machines. Those inspection protocols were added to the Belgian legislation and implemented since 2011. The inspection protocol for greenhouse sprayers was mainly based on the two existing protocols (field and orchard sprayers) as the working principle of those machines was similar.Soil disinfection machines used on Belgian territory needed another approach because of the differences in pressurising and application technique compared to classical spraying machines. Soil disinfection machines use a closed tank containing the vaporous disinfectant. The tank is pressurised by a compressor or a diving cylinder. As concerns the injector side of those machines there are different possibilities. Some are using a manifold with restrictor plates or a small tap per injector, others use narrow tubes towards the injectors, and sometimes nozzles are used. As one can see, there are no standard inspection methods available for those types of machines. Neither a standard spray pattern measurement, nor a separate pressure and nozzle testing is possible on most of those machines. On top there are some important safety aspects that need special attention due to the hazardous products used. The Belgian inspection protocol was almost completely developed in-house and makes it possible to inspect soil-disinfection machines in an accurate, safe and economical way
Wireless flow-sensor to inspect spray rate controllers
In Belgium, the mandatory inspection of sprayers was already started up in 1996 and the 8th inspection cycle (2017-2018-2019) is currently running. The inspection of sprayers is performed by official and mobile teams ruled by two inspection authorities and the management is done by the Federal Ministry for Consumer Protection, Public Health and the Environment (FAVV). In the Flemish region the inspection is delegated to the Institute for Agricultural and Fisheries Research (ILVO). In the past decade the number of field crop sprayers equipped with a spray rate controller increased significantly. In the first inspection cycle (1996-1998), only 4.58% of the field crop sprayers were equipped with a spray rate controller in Flanders. In the 7th inspection cycle (2014-2016), this percentage increased significantly to 26.92%. As the original inspection method for spray rate controllers showed some lacks and was time consuming, ILVO developed a simple and reliable method to test rate controllers on field crop and orchard sprayers.In Belgium, the mandatory inspection of sprayers was already started up in 1996 and the 8th inspection cycle (2017-2018-2019) is currently running. The inspection of sprayers is performed by official and mobile teams ruled by two inspection authorities and the management is done by the Federal Ministry for Consumer Protection, Public Health and the Environment (FAVV). In the Flemish region the inspection is delegated to the Institute for Agricultural and Fisheries Research (ILVO). In the past decade the number of field crop sprayers equipped with a spray rate controller increased significantly. In the first inspection cycle (1996-1998), only 4.58% of the field crop sprayers were equipped with a spray rate controller in Flanders. In the 7th inspection cycle (2014-2016), this percentage increased significantly to 26.92%. As the original inspection method for spray rate controllers showed some lacks and was time consuming, ILVO developed a simple and reliable method to test rate controllers on field crop and orchard sprayers
Complex effective index in graphene-silicon waveguides
We report for the first time and characterize experimentally the complex optical
conductivity of graphene on silicon photonic waveguides. This permits us to predict
accurately the behavior of photonic integrated devices encompassing graphene layers.
Exploiting a Si microring add/drop resonator, we show the effect of electrical gating of
graphene on the complex effective index of the waveguide by measuring both the wavelength
shift of the resonance and the change in the drop peak transmission. Due to electro-refractive
effect of graphene a giant (>10 123) change in the effective index is demonstrated for the first
time on Si photonics waveguides and this large effect will crucially impact performances and
consumption of Si photonics devices. We confirmed the results by two independent
experiments involving two different gating schemes: Si gating through the ridge waveguide,
and polymer-electrolyte gating. Both the experiments demonstrate a very large phase effect in
good agreement with numerical calculations. The reported results validate the Kubo model
for the case of graphene-Si photonics interfaces and for propagation in this type of
waveguide. This is fundamental for the next design and fabrication of future graphene-silicon
photonics devices
On quantum mean-field models and their quantum annealing
This paper deals with fully-connected mean-field models of quantum spins with
p-body ferromagnetic interactions and a transverse field. For p=2 this
corresponds to the quantum Curie-Weiss model (a special case of the
Lipkin-Meshkov-Glick model) which exhibits a second-order phase transition,
while for p>2 the transition is first order. We provide a refined analytical
description both of the static and of the dynamic properties of these models.
In particular we obtain analytically the exponential rate of decay of the gap
at the first-order transition. We also study the slow annealing from the pure
transverse field to the pure ferromagnet (and vice versa) and discuss the
effect of the first-order transition and of the spinodal limit of metastability
on the residual excitation energy, both for finite and exponentially divergent
annealing times. In the quantum computation perspective this quantity would
assess the efficiency of the quantum adiabatic procedure as an approximation
algorithm.Comment: 44 pages, 23 figure
Analytical performance specifications for the measurement uncertainty of 24,25-dihydroxyvitamin D examinations
Objectives: The exploration of the metabolites in the degradation pathways of vitamin D (VTD) has gained importance in recent years and simultaneous quantitation of twenty-five-hydroxy vitamin D (25(OH)D) mass concentration together with 24,25-dihydroxyvitamin D (24,25(OH)2D) has been proposed as a newer approach to define VTD deficiency. Yet, no data are available on 24,25(OH)2D biological variation (BV). In this study, we evaluated 24,25(OH)2D's BV on the European Biological Variation Study (EuBIVAS) cohort samples to determine if analytical performance specifications (APS) for 24,25(OH)2D could be generated. Methods: Six European laboratories recruited 91 healthy participants. 25(OH)D and 24,25(OH)2D concentrations in K3-EDTA plasma were examined weekly for up to 10 weeks in duplicate with a validated LC-MS/MS method. The Vitamin D Metabolite Ratio (24,25(OH)2D divided by 25(OH)D × 100) was also calculated at each time point. Results: Linear regression of the mean 24,25(OH)2D concentrations at each blood collection showed participants were not in steady state. Variations of 24,25(OH)2D over time were significantly positively associated with the slopes of 25(OH)D concentrations over time and the concentration of 25(OH)D of the participant at inclusion, and negatively associated with body mass index (BMI), but not with age, gender, or location of the participant. The variation of the 24,25(OH)2D concentration in participants over a 10 weeks period was 34.6%. Methods that would detect a significant change linked to the natural production of 24,25(OH)2D over this period at p<0.05 would need a relative measurement uncertainty (u%)<14.9% while at p<0.01, relative measurement uncertainty should be <10.5%. Conclusions: We have defined for the first time APS for 24,25(OH)2D examinations. According to the growing interest in this metabolite, several laboratories and manufacturers might aim to develop specific methods for its determination. The results presented in this paper are thus necessary prerequisites for the validation of such methods.</p
Si1-x Ge x /Si Interface Profiles Measured to Sub-Nanometer Precision Using uleSIMS Energy Sequencing
Enteric coated HPMC capsules plugged with 5-FU loaded microsponges: a potential approach for treatment of colon cancer
How does banking market power affect bank opacity? Evidence from analysts' forecasts
Whilst the ongoing banking regulatory reforms towards a comprehensive Basel III framework emphasise bank transparency, disclosure and a competitive banking market environment, very little is known about the empirical relationship between bank opacity and banking competition. We investigate the impact of competition, as measured by the individual bank's pricing power in the banking market, on bank opacity using a large sample of US bank holding companies over the 1986–2015 period. We uncover new evidence, on the competition-bank opacity nexus, which suggests that banks with higher market power and operating in less competitive banking markets have lower analysts' forecast errors and dispersions and may thus be less opaque. This effect is more pronounced for the 2007–09 global financial crisis period. Our evidence is robust to controlling for analysts' characteristics, bank fixed-effects and endogeneity problems
Modulations of the Chicken Cecal Microbiome and Metagenome in Response to Anticoccidial and Growth Promoter Treatment
With increasing pressures to reduce or eliminate the use of antimicrobials for growth promotion purposes in production animals, there is a growing need to better understand the effects elicited by these agents in order to identify alternative approaches that might be used to maintain animal health. Antibiotic usage at subtherapeutic levels is postulated to confer a number of modulations in the microbes within the gut that ultimately result in growth promotion and reduced occurrence of disease. This study examined the effects of the coccidiostat monensin and the growth promoters virginiamycin and tylosin on the broiler chicken cecal microbiome and metagenome. Using a longitudinal design, cecal contents of commercial chickens were extracted and examined using 16S rRNA and total DNA shotgun metagenomic pyrosequencing. A number of genus-level enrichments and depletions were observed in response to monensin alone, or monensin in combination with virginiamycin or tylosin. Of note, monensin effects included depletions of Roseburia, Lactobacillus and Enterococcus, and enrichments in Coprococcus and Anaerofilum. The most notable effect observed in the monensin/virginiamycin and monensin/tylosin treatments, but not in the monensin-alone treatments, was enrichments in Escherichia coli. Analysis of the metagenomic dataset identified enrichments in transport system genes, type I fimbrial genes, and type IV conjugative secretion system genes. No significant differences were observed with regard to antimicrobial resistance gene counts. Overall, this study provides a more comprehensive glimpse of the chicken cecum microbial community, the modulations of this community in response to growth promoters, and targets for future efforts to mimic these effects using alternative approaches
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