482 research outputs found
An Approach to the Simulation of a Batch-respirometer
Dynamic models in activated sludge processes have demonstrated to be a reliable and useful instrument in design and management of wastewater treatment plants. The biochemical nature of the processes involved the models which need a specific calibration
to local conditions. A common method to determine kinetic and stoichiometric parameters of the biomass or wastewater/sludge fractionations is respirometry. Theoretically, nearly all biomass parameters and fractions can be estimated by respirometry, but a
lot of difficulties rise when some parameters, such as saturation and hydrolysis rate constants, have to be drawn from experimental data.
The aim of our work is the setting up of a simple method to calibrate Activated Sludge Model No. 1 applying traditional batch respirometric tests together with dynamic simulations of the respirometer itself
Mid-infrared spectroscopy for large-scale phenotyping of bovine colostrum gross composition and immunoglobulin concentration
Immunoglobulin G is the fundamental antibody for acquisition of passive transfer of immunity in ruminant newborns. Colostrum, in fact, must be administered as soon as possible after birth to ensure a successful transfer of IgG from the dam to the calf. Assessment of colostrum Ig concentration and gross composition via gold standards is expensive, time consuming, and hardly implementable for large-scale investigations. Therefore, in the present study we evaluated the predictive ability of mid-infrared spectroscopy (MIRS) as an indirect determination method. A total of 714 colostrum samples collected within 6 h from parturition from Italian Holstein cows, 30% primiparous and 70% pluriparous, were scanned using a benchtop spectrometer after dilution in pure water. The prediction models were developed by correlating spectral information with the reference measurements: IgG concentration (93.54 ± 33.87 g/L), total Ig concentrations (102.82 ± 35.04 g/L), and content of protein (14.71 ± 3.51%), fat (4.61 ± 3.04%), and lactose (2.36 ± 0.51 mg/100 mg). We found a good to excellent performance in prediction of colostrum IgG concentration and traditional composition traits in cross-validation (R2CV ≥ 0.92) and a promising and good predictive ability in external validation with R2V equal to 0.84, 0.89, and 0.74 for IgG, protein, and fat, respectively. In the case of IgG and protein content, for example, the coefficient of determination in external validation was greater than 0.84. The other Ig fractions, A and M, presented insufficient prediction accuracy likely due to their extremely low concentration compared with IgG (4.56 and 5.06 g/L vs. 93.54 g/L). The discriminant ability of MIRS-predicted IgG and protein content was outstanding when trying to classify samples according to the quality level (i.e., low vs. high concentration of IgG). In particular, the cut-off that better discriminate low- from high-quality colostrum was 75.40 g/L in the case of the MIRS-predicted IgG and 13.32% for the MIRS-predicted protein content. Therefore, MIRS is proposed as a rapid and cheap tool for large-scale punctual IgG, protein, and lactose quantification and for the screening of low-quality samples. From a practical perspective, there is the possibility to install colostrum models in the MIRS benchtop machineries already present in laboratories in charge of official milk testing. Colostrum phenotypes collected on an individual basis will be useful to breeders for the definition of specific selection strategies and to farmers for management scopes. Finally, our findings may be relevant for other stakeholders, given the fact that colostrum is an emerging ingredient for the animal and human food and pharmaceutical industry
Characterization and BMP Tests of Liquid Substrates for High-rate Anaerobic Digestion
This work was focused on the physicochemical characterization and biochemical methane potential (BMP) tests of some liquid organic substrates, to verify if they were suitable for undergoing a process of high-velocity anaerobic digestion. The selected substrates were: first and second cheese whey, organic fraction of municipal solid waste
(OFMSW) leachate, condensate water and slaughterhouse liquid waste. Firstly, a physicochemical characterization was performed, using traditional and macromolecular parameters; then, batch anaerobic tests were carried out, and some continuous tests were
planned.
The results revealed that all the analyzed substrates have a potential to be anaerobically treated. Valuable information about treatment rate for a high-velocity anaerobic digestion process was obtained. Start-up of a lab-scale UASB reactor, treating diluted cheese whey, was successfully achieved with good COD removal efficiency. These preliminary results are expected to be further investigated in a successive phase, where continuous tests will be conducted on condensate water and OFMSW leachate.
This work is licensed under a Creative Commons Attribution 4.0 International License
Application of a handheld near-infrared spectrometer to predict gelatinized starch, fiber fractions, and mineral content of ground and intact extruded dry dog food
The aim of the present study was to investigate the ability of a handheld near-infrared spectrometer to predict total and gelatinized starch, insoluble fibrous fractions, and mineral content in extruded dry dog food. Intact and ground samples were compared to determine if the homogenization could improve the prediction performance of the instrument. Reference analyses were performed on 81 samples for starch and 99 for neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and minerals, and reflectance infrared spectra (740 to 1070 nm) were recorded with a SCiO™ near-infrared (NIR) spectrometer. Prediction models were developed using modified partial least squares regression and both internal (leave-one-out cross-validation) and external validation. The best prediction models in cross-validation using ground samples were obtained for gelatinized starch (residual predictive deviation, RPD = 2.54) and total starch (RPD = 2.33), and S (RPD = 1.92), while the best using intact samples were obtained for gelatinized starch (RPD = 2.45), total starch (RPD = 2.08), and K (RPD = 1.98). Through external validation, the best statistics were obtained for gelatinized starch, with an RPD of 2.55 and 2.03 in ground and intact samples, respectively. Overall, there was no difference in prediction models accuracy using ground or intact samples. In conclusion, the miniaturized NIR instrument offers the potential for screening purposes only for total and gelatinized starch, S, and K, whereas the results do not support its applicability for the other traits
The effect of using mixed initiator systems on the efficiency of photopolymerization of dental resins
A study was performed in order to determine the efficiency of the simultaneous use of the photoinitiators phenylpropanedione (PPD) and camphorquinone (CQ) in the polymerization of acrylic polymers and evaluate possible mechanisms leading to synergism or antagonism. It was found that efficiencies of both initiators taken individually are higher than that of their mixture, indicating that when both dyes are used simultaneously there will be an energy transfer from the more efficient initiator (CQ) to the less efficient one (PPD). Also, there was no proof of any reaction between the amine present in the CQ formulation and the PPD excited state.Foi realizado um estudo para determinar a eficiência da utilização simultânea dos fotoiniciadores fenilpropanodiona (PPD) e canforquinona (CQ) para a polimerização de polímeros acrílicos e avaliar possíveis mecanismos que levem à sinergia ou antagonismo. Foi encontrado que as eficiências de ambos iniciadores usados individualmente são maiores que a da mistura, indicando que quando os iniciadores são usados simultaneamente há uma transferência de energia do iniciador mais eficiente (CQ) para o menos eficiente (PPD). Também, não foi encontrada nenhuma evidência de reação entre a amina presente na formulação da CQ e o PPD no estado excitado.FAPESPCNP
Child Under-weight and Agricultural Productivity in India: Implications for Public Provisioning and Women’s Agency
This study is part of the ongoing research program on Leveraging Agriculture for Nutrition in South Asia (LANSA) funded by UK Aid from the Department for International Development, UK. The authors are consultants or regular staff of M.S. Swaminathan Research Foundation, India, one of the six partner institutions of LANSA.A recent global hunger index indicated a 12 percent decline in child underweight rates. This
study attempts an empirical explanation of the factors that influence child underweight rates at
the district level. Agricultural land productivity, share of women educated above the secondary
level and participating in work, maternal, and child health seem to contribute to the reduction
in child underweight. However government health and water supply facilities turn out to be
ineffective
Age dependence of serum beta-N-acetylhexosaminidase (NAG) activity
Serum Nacetyl-beta-Dglucosaminidase (NAG; EC 3.2.1.30) is a hexosaminidase and may be a predictor of vascular injury, e.g., in infant respiratory distress syndrome, pneumonia, bronchopulmonary dysplasia and necrotizing enterocolitis. To estimate the new diagnostic prospects we have modified our urinary NAG assay. In this sensitive colorimetric microassay, VRAGlcNAc was used as a substrate. In the present study the age dependence of serum NAG activity was investigated in newborn babies, infants (124 months), children (218 years) and adults (1980 years). Serum NAG activity was found to be agedependent; it is higher in early childhood (1159 U/l) but decreases to a constant value at the age of 12 years. After the age of 2 years it is similar to adults NAG (1030 U/l). In pediatrics agematched reference ranges must be taken into consideration
Treatment of Landfill Leachate by H2O2 Promoted Wet Air Oxidation: COD-AOX Reduction, Biodegradability Enhancement and Comparison with a Fenton-type Oxidation
Treatment experiments of a landfill leachate were performed by wet air oxidation (WAO) with the addition of H2O2 (as free radical promoter), and a Fenton-type (at pH ≈ 7) process, in order to compare COD (chemical oxygen demand) and AOX (adsorbable
organic halogen) reduction as well as biodegradability enhancement measured by OUR respirometric parameter. The WAO reactions were performed in a batch reactor at various temperatures in the range of T = 430-500 K employing a concentration of c = 0.88 mol L–1 of H2O2. The same H2O2 concentration was used in the Fenton-type-pH ≈ 7 experimental session considering H2O2/Fe(II) mole ratios of 5, 10 and 15. Similar results were obtained in COD abatement but appreciably different performance in AOX removal and biodegradability enhancement was observed. A comparison between the treatment trials brought to the evidence that Fenton-Type-pH ≈ 7 process has poor performance in biodegradability enhancement, diversely the H2O2 promoted WAO get to better performances even at mild temperature. This process could be considered as advantageous solution in landfill leachate pre-treatment when the main objectives are COD and AOX degradation together with the biodegradability enhancement for final treatment in common biological aerobic wastewater treatment plants
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