Quaternary warping at Gorge Saddle, western Southland

Gorge Saddle is one low point on a drainage divide between Fiordland and the Southland Plain. Eastward sloping Quaternary terraces east of the divide and westward sloping terraces to the west contain granitic pebbles which could have been derived only from the west. This suggests doming at the present divide concurrent with transport from the west

Sea-cliff Erosion with Rising Sea-Level along Shores Exposing Glacial Material in Atlantic Canada: The Effect of Bedrock Slope and an Example from Isle Madame, Nova Scotia

Rapid retreat rates of sea cliffs exposing glacial material are a widespread problem, especially in Atlantic Canada, and one that will continue. Prediction of retreat rates at specific sites involves many variables, but a factor that has commonly been overlooked in such prediction is the slope of the bedrock surface under the glacial material. A glaciated bedrock platform is generally necessary to establish a stable situation of temporary equilibrium, and as sea-level rises, the bedrock slope determines the location of the new equilibrium position. An example from Nova Scotia shows that bedrock slope is so low on some coasts that the only long-range limiting factor is kinetic, i.e. how fast hydrodynamic energy can remove glacial material. Prediction of coastal retreat scenarios requires better information on the bedrock surface than is commonly available.SOMMAIRELes taux de retrait rapide des falaises qui exposent des matériaux glaciaires est un problème très répandu et qui va perdurer, surtout dans le Canada atlantique. La prévision des taux de retrait sur des sites spécifiques comporte de nombreuses variables et, la pente du substratum rocheux sur lequel reposent ces matériaux glaciaires et une variable qui a souvent été négligée. L’existence d’un substratum rocheux glacié est généralement une condition nécessaire pour l’établissement d’une situation d'équilibre stable temporaire, et lorsque le niveau de la mer monte, la pente du substratum rocheux a une influence déterminante sur le lieu de la nouvelle position d'équilibre. Un exemple en Nouvelle-Écosse montre que la pente du substratum rocheux est si faible sur certaines côtes que le seul facteur déterminant à long terme est la cinétique, c'est-à-dire la vitesse d’abrasion du matériau glaciaire correspondant à l’énergie hydrodynamique. La prévision des scénarios de retrait de la ligne côtière requière une meilleure connaissance du substratum rocheux.

Provenance of the Lower Carboniferous Horton Group, Petit-de-Grat Island, Nova Scotia, as revealed by detrital zircon ages

A quartz sandstone bed in a dominantly conglomeratic section in the central part of the Lower Carboniferous Horton Group on Petit-de-Grat Island, offshore southern Cape Breton Island, Nova Scotia, contains detrital zircon grains with ages ranging from mid-Devonian to Archean. The similarity of the Devonian and Neoproterozoic age spectrum to ages of igneous units in the adjacent Avalonian Mira terrane, in particular the Coastal belt, indicates that it was the main source area. This interpretation is supported by the similarity of the Neoproterozoic and older detrital zircon age spectrum to that of the detrital zircon age spectrum in a Cambrian sandstone unit from the Mira terrane. This interpretation indicates post-depositional dextral fault motion between the Isle Madame area and the Coastal belt.RésuméUne couche de grès quartzeux repérée dans une section principalement conglomératique dans la partie centrale du groupe de Horton du Carbonifère inférieur sur l’île Petit-de-Grat, au sud de l’île du Cap-Breton, en Nouvelle- Écosse, contient des grains de zircon détritique dont l’âge va du Dévonien moyen à l’Archéen. La similitude du spectre d’âge du Dévonien et du Néoprotérozoïque avec celui des unités ignées trouvées dans le terrane Mira d’Avalon adjacent, en particulier la ceinture côtière, indique qu’il s’agit de la région source principale. Cette interprétation est étayée par la similitude du spectre d’âge du zircon détritique du Néoprotérozoïque et de périodes plus anciennes avec celui du zircon détritique trouvé dans une unité de grès du Cambrien provenant du terrane Mira. Cette interprétation indique un mouvement postsédimentaire d’une faille dextre entre la région de l’île Madame et la ceinture côtière.[Traduit par la redaction

Verification of computer-aided designs of traveling-wave tubes utilizing novel dynamic refocusers and graphite electrodes for the multistage depressed collector

A computational procedure for the design of TWT-refocuser-MDC systems was used to design a short dynamic refocusing system and highly efficient four-stage depressed collector for a 200-W, 8- to 18-GHz, TWT. The computations were carried out with advanced, multidimensional computer programs which model the electron beam as a series of disks of charge and follow their trajectories from the RF input of the TWT, through the slow-wave structure and refocusing section, to their points of impact in the depressed collector. Secondary emission losses in the MDC were treated semi-quantitatively by injecting a representative beam of secondary electrons into the MDC analysis at the point of impact of each primary beam. A comparison of computed and measured TWT and MDC performance showed very good agreement. The electrodes of the MDC were fabricated from a particular form of isotropic graphite that was selected for its low secondary electron yield, ease of machinability, and vacuum properties. This MDC was tested (at CW) for more than 1000 hr with negligible degradation in TWT and MDC performances

Comparison of the one meter tangent field to critical fusion frequency field on patients showing a visual field defect

Comparison of the one meter tangent field to critical fusion frequency field on patients showing a visual field defec

Understanding the scale and nature of outcome change in area-regeneration programmes: evidence from the New Deal for Communities Programme in England

The New Deal for Communities (NDC) Programme is one of the most intensive area-based initiatives (ABIs) launched in England. Between 1998 and 2010, 39 NDC Partnerships were charged with improving conditions in relation to six outcomes within deprived neighbourhoods, each accommodating around 9,800 people. Data point to only modest change, much of which reflected improving attitudes towards the area and the environment. There are problems in identifying positive people-based outcomes because relatively few individuals benefit from relevant initiatives. Few positive benefits leak out of NDC areas. Transformational change was always unlikely bearing in mind the limited nature of additional resources, and because only a minority of individuals directly engage with NDC projects. This evidence supports perspectives of ABIs rooted in 'local-managerialism'

Technology Development for the Caltech Submillimeter Observatory Balanced Receivers

The Caltech Submillimeter Observatory (CSO) is located on top of Mauna Kea, Hawaii, at an altitude of 4.2 km. The existing suite of facility heterodyne receivers covering the submillimeter band is rapidly aging and in need of replacement. To facilitate deep integrations and automated spectral line surveys, a family of remote programmable, synthesized, dual-frequency balanced receivers covering the astronomical important 180 - 720 GHz atmospheric windows is in an advanced stage of development. Installation of the first set of receivers is expected in the spring of 2012. Dual-frequency observation will be an important mode of operation offered by the new facility instrumentation. Two band observations are accomplished by separating the H and V polarizations of the incoming signal and routing them via folded optics to the appropriate polarization sensitive balanced mixer. Scientifically this observation mode facilitates pointing for the higher receiver band under mediocre weather conditions and a doubling of scientific throughput (2 x 4 GHz) under good weather conditions.Comment: 12 pages, 17 figures; IEEE Terahertz Science & Technology, January 2012, Volume 2, Issue