Sensitivity Analysis of Computations of the Vapor-Liquid Equilibria of Methane + Methanol or Glycols at Gas Hydrate Formation Conditions

The Soave-Redlich-Kwong (SRK-EOS) and Peng-Robinson (PR-EOS) equations of state are used often to describe the behavior of pure substances and mixtures despite difficulties in handling substances, like water, with high polarity and hydrogen bonding. They were employed in studying the binary vapor-liquid equilibria (VLE) of methane + methanol, monoethylene glycol (MEG), and triethylene glycol (TEG). These liquids are used to inhibit the formation of gas hydrates. The investigation focused on the conditions at which methane-water clathrates can form 283.89 K to 323.56 K and 5.01 MPa to 18.48 MPa. The pressure of methane in methanol is overestimated by a factor of two by either the SRK-EOS or the PR-EOS. In the methane + MEG system, the predicted pressures for both equations of state are generally less than experimental pressure except for the highest concentration of methane in MEG calculated by the SRK-EOS. In the methane + TEG system, the predictions of both models are close and trend similarly. Because of the comparative lack of extensive experimental methane + TEG data, the similarity of the methane + TEG computed results can be used as a basis for further study of this system experimentally

Introduction to the nonequilibrium functional renormalization group

In these lectures we introduce the functional renormalization group out of equilibrium. While in thermal equilibrium typically a Euclidean formulation is adequate, nonequilibrium properties require real-time descriptions. For quantum systems specified by a given density matrix at initial time, a generating functional for real-time correlation functions can be written down using the Schwinger-Keldysh closed time path. This can be used to construct a nonequilibrium functional renormalization group along similar lines as for Euclidean field theories in thermal equilibrium. Important differences include the absence of a fluctuation-dissipation relation for general out-of-equilibrium situations. The nonequilibrium renormalization group takes on a particularly simple form at a fixed point, where the corresponding scale-invariant system becomes independent of the details of the initial density matrix. We discuss some basic examples, for which we derive a hierarchy of fixed point solutions with increasing complexity from vacuum and thermal equilibrium to nonequilibrium. The latter solutions are then associated to the phenomenon of turbulence in quantum field theory.Comment: Lectures given at the 49th Schladming Winter School `Physics at all scales: The Renormalization Group' (to appear in the proceedings); 24 pages, 3 figure

Maternal Colonization With Group B Streptococcus and Serotype Distribution Worldwide: Systematic Review and Meta-analyses.

Background: Maternal rectovaginal colonization with group B Streptococcus (GBS) is the most common pathway for GBS disease in mother, fetus, and newborn. This article, the second in a series estimating the burden of GBS, aims to determine the prevalence and serotype distribution of GBS colonizing pregnant women worldwide. Methods: We conducted systematic literature reviews (PubMed/Medline, Embase, Latin American and Caribbean Health Sciences Literature [LILACS], World Health Organization Library Information System [WHOLIS], and Scopus), organized Chinese language searches, and sought unpublished data from investigator groups. We applied broad inclusion criteria to maximize data inputs, particularly from low- and middle-income contexts, and then applied new meta-analyses to adjust for studies with less-sensitive sampling and laboratory techniques. We undertook meta-analyses to derive pooled estimates of maternal GBS colonization prevalence at national and regional levels. Results: The dataset regarding colonization included 390 articles, 85 countries, and a total of 299924 pregnant women. Our adjusted estimate for maternal GBS colonization worldwide was 18% (95% confidence interval [CI], 17%-19%), with regional variation (11%-35%), and lower prevalence in Southern Asia (12.5% [95% CI, 10%-15%]) and Eastern Asia (11% [95% CI, 10%-12%]). Bacterial serotypes I-V account for 98% of identified colonizing GBS isolates worldwide. Serotype III, associated with invasive disease, accounts for 25% (95% CI, 23%-28%), but is less frequent in some South American and Asian countries. Serotypes VI-IX are more common in Asia. Conclusions: GBS colonizes pregnant women worldwide, but prevalence and serotype distribution vary, even after adjusting for laboratory methods. Lower GBS maternal colonization prevalence, with less serotype III, may help to explain lower GBS disease incidence in regions such as Asia. High prevalence worldwide, and more serotype data, are relevant to prevention efforts

The Importance of Informational Components of Sparkling Wine Labels Varies with Key Consumer Characteristics

Wine label information is an important aid for consumers in making purchase decisions. However, the influence of label information types in the context of sparkling wines is poorly understood, despite the global growth of this product class. Using an online survey of 576 Ontario sparkling wine consumers, we sought to examine this knowledge gap using two complementary approaches. First, participants were presented with a set of two mock sparkling wine labels, selected at random, from a set of eight conditions. One condition (control) contained all seven of the information types previously identified (endorsements, parentage, attributes, target end use, target end user, manufacture, nonpareil), whereas the other seven omitted one of each of these elements. Respondents then rated their willingness to buy, willingness to pay, and the perception of quality. Lastly, they self-rated the importance placed on 14 different label information statements when purchasing sparkling wine (5-point Likert scale from 1–not at all important to 5–extremely important). Results show that including a description of the wine’s sensory attributes on sparkling wine labels is important to consumers overall, except for those with a high subjective knowledge of sparkling wine, and those who normally spend more than CAD 30 per bottle, as these groups are more willing to buy, willing to pay, and rate their perception of quality higher for labels that do not include attribute information. Grape variety/blend and production region information are rated high in importance. Alcohol content is more important to young consumers and those who prefer Prosecco-style sparkling wines, whereas vintage/year is more important to consumers who prefer Champagne-style sparkling wines. Expert endorsements are rated low in importance, and younger consumers are more willing to buy sparkling wine with the endorsement information removed. We conclude that sparkling wine label information content should be optimised for different market segments and consumer characteristics. This study provides important insights that can guide sparkling wine marketers and retailers in this process

The Importance of Informational Components of Sparkling Wine Labels Varies with Key Consumer Characteristics

Wine label information is an important aid for consumers in making purchase decisions. However, the influence of label information types in the context of sparkling wines is poorly understood, despite the global growth of this product class. Using an online survey of 576 Ontario sparkling wine consumers, we sought to examine this knowledge gap using two complementary approaches. First, participants were presented with a set of two mock sparkling wine labels, selected at random, from a set of eight conditions. One condition (control) contained all seven of the information types previously identified (endorsements, parentage, attributes, target end use, target end user, manufacture, nonpareil), whereas the other seven omitted one of each of these elements. Respondents then rated their willingness to buy, willingness to pay, and the perception of quality. Lastly, they self-rated the importance placed on 14 different label information statements when purchasing sparkling wine (5-point Likert scale from 1–not at all important to 5–extremely important). Results show that including a description of the wine’s sensory attributes on sparkling wine labels is important to consumers overall, except for those with a high subjective knowledge of sparkling wine, and those who normally spend more than CAD 30 per bottle, as these groups are more willing to buy, willing to pay, and rate their perception of quality higher for labels that do not include attribute information. Grape variety/blend and production region information are rated high in importance. Alcohol content is more important to young consumers and those who prefer Prosecco-style sparkling wines, whereas vintage/year is more important to consumers who prefer Champagne-style sparkling wines. Expert endorsements are rated low in importance, and younger consumers are more willing to buy sparkling wine with the endorsement information removed. We conclude that sparkling wine label information content should be optimised for different market segments and consumer characteristics. This study provides important insights that can guide sparkling wine marketers and retailers in this process