Beach sediment temperature variations through depth and time

Data obtained from a site at mean tide level on Belfast Lough, Northern Ireland, show temperature fluctuations on various timescales. Hourly means differ markedly from month to month but are similar for different depths during the same month. The short-term temperature fluctuations recorded at the surface are largely dissipated at a sediment depth of 20 cm with the proportion of total flux occurring at any depth remaining similar irrespective of the absolute temperature range. It is suggested that temperature flux ratios may provide an objective in situ assessment of beach exposure and/or water flow through sediments. A plea for a standardized methodology is made.     

A concept for a superconducting tunnelling junction based spectrograph

We describe a multi-order spectrograph concept suitable for 8-m class telescopes, using the intrinsic spectral resolution of superconducting tunnelling junction detectors to sort the spectral orders. The spectrograph works at low orders, 1–5 or 1–6, and provides spectral coverage with a resolving power of   R ≃ 8000  from the atmospheric cut-off at 320 nm to the long-wavelength end of the infrared H or K band at 1800 nm or 2400 nm. We calculate that the spectrograph would provide substantial throughput and wavelength coverage, together with high time resolution and sufficient dynamic range. The concept uses currently available technology, or technologies with short development horizons, restricting the spatial sampling to two linear arrays; however, an upgrade path to provide more spatial sampling is identified. All of the other challenging aspects of the concept – the cryogenics, thermal baffling and magnetic field biasing – are identified as being feasible.     

North Atlantic sea-level and circulation

Summary. Monthly sea-levels from an extensive array of North Atlantic tide gauges (26-50N) are examined. The spatial scale of the sea-level variations, and the reasons for them, are discussed; one application of such a study is clearly in the design of a tide gauge network for monitoring eustatic changes of sea-level.
The spatial scale of the sea-level changes is large. There is a coherent sea-level signal which can be traced along the eastern boundary of the North Atlantic from Newlyn (50N) to Tenerife (28N). There are also two distinct groupings of tide gauges along the western boundary, separated by Cape Hatteras.
The contribution of local air pressure and wind stress is quantified at each gauge through multiple regression techniques and the gains are then interpreted in terms of recent theoretical and numerical modelling studies. For example, the gains suggest that the wind-forced boundary current along the Nova Scotian shelf is trapped to within about 16 km of the coast.
The influence of local meteorology cannot account for the large-scale modes of variability. The coherent signal along the eastern boundary is correlated with changes in the Sverdrup transport of the North Atlantic and hence the large-scale wind field. The two modes on the western boundary appear to be related to baroclinic boundary current variations.
The Newlyn sea-level record is finally 'corrected' for some of the above effects to illustrate the utility of such a residual series in the identification of eustatic changes and vertical crustal movement.     

Towards identifying sources of subsurface flow: A comparison of components identified by a physically based runoff model and those determined by chemical mixing techniques

A physically-based semidistributed model, TOPMODEL, is applied to a 340 hectare spruce forested catchment in mid-Wales. the model is calibrated to runoff and the subsurface flow is divided into components of flow identified by depth of origin. in addition, chemical mixing techniques are used to provide a hydrograph separation between acidic soil waters and well buffered deep waters. the short-term variations in the components of flow identified by these two approaches compare well.     

Macroscopic quantum resonators (MAQRO)

Quantum physics challenges our understanding of the nature of physical reality and of space-time and suggests the necessity of radical revisions of their underlying concepts. Experimental tests of quantum phenomena involving massive macroscopic objects would provide novel insights into these fundamental questions. Making use of the unique environment provided by space, MAQRO aims at investigating this largely unexplored realm of macroscopic quantum physics. MAQRO has originally been proposed as a medium-sized fundamental-science space mission for the 2010 call of Cosmic Vision. MAQRO unites two experiments: DECIDE (DECoherence In Double-Slit Experiments) and CASE (Comparative Acceleration Sensing Experiment). The main scientific objective of MAQRO, which is addressed by the experiment DECIDE, is to test the predictions of quantum theory for quantum superpositions of macroscopic objects containing more than 10⁸ atoms. Under these conditions, deviations due to various suggested alternative models to quantum theory would become visible. These models have been suggested to harmonize the paradoxical quantum phenomena both with the classical macroscopic world and with our notion of Minkowski space-time. The second scientific objective of MAQRO, which is addressed by the experiment CASE, is to demonstrate the performance of a novel type of inertial sensor based on optically trapped microspheres. CASE is a technology demonstrator that shows how the modular design of DECIDE allows to easily incorporate it with other missions that have compatible requirements in terms of spacecraft and orbit. CASE can, at the same time, serve as a test bench for the weak equivalence principle, i.e., the universality of free fall with test-masses differing in their mass by 7 orders of magnitude.     

Optimizing GPS-guidance transit route for cable crane collision avoidance using artificial immune algorithm

GPS Solutions - A cable crane collision accident usually causes serious damage to workers, equipment and materials. Owing to the emergence of global position system (GPS), some new collision...