The atomic structure of low-index surfaces of the intermetallic compound InPd

The intermetallic compound InPd (CsCl type of crystal structure with a broad compositional range) is considered as a candidate catalyst for the steam reforming of methanol. Single crystals of this phase have been grown to study the structure of its three low-index surfaces under ultra-high vacuum conditions, using low energy electron diffraction (LEED), X-ray photoemission spectroscopy (XPS), and scanning tunneling microscopy (STM). During surface preparation, preferential sputtering leads to a depletion of In within the top few layers for all three surfaces. The near-surface regions remain slightly Pd-rich until annealing to ∼580 K. A transition occurs between 580 and 660 K where In segregates towards the surface and the near-surface regions become slightly In-rich above ∼660 K. This transition is accompanied by a sharpening of LEED patterns and formation of flat step-terrace morphology, as observed by STM. Several superstructures have been identified for the different surfaces associated with this process. Annealing to higher temperatures (≥750 K) leads to faceting via thermal etching as shown for the (110) surface, with a bulk In composition close to the In-rich limit of the existence domain of the cubic phase. The Pd-rich InPd(111) is found to be consistent with a Pd-terminated bulk truncation model as shown by dynamical LEED analysis while, after annealing at higher temperature, the In-rich InPd(111) is consistent with an In-terminated bulk truncation, in agreement with density functional theory (DFT) calculations of the relative surface energies. More complex surface structures are observed for the (100) surface. Additionally, individual grains of a polycrystalline sample are characterized by micro-spot XPS and LEED as well as low-energy electron microscopy. Results from both individual grains and “global” measurements are interpreted based on comparison to our single crystals findings, DFT calculations and previous literature.

Quantification of the probability of containment failure caused by an in-vessel steam explosion for the Sizewell B PWR

AEA Technology has provided an assessment of the probability of α-mode containment failure for the Sizewell B PWR. After a preliminary review of the methodologies available it was decided to use the probabilistic approach described in the paper, based on an extension of the methodology developed by Theofanous et al. (Nucl. Sci. Eng. 97 (1987) 259–325). The input to the assessment is 12 probability distributions; the bases for the quantification of these distributions are discussed. The α-mode assessment performed for the Sizewell B PWR has demonstrated the practicality of the event-tree method with input data represented by probability distributions. The assessment itself has drawn attention to a number of topics, which may be plant and sequence dependent, and has indicated the importance of melt relocation scenarios. The α-mode failure probability following an accident that leads to core melt relocation to the lower head for the Sizewell B PWR has been assessed as a few parts in 10 000, on the basis of current information. This assessment has been the first to consider elevated pressures (6 MPa and 15 MPa) besides atmospheric pressure, but the results suggest only a modest sensitivity to system pressure.

Multiple PID mapping using neural networks in a MIMO steam generator system

A neural network was used to map three PID operating regions for a two-input two-output steam generator system. The network was used in stand alone feedforward operation to control the whole operating range of the process, after being trained from the PID controllers corresponding to each control region. The network inputs are the plant error signals, their integral, their derivative and a 4-error delay train.

Reforming the CDM for sustainable development: lessons learned and policy futures

The Clean Development Mechanism (CDM) has successfully demonstrated that market-based mechanisms can achieve some cost effective emissions reductions in developing countries. However the distribution of CDM projects has been extremely uneven across countries and regions, and a few technologies and sectors have dominated the early stages of CDM experience. This has caused some to question whether the CDM has fallen short of its potential in contributing to sustainable development. We review the broad patterns of CDM project approvals and evaluate 10 CDM projects according to their sustainability benefits. The difficulty of defining “sustainable development” and the process of defining criteria by individual non-Annex 1 governments has meant that sustainable development concerns have been marginalized in some countries. Given these observed limitations, we present possible CDM policy futures, focusing on the main proposals for a post-2012 climate regime. Five options for enhancing the sustainable development benefits in the CDM are discussed, including proactive approaches to favour eligibility of emission reduction projects which ensure such co-benefits.

Rheology of milk foams produced by steam injection

Rheology of milk foams generated by steam injection was studied during the transient destabilization process using steady flow and dynamic oscillatory techniques: yield stress (τ_y) values were obtained from a stress ramp (0.2 to 25 Pa) and from strain amplitude sweep (0.001 to 3 at 1 Hz of frequency); elastic (G') and viscous (G") moduli were measured by frequency sweep (0.1 to 150 Hz at 0.05 of strain); and the apparent viscosity (η_a) was obtained from the flow curves generated from the stress ramp. The effect of plate roughness and the sweep time on τ_y was also assessed. Yield stress was found to increase with plate roughness whereas it decreased with the sweep time. The values of yield stress and moduli—G' and G"—increased during foam destabilization as a consequence of the changes in foam properties, especially the gas volume fraction, φ, and bubble size, R_32 (Sauter mean bubble radius). Thus, a relationship between τ_y, φ, R_32, and σ (surface tension) was established. The changes in the apparent viscosity, η, showed that the foams behaved like a shear thinning fluid beyond the yield point, fitting the modified Cross model with the relaxation time parameter (λ) also depending on the gas volume fraction. Overall, it was concluded that the viscoelastic behavior of the foam below the yield point and liquid-like behavior thereafter both vary during destabilization due to changes in the foam characteristics.

Reforming the House of Lords: difficult but not impossible

Despite apparent cross-party and public support, Nick Clegg’s plan to reform the House of Lords is dead. This article asks what explains its demise and analyses whether comprehensive Lords reform is ever likely to get off the ground in the future.

Apartment ownership: the English version needs reforming

In this contribution, the English commonhold system, which enables the development of freehold units in a multi-unit development, is critically re-visited. Provision is made for the development of freehold apartments on land with a registered commonhold title. At the date of registration, a management body for the scheme, the commonhold association, must be in place. Each purchaser of a unit in the relevant building obtains freehold property on purchase. The property and management of the building housing the units and of the common areas of the scheme are, by contrast, withheld from unit holders and vested in the commonhold association, which is a special kind of body corporate. Since the coming into force of the English legislation, a set of defects have been detected. This contribution re-assesses the main problem areas and makes a number of reform suggestions drawing on material from a number of jurisdictions, notably South Africa, France and Germany. Avoidable problems are likely to arise with any conversions to commonhold from the predominant English long lease system, owing to the narrowness of the conversion rules. The manner in which ownership of units and the common parts are regulated, a key aspect in any such system, merits re-assessment. It seems that here the English rules survive comparison. The rules pertaining to constitution of the commonhold association fail to provide sufficient safeguards for unpaid scheme creditors. The rules relating leasing of commonhold units seem inadequately thought out. There is a conspicuous absence of real remedies for non-payment of assessments by unit holders. The effect of these and other aspects may help to explain why commonhold has had a limited numerical impact. The time for a second generation reforming statute may have come.

Production of milk foams by steam injection: the effects of steam pressure and nozzle design

Foam properties depend on the physico-chemical characteristics of the continuous phase, the method of production and process conditions employed; however the preparation of barista-style milk foams in coffee shops by injection of steam uses milk as its main ingredient which limits the control of foam properties by changing the biochemical characteristics of the continuous phase. Therefore, the control of process conditions and nozzle design are the only ways available to produce foams with diverse properties. Milk foams were produced employing different steam pressures (100-280 kPa gauge) and nozzle designs (ejector, plunging-jet and confined-jet nozzles). The foamability of milk, and the stability, bubble size and texture of the foams were investigated. Variations in steam pressure and nozzle design changed the hydrodynamic conditions during foam production, resulting in foams having a range of properties. Steam pressure influenced foam characteristics, although the net effect depended on the nozzle design used. These results suggest that, in addition to the physicochemical determinants of milk, the foam properties can also be controlled by changing the steam pressure and nozzle design.

Reforming theatre in Farnese Parma: the case of the Accademia degli Innominati (1574-1608)

The essay explores the socio-cultural role of the main academy in Parma, the Innominati (1574-1608), which flourished in the years when the Farnese dynasty was beginning to assert more forcefully its political control over the new state of Parma and Piacenza. The Innominati was from the start associated with the ruling dynasty, who must have recognized the importance of its cultural activities to strengthening their regime, particularly in the absence of a strong local university. This essay explores the institution’s contested position within the cultural landscape – as reflected also in its membership of courtiers, clergymen, and feudal aristocrats with more ambivalent relations with the Farnese. In particular, the focus falls on the theatrical activities of the group during the 1580s, a decade which saw the establishment of the Parma Index (1580) and the succession of the internationally celebrated Duke Alessandro Farnese (1587). Based on the little surviving evidence it is argued that the Academy in the 1580s became a creative hub for theatrical experimentation – through theoretical debate and composition, and possibly even performance. However, as relations between the Farnese and the local elites, especially feudal aristocrats, became more contested the Academy’s theatrical production and the public memory of this became increasingly controlled.

Two daily smoke maxima in eighteenth century London air

Varied electrostatics experiments followed Benjamin Franklin's pioneering atmospheric investigations. In Knightsbridge, Central London, John Read (1726–1814) installed a sensing rod in the upper part of his house and, using a pith ball electrometer and Franklin chimes, monitored atmospheric electricity from 1789 to 1791. Atmospheric electricity is sensitive to weather and smoke pollution. In calm weather conditions, Read observed two daily electrification maxima in moderate weather, around 9 am and 7 pm. This is likely to represent a double diurnal cycle in urban smoke. Before the motor car and steam railways, one source of the double maximum smoke pattern was the daily routine of fire lighting for domestic heating.

Granger causality of coupled climate processes: Ocean feedback on the North Atlantic oscillation

This study uses a Granger causality time series modeling approach to quantitatively diagnose the feedback of daily sea surface temperatures (SSTs) on daily values of the North Atlantic Oscillation (NAO) as simulated by a realistic coupled general circulation model (GCM). Bivariate vector autoregressive time series models are carefully fitted to daily wintertime SST and NAO time series produced by a 50-yr simulation of the Third Hadley Centre Coupled Ocean-Atmosphere GCM (HadCM3). The approach demonstrates that there is a small yet statistically significant feedback of SSTs oil the NAO. The SST tripole index is found to provide additional predictive information for the NAO than that available by using only past values of NAO-the SST tripole is Granger causal for the NAO. Careful examination of local SSTs reveals that much of this effect is due to the effect of SSTs in the region of the Gulf Steam, especially south of Cape Hatteras. The effect of SSTs on NAO is responsible for the slower-than-exponential decay in lag-autocorrelations of NAO notable at lags longer than 10 days. The persistence induced in daily NAO by SSTs causes long-term means of NAO to have more variance than expected from averaging NAO noise if there is no feedback of the ocean on the atmosphere. There are greater long-term trends in NAO than can be expected from aggregating just short-term atmospheric noise, and NAO is potentially predictable provided that future SSTs are known. For example, there is about 10%-30% more variance in seasonal wintertime means of NAO and almost 70% more variance in annual means of NAO due to SST effects than one would expect if NAO were a purely atmospheric process.

Ideational change in the WTO and its impacts on EU agricultural policy institutions and the CAP

This paper argues that the Uruguay Round Agreement on Agriculture (URAA) introduced the market liberal paradigm as the ideational underpinning of the new farm trade regime. Though the immediate consequences in terms of limitations on agricultural support and protection were very modest, the Agreement did impact on the way in which domestic farm policy evolves. It forced EU agricultural policy makers to consider the agricultural negotiations when reforming the Common Agricultural Policy (CAP). The new paradigm in global farm trade resulted in a process of institutional layering in which concerns raised in the World Trade Organization (WTO) were gradually incorporated in EU agricultural institutions. This has resulted in gradual reform of the CAP in which policy instruments have been changed in order to make the CAP more WTO compatible. The underlying paradigm, the state-assisted paradigm, has been sustained though it has been rephrased by introducing the concept of multifunctionality.

Crumpet structures: experimental and modelling studies

Crumpets are made by heating fermented batter on a hot plate at around 230°C. The characteristic structure dominated by vertical pores develops rapidly: structure has developed throughout around 75% of the product height within 30s, which is far faster than might be expected from transient heat conduction through the batter. Cooking is complete within around 3 min. Image analysis based on results from X-ray tomography shows that the voidage fraction is approximately constant and that there is continual coalescence between the larger pores throughout the product although there is also a steady level of small bubbles trapped within the solidified batter. We report here experimental studies which shed light on some of the mechanisms responsible for this structure, together with some models of key phenomena.Three aspects are discussed here: the role of gas (carbon dioxide and nitrogen) nuclei in initiating structure development; convective heat transfer inside the developing pores; and the kinetics of setting the batter into an elastic solid structure. It is shown conclusively that the small bubbles of carbon dioxide resulting from the fermentation stage play a crucial role as nuclei for pore development: without these nuclei, the result is not a porous structure, but rather a solid, elastic, inedible, gelatinized product. These nuclei are also responsible for the tiny bubbles which are set in the final product. The nuclei form the source of the dominant pore structure which is largely driven by the, initially explosive, release of water vapour from the batter together with the desorption of dissolved carbon dioxide. It is argued that the rapid evaporation, transport and condensation of steam within the growing pores provides an important mechanism, as in a heat pipe, for rapid heat transfer, and models for this process are developed and tested. The setting of the continuous batter phase is essential for final product quality: studies using differential scanning calorimetry and on the kinetics of change in the visco-elastic properties of the batter suggest that this process is driven by the kinetics of gelatinization. Unlike many thermally driven food processes the rates of heating are such that gelatinization kinetics cannot be neglected. The implications of these results for modelling and for the development of novel structures are discussed.

Effects of drying methods and conditions on antimicrobial activity of edible chitosan films enriched with galangal extract

The aim of this work was to study the effects of drying methods and conditions (i.e., ambient drying, hot air drying at 40 degrees C, vacuum drying and low-pressure superheated steam drying within the temperature range of 70-90 degrees C at an absolute pressure of 10 kPa) as well as the concentration of galangal extract on the antimicrobial activity of edible chitosan films against Staphylococcus aureus. Galangal extract was added to the film forming solution as a natural antimicrobial agent in the concentration range of 0.3-0.9 g/100 g. Fourier transform infrared (FTIR) spectra and swelling of the films were also evaluated to investigate interaction between chitosan and the galangal extract. The antimicrobial activity of the films was evaluated by the disc diffusion and viable cell count method, while the morphology of bacteria treated with the antimicrobial films was observed via transmission electron microscopy (TEM). The antimicrobial activity, swelling and functional group interaction of the antimicrobial films were found to be affected by the drying methods and conditions as well as the concentration of the galangal extract. The electron microscopic observations revealed that cell wall and cell membrane of S. aureus treated by the antimicrobial films were significantly damaged. (C) 2009 Elsevier Ltd. All rights reserved.