Brander, R.W., and A.D. Short, Flow kinematics of low-energy rip current systems, Journal of Coastal Research, 17 (2), 468-481, 2001.

Measurements of hydrodynamics and topography were obtained during two separate field experiments at Palm Beach, NSW, Australia in order to assess flow characteristics within rip current systems during accretionary conditions. At an evolutionary time scale (days-weeks), feeder channel flow decreased and rip-neck flow velocity increased during a cycle of intermediate beach state evolution. At shorter time scales (hours), rip current velocity is inversely related to changes in water depth and is clearly modulated by the tide. Spatially, rip current velocity increases progressively both longshore from the feeders to the lip-neck and offshore within the rip- neck itself. Flow velocity is not constant across the rip channel and increases towards the middle and deeper section of the rip channel. Vertical velocity profiles within the rip-neck and feeder channels show an initial increase in flow magnitude above the bed, with maxima towards the middle of the flow and then a subsequent decrease towards the surface. Evidence of pulsatory rip flow behaviour was found at infragravity frequencies in both rip-feeder and rip-neck environments. Infragravity energy was dominant in the feeder channels during the observed beach state evolution and increased in the rip- neck as the system evolved towards transverse bar and low tide terrace and rip beach states. There is evidence to suggest that topography may exert direct controls on rip flow. The results of this study provide both new quantitative information on the flow kinematics of rip currents and confirm findings of previous studies.

Ashworth, P.J., J.L. Best, J.E. Roden, C.S. Bristow, and G.J. Klaassen, Morphological evolution and dynamics of a large, sand braid- bar, Jamuna River, Bangladesh, Sedimentology, 47 (3), 533-555, 2000.

The initiation and evolution of a kilometre-scale, sand braid- bar was monitored during a 28-month survey period from 1993 to 1996 in one of the world's largest braided rivers, the Jamuna River, Bangladesh. Repeated bathymetric surveys through two monsoon flood seasons, combined with bar-top surveys during exposure of the bar at low flow, provide the most detailed chronology of braid-bar growth yet compiled for a large sand- bed river. During rising and peak flow of the 1994 monsoon flood, a 1.5-km-long, 0.5-km-wide, 12-m-high, symmetrical mid- channel bar was deposited in the centre of a major channel downstream of a zone of flow convergence and significant bank erosion. Initial deposition and growth of the bar core were probably caused by amalgamation of dunes that are present in the Jamuna channels at all flow stages. Bar-top aggradation continued through downstream migration of an 'accretionary dune front', a 3-m-high, angle-of-repose slipface that was composed of amalgamated, 0.5- to 1-m-high dunes. At waning and low flow, the mid-channel bar widened by up to 1 km through the lateral accretion of dunes onto the margins of the initial bar core. A low-velocity zone in the sheltered wake region of the bar-tail led to the accumulation of substantial volumes of silts and clays. During the rising and peak flows of the next monsoon flood, the mid-channel bar extended its bar-tail by up to 1.5 km, as one of the anabranches became dominant, and flow was deflected across the bar-tail. Accretion at the bar-tail generated a lobate, transverse bar-front with a 10-m-high, angle-of-repose avalanche face. Emergence of several smaller bars along this depositional front produced an overall reach morphology that more closely resembled an alternate bar rather than several mid-channel bars. The conversion of a mid-channel bar to an alternate bar is contrary to many previous descriptions of the braiding process.

Brander, R.W., and A.D. Short, Morphodynamics of a large-scale rip current system at Muriwai Beach, New Zealand, Marine Geology, 165 (1-4), 27-39, 2000.

Field measurements of rip spacing, nearshore morphology, water surface elevation and eulerian and lagrangian Rows were made in order to investigate the morphodynamics of a large-scale rip current system at Muriwai Beach, New Zealand. Muriwai is a high-energy meso-tidal beach characterised by modal breaker wave heights of 2.5 m and incident wave periods of 10-15 s. The monitored rip system was characterised by a 400 m long, 75 m wide longshore feeder channel and a 150 m wide rip-neck channel oriented obliquely to the shore and extending over a distance of almost 400 m. During the experiment, the beach evolved from a longshore bar-trough and rip state to a transverse bar and rip configuration. Mean eulerian how velocities obtained from ducted flowmeters deployed on the margin of the feeder channel and rip-neck were on the order of 1 m s(-1) and instantaneous Rows were commonly in excess of 2 m s(-1). Mean lagrangian surface flow velocities extending from the base of the feeder through to the rip-head were obtained by tracking rip Boaters and were on the order of 0.7 m s(-1), with maximums in the rip- neck region of 1.4 m s(-1). A distinct tidal modulation of rip current flow existed with maximum velocities occurring at low tide and minimum velocities at high tide. Comparison with other rip studies suggests that although the magnitude of the morphodynamic and hydrodynamic processes occurring within large-scale rip systems is extreme, the behaviour of these rip systems is very similar to low-energy rips with much smaller spatial scales. There is evidence to suggest that distinct morphodynamic scaling relationships exist between these environments. (C) 2000 Elsevier Science B.V. All rights reserved.

Pardoe, C.H., and A.M. Wilson, In vitro mechanical properties of different equine hoof wall crack fixation techniques, Equine Veterinary Journal, 31 (6), 506-509, 1999.

Hoof wall cracks need mechanical stabilisation to allow healing. Common techniques are fixation with screws, wires and plates or bonding of a patch across the crack. An in vitro system to determine the shear properties of equine hoof crack repairs is described. The force and displacement at yield, stiffness and ultimate force were determined for 4 repair techniques based on an acrylic material, polyurethane patch attached with cyanoacrylate adhesive, steel plate attached with screws and a transverse metal bar cut into the hoof wall. The cyanoacrylate bonded patch repair had lower values for all parameters measured (n = 8, P<0.05) and the other 3 repairs had similar mechanical properties, This study demonstrates that acrylic adhesive repairs can resist similar shear forces to traditional screw plate repairs without risk of penetrating into the sensitive structures of the foot. The transverse bar mounted across the crack had similar resistance to shear as the much larger screw plate and plain bonding repair techniques. This novel technique may be a useful adjunct to other repair methods.

Dubois, J.M.M., and L. Nadeau, Morphosedimentology of an intertidal rock platform in a cold temperature zone (Ile d'Anticosti, Quebec), Canadian Geographer-Geographe Canadien, 43 (1), 84-98, 1999.

Intertidal rock-platform is the dominant coastal landform of southwest Anticosti Island and is also the main control of coastal dynamics. Transverse bars are the most remarkable sediment bodies being formed at the surface of this limestone rock-platform. The bars extend on the landward side of small bedrock knells that were produced by differential erosion of the shore platform, and so we propose the name of 'platform edge transverse bar'. Bar sediments consist almost exclusively of limestone cobbles that are derived from the surrounding platform. Pebble roundness and grain-size trends indicate that sediments are coarser and very angular at the proximal end of the bars, near the outer limit of the platform; clasts become progressively better rounded and finer-grained as they are transported shoreward by waves and longshore currents. Whether at high or low tide, wave attenuation takes place mainly at the outer limit of the platform; this provides an explanation for the apparently low rate of shoreline erosion, and it also suggests that only severe storms are likely to displace the coarse intertidal sediments and to modify the main coastal landforms. However, the presence of sediments on the platform indicates that some erosion is taking place, mainly by frost action. The rocky coastal platform with its low erosion rate is thus a highly stable landform, and, as a result, coastline evolution seems to be slow in the 50 years period of an airphoto analysis.

Chen, D.X., and J.L. Munoz, AC impedance and circular permeability of slab and cylinder, Ieee Transactions On Magnetics, 35 (3), 1906-1923, 1999.

Brander, R.W., Field observations on the morphodynamic evolution of a low- energy rip current system, Marine Geology, 157 (3-4), 199-217, 1999.

A field experiment was conducted at Palm Beach, NSW, Australia to investigate morphodynamic relationships operating within a rip current system during a near complete sequence of beach state evolution under decreasing energy conditions. Observations and measurements were obtained from nearshore surveys, multiple dye releases, oblique photographs, and the deployment of various combinations of nine ducted impeller flow meters and five pressure sensors over a seven-day period in rip and feeder channels. The dataset provides a unique opportunity to assess and quantify aspects of the accretionary model of Wright and Short (Mar. Geol., 56, 1984, 93-118) for intermediate beaches. The morphology of the main rip channel exhibited distinct sequential adjustments with a narrowing of channel width, an increase in channel depth, a reduction in the cross-sectional area available for rip flow, and an increase in morphological relief. Rip flow velocity increased during the observed evolution and was also modulated by the tide, experiencing maximums at low tide and minimums at high tide. Morphologic and kinematic adjustments of the rip system were most pronounced during the transition to a transverse bar and rip state. The existence of a dominant feeder in a twin feeder and rip system contributed to the migration and establishment of a rip-head over the seaward slope of the opposite longshore bar. Net erosion in the rip channel was balanced by net deposition in the feeder channels and bar crests and qualitative observations suggest that this rip-head bar both receives transported sediments from the rip channel and contributes sediments to the ongoing accretion of the beach system. A direct relationship was found to exist between rip morphology and flow with lip velocity increasing as cross- sectional rip channel area decreases and these results are incorporated in a conceptual modification of the model of Wright and Short. The results of this study are restricted to a subset of commonly occurring beaches, but show that accretionary beach state evolution on intermediate beaches is indeed characterised by an increase in rip current velocity, the nature of which can be linked to morphologic control. In addition, the rip-head bar is identified as a potentially key component of low-energy rip system evolution. (C) 1999 Elsevier Science B.V. Al rights reserved.

Suzuki, M.S., A.R.C. Ovalle, and E.A. Pereira, Effects of sand bar openings on some limnological variables in a hypertrophic tropical coastal lagoon of Brazil, Hydrobiologia, 368, 111-122, 1998.

This study describes the spatial and temporal dynamics of several physical, chemical and biological variables in the Grussai lagoon, and their relationship to ephemeral sand bar openings and to a constant in natura waste water input. The spatial variation in pH, dissolved oxygen, electrical conductivity, total alkalinity and nutrients (e.g. soluble reactive silicate, soluble reactive phosphate and ammonium) was associated to the anoxic and nutrient rich groundwater discharge, the development of aquatic macrophytes, the biological activities of phytoplanktonic community and the marine influence. During the period when the sand bar was closed (isolated), the lagoon water was supersaturated with dissolved oxygen and exhibited high values of pH (8-10), total alkalinity (3.000-5.000 mu eq l(-1)), and chlorophyll a contents (60-300 mu g l(-1)), and had low values of dissolved nutrients (nearly undetectable). These suggest a biological processes dominance. When the sand bar was opened, there was an enrichment with dissolved inorganic nutrients (e.g. ammonium and soluble reactive phosphorus up to 120 and 5 mu M, respectively) and a decrease in pH (below 8), total alkalinity (below 3.000 mu eq l(-1)) and dissolved oxygen during the initial second to eight days. Subsequently there was a period when the physical and chemical characteristics of seawater prevailed. The lagoon returned to the pre-opening water conditions in a few days (similar to 10-20). This quick return implies highly efficient biological mechanisms. The high levels of chlorophyll a, total nitrogen and phosphorus in the water column indicate a high eutrophication stage in the Grussai lagoon during the sand bar closed periods.

Gallagher, E.L., S. Elgar, and R.T. Guza, Observations of sand bar evolution on a natural beach, Journal of Geophysical Research-Oceans, 103 (C2), 3203-3215, 1998.

Waves, currents, and the location of the seafloor were measured on a barred beach for about 2 months at nine locations along a cross-shore transect extending 255 m from 1 to 4 m water depth. The seafloor location was measured nearly continuously, even in the surf zone during storms, with sonar altimeters mounted on fixed frames. The crest of a sand bar initially located about 60 m from the shoreline moved 130 m offshore (primarily when the offshore significant wave height exceeded about 2 m), with 1.5 m of erosion near the initial location and I m of accretion at the final location. An energetics-type sediment transport model driven by locally measured near-bottom currents predicts the observed offshore bar migration, but not the slow onshore migration observed during low-energy wave conditions. The predicted offshore bar migration is driven primarily by cross- shore gradients in predicted suspended sediment transport associated with quasi-steady, near-bottom, offshore flows. These strong (> 50 cm/s) currents, intensified near the bar crest by wave breaking, are predicted to cause erosion on the shoreward slope of the bar and deposition on the seaward side. The feedback amoung morphology, waves, circulation, and sediment transport thus forces offshore bar migration during storms.

Liu, K.W., Stratigraphy and depositional environments of the Natal Group at Park Rynie Beach, KwaZulu-Natal Province, South African Journal of Geology, 100 (2), 137-150, 1997.

A composite stratigraphic sequence, constituting the upper portion of the Lower Palaeozoic Natal Group, is well exposed on the beach at Park Rynie. The total sequence is 72.29 m thick and consists mainly of medium-to very coarse-grained feldspathic sandstone with lesser amounts of mudstone and siltstone. This sequence can be subdivided into thirteen cyclothems; of which eleven are fining upward, one coarsening upward, and one holocyclothem. The eleven lining-upward cyclothems represent cyclic episodes of braided channel deposition and abandonment and suggest that the channels were frequently shifting and, therefore, creating a wide channel belt in the lower reaches of the braided river system. The holocyclothem records building up and abandonment of transverse bars which, probably, were affected also by a short-lived marine incursion. The coarsening-upward cyclothem 13, showing conspicuous large-scale tabular cross-bedding and textural rhythmic couplets, shows the development process of a river- mouth bar from its initial stage, through an active stage, into a mature stage. Based on the lithology, sedimentary structures, sand body geometry, and stacked facies architecture, ten sedimentary facies and seven facies associations are recognized. These record the existence of seven major sedimentary environments, namely, braided channel, flooding sheet-flow, migrated channel, crevasse splay, overbank or abandoned channel, transverse bar, and river-mouth bar. The nature of sedimentary facies and facies architecture strongly suggests that the stratigraphic sequence of the Natal Group at Park Rynie Beach is a transitional sequence recording a change in depositional processes from a braided river to a river-mouth bar. This new information suggests that the shoreline for the upper portion of the Natal Group was located at the Park Rynie area, rather than at Hibberdene or Port Shepstone as proposed by earlier studies. Based on the Park Rynie section, integrated with other observations, the author proposes that the reddish colour, and the tripler and duplex facies architectures could be used as identification characteristics for fluviatile sediments.

Masselink, G., and B. Hegge, Morphodynamics of meso- and macrotidal beaches: Examples from central Queensland, Australia, Marine Geology, 129 (1-2), 1-23, 1995.

Detailed measurements of the morphology, waves, and longshore and cross-shore currents were conducted on two beaches on the low- to medium-energy, macrotidal coastline of central Queensland (Australia). Nine Mile Beach is characterised by a relatively steep upper profile, a low-gradient intertidal zone with one or two swash bars, transverse bar/rip morphology at low-tide level and a very low-gradient, dissipative subtidal zone. The beach is composed of fine to medium sand and experiences a modal wave height of 0.75 m and a mean spring- tide range of 3.6 m. Lambert's Beach possesses a steep, coarse- grained, reflective upper profile, and a low-gradient dissipative low tide terrace composed of fine to medium sand. Subdued rip channels intersect the low tide terrace and the beach is subject to a modal wave height of 0.6 m and a mean spring-tide range of 4.6 m. The two beaches are classified as Low Tide Bar/Rip and Low Tide Terrace beaches, respectively, following the model of Masselink and Short (1993). During the present investigation, the Low Tide Bar/Rip beach (Nine Mile Beach) exhibited a larger temporal variability than the Low Tide Terrace beach (Lambert's Beach), despite similar hydrodynamic conditions over the survey period. This difference is principally attributed to the differences in the beach morphologies and the types of morphological changes that occurred. On Nine Mile Beach, morphologic changes were primarily associated with secondary features (swash bars and low tide bar/rip system), whereas on Lambert's Beach the changes in morphology were largely the result of adjustments of the overall beach profile. A number of surf zone processes were investigated, including incident-wave attenuation, infragravity-wave energy, bed return flow and longshore currents. The influence of the tide on surf zone dynamics was found to be insignificant, except in the case of longshore currents. On Nine Mile Beach, the longshore current associated with the nearshore cell circulation was stronger during low tide. On Lambert's Beach, the shore-parallel current on the low tide terrace was largely driven by the tide. A beach profile zonation was defined for Nine Mile Beach and Lambert's Beach based on an examination of the varying influence of swash, surf zone and shoaling wave processes. The four-part tidal zonation consists of: (1) an upper intertidal zone across which swash and aeolian processes are the major influence; (2) a mid- intertidal zone dominated by swash and surf zone processes; (3) a lower intertidal zone controlled by surf zone and shoaling wave processes; and (4) a subtidal zone largely influenced by shoaling wave processes.

Krzyszkowski, D., Sedimentology of Wartanian Outwash Near Belchatow, Central Poland, Boreas, 23 (2), 149-163, 1994.

The braided outwash of Wartanian age near Belchatow, central Poland, was formed synchronously by two river systems: glacier streams flowing from the northwest and west and periglacial rivers flowing from the south and southwest. An extensive alluvial fan was formed which later developed into a highly aggrading fan due to a rising water level in the proglacial lake to the north. Braided streams were represented by relatively low-energy systems with shallow-channel and/or transverse bar deposition. Sporadically, rapid inflows of meltwater caused more energetic conditions and formation of large scours. The latter were found only in the glacier streams and this was confirmed by palaeocurrent measurements and analyses of quartz roundness.

Bilong, C.F.B., E. Birgi, and L. Euzet, Urogyrus Chichlidarum Gen-Nov, Sp-Nov, Urogyridae Fam Nov, Parasitic Monogenean Found in the Urinary-Bladder of Cameroon Cichlidae, Canadian Journal of Zoology-Revue Canadienne De Zoologie, 72 (3), 561-566, 1994.

Ohare, T.J., and A.G. Davies, Sand-Bar Evolution Beneath Partially-Standing Waves - Laboratory Experiments and Model Simulations, Continental Shelf Research, 13 (11), 1149-1181, 1993.

Shore-parallel bars provide a possible mechanism by which a beach may protect itself from the full force of incident waves. Previous laboratory and theoretical studies have shown that strong wave reflection occurs when the bar spacing is equal to half the surface wavelength. Moreover, experiments with erodible beds have indicated that bars with half-wavelength spacings may form as a result of a standing wave component of the wavefield, and that their growth may be coupled with increased wave reflection. In the present study, the interaction of an erodible bed with a partially-standing wavefield is investigated by a series of laboratory experiments and model simulations. The model predicts the wavefield at each stage of development of the bed, together with the wave-induced residual flows. It then uses a simple transport model to determine sediment motion associated with vortex shedding from small-scale tipples and residual motion of suspended sediment. Thus the model predicts the evolving bed profile, and the interaction of the bed with the wavefield. This interaction has not been modelled previously. The model simulations and laboratory experiments agree well, indicating in all cases that bars form with half-wavelength spacings. The exact response of the sediment/wave system depends on the sediment used. For coarse sand, transport as vortex load dominates and bars form with crests just up-wave of the nodes of surface elevation. Bar growth is associated with enhanced wave reflection and there is a resonant coupling between the bars and surface waves. For fine sand, suspended load transport dominates and bars form beneath antinodes. There is little additional reflection of the incident wave but, instead, trapping of wave energy between the bars and the beach occurs. These different responses of the bed may have important consequences for natural barred beaches.

Dalrymple, R.W., R.J. Knight, B.A. Zaitlin, and G.V. Middleton, Dynamics and Facies Model of a Macrotidal Sand-Bar Complex, Cobequid Bay Salmon River Estuary (Bay of Fundy), Sedimentology, 37 (4), 577-612, 1990.


Lippmann, T.C., and R.A. Holman, The Spatial and Temporal Variability of Sand-Bar Morphology, Journal of Geophysical Research-Oceans, 95 (C7), 11575-11590, 1990.


Ohare, T.J., and A.G. Davies, A Laboratory Study of Sand-Bar Evolution, Journal of Coastal Research, 6 (3), 531-544, 1990.


Das, S., and S. Sengupta, Mechanics of Formation of a Nearshore Sand-Bar in Ebb-Tidal- Spit - a Theoretical-Study, Indian Journal of Marine Sciences, 17 (4), 270-275, 1988.


Lippmann, T.C., and R.A. Holman, Quantification of Sand-Bar Morphology - a Video Technique Based On Wave Dissipation, Journal of Geophysical Research-Oceans, 94 (C1), 995-1011, 1989.


Walther, W., and M. Heners, Denture Framework Construction Without Transverse Bar and With Rigid Support - a Clinical Long-Term Study, Deutsche Zahnarztliche Zeitschrift, 43 (10), 1127-1130, 1988.


Shaw, P., and R. Crossley, Formation of the Holocene Lake Chilwa Sand-Bar - a Discussion, Catena, 10 (3), 281-282, 1983.


Lancaster, N., Formation of the Holocene Lake Chilwa Sand-Bar - Reply, Catena, 10 (3), 283-283, 1983.


Ransford, A.O., and M.A. Edgar, A Transverse Bar System to Supplement Harrington Distraction Instrumentation in Scoliosis - a Radiological Study During Operation, Journal of Bone and Joint Surgery-British Volume, 64 (2), 226-227, 1982.


Heathershaw, A.D., Seabed-Wave Resonance and Sand-Bar Growth, Nature, 296 (5855), 343-345, 1982.


Taylor, R., and P. Cunningham, Tests On Transverse Bar Shear Connector For Composite Reinforced-Concrete, Proceedings of the Institution of Civil Engineers Part 2- Research and Theory, 63 (DEC), 913-920, 1977.


Singh, I.B., Bedding Structures in a Channel Sand Bar of Ganga River Near Allahabad, Uttar-Pradesh, India, Journal of Sedimentary Petrology, 47 (2), 747-752, 1977.


Johnson, H.D., Shallow Marine Sand Bar Sequences - Example From Late Precambrian of North Norway, Sedimentology, 24 (2), 245-&, 1977.


Exon, N.F., Extensive Offshore Sand Bar Field in Western Baltic Sea, Marine Geology, 18 (3), 197-212, 1975.


Hobday, D.K., and H.G. Reading, Fair Weather Versus Storm Processes in Shallow Marine Sand Bar Sequences in Late Precambrian of Finnmark, North Norway, Journal of Sedimentary Petrology, 42 (2), 318-&, 1972.