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Resulting Values (resulting + value)
Selected AbstractsExplosion energies, nickel masses and distances of Type II plateau supernovaeMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2003D. K. Nadyozhin ABSTRACT The hydrodynamical modelling of Type II plateau supernova (SNIIP) light curves predicts a correlation between three observable parameters (plateau duration, absolute magnitude and photospheric velocity at the middle of the plateau) on the one hand, and three physical parameters (explosion energy E, mass of the envelope expelled and pre-supernova radius R) on the other. The correlation is used, together with adopted distances from the expanding photosphere method, to estimate and R for a dozen well-observed SNIIP. For this set of supernovae, the resulting value of E varies within a factor of 6 (0.5 ,E/1051 erg , 3), whereas the envelope mass remains within the limits . The pre-supernova radius is typically 200,600 R,, but can reach ,1000 R, for the brightest supernovae (e.g. SN 1992am). A new method of determining the distance of SNIIP is proposed. It is based on the assumption of a correlation between the explosion energy E and the 56Ni mass required to power the post-plateau light curve tail through 56Co decay. The method is useful for SNIIP with well-observed bolometric light curves during both the plateau and radioactive tail phases. The resulting distances and future improvements are discussed. [source] REACH-driven developments in analysis and physicochemistry,FLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2010A. Chaintreau Abstract The enforcement of the REACH regulation in the fragrance domain has created new challenges for the analytical and physical chemist. Many chemicals used as perfumery ingredients are hydrophobic, because low-polar compounds exhibit a higher substantivity (i.e. persistence after application) than do polar compounds. As a result, the usual protocols are often unsuitable and new methods must be developed. Biodegradation studies sometimes call for the quantification of traces of such hydrophobic analytes in complex media (e.g. waste water, aqueous surfactant solutions). Existing sample preparation techniques are either inefficient or time consuming. A new approach is proposed, based on single-use absorbants, which allows accurate quantification down to the 100 ppb range. This extremely simple technique allows good throughput analyses. Determining the environmental profile of a compound requires the determination of some physical constants. Among these, solubility in water can be obtained from theoretical models or experimentally, but the resulting values may greatly differ as a function of the model or the protocol. Several experimental approaches are critically discussed and compared with a reference technique. The air-to-water partition coefficients are determined by using an improved version of the previously developed static-and-trapped headspace technique. Copyright © 2009 John Wiley & Sons, Ltd. [source] Authentication of Green Asparagus Varieties by Near-Infrared Reflectance SpectroscopyJOURNAL OF FOOD SCIENCE, Issue 2 2001D.P. Perez ABSTRACT: Near-infrared reflectance spectroscopy (NIRS) was used for the authentication of 2 green asparagus varieties (Taxara and UC-157), grown in Huetor-Tajar (Granada, Spain) protected by the Quality Specific Appellation "Espárragos de Huétor-Tájar". To develop the prediction model, the method chosen was modified partial least square (MPLS) regression. Two sample sets (N = 219 and N2 = 145 samples, respectively) were used to obtain the calibration equations. The standard error of cross-validation (SECV) and the r2 value were 0.082 and 0.97, respectively, for the 1st calibration set and 0.077 and 0.97 for the 2nd calibration set. The 2nd chemometric model obtained was tested with independent validation sample set (N3 = 74 samples), and the resulting values for standard error of prediction (SEP) and for r2 were 0.07 and 0.96, respectively. These results prove that NIRS is an accurate technology for identification and authentication of asparagus varieties and easily implemented in industry. [source] Impact of enzymatic treatment on chemical composition, physicochemical properties and radical scavenging activity of goldenberry (Physalis peruviana L.) juiceJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2007Mohamed Fawzy Ramadan Abstract Tropical pulpy juices play an important role in nutrition as an excellent base for low-calorie and dietetic products. Goldenberry (Physalis peruviana L.) is one of the most promising exotic fruits and many interesting functional products could be developed from these berries. In this work we are reporting, for the first time, on the chemical composition and some physicochemical parameters of the goldenberry fruit juice. We have also investigated how some of these properties are affected by enzymatic treatment and pasteurisation. By enzymation, not only is the yield of juice increased, but also the macro- and micro-components. Application of enzymes, moreover, leads to juices with higher pulp content, higher acidity and higher total soluble solids. On the other side, enzyme-treated juices were characterised by lower alcohol-soluble solids and pH values. Water- and fat-soluble bioactives were estimated in appreciable amounts in the juice. The antioxidative potential of different processed juices was assessed by means of bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radicals and the resulting values were correlated with each of the antioxidant compounds. The results obtained can be considered very satisfactory and the juice could be widely appreciated when compared with other products commonly available on the market. The data are helpful for the optimisation of goldenberry juice production. It was the purpose to present a comprehensive assessment of the goldenberry juice and to address the potential for its delivery in functional drinks. Copyright © 2006 Society of Chemical Industry [source] A METHOD FOR SIMPLIFYING LARGE ECOSYSTEM MODELSNATURAL RESOURCE MODELING, Issue 2 2008JOCK LAWRIE Abstract Simplifying large ecosystem models is essential if we are to understand the underlying causes of observed behaviors. However, such understanding is often employed to achieve simplification. This paper introduces two model simplification methods that can be applied without requiring intimate prior knowledge of the system. Their utility is measured by the resulting values of given model diagnostics relative to those of the large model. The first method is a simple automated procedure for nondimensionalizing large ecosystem models, which identifies and eliminates terms that have little effect on model diagnostics. Some of its limitations are then addressed by the rate elimination method, which measures the relative importance of model terms using least-squares regression. The methods are applied to a model of the nitrogen cycle in Port Phillip Bay, Victoria, Australia. The rate elimination method provided more insights into the causal relationships built into the model than the nondimensionalizing method. It also allowed the reduction of the model's dimension. Thus it is a useful first step in model simplification. [source] The apparent temperature response of leaf respiration depends on the timescale of measurements: a study of two cold climate speciesPLANT BIOLOGY, Issue 2 2008D. Bruhn Abstract Productivity and climate models often use a constant Q10 for plant respiration, assuming tight control of respiration by temperature. We studied the temperature response of leaf respiration of two cold climate species (the Australian tree Eucalyptus pauciflora and the subantarctic megaherb Pringlea antiscorbutica, both measured in a field setting) on a short timescale (minutes) during different times within a diel course, and on a longer timescale, using diel variations in ambient temperature. There were great variations in Q10 depending on measuring day, measuring time and measuring method. When Q10 was calculated from short-term (15 min) manipulations of leaf temperature, the resulting values were usually markedly smaller than when Q10 was calculated from measurements at ambient leaf temperatures spread over a day. While for E. pauciflora, Q10 estimates decreased with rising temperature (corroborating the concept of a temperature-dependent Q10), the opposite was the case for P. antiscorbutica. Clearly, factors other than temperature co-regulate both leaf respiration rates and temperature sensitivity and contribute to diel and seasonal variation of respiration. [source] | |||||||||||||