Design and development of a water vapor electrolysis unit

Design and development of water vapor electrolysis unit for oxygen productio

Igneous Rock Associations 12. A Geologist’s Look at Archaeological Ceramics and Glass

Ceramics and glass represent synthetic metamorphic rocks and obsidian, respectively. Consequently, it is not surprising that many archaeologists have collaborated with geologists on projects dealing not only with lithic artifacts, but with ceramic and glass objects as well. This paper presents an overview of these latter two materials from a geological perspective, considering in turn how they are characterized and classified, their ages constrained, provenance and in some instances use determined, and how they were made. SOMMAIRELa céramique et le verre représentent respectivement des roches métamorphiques et l'obsidien synthétiques. En conséquence, il n'est pas étonnant que beaucoup d'archéologues aient collaboré avec des géologues sur des projets traitant non seulement des objets façonnés lithiques, mais également des objets en céramique et en verre. Ce document présente un aperçu de ces derniers deux matériaux d'une perspective géologique, considérant comment ils sont caractérisés et classifiés, leurs âges, provenances et emploies parfois déterminés, et comment elles ont été faites

A petrochemical study of basaltic layering at Henley Harbour, Labrador, using multidimensional scaling

Lack of internal textural evidence for flow tops and small chemical variability among late Proterozoic basalt samples suggest the presence of a single flow at Henley Harbour, Labrador, Canada, despite spectacular, m-scale layering in outcrop. Total chemical variation just slightly exceeds analytical uncertainty for many elements. Multidimensional scaling (MDS) enhances "effective" analytical precision by allowing all data (elements and samples) to be compared simultaneously. Scaling of elements reveals element associations/patterns consistent with igneous controls on distribution, even for alteration-sensitive (Na, K, Sr) elements. MDS also shows that the m-scale layering has a chemical fingerprint. However, to explain chemical variability between layers using mass balance calculations and averaged whole-rock data requires unreasonable (low temperature) phenocryst compositions. Textural features of the m-scale layering record changes in cooling regime between the bottom and center of the flow but chemical variation may reflect changing magma compositions during formation of an inflated flow. However, mass balance calculations suggest that large-scale chemical variation reflects the migration of residual liquid, perhaps as vesicle plumes, within an initially chemically homogeneous flow. Low in the flow (layer 1), metres-long but cm-scale raised and eroded subhorizontal "bands" superficially resemble segregation veins but lack coarse-grained textures. MDS confirms that raised and eroded samples are chemically distinct. Mass balance indicates that banding is not related to phenocryst percentages but may reflect the abundance of a residual liquid resembling the liquid explaining compositional variation between large-scale layers. Alignment of microlites and variations in the quantity of altered residual-liquid glass suggest that banding is related to magma movement during extrusion. It is possible that banding of this type has not been recognized before. RESUMÉ L'absence d'attestation texturale interne des sommets d'écoulement et la faible variabilité chimique entre les échantillons de basalte du Protérozoïque tardif laissent supposer la présence d'un écoulement unique à Henley Harbour, Labrador, Canada, malgré la stratification spectaculaire à moyenne échelle de l'affleurement. La variation totale des compositions chimiques dépasse tout juste légèrement l'incertitude analytique de nombreux éléments. L'analyse multidimensionnelle (AMD) améliore la précision analytique « effective » en permettant une comparaison simultanée de toutes les données (éléments et échantillons). L'analyse des éléments révèle des associations/dispositions d'éléments correspondant à des contrôles ignés de la répartition, même dans le cas des éléments sensibles à l'altération (Na, K, Sr). L'AMD révèle par ailleurs que la stratification à moyenne échelle présente une empreinte chimique. L'explication de la variabilité chimique entre les couches au moyen de calculs du bilan pondéral et de moyennes des données sur la roche totale nécessite cependant des compositions de phénocristaux excessives (basse température). Les caractéristiques texturales du fil de stratification à moyenne échelle changent en régime de refroidissement entre le fond et le centre de l'écoulement, mais la variation des compositions chimiques peut correspondre à des compositions magmatiques changeantes pendant la formation d'un écoulement gonflé. Les calculs du bilan pondéral laissent toutefois supposer que la variation des compositions chimiques à grande échelle témoigne de la migration de liquides résiduels, peut-être sous forme de panaches de vacuoles à l'intérieur d'un écoulement initialement homogène du point de vue chimique. Au bas de l'écoulement (première strate), des « bandes » subhorizontales de plusieurs mètres de longueur mais érodées et soulevées de quelques centimètres ressemblent superficiellement à des filons d'exsudation mais sont dépourvues de textures à grain grossier. L'AMD confirme que les échantillons soulevés et erodes sont chimiquement distincts. Le bilan pondéral révèle que le rubanement n'est pas lié au pourcentage de phénocristaux, mais qu'il témoigne de l'abondance d'un liquide résiduel ressemblant au liquide expliquant la variation des compositions entre les strates à grande échelle. L'alignement des microlites et les variations de la quantité de verre soluble résiduel altéré laissent supposer que le rubanement est apparenté à un déplacement magmatique survenu pendant l'extrusion. Il est possible qu'on n'ait pas décelé un rubanement de ce genre auparavant

Reducing weight and increasing physical activity in people at high risk of cardiovascular disease: a randomised controlled trial comparing the effectiveness of enhanced motivational interviewing intervention with usual care.

OBJECTIVE: The epidemic of obesity is contributing to the increasing prevalence of people at high risk of cardiovascular disease (CVD), negating the medical advances in reducing CVD mortality. We compared the clinical and cost-effectiveness of an intensive lifestyle intervention consisting of enhanced motivational interviewing in reducing weight and increasing physical activity for patients at high risk of CVD. METHODS: A three-arm, single-blind, parallel-group randomised controlled trial was conducted in consenting primary care centres in south London. We recruited patients aged 40-74 years with a QRisk2 score ≥20.0%, which indicates the probability of having a CVD event in the next 10 years. The intervention was enhanced motivational interviewing which included additional behaviour change techniques and was delivered by health trainers in 10 sessions over 1 year, in either group (n=697) or individual (n=523) format. The third arm received usual care (UC; n=522). The primary outcomes were physical activity (mean steps/day) and weight (kg). Secondary outcomes were changes in low-density lipoprotein cholesterol and CVD risk score. We estimated the relative cost-effectiveness of each intervention. RESULTS: At 24 months, the group and individual interventions were not more effective than UC in increasing physical activity (mean difference=70.05 steps, 95% CI -288.00 to 147.90 and mean difference=7.24 steps, 95% CI -224.01 to 238.50, respectively), reducing weight (mean difference=-0.03 kg, 95% CI -0.49 to 0.44 and mean difference=-0.42 kg, 95% CI -0.93 to 0.09, respectively) or improving any secondary outcomes. The group and individual interventions were not cost-effective at conventional thresholds. CONCLUSIONS: Enhancing motivational interviewing with additional behaviour change techniques was not effective in reducing weight or increasing physical activity in those at high CVD risk

A comparison of analytical and numerical model predictions of shallow soil temperature variation with experimental measurements

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.In several fields of enquiry such as geothermal energy, geology and agriculture, it is of interest to study the thermal behaviour of shallow soils. For this, several analytical and numerical methodologies have been proposed to analyse the temperature variation of the soil in the short and long term. In this paper, a comparative study of different models (sinusoidal, semi-infinite and finite difference method) is conducted to estimate the shallow soil temperature variation in the short and long term. The models were compared with hourly experimental measured data of soil temperature in Leicester, UK, at depths between 0.75 and 2.75 m. The results show that the sinusoidal model is not appropriate to evaluate the short-term temperature variations, such as hourly or daily fluctuations. Likewise, this model is highly affected by the undisturbed ground temperature and can lead to very high errors. Regarding the semi-infinite model, it is accurate enough to predict the short-term temperature variation. However, it is useless to predict the long-term variation at depths greater than 1 m. The finite difference method (FDM) considering the air temperature as a boundary condition for the soil surface is the most accurate approach for estimating both short and long-term temperature variations while the FDM with heat flux as boundary condition is the least accurate approach due to the uncertainty of the assumed parameters. The ranges of errors for the sinusoidal, semi-infinite and FDM are found to be from 76.09 to 142.13%, 12.11 to 104.88% and 1.82 to 28.14% respectively