A structural, spectroscopic and theoretical study of the triphenylphosphine chalcogenide complexes of tungsten carbonyl, [W(XPPh3)(CO)5], X=O, S, Se

The series [W(XPPh3)(CO)5], X=O, S, Se has been structurally determined by X-ray crystallography and fully characterised spectroscopically to provide data for comparing the bonding of the Ph3PX ligands to the metal. The P-X-W angles are 134.3°, 113.2° and 109.2°, respectively, for X=O, S, Se. The bonding has been analysed using EHMO calculations which suggest that lower P-X-W angles depend on the relative importance of σ-bonding, which in turn depends on the chalcogen in the order X=Se > S > O. The effect is enhanced by lower energies of the metal σ and π orbital energies

Exploring site formation and building local contexts through wiggle-match radiocarbon dating: re-dating of the Firth of Clyde Crannogs, Scotland

There are at least four wooden intertidal platforms, also known as marine crannogs, in the Firth of Clyde, on the west coast of Scotland. The interpretation of these sites partly depends on their dating and, if coeval, they could point to the presence of a native maritime hub. Furthermore, the spatial coincidence with the terminus of the Antonine Wall has led to speculation about the role they may have played in Roman-native interaction during the occupation of southern Scotland in the early first millennium cal ad. Hence, a better absolute chronology is essential to evaluate whether the marine crannogs were contemporary with one another and whether they related to any known historic events. This article presents results of a wiggle-match dating project aimed at resolving these uncertainties at two of the sites in question, Dumbuck and Erskine Bridge crannogs. The results show that the construction of these sites pre-date direct Roman influence in Scotland. Furthermore, the results indicate that the two sites were built at least 300 years apart, forcing us to consider the possibility that they may have functioned in very different historical contexts. Other findings include technical observations on the fine shape of the radiocarbon calibration curve near the turn of the first millennia bc/ad and potential evidence for persistent contamination in decayed and exposed sections of waterlogged alder

"So, Tell Me What Users Want, What They Really, Really Want!"

Equating users' true needs and desires with behavioural measures of 'engagement' is problematic. However, good metrics of 'true preferences' are difficult to define, as cognitive biases make people's preferences change with context and exhibit inconsistencies over time. Yet, HCI research often glosses over the philosophical and theoretical depth of what it means to infer what users really want. In this paper, we present an alternative yet very real discussion of this issue, via a fictive dialogue between senior executives in a tech company aimed at helping people live the life they `really' want to live. How will the designers settle on a metric for their product to optimise

The Early Stages of Deposition of Magnetite Particles onto Alloy-800 Heat Exchange Surfaces under Subcooled Boiling Conditions

The data collected during experiments in water loops on the fouling of heat exchange surfaces with magnetite particles often display a dip in the deposit accumulation curve at about 10 – 20 hours into the experiment. Generally the dips are small enough to be considered part of the scatter and may not even be discernible in long runs with considerable amounts of deposit. We have examined this phenomenon in a series of short experiments lasting up to a maximum of 40 hours. The test section of the recirculating water loop used for the study contained a heat exchanger tube of Alloy-800. Synthetic magnetite colloids were suspended in the coolant, which was usually maintained at 60°C or 90°C, and their deposition onto the tube was monitored for different conditions of pH, flow rate and heat flux. For a pH where deposition should be dominated by transport processes, deposition curves all displayed a “knee” at about 5 – 10 hours, regardless of whether the tube was heated or not. The curve shape can be explained in terms of a layered growth of the deposit, the first layer conditioning the surface for the growth of subsequent layers. First-order phenomenological coefficients in a simple model reproduce the curves quite well

Radiocarbon wiggle-match dating in the intertidal zone

Radiocarbon wiggle-match dating is a technique that can combine the versatility of radiocarbon dating with chronological information from tree-rings. This makes it useful in contexts where timbers are preserved, but dendrochronological dating is impossible. As intertidal and marine timbers are waterlogged, this can favor their preservation and hence allow wiggle-match 14C dating, which can be of significant help in deriving relatively precise chronologies for a range of coastal structures. As the technique depends on making multiple radiocarbon measurements towards a single date, efficiency in application is the key and hence a number of practical considerations need to be taken into account in advance of conducting a dating program. This paper discusses some of these practical concerns and reviews them in the context of the intertidal crannogs in the Firth of Clyde on the west coast of Scotland

Cure behavior and thermo-mechanical properties of dual-cure thermoset resins containing functionalized fillers

Thermoset polymers are of interest for many structural applications due to their mechanical, thermal, and chemical resiliency in comparison to thermoplastic polymers. Dual-cure resins are comprised of multiple thermoset polymers that are cured using different stimuli or variations of the same stimuli (i.e. temperatures, wavelengths, etc.). Sequential curing of the resin, via UV exposure followed by thermal exposure, creates interpenetrating polymer networks which enhance the overall mechanical properties compared to either parent material. The addition of inorganic fillers alters the rheology and printability of the resin in addition to improving mechanical properties. When these fillers are functionalized with epoxy and/or acrylate groups, we hypothesize that they will not only further improve the mechanical properties, but also aid in each individual network formation. This research describes the influence of different filler materials and filler surface functionalization on the cure behavior and thermomechanical properties of a UV/thermal acrylate-epoxy dual-cure system for use in direct ink write additive manufacturing. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA000352

“Who knows?” Reading the Book of Jonah as a Satirical Challenge to Theodicy of the Exile

Several scholars have challenged the reading of the final line of Jonah as a rhetorical question (“Should I not be concerned about Nineveh?”) and understand the Hebrew text instead to be a declaration by God that he will not be concerned about Nineveh. This reading has been resisted by some who argue that it would make little sense for the book to end on a negative note that God does not care about people who repent. This thesis examines the grammatical issues to determine which of the interrogatory or declarative readings has the stronger case; how a declaratory reading of the final line has an impact on how we read the book overall; and what such a reading has to say about the primary messages of the story. This thesis proposes that the book of Jonah was written to challenge theodicies which failed, from the writer’s perspective, to provide satisfying answers or offer comfort in the context of the exile. It examines evidence of irony, satire or parody in the Hebrew Bible in general and in Jonah in particular to determine if the use of these literary devices should also guide our interpretation of the final lines of Jonah. It analyses other texts in the Hebrew Bible which seem to be cited or alluded to in Jonah, concludes that these literary precursors are often parodied in Jonah, and argues that the purpose and effect of such parody is not to ridicule the earlier texts themselves, but rather a theological position taken by some who appealed to them. Possible targets of this parody and the book’s likely audience are discussed, and similarities with other biblical literature of the period are analysed. It concludes that the book of Jonah is best described as a satirical challenge to theodicy of the exile. The final line has the effect of turning the reader’s or listener’s attention back to an earlier question: “Who knows? Perhaps God will turn and relent” and implies a satirical answer to this question: no one knows, or can know, what God will do

Screen time is associated with adiposity and insulin resistance in children

Higher screen time is associated with type 2 diabetes (T2D) risk in adults, but the association with T2D risk markers in children is unclear. We examined associations between self-reported screen time and T2D risk markers in children. Survey of 4495 children aged 9-10 years who had fasting cardiometabolic risk marker assessments, anthropometry measurements and reported daily screen time; objective physical activity was measured in a subset of 2031 children. Compared with an hour or less screen time daily, those reporting screen time over 3 hours had higher ponderal index (1.9%, 95% CI 0.5% to 3.4%), skinfold thickness (4.5%, 0.2% to 8.8%), fat mass index (3.3%, 0.0% to 6.7%), leptin (9.2%, 1.1% to 18.0%) and insulin resistance (10.5%, 4.9% to 16.4%); associations with glucose, HbA1c, physical activity and cardiovascular risk markers were weak or absent. Associations with insulin resistance remained after adjustment for adiposity, socioeconomic markers and physical activity. Strong graded associations between screen time, adiposity and insulin resistance suggest that reducing screen time could facilitate early T2D prevention. While these observations are of considerable public health interest, evidence from randomised controlled trials is needed to suggest causality. [Abstract copyright: Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Decision-making on HVAC&R systems selection: a critical review

Buildings account for more than 40% of total energy consumption in most countries and more than 55% of this energy is used by heating, ventilation, air-conditioning and refrigeration (HVAC&R) systems. This significant energy demand, together with the global need to impose energy-efficiency measures, underlines the importance of selecting the most appropriate HVAC&R system in the early stages of a design process. However, this state-of-the-art study reveals that there is no review paper available in the open literature to critically analyse the existing methods for HVAC&R systems selection. Therefore, the aim of this paper is to critically review the body of knowledge on the adopted approach for HVAC&R systems selection. Based on the comprehensive literature review, the needs and gaps in this field are identified. It is revealed that the integration of probabilistic climate changes into the decision-making processes is one of the main areas that should be addressed in future studies. In addition, reliability and Life Cycle Cost of the systems, health and well-being, occupants’ satisfaction and indoor air quality are of paramount factors that should be taken into account in the decision-making process for HVAC&R systems selection