TWO-PHASE FRICTION FACTOR IN GAS-LIQUID PIPE FLOW

An improved friction factor prediction model for two-phase gas-liquid pipe flow is proposed. The model is based on a previous no-slip formulation where a mixture Reynolds number was defined. In this study, the mixture Reynolds number is modified by introducing slip-ratio information through the inclusion of void-fraction and flow-pattern dependent models. An experimental database reconstituted from the available literature and new frictional pressure-drop data for air-water horizontal flow in an I.D. 0.0204m pipe are also presented. The full database considers several different flow conditions for horizontal two-phase flow of refrigerants and air-water mixtures. It was compared to predictions of models from the literature as well as the new proposed model. We found that the proposed and Müller-Steinhagen-and-Heck methods provide better agreement for the current experimental database. It is shown that the inclusion of void-fraction information on the previous mixture Reynolds definition improves the friction-factor predictio

The moduli of Certain Curves of Genus Three in Characteristic Two

We study curves of genus 3 over algebraically closed fields of characteristic 2 with the canonical theta characteristic totally supported in one point. We compute the moduli dimension of such curves and focus on some of them which have two Weierstrass points with Weierstrass directions towards the support of the theta characteristic. We answer questions related to order sequence and Weierstrass weight of Weierstrass points.Key words: curves of genus three, characteristic two, theta characteristic.

Postmenopausal women with osteoporosis consume high amounts of vegetables but insufficient dairy products and calcium to benefit from their virtues: the CoLaus/OsteoLaus cohort.

We evaluated the associations between nutrients, dietary patterns or compliance to dietary guidelines and bone health among postmenopausal women from the CoLaus/OsteoLaus cohort. Postmenopausal women with osteoporosis consume a high amount of vegetables but insufficient amount of dairy products and calcium to benefit from their adherence to dietary guidelines. Diet plays a significant role in the prevention of osteoporosis (OP). We evaluated the associations between nutrients, dietary patterns or compliance (expressed in odds of meeting) to dietary Swiss guidelines and bone health (T score < - 2.5 SD, TBS < 1230) among postmenopausal women. One thousand two hundred fifteen women (64.3 ± 7.5 years) from the CoLaus/OsteoLaus cohort (Lausanne, Switzerland) had their dietary intake assessed using a validated food frequency questionnaire. Bone mineral density (BMD), trabecular bone score (TBS) and vertebral fractures were evaluated with DXA. OP risk factors, calcium supplements (> 500 mg) and prevalent major OP fractures were assessed by questionnaire. One hundred eighty of 1195 women had OP according to BMD, 87/1185 a low TBS and 141/1215 prevalent major OP fractures. In multivariate analysis (adjusted for total energy intake, age, antiosteoporotic treatment, educational level, BMI, sedentary status and diabetes), OP women consumed more vegetable proteins (21.3 ± 0.4 vs 19.6 ± 0.2 g/day), more fibres (18.2 ± 0.5 vs 16.5 ± 0.2 g/day), less animal proteins (40.0 ± 1.1 vs 42.8 ± 0.4 g/day), less calcium (928 ± 30 vs 1010 ± 12 mg/day) and less dairy products (175 ± 12 vs 215 ± 5 g/day), all p ≤ 0.02. According to guidelines, OP women had a tendency to higher compliance for vegetables (OR (95% CI) 1.50 (0.99-2.26)) and a lower compliance for dairy (OR (95% CI) 0.44 (0.22-0.86)) than those without OP. Women taking calcium supplements consumed significantly higher amounts of dairy products. No association was found between TBS values or prevalent OP fractures and any dietary components. Postmenopausal women with OP consume a high amount of vegetables but insufficient amount of dairy products and calcium. TBS does not seem to be influenced by diet

The Benefit of Menopausal Hormone Therapy on Bone Density and Microarchitecture Persists After its Withdrawal.

Menopausal hormone therapy (MHT) favorably affects bone mineral density (BMD). Whether MHT also affects bone microarchitecture, as assessed by trabecular bone score (TBS), has never been evaluated. Our objective was to assess the effect of MHT on TBS and BMD before and after its withdrawal. This was a cross-sectional study. This study included the general community. Data were collected from the OsteoLaus cohort (1500 women aged 50-80 years). After exclusion of women with bone-modulating treatments, 1279 women were categorized according to MHT status into current (CU), past (PU), and never (NU) users. Spine TBS and BMD at lumbar spine, femoral neck, and total hip were assessed by dual X-ray absorptiometry. Age- and body mass index-adjusted analysis showed higher TBS values in CU vs PU or NU (1.31 ± 0.01, 1.29 ± 0.01, and 1.27 ± 0.01, respectively; P < .001). All BMD values were significantly higher in CU vs PU or NU. Compared to NU, PU exhibited higher lumbar spine (0.94 ± 0.01 vs 0.91 ± 0.01 g/cm(2); P = .017) and total hip (0.86 ± 0.01 vs 0.84 ± 0.01 g/cm(2); P = .026) BMD and a trend for higher TBS (P = .066). The 10-year loss of TBS and BMD at lumbar spine and total hip was significantly lower for both CU and PU vs NU. MHT duration had no effect on bone parameters. In PU, the residual effect on TBS and BMD was significantly more prominent in early discontinuers (<2 years). MHT is associated with bone microarchitecture preservation, as assessed by TBS. The effect of MHT on TBS and BMD persists at least 2 years after withdrawal

The Metabolic Benefits of Menopausal Hormone Therapy Are Not Mediated by Improved Nutritional Habits. The OsteoLaus Cohort.

Menopause alters body composition by increasing fat mass. Menopausal hormone therapy (MHT) is associated with decreased total and visceral adiposity. It is unclear whether MHT favorably affects energy intake. We aimed to assess in the OsteoLaus cohort whether total energy intake (TEI) and/or diet quality (macro- and micronutrients, dietary patterns, dietary scores, dietary recommendations)-evaluated by a validated food frequency questionnaire-differ in 839 postmenopausal women classified as current, past or never MHT users. There was no difference between groups regarding TEI or consumption of macronutrients. After multivariable adjustment, MHT users were less likely to adhere to the unhealthy pattern 'fat and sugar: Current vs. never users [OR (95% CI): 0.48 (0.28-0.82)]; past vs. never users [OR (95% CI): 0.47 (0.27-0.78)]. Past users exhibited a better performance in the revised score for Mediterranean diet than never users (5.00 ± 0.12 vs. 4.63 ± 0.08, p < 0.04). Differences regarding compliance with dietary recommendations were no longer significant after adjustment for covariates. Overall, these results argue against a major role of TEI and diet quality as possible mediators of the MHT metabolic benefits. Future research on this relationship should focus on other potential targets of MHT, such as resting energy expenditure and physical activity

Collective vs local measurements in qubit mixed state estimation

We discuss the problem of estimating a general (mixed) qubit state. We give the optimal guess that can be inferred from any given set of measurements. For collective measurements and for a large number $N$ of copies, we show that the error in the estimation goes as 1/N. For local measurements we focus on the simpler case of states lying on the equatorial plane of the Bloch sphere. We show that standard tomographic techniques lead to an error proportional to $1/N^{1/4}$, while with our optimal data processing it is proportional to $1/N^{3/4}$.Comment: 4 pages, 1 figure, minor style changes, refs. adde

The quorum sensing com system regulates pneumococcal colonisation and invasive disease in a pseudo-stratified airway tissue model.

BACKGROUND The effects of the com quorum sensing system during colonisation and invasion of Streptococcus pneumoniae (Spn) are poorly understood. METHODS We developed an ex vivo model of differentiated human airway epithelial (HAE) cells with beating ciliae, mucus production and tight junctions to study Spn colonisation and translocation. HAE cells were inoculated with Spn wild-type TIGR4 (wtSpn) or its isogenic ΔcomC quorum sensing-deficient mutant. RESULTS Colonisation density of ΔcomC mutant was lower after 6 h but higher at 19 h and 30 h compared to wtSpn. Translocation correlated inversely with colonisation density. Transepithelial electric resistance (TEER) decreased after pneumococcal inoculation and correlated with increased translocation. Confocal imaging illustrated prominent microcolony formation with wtSpn but disintegration of microcolony structures with ΔcomC mutant. ΔcomC mutant showed greater cytotoxicity than wtSpn, suggesting that cytotoxicity was likely not the mechanism leading to translocation. There was greater density- and time-dependent increase of inflammatory cytokines including NLRP3 inflammasome-related IL-18 after infection with ΔcomC compared with wtSpn. ComC inactivation was associated with increased pneumolysin expression. CONCLUSIONS ComC system allows a higher organisational level of population structure resulting in microcolony formation, increased early colonisation and subsequent translocation. We propose that ComC inactivation unleashes a very different and possibly more virulent phenotype that merits further investigation

Photonic Technologies for Millimeter- and Submillimeter-wave Signals

[EN] Fiber optic components offer a competitive implementation for applications exploiting the millimeter-wave and THz regimes due to their capability for implementing broadband, compact, and cost-effective systems. In this paper, an outline of the latest technology developments and applications of fiber-optic-based technologies for the generation, transmission, and processing of high-frequency radio signals is provided. © 2012 B. Vidal et al.B. Vidal would like to thank the Spanish Ministerio de Economia y Competitividad for its support through Project TEC2009-08078. T. Nagatsuma would like to acknowledge the financial support provided by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (A) 23246067, 2011 and the JST-ANR WITH program.Vidal Rodriguez, B.; Nagatsuma, T.; Gomes, NJ.; Darcie, TE. (2012). Photonic Technologies for Millimeter- and Submillimeter-wave Signals. Advances in Optical Technologies. 2012:1-17. doi:10.1155/2012/925065S117201

Utilização do Conceito de Conjuntos Nebulosos na Otimização de Ferramentas de Priorização em Ergonomia: O Caso da Matriz SIC-Fuzzy

A matriz de Priorização tem sido uma das ferramentas mais frequentes para auxiliar nas tomadas de decisões relacionadas a projetos. Por sua vez, as ações ergonômicas resultam em múltiplas necessidades de enquadramento, sendo algumas delas mais urgentes e necessárias, ou ainda outras complexas, que exijam ações de engenharia e, portanto, tendem a demorar a serem implementadas. Assim, matrizes de priorização possibilitariam eleger, por critérios diferenciados, os fatores de riscos e a urgência de cada problema que demanda uma determinada ação. A Matriz SIC/Fuzzy é uma evolução da Matriz de Priorização SIC ®, ferramenta desenvolvida pelo laboratório GENTE/Fuzzy da UFRJ. Ela relaciona os itens a serem analisados por critérios de saúde e segurança ocupacional, sendo utilizada no processo de tomada de decisão em ergonomia. O índice “SIC” permite, portanto, determinar o grau de gravidade ocupacional de cada posto de trabalho. A apropriação da Lógica Fuzzy à ferramenta original incorpora variáveis que representam atributos cognitivos humanos, transformando-os em um formato numérico que pode ser quantificado e mensurado. A teoria fuzzy é usada, essencialmente, para mapear modelos quantitativos de tomada de decisão e em métodos de representação em ambientes de incertezas e imprecisões. Neste contexto, pode-se utilizá-la juntamente com indicadores de priorização por criticidade utilizados em Ergonomia. O trabalho descreve o modelo e apresenta experiências iniciais de sua aplicação

Influence of sugar type on the bioavailability of cocoa flavanols.

The beneficial effects of cocoa on vascular function are mediated by the absorption of monomeric flavanols into the circulation from the small intestine. As such, an understanding of the impact of the food matrix on the delivery of flavanols to the circulation is critical in assessing the potential vascular impact of a food. In the present study, we investigated the impact of carbohydrate type on flavanol absorption and metabolism from chocolate. A randomised, double-blind, three-arm cross-over study was conducted, where fifteen volunteers were randomly assigned to either a high-flavanol (266 mg) chocolate containing maltitol, a high-flavanol (251 mg) chocolate with sucrose or a low-flavanol (48 mg) chocolate with sucrose. Test chocolates were matched for micro- and macronutrients, including the alkaloids theobromine and caffeine, and were similar in taste and appearance. Total flavanol absorption was lower after consumption of the maltitol-containing test chocolate compared with following consumption of its sucrose-containing equivalent (P = 0·002). Although the O-methylation pattern observed for absorbed flavanols was unaffected by sugar type, individual levels of unmethylated ( - )-epicatechin metabolites, 3'-O-methyl-epicatechin and 4'-O-methyl-epicatechin metabolites were lower for the maltitol-containing test chocolate compared with the sucrose-containing equivalent. Despite a reduction in the total plasma pool of flavanols, the maximum time (T max) was unaffected. The present data indicate that full assessment of intervention treatments is vital in future intervention trials with flavanols and that carbohydrate content is an important determinant for the optimal delivery of flavanols to the circulation