Search results for "Process Engineering"
showing 10 items of 931 documents
Synthesis and influence of fatty acid esters on the foliar penetration of herbicides
1998
Abstract Synthesis of mono-esters of tetraethylene glycol and di-esters of tetraethylene glycol was accomplished from fatty acids and tetraethylene glycol in the absence of solvent and catalyst. Esterification was studied in a batch reactor by using a response surface methodology to evaluate the influence of synthesis variables such as molar substrate ratio of fatty acid relative to tetraethylene glycol (1.39–7.52), temperature (145–167°C), reaction time (0.5–8 h) on the yield of mono- and di-esters of tetraethylene glycol. A multipurpose reactor was developed for the transformation of fatty acids into pure α-monoglycerides. The 1-monoglycerides of heptanoic, undecelenic, oleic, linoleic an…
Cheese flavour : instrumental techniques
2004
This chapter discusses instrumental techniques to analyze cheese flavor. It focuses on recent advances made to study and identify the taste-active components present in the water-soluble fraction of cheese. A general procedure for the preparation of fractions involves an extraction of grated cheese by water followed by a fractionation scheme, generally adapted from the fractionation protocol used to isolate cheese nitrogen fractions in the study of proteolysis in cheese during ripening. However, as sub-fractions have to be evaluated sensorially to assess their relative sensory impact and try to link it to their chemical composition, a suitable eluent has to be used in the chromatographic st…
Emerging extraction
2015
Traditional extraction methods include usually high temperature treatment (more than 100°C) with the subsequent risk of thermal denaturation or transformation of the target molecules. Moreover, these techniques are very time-consuming and require relatively large quantities of solvents. On the other hand, the use of environmentally friendly technologies has led researchers and the food industry to develop new alternative processes that can extract valuable compounds from different sources and food wastes of different origin. This chapter describes the potential use of emerging technologies such as ultrasound-assisted extraction (UAE), laser ablation, pulsed electric fields (PEF), high volta…
Magnitude, temporal trends, and projections of the global prevalence of blindness and distance and near vision impairment: a systematic review and me…
2017
PubMed: 28779882
Cerebral plasmogens and aldehydes in senescence-accelerated mice P8 and R1 : Acomparison between weaned, adult and aged mice
2006
International audience; In contrast with senescence-accelerated mice R1, SAM P8 show abnormal aging characteristics. Changes occurring during aging could be mainly caused by free radical reactions. The brain is a plasmalogen-rich tissue. These particular phospholipids may act as endogenous antioxidants, be oxidized and release long chain aldehydes and α-hydroxyaldehydes during oxidative stress. The aim of this study was to examine by GC/MS the age- and strain-related levels of plasmalogens, aldehydes and α-hydroxyaldehydes in brain homogenates of SAM P8 and R1 at weaning, 5 months and 9 months of age in order to better understand the differences between both strains. In SAM R1, the evolutio…
In senescence accelerated mouse (SAM) heart, the protective effect of postconditioning is associated with a decrease in oxidative stress
2006
Supplément vol.27, World Congress of Cardiology 2006; International audience; The senescent heart susceptibility to ischemia (I) triggers multiple processes especially oxidative stress but precise mechanisms remain unclear. New animal’s models such as "Senescence Accelerated Mouse" Prone 8 (SAM-P8) and their control (SAM-R1) can be useful for a better understanding of aging process. We studied heart adaptation of these mice to I/reperfusion (R) sequence and a putative cardioprotector effect of post-conditioning (PC). Isolated working mice (8 months) hearts were subjected to a global total ischemia (20 minutes at 38°C), followed by 40 minutes of reperfusion. 4 groups of hearts were constitut…
Approche nutritionnelle de la thérapie du syndrome de l'œil sec : prévention par les acides gras polyinsaturés
2008
Dry eye disease affects 15% of the population over the age of 65. It is characterized mainly by inflammation of the ocular surface (tear film, conjunctiva and cornea) which represents a relevant target for therapeutic strategies. The side effects and long-term intolerance of anti-inflammatory drugs give rise to an increasing interest for dietary components exhibiting anti-inflammatory properties, such as polyunsaturated fatty acids (PUFAs). In these studies, we developed a scopolamine-induced dry eye model in the rat that mimics changes occurring in Humans suffering from moderate dry eye. We described the time course of clinical signs, inflammation and mucin production loss. We investigated…
Texture - flavour cross-modal interactions in dairy desserts: physico-chemical or cognitive mecanisms?
2006
International audience
Comparison of novel and conventional calibration techniques for the analysis of urine samples using plasma source mass spectrometry combined with a n…
2012
The accuracy and precision of the analytical data from the analysis of liquid samples with high matrix load often suffer from a compromised performance of the sample introduction system. This is especially significant in the case of miniaturized, pneumatic low flow nebulizers. Alternative low-flow sampling devices based on different operating principles are imperative to overcome this drawback. The superior performance of such an alternative liquid sample introduction system for ICP-MS, the drop-on-demand (DOD) aerosol generator based on thermal inkjet technology, was recently outlined by the same group for the analysis of aqueous standard solutions. Current improvements of the system now a…
Researches on the Alternative Fuels Which Can Be Used to Motors
2010
The alternative fuels are substances or materials used as fuel, other than the old conventional fuels (oil, natural gases and coals). 
 The paper analyses the most important alternative fuels, such as: bio-diesel, alcohols and hydrogen, presenting at each category the main important characteristics, the advantages and disadvantages presented by them. 
 The methyl-ester which is known as bio-diesel can be used in all motors with ignition by compression, alone or mixed in any proportion with oil, with minor modifications at the injection system. Bio-diesel fuel assures the same motor power as oil does, having even a bigger cetanic number than the usual oil. After tests, it was obser…