Design and testing of transonic linear cascade tunnel with optimized slotted walls

In linear cascade wind tunnel tests, a high level of pitchwise periodicity is desirable to reproduce the azimuthal periodicity in the stage of an axial compressor or turbine. Transonic tests in a cascade wind tunnel with open jet boundaries have been shown to suffer from spurious waves, reflected at the jet boundary, that compromise the flow periodicity in pitch. This problem can be tackled by placing at this boundary a slotted tailboard with a specific wall void ratio s and pitch angle a. The optimal value of the s-a pair depends on the test section geometry and on the tunnel running conditions. An inviscid two-dimensional numerical method has been developed to predict transonic linear cascade flows, with and without a tailboard, and quantify the nonperiodicity in the discharge. This method includes a new computational boundary condition to model the effects of the tailboard slots on the cascade interior flow. This method has been applied to a six-blade turbine nozzle cascade, transonically tested at the University of Leicester. The numerical results identified a specific slotted tailboard geometry, able to minimize the spurious reflected waves and regain some pitchwise flow periodicity. The wind tunnel open jet test section was redesigned accordingly. Pressure measurements at the cascade outlet and synchronous spark schlieren visualization of the test section, with and without the optimized slotted tailboard, have confirmed the gain in pitchwise periodicity predicted by the numerical model. Copyright © 2006 by ASME.

The sustainability and assessment of drystone retaining walls

The art of drystone walling is a highly sustainable traditional practice which uses local materials and craftsmen. As no
mortar is used they have low embodied carbon, and much repair work or rebuilding can be carried out using very little if any new
materials. However local practices developed to suit local materials, leading to a range of construction styles, making them difficult to
assess. This paper examines a range of construction styles of drystone retaining walls in use across the United Kingdom.
Understanding of the substantial variations of construction style is essential to enable proper assessment of these structures. Different
frictional and weathering characteristics, and the naturally occurring shapes of stone found in an area, all affect the ways in which the
stones have traditionally been assembled into walls. Ease of construction also plays a part, as the craftsman will naturally wish to
achieve a robust construction in a way that is economical of time and effort. Aesthetics may be very important, for both client and
craftsman. It is also shown that construction style is influenced by the location and function of the structures, with harbour walls<br/>particularly likely to have unique characteristics, and the reasons for this are explored.

Offenders' Risk-Taking Attitude Inside and Outside the Prison Walls

It has long been assumed that risk taking is closely associated with criminal behavior. One reason for placing criminals behind bars-aside from punishment and protecting the public-is to prevent them from engaging in further risky criminal activities. Limited attention has been paid to whether being inside or outside prison affects offenders' risk-taking behaviors and attitudes. We compared risk-taking behaviors and attitudes in five risk domains (ethical, financial, health/safety, recreational, social) among 75 incarcerated offenders (i.e., offenders who are currently in prison) and 45 ex-offenders (i.e., offenders who have just been released from prison). Ex-offenders reported higher likelihood of engaging in risky behavior, driven largely by a willingness to take more risks in the recreational and ethical domains. Benefits attributed to risk taking as well as risk perception did not differ between incarcerated and ex-offenders, indicating that the opportunity to take risks might underlie behavioral risk intentions. Our results also indicate that risk-taking activities are better predicted by the expected benefits rather than by risk perception, aside from the health/safety domain. These results highlight the importance of studying the person and the environment and examining risk taking in a number of content domains.

Search protocols for hidden forensic objects beneath floors and within walls

The burial of objects (human remains, explosives, weapons) below or behind concrete, brick, plaster or tiling may be associated with serious crime and are difficult locations to search. These are quite common forensic search scenarios but little has been published on them to-date. Most documented discoveries are accidental or from suspect/witness testimony. The problem in locating such hidden objects means a random or chance-based approach is not advisable. A preliminary strategy is presented here, based on previous studies, augmented by primary research where new technology or applications are required. This blend allows a rudimentary search workflow, from remote desktop study, to non-destructive investigation through to recommendations as to how the above may inform excavation, demonstrated here with a case study from a homicide investigation. Published case studies on the search for human remains demonstrate the problems encountered when trying to find and recover sealed-in and sealed over locations. Established methods include desktop study, photography, geophysics and search dogs:these are integrated with new technology (LiDAR and laser scanning; photographic rectification; close quarter aerial imagery; ground-penetrating radar on walls and gamma-ray/neutron activation radiography) to propose this possible search strategy.

Sequential injection of domain walls into ferroelectrics at different bias voltages: Paving the way for “domain wall memristors”

Simple meso-scale capacitor structures have been made by incorporating thin (300 nm) single crystal lamellae of KTiOPO4 (KTP) between two coplanar Pt electrodes. The influence that either patterned protrusions in the electrodes or focused ion beam milled holes in the KTP have on the nucleation of reverse domains during switching was mapped using piezoresponse force microscopy imaging. The objective was to assess whether or not variations in the magnitude of field enhancement at localised “hot-spots,” caused by such patterning, could be used to both control the exact locations and bias voltages at which nucleation events occurred. It was found that both the patterning of electrodes and the milling of various hole geometries into the KTP could allow controlled sequential injection of domain wall pairs at different bias voltages; this capability could have implications for the design and operation of domain wall electronic devices, such as memristors, in the future.

Increasingly ‘Irrational’ Party Systems: Evidence that There Are Increasingly More Than Two at the District level

Recent work has noted an increase in the number of parties at the national level in both proportional and majoritarian electoral systems. While the conventional wisdom maintains that the incentives provided by the electoral system will prevent the number of parties at the district level from exceeding two in majoritarian systems, the evidence presented here demonstrates otherwise. I argue that this has occurred because the number of cleavages articulated by parties has increased as several third parties have begun articulating cleavages that are not well represented by the two larger parties.

Party agency and the religious-secular cleavage in post-Communist countries: The case of Romania

Research focusing on several post-communist countries has found evidence of social cleavage effects on political behaviour similar to those found in Western Europe. In some post-communist countries, however, social cleavage effects appear far weaker (if at all). To understand why this is the case, I perform a case study of Romania, focusing on the religious–secular cleavage. Drawing upon research that emphasises the role of parties in forming cleavages, I argue that the reason for the absence of social cleavage effects is due to party competition for the same group of voters by parties from opposing ends of the ideological spectrum. By shifting their positions, some parties have prevented the appearance of cleavages by shaping individuals' perceptions of the parties and, in doing so, have even altered individuals' own left–right self-placements.

The Effect of the Secret Ballot on Party System Fragmentation: A Test of Three Competing Arguments

Few studies have examined the impact that the adoption of the secret ballot had on party system fragmentation outside the United States. This article tests arguments maintaining that the adoption of the secret ballot had a negative, positive or nil effect on party system fragmentation. Using time-series cross-sectional data from
several countries adopting the secret ballot around the turn of the twentieth century, the results demonstrate that the adoption of the secret ballot did not hinder – though did not favour, either – the development of multiparty systems.

What’s in a (Party) Name?: Examining preferences, discipline, and social identity in a parliamentary free vote

In trying to understand the effects of political parties on shaping the voting behaviour of legislators, research has attempted the difficult task of separating the effects of preferences from rules used by party leaders to enforce discipline. However, little research has explored the prospect that party labels also reflect a social identity that is independent of legislators’ preferences and the rules used by party leaders to enforce discipline. In this study we examine that possibility, employing a data set that permits us to control both for leadership-based effects and legislator preferences on a 2000 free vote dealing with stem cell research. Using the British Representation Studies 1997 – which interviewed Members of Parliament regarding their preferences on several key issues related to the bill – we find significant evidence that party-as-identification plays a role in shaping how legislators vote, even after preferences and discipline are accounted for.

What’s information got to do with it? Third-party voting in plurality systems

Although strategic voting theory predicts that the number of parties will not exceed two in single-member district plurality systems, the observed number of parties often does. Previous research suggests that the reason why people vote for third parties is that they possess inaccurate information about the parties’ relative chances of winning. However, research has yet to determine whether third-party voting persists under conditions of accurate information. In this article, we examine whether possessing accurate information prevents individuals from voting for third-placed parties in the 2005 and 2010 British elections. We find that possessing accurate information does not prevent most individuals from voting for third-placed parties and that many voters possess reasonably accurate information regarding the viability of the parties in their constituencies. These findings suggest that arguments emphasizing levels of voter information as a major explanation for why multiparty systems often emerge in plurality systems are exaggerated.

The organizational ecology of ethnic cleavages: The nonlinear effects of ethnic diversity on party system fragmentation

The conventional wisdom regarding party system fragmentation assumes that the effects of electoral systems and social cleavages are linear. However, recent work applying organizational ecology theories to the study of party systems has challenged the degree to which electoral system effects are linear. This paper applies such concepts to the study of social cleavages. Drawing from theories of organizational ecology and the experience of many ethnically diverse African party systems, I argue that the effects of ethnic diversity are nonlinear, with party system fragmentation increasing until reaching moderate levels of diversity before declining as diversity reaches extreme values. Examining this argument cross-nationally, the results show that accounting for nonlinearity in ethnic diversity effects significantly improves model fit.

Holding parties responsible at election time: Multi-level, multi-party government and electoral accountability

This paper highlights the crucial role played by party-specific responsibility attributions in performance-based voting. Three models of electoral accountability, which make distinct assumptions regarding citizens' ability to attribute responsibility to distinct governing parties, are tested in the challenging Northern Ireland context - an exemplar case of multi-level multi-party government in which expectations of performance based voting are low. The paper demonstrates the operation of party-attribution based electoral accountability, using data from the 2011 Northern Ireland Assembly Election Study. However, the findings are asymmetric: accountability operates in the Protestant/unionist bloc but not in the Catholic/nationalist bloc. This asymmetry may be explained by the absence of clear ethno-national ideological distinctions between the unionist parties (hence providing political space for performance based accountability to operate) but the continued relevance in the nationalist bloc of ethno-national difference (which limits the scope for performance politics). The implications of the findings for our understanding of the role of party-specific responsibility attribution in performance based models of voting, and for our evaluation of the quality of democracy in post-conflict consociational polities, are discussed.