Asymmetric Dual Axis Energy Recovery Linac for Ultra-High Flux sources of coherent X-ray/THz radiation: Investigations Towards its Ultimate Performance

In order for sources of coherent high brightness and intensity THz and X-Ray radiation to be accepted by university or industrial R&D laboratories, truly compact, high current and efficient particle accelerators are required. The demand for compactness and efficiency can be satisfied by superconducting RF energy recovery linear accelerators (SRF ERL) allowing effectively minimising the footprint and maximising the efficiency of the system. However such set-ups are affected by regenerative beam-break up (BBU) instabilities which limit the beam current and may terminate the beam transport as well as energy recuperation. In this paper we suggest and discuss a SRF ERL with asymmetric configuration of resonantly coupled accelerating and decelerating cavities. In this type of SRF ERL an electron bunch is passing through accelerating and decelerating cavities once and, as we show in this case, the regenerative BBU instability can be minimised allowing high currents to be achieved. We study the BBU start current in such an asymmetric ERL via analytical and numerical models and discuss the properties of such a system

Integrating Methods and Strategies from Language Teaching and Business Studies in Languages for Specific Business Purposes Courses

It has been argued that acquisition of skills in the use of foreign languages is comparable to the development of competence in other skills (Drew & Ottewill, 1998). The foreign language learner must actively participate in the learning process and practice the skills required in order to achieve success. Thus, learning to communicate in a foreign language emphasises experimentation and concrete experience. On the other hand, abstract conceptualisation, reflective observation, and the development and testing of theories and ideas are more important for business studies. However, language studies and skills acquired are often related to the development of the soft applied skills of business communication and workplace competence. This paper argues that the two approaches to learning foreign languages and acquiring business competence are complementary and supportive. This can be accomplished by providing in two ways. First, courses in Languages for Specific Business Purposes can be offered that draw on an interdisciplinary approach based on recent studies in business discourse (Bargiela-Chiappini & Nickerson, 1999, 2002, 2003; Charles & Marschan-Piekkari, 2002; Planken, 2005; Poncini, 2003). Second, one can provide communicative activities, such as case studies and simulations emphasizing conceptual models and reflective observation, as well as language teaching related to business discourse situations and the strategic nature of the communicative event

Emotional and Adrenocortical Responses of Infants to the Strange Situation: The Differential Function of Emotional Expression

The aim of the study was to investigate biobehavioural organisation in infants with different qualities of attachment. Quality of attachment (security and disorganisation), emotional expression, and adrenocortical stress reactivity were investigated in a sample of 106 infants observed during Ainsworth’s Strange Situation at the age of 12 months. In addition, behavioural inhibition was assessed from maternal reports. As expected, securely attached infants did not show an adrenocortical response. Regarding the traditionally defined insecurely attached groups, adrenocortical activation during the strange situation was found for the ambivalent group, but not for the avoidant one. Previous ndings of increased adrenocortical activity in disorganised infants could not be replicated. In line with previous ndings, adrenocortical activation was most prominent in insecure infants with high behavioural inhibition indicating the function of a secure attachment relationship as a social buffer against less adaptive temperamental dispositions. Additional analyses indicated that adrenocortical reactivity and behavioural distress were not based on common activation processes. Biobehavioural associations within the different attachment groups suggest that biobehavioural processes in securely attached infants may be different from those in insecurely attached and disorganised groups. Whereas a coping model may be applied to describe the biobehavioural organisation of secure infants, an arousal model explanation may be more appropriate for the other groups

LSP in Canadian Higher Education: What We Can Learn from Program Reviews

Using university periodic program review documents, this study investigated the major stakes in offering programs in language study for field specific purposes, or languages for specific purposes (LSP), at Canadian institutions of higher education, and the most frequent recommendations found in the external reviewers’ reports. A conceptual framework of the LSP field was developed for thematic coding using QDA Miner, a mixed-method approach to data analysis. The qualitative and quantitative analyses revealed that the three most important stakes for the discipline are relevance for employment needs, correspondence to stakeholder needs and interdisciplinary cooperation. The external reviewers recommended 1) developing strategies for updating, revising and reorganising courses and programs in response to the changing needs of students and society; 2) encouraging units to develop initiatives that favour international opportunities and interdisciplinary collaboration; and 3) creating tenure-track faculty positions. These findings shed light on the value of the formative function of program evaluation for developing curricula that provide quality, pertinent professional language studies

Viewpoint consistency in Z and LOTOS: A case study

Specification by viewpoints is advocated as a suitable method of specifying complex systems. Each viewpoint describes the envisaged system from a particular perspective, using concepts and specification languages best suited for that perspective. Inherent in any viewpoint approach is the need to check or manage the consistency of viewpoints and to show that the different viewpoints do not impose contradictory requirements. In previous work we have described a range of techniques for consistency checking, refinement, and translation between viewpoint specifications, in particular for the languages LOTOS and Z. These two languages are advocated in a particular viewpoint model, viz. that of the Open Distributed Processing (ODP) reference model. In this paper we present a case study which demonstrates how all these techniques can be combined in order to show consistency between a viewpoint specified in LOTOS and one specified in Z. Keywords: Viewpoints; Consistency; Z; LOTOS; ODP

Waiting costs and limit order book liquidity: Evidence from the ex-dividend deadline in Australia

In theoretical models of limit order books populated with liquidity traders there is a link between order aggressiveness, spreads, and the cost of waiting for execution. We directly test these models using an experimental setting where waiting time is important for traders, namely the ex-dividend day. Consistent with these models, we find that order placement is more aggressive before stocks begin trading ex-dividend. Stocks with higher expected costs of delaying execution experience larger declines in order aggressiveness from the cum-day to the ex-day. Waiting costs also impact effective bid-ask spreads, which fall on the cum-day before rising on the ex-day. © 2014 Elsevier B.V

Optimizing the tuning range of the Fermilab Recycler 53MHz RF cavities by exploiting the avoided crossing of the tuner and cavity modes

The electromagnetic eigenmodes of the Fermilab Recycler RF cavities were simulated with ACE3P running on NERSC's 'Perlmutter' supercomputer in an attempt to optimize their tuning range to comfortably support slip-stacking. A theory, based on coupled circuits and avoided crossings, was developed to explain the origins of the tuning range for tuner-cavity waveguide systems. This provided a logical, rigorous method to carry out this optimization, although engineering problems due to high voltages in the tuner and the operational $\mu$ range of the garnet had to be carefully implemented. It was shown that the desired goal of 10kHz of tuning was not attainable with the current cavity specifications. The maximum tuning range obtained was 5.59kHz for a single tuner with a coaxial line of length 63in. A double tuner cavity was also studied using the simulation software, although with little improvement in the tuning range. A promising technique to improve the tuning range involving the desynchronization of the garnets' magnetic permeabilities is proposed