Energy Analysis In The Assessment Of The U.K. Wave Energy Programme, 1978

1.1 In a long term situation of rising energy prices convention al economic appraisal of energy technologies has a number of shortcomings. It is not possible to determine the inflationary effects of energy price rises on costs and also it is a very uncertain guide in R & D planning. By using energy analysis the energy element in costs and the inflationary effects of price rises can be determined directly . Also the net energy requirement is an index of merit which is available during the R & D phase and can be related theoretically to the economics of a technology. It provides a good indicator, during R & D, of economic potential. 1.2 The calculations reported here for wave energy systems are based mainly on information contained in RPT 1978 draft report and hence relate to the reference designs as then conceived. 1.3 The modal net energy requirements (energy input/energy output) for the 1978 Reference Designs on a primary energy basis are as follows National Engineering Laboratories (NEL) 2.79 GJ₍ₜ₎/GJ₍ₑ₎ Wavepowe r Limited ( WPL) 1.45 GJ₍ₜ₎/GJ₍ₑ₎ Hydraulics Research S t ation (HRS) 3.27 GJ₍ₜ₎/GJ₍ₑ₎ Sea Energy Associates (SEA) 2.89 GJ₍ₜ₎/GJ₍ₑ₎ French Flexible Bag (FFB) 0.46 GJ₍ₜ₎/GJ₍ₑ₎ 1.4 On the basis of this information only the FFB satisfies the basic criteria of energetic viability. This criteria is that the net energy requirement of a wave energy system should be less than one. 1.5 While it is not possible as yet to establish the precise relationships between energy requirement and economic viability, clearly the 'energy returns' of the FFB are so low as to make it doubtful that this device would ever be economically viable in this form. 1.6 It is possible to model simply the relationship between energy requirements and costs. This indicates that a technology with a high energy requirement will suffer rapid cost inflation as energy prices rise. Depending on estimates of the value of output electricity (compared with the value of firm electricity) it seems that energy prices will have to rise 13 times before the FFB becomes economically viable. This is far beyond the limits of current medium term and even long-term planning horizons . l.7 It is difficult to imagine any realistic economic circumstances which may develop in the medium and long term which would make wave energy, in this form, economically viable. 1.8 To radically alter this assessment will r e quire a reduction in net energy requirement by factors ranging from 2.3 (FFB) to 16 (HRS). These improvements can only be achieved by substantial reductions in masses of structural and mooring materials per unit output together with improvements in the average load factor of all installed machinery. 1.9 Energy analysis raises serious questions about the wave energy programme. These must be answered convincingly before a rational case for committing major funds to the further development of these designs can be made. In particular the current emphasis on design for production would seem to be premature when basic problems of device size remain unresolved. 1.10 Further work is required constructing models of the net energy requirement of all devices in the prograrmme in terms of major system parameters (structural size, peak/average power ratings etc . ). Also energy analysis of new concepts and generic studies of wave energy devices is required. In this way established devices and new concept s will be analysed in a systematic way and it may be possible to identify directions of development which will offer the possibility of wave energy devices with low net energy requirements and with the ultimate potential to be economically viable

The missing piece of the South Atlantic jigsaw: when continental break-up ignores crustal heterogeneity

Crustal heterogeneity is considered to play a critical role in the position of continental break-up, yet this can only be demonstrated when a fully constrained pre-break-up configuration of both conjugate margins is achievable. Limitations in our understanding of the pre-break-up crustal structure in the offshore region of many margins preclude this. In the southern South Atlantic, which is an archetypal conjugate margin, this can be achieved because of the high confidence in plate reconstruction. Prior to addressing the role of crustal heterogeneity, two questions have to be addressed: first, what is the location of the regionally extensive Gondwanan Orogeny that remains enigmatic in the Orange Basin, offshore South Africa; and, second, although it has been established that the Argentinian Colorado rift basin has an east–west trend perpendicular to the Orange Basin and Atlantic spreading, where is the western continuation of this east–west trend? We present here a revised structural model for the southern South Atlantic by identifying the South African fold belt offshore. The fold belt trend changes from north–south to east–west offshore and correlates directly with the restored Colorado Basin. The Colorado–Orange rifts form a tripartite system with the Namibian Gariep Belt, which we call the Garies Triple Junction. All three rift branches were active during the break-up of Gondwana, but during the Atlantic rift phase the Colorado Basin failed while the other two branches continued to rift, defining the present day location of the South Atlantic. In addressing these two outstanding questions, this study challenges the premise that crustal heterogeneity controls the position of continental break-up because seafloor spreading demonstrably cross-cuts the pre-existing crustal heterogeneity. Furthermore, we highlight the importance of differentiating between early rift evolution and subsequent rifting that occurs immediately prior to seafloor spreading

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

Late Paleozoic geology of the Queensland Plateau (offshore northeastern Australia)

The southwestern Pacific region consists of segmented and translated continental fragments of the Gondwanan margin. Tectonic reconstructions of this region are challenged by the fact that many fragmented continental blocks are submerged and/or concealed under younger sedimentary cover. The Queensland Plateau (offshore northeastern Australia) is one such submerged continental block. We present detrital zircon geochronological and morphological data, complemented by petrographic observations, from samples obtained from the only two drill cores that penetrated the Paleozoic metasedimentary strata of the Queensland Plateau (Ocean Drilling Program leg 133, sites 824 and 825). Results provide maximum age constraints of 319.4 +/- 3.5 and 298.9 +/- 2.5 Ma for the time of deposition, which in conjunction with evidence for deformation, indicate that the metasedimentary successions are most likely upper Carboniferous to lower Permian. A comparison of our results with a larger dataset of detrital zircon ages from the Tasmanides suggests that the Paleozoic successions of the Queensland Plateau formed in a backarc basin that was part of the northern continuation of the New England Orogen and/or the East Australian Rift System. However, unlike most of the New England Orogen, a distinctive component of the detrital zircon age spectra of the Mossman Orogen is also recognised, suggesting the existence of a late Paleozoic drainage system that crossed the northern Tasmanides en route from the North Australian Craton. A distinctive shift from abraded zircon grains to grains with well-preserved morphology at ca 305 Ma reflects a direct drainage of first-cycle sediments, most likely from an outboard arc and/or backarc magmatism

Tin whisker mitigation by means of a postelectroplating electrochemical oxidation treatment

There are very few studies that have investigated directly the effect of an oxide film on tin whisker growth, since the ‘cracked oxide theory’ was proposed by Tu in 19941. The current study has investigated the effect of an electrochemically produced oxide on tin whisker growth, for both Sn-Cu electrodeposits on Cu and pure Sn electrodeposits on brass. X-ray photoelectron spectroscopy (XPS) has been used to investigate the effect of the applied electrochemical oxidation potential on the oxide film thickness. Focused ion beam (FIB) has been used to prepare cross sections from electrodeposited samples to investigate the influence of the electrochemically formed oxide film on deposit microstructure during long-term room temperature storage. The XPS studies show that the thickness of electrochemically formed oxide film is directly influenced by the applied potential and the total charge passed. Whisker growth studies show that the electrochemical oxidation treatment mitigates whisker growth for both Sn-Cu electrodeposits on Cu and pure Sn electrodeposits on brass. For Sn electrodeposits on brass, the electrochemically formed oxide greatly reduces both the formation of zinc oxide at the surface and the formation of intermetallic compounds, which results in the mitigation of tin whisker growth. For Sn-Cu electrodeposits on Cu, the electrochemically formed oxide has no apparent effect on intermetallic compound formation and acts simply as a physical barrier to hinder tin whisker growth

Preferred reporting items for studies mapping onto preference-based outcome measures: The MAPS statement

'Mapping' onto generic preference-based outcome measures is increasingly being used as a means of generating health utilities for use within health economic evaluations. Despite publication of technical guides for the conduct of mapping research, guidance for the reporting of mapping studies is currently lacking. The MAPS (MApping onto Preference-based measures reporting Standards) statement is a new checklist, which aims to promote complete and transparent reporting of mapping studies. The primary audiences for the MAPS statement are researchers reporting mapping studies, the funders of the research, and peer reviewers and editors involved in assessing mapping studies for publication. A de novo list of 29 candidate reporting items and accompanying explanations was created by a working group comprised of six health economists and one Delphi methodologist. Following a two-round, modified Delphi survey with representatives from academia, consultancy, health technology assessment agencies and the biomedical journal editorial community, a final set of 23 items deemed essential for transparent reporting, and accompanying explanations, was developed. The items are contained in a user friendly 23 item checklist. They are presented numerically and categorised within six sections, namely: (i) title and abstract; (ii) introduction; (iii) methods; (iv) results; (v) discussion; and (vi) other. The MAPS statement is best applied in conjunction with the accompanying MAPS explanation and elaboration document. It is anticipated that the MAPS statement will improve the clarity, transparency and completeness of reporting of mapping studies. To facilitate dissemination and uptake, the MAPS statement is being co-published by eight health economics and quality of life journals, and broader endorsement is encouraged. The MAPS working group plans to assess the need for an update of the reporting checklist in five years' time. This statement was published jointly in Applied Health Economics and Health Policy, Health and Quality of Life Outcomes, International Journal of Technology Assessment in Health Care, Journal of Medical Economics, Medical Decision Making, PharmacoEconomics, and Quality of Life Research

A “Learning Revolution”? Investigating Pedagogic Practices around Interactive Whiteboards in British Primary Classrooms

Interactive whiteboards have been rapidly introduced into all primary schools under UK Government initiatives. These large, touch-sensitive screens, which control a computer connected to a digital projector, seem to be the first type of educational technology particularly suited for whole-class teaching and learning. Strong claims are made for their value by manufacturers and policy makers, but there has been little research on how, if at all, they influence established pedagogic practices, communicative processes and educational goals. This study has been designed to examine this issue, using observations in primary (elementary) school classrooms. It is funded by the UK Economic and Social Research Council and builds on the authors’ previous research on ICT in educational dialogues and collaborative activities

Teacher interventions in small group work in secondary mathematics and science lessons

Collaborative problem solving, when students work in pairs or small groups on a curriculum-related task, has become an increasingly common feature of classroom education. This paper reports a study of a topic which has received relatively little attention: how teachers can most usefully intervene when students are working in a group, but have encountered some sort of problem. The data used comes from a large scale interventional study of mathematics and science teaching in secondary schools in south east England, in which interactions between teachers and students were recorded in their usual classrooms. We identify the typical problem situations which lead to teachers’ interventions, and describe the different ways teachers were observed to intervene. We examine the different types of intervention, and consider how effective they are in helping group work proceed in a productive manner. Finally, we offer some conclusions about the practical implications of these findings.This is the final version of the article. It was first available from Taylor & Francis via http://dx.doi.org/10.1080/09500782.2015.112536

Del Pezzo surfaces of degree 1 and jacobians

We construct absolutely simple jacobians of non-hyperelliptic genus 4 curves, using Del Pezzo surfaces of degree 1. This paper is a natural continuation of author's paper math.AG/0405156.Comment: 24 page