Use of NIR to Estimate Nitrogen Degradability of Forage

Near infra red spectrometry (NIRS) is commonly used to characterise animal feeds at the level of their intrinsic composition (dry matter, protein, fat, fiber) as well of their digestibility (Dardenne et al.,1991). The use of new systems in the evaluation of the protein value has induced the necessity to determine parameters such as the theoretical ruminal degradability of nitrogen (DT). The definition of this criterion necessitates the implementation of the nylon bag technique which is time consuming and costly and is reserved to reference laboratories. An alternative to this technique, based on an enzymatic hydrolysis of the proteinic content, has been developed by Aufrère et al.( 1988) whose work has lead to define a relationship between the theoretical degradability measured in sacco (DT) and the enzymatic degradability of proteins (DE) for compound feeds. Resuming their work, Kamoun (1995) has adapted the methodology to forage substrates and determined for the former a same relationship. The study presents for forage substrates a predictive model of the enzymatic degradability of nitrogen by Near Infra Red Spectrometry, based on 69 samples of wilted grass silage analysed by the reference method. Characteristics of this model are SE 2.24, R2 0.74

Monitoring of Intake and Energetic Efficiency of the Grass in a Pasture Rotationally Grazed by Bulls using NIRS Applied to the Faeces

The objective of this approach was to characterise variations that one can observe in the course of a pasture season using near infrared spectrometry (NIRS) applied to the analysis of the grass and faeces collected during the season. Available grass and faeces of Belgian Blue White young bulls have been collected 3 times a week since the beginning of May until mid-October. The samples have been predicted in NIRS technique according to a calibration previously developed on the faeces of sheep fed ad libitum in cage with green grass. The NIRS provides a useful tool to provide a relative description and a monitoring of the evolution of the quality and of the daily intake of grass, that could provide useful information to adapt the supplementation according to the changing quality of the grass

A Rapid Estimation of Nitrogen Bound to Neutral Detergent Fibre in Forages by Near Infrared Reflectance Spectroscopy

Near infrared reflectance spectroscopy (NIRS) is widely used as a rapid method for the evaluation of the chemical composition or the nutritive value of foodstuffs (Givens et al., 1997). The determination of the neutral detergent fibre (NDF) bound N (NDF-N), which is highly variable in forages (Shayo & Udén, 1999), is expensive. The purpose of this study was to test the use of NIRS in the prediction of NDF-N in various forages

Qualité des pommes de terre : nouvelles méthodes d'évaluation calibrées sur l'analyse sensorielle

Quality of potatoes : new assessment methods calibrated by means of sensory analysis [frying index]. For the potato sector, raw material quality became an important criterium because it determines the type of use and the transformation ability of the tubers. It is now primordial to be able to identify the quality level of a share by reliable and objective methods. The qualitative criteria of potatoes are for the most estimated via sensory tests. During this survey, we measured several texture descriptors (desintegration, flouriness, granulation), the flesh colour, the after-cooking blackening susceptibility, the taste intensity and the after-frying coloration of the samples. In order to get rid of the human subjectivity, we studied the potentialities of near infrared spectrometry (NIRS) and of image analysis to predict or to measure these sensory behaviours. We observed high correlation between real values and values predicted by NIRS models, mainly for texture descriptors and flesh colour. Frying index prediction by NIRS is acceptable, but less precise than its measurement by image analysis

The Use of Near Infrared Reflectance Spectroscopy (NIRS) to Follow the Leaf/Stem Ratio of Legumes During Drying

Legume-rich mixed swards allow the production of a high quantity protein-rich forage with low nitrogen input. Nevertheless, during hay or silage making, dry matter losses as high as, 40 and 25 % have been recorded (Ciotti & Cavallero, 1979; Stilmant et al., 2004). These losses have mainly been linked to the high sensitivity to physical loss of legume leaves during drying. The development of a tool to characterise leaf losses or leaf/stem ratio during drying will help us to define the technical approach to reach the best compromise between quality loss reduction and good pre-wilting of legum-rich mixed swards. The aim of the present work was to test the potentialities of near infrared reflectance spectroscopy (NIRS) to quantify legume leaf/stem ratio in mixed grass-legume swards. The mixtures tested were perennial ryegrass-white clover (PR-WC), perennial ryegrass-red clover (PR-RC), timothy-red clover (T-RC) and cocksfoot-lucerne (C-L) swards. This technique has been successfully used to quantify leaf/stem ratio in pure perennial ryegrass swards (Leconte et al. 1999)

Investigation of the solid/liquid phase transitions in the U–Pu–O system

Mixed oxides of uranium and plutonium U1-yPuyO2-x are currently studied as reference fuel for Sodium-cooled Fast Reactors (SFRs). To predict the margin to fuel melting, an accurate description of both solidus and liquidus temperatures of these materials is crucial. In this work, after a critical review of the literature data, the parameters of the liquid phase of the CALPHAD models of the Pu–O and U–Pu–O systems are reassessed based on the model of Gu´eneau et al.. A good agreement between the calculated and selected experimental data is obtained. Using this model, the melting behaviour of U1-yPuyO2±x oxides is then studied as a function of plutonium content and oxygen stoichiometry. The congruent melting for the mixed oxides is found to be shifted towards low O/M ratios compared to the end-members (UO1.97 and PuO1.95). The temperature of this congruent melting is nearly constant (3130–3140 K) along a ternary phase boundary from UO1.98 to U0.55Pu0.45O1.82 and then decreases with Pu content to a maximum of approximately 3040 K for PuO1.95. This observation is explained by the stabilisation of the hypo-stoichiometric mixed oxides due to the increase of the configurational entropy at high temperatures by the formation of oxygen vacancies and related cation mixing. The influence of the atmosphere used in the laser heating melting experiments on the oxygen stoichiometry of the sample and its solidus and liquidus temperatures is investigated. The determination of this O/M ratio after laser melting tests using XANES is also reported. The simultaneous presence of U6+, U5+, U4+, Pu3+ and Pu4+ is observed, highlighting the occurrence of charge compensation mechanisms. The samples are highly oxidised in air whereas close to stoichiometry (O/M = 2.00) in argon. These results are in agreement with the computed solidification paths. This work illustrates the complex melting behaviour of the U1-yPuyO2±x fuels and highlights the need for the CALPHAD method to accurately describe and predict the high-temperature transitions of the U–Pu–O system

A Goal-based Framework for Contextual Requirements Modeling and Analysis

Requirements Engineering (RE) research often ignores, or presumes a uniform nature of the context in which the system operates. This assumption is no longer valid in emerging computing paradigms, such as ambient, pervasive and ubiquitous computing, where it is essential to monitor and adapt to an inherently varying context. Besides influencing the software, context may influence stakeholders' goals and their choices to meet them. In this paper, we propose a goal-oriented RE modeling and reasoning framework for systems operating in varying contexts. We introduce contextual goal models to relate goals and contexts; context analysis to refine contexts and identify ways to verify them; reasoning techniques to derive requirements reflecting the context and users priorities at runtime; and finally, design time reasoning techniques to derive requirements for a system to be developed at minimum cost and valid in all considered contexts. We illustrate and evaluate our approach through a case study about a museum-guide mobile information system