MCDIT 21 - A computer code for one-dimensional elastic wave problems

Computer program for one dimensional elastic wave problems connected with structural member

Why don't zombies like hibiscus tea? A multi-subject approach to photosynthesis through the use of Grätzel cells

Traditionally, photosynthesis has been seen as the domain of biology, with some input from chemistry when dealing with chromatography, while, apart from a passing reference to the colour of leaves, physics has tended to steer clear of the process that provides the lifeblood of human existence. This article outlines how a recent technological advance can be used as a teaching resource in all three branches of science

Wave propagation in stepped and joined shells Annual report, 1 Sep. 1968 - 1 Sep. 1969

Shell impact response and wave propagation in cylindrical and conical shells by experimental and analytical method

In situ colorimetric and composite coloration efficiency measurements for electrochromic Prussian blue

An in situ colorimetric method, based on the CIE (Commission Internationale de l’Eclairage) system of colorimetry, has been successfully applied to the study of electrochromism in electrochemically deposited films of Prussian blue (iron(III) hexacyanoferrate(II), PB) on transmissive ITO/glass substrates for the first time. On electrochemical reduction of PB to Prussian white (iron(II) hexacyanoferrate(II), PW), sharp and reversible changes in the hue and saturation occur, as shown by the track of the CIE 1931 xy chromaticity coordinates. For PB, the CIELAB 1976 colour space coordinates were L* 5 73, a*5226 and b*5233, with a dominant wavelength calculated as 488 nm. Concurrently, as the intensely absorbing PB mixed-valence chromophore is ‘bleached’ to the transparent PW, a large increase in the relative luminance of the electrochromic film is observed. On oxidation of PB, the CIELAB 1976 colour space coordinates show the transition through intermediate green to the Prussian yellow (iron(III) hexacyanoferrate(III), PY) state (L* 5 94, a* 5 2 and b* 5 18), with a steady increase in relative luminance. To reliably compare the power requirement of PB films with other electrochromic systems, composite coloration efficiencies (CCE’s) have been calculated, using a tandem chronoabsorptometry/chronocoulometry method, as previously developed for organic polymer systems. Using 95% of the total transmittance change at lmax as reference point, coloration efficiencies, g 5 DA(lmax)/Q, were calculated as 143 and 150 cm2 C21 respectively for the PB/PW and PW/PB electrochromic transitions

An in situ colorimetric measurement study of electrochromism in the di-n-heptyl viologen system

An in situ colorimetric method, based on the CIE (Commission Internationale de l'Eclairage) system of colorimetry, has been applied to the study of the electrochromic N,N´-bis(n-heptyl)-4,4´-bipyridylium (‘di-n-heptyl viologen’) system in aqueous solution on transmissive ITO/glass substrates. On electrochemical reduction of the di-n-heptyl viologen di-cation, the purple di-n-heptyl viologen radical cation salt deposits as a film and the changes in hue and saturation have been tracked using CIE 1931 xy chromaticity coordinates. The CIELAB 1976 colour space coordinates of the purple di-n-heptyl viologen radical cation salt were L* = 76, a* = 33 and b* = –20, with a complementary wavelength of 548 nm. A sharp decrease in luminance was found on formation of the di-n-heptyl viologen radical cation salt. Colour coordinates for the reverse (oxidation) direction plots show hysteresis, implying that specific choice of colour values depends on both the potential applied and from which direction the potential is changed

Measuring sustainable intensification: combining composite indicators and efficiency analysis to account for positive externalities in cereal production

We combine the use of a stochastic frontier analysis framework and composite indicators for farm provision of environmental goods to obtain a farm level composite indicator reflecting sustainable intensification. The novel sustainable intensification composite indicator that is developed accounts for multidimensional market and non-market outputs, namely the economic performance of cereal farms (i.e. market production value) and the associated positive environmental impacts of production (e.g. positive environmental externalities). The composite indicator integrates three different indicators for the provision of environmental goods into a stochastic frontier analysis: a) agri-environmental payments; b) the ratio of rough grassland and permanent pasture area to total utilised agricultural area; and c) land use diversity, as measured by the Shannon Index. We apply this approach to a panel of data for 106 cereal farms in England and Wales during the period 2010–2012. Results indicate that farm rankings on the indicator vary substantially depending on the weight given to the different environmental aspects/indicators, suggesting that single indicators of the provision of environmental goods may not provide a true reflection of the environmental performance of farms. We illustrate a simple approach that captures the aspects of sustainable intensification of farms in a much more holistic way, i.e. by producing a distribution of sustainable intensification scores for each farm reflecting different weightings of evaluation criteria. To reduce the dimensionality of this distribution farms are classified into four distinct groups according to the shape of this distribution, with some farms found to perform well under all combinations of weights for evaluation criteria, while others always perform poorly. This distribution-based analysis provides a greater depth of information than traditional approaches based on the generation of a single sustainable intensification score

Nest site selection by sea turtles

The distribution of 38 nests of loggerhead turtles (Caretta caretta) on beaches on Sanibel and Captiva islands, south-western Florida (26°26\u27N 82°16\u27W), and of 70 first digging attempts by green turtles (Chelonia mydas) on Ascension Island (7°57\u27S 14°22\u27W), was quantified. For loggerhead turtles on Sanibel and Captiva, nests were clumped close to the border between the open sand and the supra-littoral vegetation that backed the beaches. This spatial pattern of nests was closely reproduced by assuming simply that turtles crawled a random distance above the most recent high water line prior to digging. In contrast, green turtles on Ascension Island clumped their first digging attempts on the uneven beach above the springs high water line, crawling up to 80 m to reach this beach zone

The initiation and development of metamorphic foliation in the Otago Schist, Part 2: evidence from quartz grain-shape data

Shape, size and orientation measurements of quartz grains sampled along two transects that cross zones of increasing metamorphic grade in the Otago Schist, New Zealand, reveal the role of quartz in the progressive development of metamorphic foliation. Sedimentary compaction and diagenesis contributed little to the formation of a shape-preferred orientation (SPO) within the analysed samples. Metamorphic foliation was initiated at sub-greenschist facies conditions as part of a composite S1-bedding structure parallel to the axial planes of tight to isoclinal F1 folds. An important component of this foliation is a pronounced quartz SPO that formed dominantly by the effect of dissolution?precipitation creep on detrital grains in association with F1 strain. With increasing grade, the following trends are evident from the SPO data: (i) a progressive increase in the aspect ratio of grains in sections parallel to lineation, and the development of blade-shaped grains; (ii) the early development of a strong shape preferred orientation so that blade lengths define the linear aspect of the foliation (lineation) and the intermediate axes of the blades define a partial girdle about the lineation; (iii) a slight thinning and reduction in volume of grains in the one transect; and (iv) an actual increase in thickness and volume in the survivor grains of the second transect. The highest-grade samples, within the chlorite zone of the greenschist facies, record segregation into quartz- and mica-rich layers. This segregation resulted largely from F2 crenulation and marks a key change in the distribution, deformation and SPO of the quartz grains. The contribution of quartz SPO to defining the foliation lessens as the previously discrete and aligned detrital quartz grains are replaced by aggregates and layers of dynamically recrystallized quartz grains of reduced aspect ratio and reduced alignment. Pressure solution now affects the margins of quartz-rich layers rather than individual grains. In higher-grade samples, therefore, the rock structure is characterized increasingly by segregation layering parallel to a foliation defined predominantly by mica SPO

Partner or supplier: an examination of client/agency relationships in an IMC context

There is growing evidence from practitioners that the advertising industry is in a state of crisis. As campaigns become more integrated and multi-disciplinary, the relationship between advertising agencies and clients is being tested to its limits and is presently considered to be at an all-time low. Agencies feel less valued and are being excluded from C-suite discussion. Clients feel that agencies do not appreciate the changing landscape and how the customer experience is now key. Both sides recognise the need for more trust and collaboration. This study applies the agency theory and the social power theory to understand the pressures that the relationship is under. It looks for evidence that IMC is creating a movement away from a business alliance relationship by comparing qualitative data collected from both agencies and clients, using NVivo to identify themes. The findings identify four themes which illustrate this shift towards a supplier relationship: the client ownership of the customer journey, the lack of a strategic role of agencies, the challenges of agency collaboration and difficulties of agency specialisation

The failed liberalisation of Algeria and the international context: a legacy of stable authoritarianism

The paper attempts to challenge the somewhat marginal role of international factors in the study of transitions to democracy. Theoretical and practical difficulties in proving causal mechanisms between international variables and domestic outcomes can be overcome by defining the international dimension in terms of Western dominance of world politics and by identifying Western actions towards democratising countries. The paper focuses on the case of Algeria, where international factors are key in explaining the initial process of democratisation and its following demise. In particular, the paper argues that direct Western policies, the pressures of the international system and external shocks influence the internal distribution of power and resources, which underpins the different strategies of all domestic actors. The paper concludes that analysis based purely on domestic factors cannot explain the process of democratisation and that international variables must be taken into more serious account and much more detailed