130 research outputs found
Quantitative analysis and detection of chaptalization and watering down of wine using isotope ratio mass spectrometry
In early 1990's European Union has established new isotopic approach for detection of wine authenticity. In this article we setup the possibility of using new approach using new EIM - Module - IRMS (Ethanol Isotope Measurement - Module - Isotope Ratio Mass Spectrometry) instrumental technique and new analytical parameter delta D-n(delta H-2(n)) wine ethanol value, which represents delta H-2 value of non-exchangeable hydrogen stable isotope ratio in ethanol, with other isotopic species (delta O-18 values in wine water) to improve detection of illegal wine production practices such as addition of sugar and/or dilution with water. Total of 42 wine samples were analyzed. 10 wine samples (out of 42) were prepared from grapes by alcoholic fermentation and analyzed for delta D-n values of ethanol. 19 wine samples (out of 42) were collected from wine producers in Serbia plus 1 wine samples designated from United States was taken from Serbian market and analyzed for delta D-n values of ethanol, delta O-18 values in wine water and also delta C-13 values in wine ethanol. Furthermore 9 wine samples (out of 42) were taken from Hungarian market and analyzed for delta D-n values of ethanol, and also 3 wine samples (out of 42) were taken from Austrian market and analyzed for delta D-n values of ethanol. All experiments were done in 4 isotope laboratories located in US, Austria, Hungary and People's Republic of China. delta D-n values of ethanol were measured by using EIM Module connected to FlashHT 2000 pyrolizer (one laboratory - Imprint Analytics GmbH, Austria), while in other 3 laboratories (US - COIL - Cornell University, Stable Isotope Laboratory, Hungary - Isotoptech Ltd, Debrecen, Hungary and China - C.N.R.I.F.F.I. - China National Institute of Food and Fermentation Industries Limited) EIM Module was connected to TC/EA (High Temperature Conversion Elemental Analyzer). Peripherals in all laboratories were further interfaced with isotope ratio mass spectrometer. Furthermore delta O-18 values in wine water were measured by using Gas Bench II interfaced also with isotope ratio mass spectrometer (one laboratory - US). Obtained results from all 4 laboratories have shown that this new approach which uses delta D-n in wine ethanol is more effective in improving detection of illegal wine production practices (sugar enrichment and water dilution) and origin of ethanol, and also detecting the addition of corn or beet sugar, sugar syrup to wine, or dilution of grape must with water prior to alcoholic fermentation
Biofluorescence in Catsharks (Scyliorhinidae): Fundamental description and relevance for elasmobranch visual ecology
Biofluorescence has recently been found to be widespread in marine fishes, including sharks. Catsharks, such as the Swell Shark (Cephaloscyllium ventriosum) from the eastern Pacific and the Chain Catshark (Scyliorhinus retifer) from the western Atlantic, are known to exhibit bright green fluorescence. We examined the spectral sensitivity and visual characteristics of these reclusive sharks, while also considering the fluorescent properties of their skin. Spectral absorbance of the photoreceptor cells in these sharks revealed the presence of a single visual pigment in each species. Cephaloscyllium ventriosum exhibited a maximum absorbance of 484 +/- 3 nm and an absorbance range at half maximum (lambda(1/2max)) of 440-540 nm, whereas for S. retifer maximum absorbance was 488 +/- 3 nm with the same absorbance range. Using the photoreceptor properties derived here, a "shark eye" camera was designed and developed that yielded contrast information on areas where fluorescence is anatomically distributed on the shark, as seen from other sharks' eyes of these two species. Phylogenetic investigations indicate that biofluorescence has evolved at least three times in cartilaginous fishes. The repeated evolution of biofluorescence in elasmobranchs, coupled with a visual adaptation to detect it; and evidence that biofluorescence creates greater luminosity contrast with the surrounding background, highlights the potential importance of biofluorescence in elasmobranch behavior and biology
Obstructions to the Existence of Sasaki-Einstein Metrics
We describe two simple obstructions to the existence of Ricci-flat Kahler
cone metrics on isolated Gorenstein singularities or, equivalently, to the
existence of Sasaki-Einstein metrics on the links of these singularities. In
particular, this also leads to new obstructions for Kahler-Einstein metrics on
Fano orbifolds. We present several families of hypersurface singularities that
are obstructed, including 3-fold and 4-fold singularities of ADE type that have
been studied previously in the physics literature. We show that the AdS/CFT
dual of one obstruction is that the R-charge of a gauge invariant chiral
primary operator violates the unitarity bound.Comment: 35 pages, 1 figure; references and a footnote adde
Recommended from our members
INFLUENCE OF STEEL ALLOY COMPOSITION ON THE PROCESS ROBUSTNESS OF AS-BUILT HARDNESS IN LASER-DIRECTED ENERGY DEPOSITION
To ensure consistent quality of additively manufactured parts, it is advantageous to identify
alloys which can meet performance criteria while being robust to process variations. Toward such
an end, this work studied the effect of steel alloy composition on the process robustness of as-built
hardness in laser-directed energy deposition (L-DED). In-situ blending of ultra-high-strength lowalloy steel (UHSLA) and pure iron powders produced 10 alloys containing 10-100% UHSLA by
mass. Thin-wall samples were deposited, and the hardness sensitivity of each alloy was evaluated
with respect to laser power and interlayer delay time. The sensitivity peaked at 40-50% UHSLA,
corresponding to phase fluctuations between lath martensite and upper bainite depending on the
cooling rate. Lower (10-20%) or higher (70-100%) alloy contents transformed primarily to ferrite
or martensite, respectively, with auto-tempering of martensite at lower cooling rates. By avoiding
martensite/bainite fluctuations, the robustness was improved.Mechanical Engineerin
N=2 supersymmetric AdS_4 solutions of M-theory
We analyse the most general N=2 supersymmetric solutions of D=11 supergravity
consisting of a warped product of four-dimensional anti-de-Sitter space with a
seven-dimensional Riemannian manifold Y_7. We show that the necessary and
sufficient conditions for supersymmetry can be phrased in terms of a local
SU(2)-structure on Y_7. Solutions with non-zero M2-brane charge also admit a
canonical contact structure, in terms of which many physical quantities can be
expressed, including the free energy and the scaling dimensions of operators
dual to supersymmetric wrapped M5-branes. We show that a special class of
solutions is singled out by imposing an additional symmetry, for which the
problem reduces to solving a second order non-linear ODE. As well as recovering
a known class of solutions, that includes the IR fixed point of a mass
deformation of the ABJM theory, we also find new solutions which are dual to
cubic deformations. In particular, we find a new supersymmetric warped AdS_4 x
S^7 solution with non-trivial four-form flux.Comment: 50 pages, 2 figures; v2: typos fixed, some intermediate formulas
added to improve clarity, references adde
The Environment of z > 1 3CR Radio Galaxies and QSOs: From Proto-clusters to Clusters of Galaxies?
Galaxie
The Intentional Use of Service Recovery Strategies to Influence Consumer Emotion, Cognition and Behaviour
Service recovery strategies have been identified as a critical factor in the success of. service organizations. This study develops a conceptual frame work to investigate how specific service recovery strategies influence the emotional, cognitive and negative behavioural responses of . consumers., as well as how emotion and cognition influence negative behavior. Understanding the impact of specific service recovery strategies will allow service providers' to more deliberately and intentionally engage in strategies that result in positive organizational outcomes. This study was conducted using a 2 x 2 between-subjects quasi-experimental design. The results suggest that service recovery has a significant impact on emotion, cognition and negative behavior. Similarly, satisfaction, negative emotion and positive emotion all influence negative behavior but distributive justice has no effect
The influence of individual cognitive style on performance in management education
This paper reports the outcomes of an empirical study undertaken to explore the possibility that cognitive style may be an important factor influencing performance on certain types of task in management education. Four hundred and twelve final-year undergraduate degree students studying management and business administration were tested using the Allinson-Hayes Cognitive Style Index. Their cognitive styles were then compared with assessment grades achieved for academic modules, the task categories of which were deemed to be consonant with either the wholist/intuitive or the analytic style of working. Overall ability defined by final degree grades was also tested against individualsâ cognitive styles. As expected, students whose dominant cognitive styles were analytic attained higher grades for long term solitary tasks involving careful planning and analysis of information. However, contrary to expectations, performance on tasks believed to be more suited to the wholist/intuitive style was also higher for analytic individuals, as was overall ability defined by final degree grades. The results were discussed in terms of the nature of the tasks and the need for methods of performance assessment that are independent of an orientation bias. Without this, it is argued, employment selection criteria may favour the wrong type of candidate in some circumstances
Milagro limits and HAWC sensitivity for the rate-density of evaporating Primordial Black Holes
postprin
- âŠ