Gas-to-gas heat exchanger design for high performance thermal energy storage

The mathematical modelling and optimization of a gas-to-gas heat exchanger with a non-constant cross sectional area is presented. The design of the cross sectional area of the heat exchanger analyzed is based on an hexagonal mesh, which would be highly impractical to fabricate in a conventional way but could be built relatively easily through modern manufacturing techniques. The geometric configuration proposed allows attaining a high exergy efficiency and a significant cost reduction, measured in terms of volume per unit of exergy transfer. The relationship that exists between the overall exergy efficiency of the heat exchanger and its cost is thoroughly explained throughout the study. The results obtained from the modelling demonstrate the premise that it is possible to realize designs for heat exchangers that are highly exergy-efficient and very cheap, owing to the small volume of material required, if the constrains imposed by the limitations of traditional manufacturing methods are set aside. Furthermore, the study reveals a very important fact: the volume of material in a heat exchanger increases in quadratic proportion to its characteristic dimension, which implies that scaling up the geometry has a strong impact on its cost-effectiveness

Time of admission to the PICU and mortality

Objectives: To evaluate for any association between time of admission to the PICU and mortality. Design: Retrospective cohort study of admissions to PICUs in the Virtual Pediatric Systems (VPS, LLC, Los Angeles, CA) database from 2009 to 2014. Setting: One hundred and twenty-nine PICUs in the United States. Patients: Patients less than 18 years old admitted to participating PICUs; excluding those post cardiac bypass. Interventions: None. Measurements and Main Results: A total of 391,779 admissions were included with an observed PICU mortality of 2.31%. Overall mortality was highest for patients admitted from 07:00 to 07:59 (3.32%) and lowest for patients admitted from 14:00 to 14:59 (1.99%). The highest mortality on weekdays occurred for admissions from 08:00 to 08:59 (3.30%) and on weekends for admissions from 09:00 to 09:59 (4.66%). In multivariable regression, admission during the morning 06:00-09:59 and midday 10:00-13:59 were independently associated with PICU death when compared with the afternoon time period 14:00-17:59 (morning odds ratio, 1.15; 95% CI, 1.04-1.26; p = 0.006 and midday odds ratio, 1.09; 95% CI; 1.01-1.18; p = 0.03). When separated into weekday versus weekend admissions, only morning admissions were associated with increased odds of death on weekdays (odds ratio, 1.13; 95% CI, 1.01-1.27; p = 0.03), whereas weekend admissions during the morning (odds ratio, 1.33; 95% CI, 1.14-1.55; p = 0.004), midday (odds ratio, 1.27; 95% CI, 1.11-1.45; p = 0.0006), and afternoon (odds ratio, 1.17; 95% CI, 1.03-1.32; p = 0.01) were associated with increased risk of death when compared with weekday afternoons. Conclusions: Admission to the PICU during the morning period from 06:00 to 09:59 on weekdays and admission throughout the day on weekends (06:00-17:59) were independently associated with PICU death as compared to admission during weekday afternoons. Potential contributing factors deserving further study include handoffs of care, rounds, delays related to resource availability, or unrecognized patient deterioration prior to transfer

Design and characterization of hybrid III–V concentrator photovoltaic–thermoelectric receivers under primary and secondary optical elements

Lattice-matched monolithic triple-junction Concentrator Photovoltaic (CPV) cells (InGa(0.495)P/GaIn(0.012)As/Ge) were electrically and thermally interfaced to two Thermoelectric (TE) Peltier module designs. An electrical and thermal model of the hybrid receivers was modelled in COMSOL Multiphysics software v5.3 to improve CPV cell cooling whilst increasing photon energy conversion efficiency. The receivers were measured for current-voltage characteristics with the CPV cell only (with sylguard encapsulant), under single secondary optical element (SOE) at x2.5 optical concentration, and under Fresnel lens primary optical element (POE) concentration between x313 and x480. Measurements were taken in solar simulators at Cardiff and Jaén Universities, and on-sun with dual-axis tracking at Jaén University. The hybrid receivers were electrically, thermally and theoretically investigated. The electrical performance data for the cells under variable irradiance and cell temperature conditions were measured using the integrated thermoelectric module as both a temperature sensor and as a solid-state heat pump. The performance of six SOE-CPV-TE hybrid devices were evaluated within two 3-receiver strings under primary optical concentration with measured acceptance angles of 1.00o and 0.89o, similar to commercially sourced CPV modules. A six-parameter one-diode equivalent electrical model was developed for the multi-junction CPV cells with SOE and POE. This was applied to extract six model parameters with the experimental I-V curves of type A receiver at 1, 3 and 500 concentration ratios. Standard test conditions (1000W/m2, 25oC and AM1.5G spectrum) were assumed based on trust-region-reflective least squares algorithm in MATLAB. The model fitted the experimental I-V curves satisfactorily with a mean error of 4.44%, and the optical intensity gain coefficient of SOE and POE is as high as 0.91, in comparison with 0.50-0.86 for crossed compound parabolic concentrators (CCPC). The determined values of diode reverse saturation current, combined series resistance and shunt resistance were similar to those of monocrystalline PV cell/modules in our previous publications. The model may be applicable to performance prediction of multi-junction CPV cells in the future

Travel, tourism, climate change and behavioral change: travelers’ perspectives from a developing country, Nigeria

While studies have examined people's understanding of climate change and its relationship to tourism, these focus largely on developed country populations. Much future tourism growth will come from developing countries following economic development; often countries where climate change will be strongly felt. Do tourists from developing countries have the same knowledge gaps about travel, tourism, and climate change as in the developed world? Will behavioral change policies be successful in encouraging more environmentally friendly approaches to climate change and tourism in developing countries? This paper presents findings from 20 in-depth interviews with active Nigerian tourists, analyzing their understanding of climate change, the links known, or not, between their travel and climate change, and their willingness to change their tourism patterns. Understanding of climate change was limited and there was conceptual confusion. Participants did not view their own travel as a cause of climate change and many were embedded in air travel practice. Participants were unwilling to change their tourism patterns to reduce their contribution to climate change. Significant structural barriers limit low carbon tourism travel in Nigeria (and other developing countries), including reliability, availability safety, and speed. Behavioral change will be difficult to achieve

Analysis of microsatellite markers in the genome of the plant pathogen Ceratocystis fimbriata

Ceratocystis fimbriata sensu lato represents a complex of cryptic and commonly plant pathogenic species that are morphologically similar. Species in this complex have been described using morphological characteristics, intersterility tests and phylogenetics. Microsatellite markers have been useful to study the population structure and origin of some species in the complex. In this study we sequenced the genome of C. fimbriata. This provided an opportunity to mine the genome for microsatellites, to develop new microsatellite markers, and map previously developed markers onto the genome. Over 6000 microsatellites were identified in the genome and their abundance and distribution was determined. Ceratocystis fimbriata has a medium level of microsatellite density and slightly smaller genome when compared with other fungi for which similar microsatellite analyses have been performed. This is the first report of a microsatellite analysis conducted on a genome sequence of a fungal species in the order Microascales. Forty-seven microsatellite markers have been published for population genetic studies, of which 35 could be mapped onto the C. fimbriata genome sequence. We developed an additional ten microsatellite markers within putative genes to differentiate between species in the C. fimbriata s.l. complex. These markers were used to distinguish between 12 species in the complex.The National Research Foundation (NRF), the South African Biosystematics Initiative (SABI), members of the Tree Protection Co-Operative Programme (TPCP), and the Department of Science and Technology (DST)/ NRF Centre of Excellence in Tree Health Biotechnology (CTHB), South Africa.http://www.elsevier.com/locate/funbiohj201

Volatile and glycosidically bound composition of Loureiro and Alvarinho wines

Composition of Loureiro and Alvarinho wines from the Vinhos Verdes region, respecting free volatile compounds as well as glycosidically bound aroma precursors, was exhaustively determined by GC-MS after adsorption on XAD-2 resin. On the whole, were identified and quantified 120 volatile compounds in the free fraction and 77 glycosidically bound compounds, belonging to C6-compounds, alcohols, fatty acids ethyl esters, esters of organic acids, acetates, monoterpenic alcohols, monoterpenic oxides and diols, C13-norisoprenoids, volatile phenols, volatile fatty acids and carbonyl compounds. Globally, the wines of the two cultivars present similar composition on volatiles. However, respecting varietal compounds, Loureiro wines are richer than Alvarinho ones with regard to C6-compounds and monoterpenic compounds, occurring the opposite for volatile phenols. It was also demonstrate that wines of both varieties may benefit the aroma reserve, present as glycoconjugates, as it is susceptible of being technologically explored. Linalool, Ho-trienol, α-terpineol, contributing with fruity and floral notes, and β-damascenone mostly for Alvarinho, confering tropical fruit notes, are the varietal compounds which may particularly influence the aroma of these wines. Respecting fermentative compounds, Alvarinho is also particularly rich in fatty acids ethyl esters related to lipid metabolism and acetates of fusel alcohols, which can provide it a fruity character; Loureiro contains higher levels of esters of organic acids and 2-phenylethanol, conferring fruity and floral notes. Sensory analysis agree with chemical analyses showing a pronounced tree and tropical fruit character for Alvarinho wines while Loureiro wines present more intense citrus fruit notes.Centre of Biological Engineering of Universidade do Minho; Estação Vitivinícola Amândio Galhano (EVAG); Solar de Serrade; EVAG; Comissão de Viticultura da Região dos Vinhos Verdes

Ceratocystidaceae exhibit high levels of recombination at the mating-type (MAT) locus

Mating is central to many fungal life cycles and is controlled by genes at the mating-type (MAT) locus. These genes determine whether the fungus will be self-sterile (heterothallic) or self-fertile (homothallic). Species in the ascomycete family Ceratocystidaceae have different mating strategies, making them interesting to consider with regards to their MAT loci. The aim of this study was to compare the composition of the MAT locus flanking regions in 11 species of Ceratocystidaceae representing four genera. Genome assemblies for each species were examined to identify the MAT locus and determine the structure of the flanking regions. Large contigs containing the MAT locus were then functionally annotated and analysed for the presence of transposable elements. Genes typically flanking the MAT locus in sordariomycetes were found to be highly conserved in the Ceratocystidaceae. The different genera in the Ceratocystidaceae displayed little synteny outside of the immediate MAT locus flanking genes. Even though species ofCeratocystis did not show much synteny outside of the immediate MAT locus flanking genes, species of Huntiella and Endoconidiophora were comparatively syntenic. Due to the high number of transposable elements present in Ceratocystis MAT flanking regions, we hypothesise that Ceratocystis species may have undergone recombination in this region.The National Research Foundation (NRF), members of the Tree Protection Co-Operative Programme (TPCP), the Department of Science and Technology (DST)/NRF Centre of Excellence in Tree Health Biotechnology (CTHB) and SARChI Chair in Fungal Genomics, South Africa.http://www.elsevier.com/locate/funbio2019-12-01hj2019BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Defining the impact of dietary macronutrient balance on PCOS traits

Lifestyle, mainly dietary, interventions are first-line treatment for women with polycystic ovary syndrome (PCOS), but the optimal diet remains undefined. We combined a hyperandrogenized PCOS mouse model with a systematic macronutrient approach, to elucidate the impact of dietary macronutrients on the development of PCOS. We identify that an optimum dietary macronutrient balance of a low protein, medium carbohydrate and fat diet can ameliorate key PCOS reproductive traits. However, PCOS mice display a hindered ability for their metabolic system to respond to diet variations, and varying macronutrient balance did not have a beneficial effect on the development of metabolic PCOS traits. We reveal that PCOS traits in a hyperandrogenic PCOS mouse model are ameliorated selectively by diet, with reproductive traits displaying greater sensitivity than metabolic traits to dietary mac ronutrient balance. Hence, providing evidence to support the development of evidence-based dietary interventions as a promising strategy for the treatment of PCOS, especially repro ductive traits.Valentina Rodriguez Paris, Samantha M. Solon-Biet, Alistair M. Senior, Melissa C. Edwards Reena Desai, Nicodemus Tedl

Gemini Observations of Galaxies in Rich Early Environments (GOGREEN) I: survey description

We describe a new Large Program in progress on the Gemini North and South telescopes: Gemini Observations of Galaxies in Rich Early Environments (GOGREEN). This is an imaging and deep spectroscopic survey of 21 galaxy systems at 1 10 in halo mass. The scientific objectives include measuring the role of environment in the evolution of low-mass galaxies, and measuring the dynamics and stellar contents of their host haloes. The targets are selected from the SpARCS, SPT, COSMOS, and SXDS surveys, to be the evolutionary counterparts of today's clusters and groups. The new red-sensitive Hamamatsu detectors on GMOS, coupled with the nod-and-shuffle sky subtraction, allow simultaneous wavelength coverage over λ ∼ 0.6–1.05 μm, and this enables a homogeneous and statistically complete redshift survey of galaxies of all types. The spectroscopic sample targets galaxies with AB magnitudes z΄ < 24.25 and [3.6] μm < 22.5, and is therefore statistically complete for stellar masses M* ≳ 1010.3 M⊙, for all galaxy types and over the entire redshift range. Deep, multiwavelength imaging has been acquired over larger fields for most systems, spanning u through K, in addition to deep IRAC imaging at 3.6 μm. The spectroscopy is ∼50 per cent complete as of semester 17A, and we anticipate a final sample of ∼500 new cluster members. Combined with existing spectroscopy on the brighter galaxies from GCLASS, SPT, and other sources, GOGREEN will be a large legacy cluster and field galaxy sample at this redshift that spectroscopically covers a wide range in stellar mass, halo mass, and clustercentric radius