Deep Trough Research Articles

Beach morphology and coastline evolution in the southern Bohai Strait

The beach studied in this paper spans a length of 51 km and is one of several long sandy beaches in the southern Bohai Strait. Due to the obstruction of islands in the northeast and the influence of the underwater topography, the wave environment in the offshore area is complex; beach types and sediment transport characteristics vary along different coasts. The coastlines extracted from six aerial photographs in different years were compared to demonstrate the evolving features. Seven typical beach profiles were selected to study the lateral beach variation characteristics. Continuous wind and wave observation data from Beihuangcheng ocean station during 2009 were employed for the hindcast of the local wave environment using a regional spectral wave model. Then the results of the wave hindcast were incorporated into the LITDRIFT model to compute the sediment transport rates and directions along the coasts and analyze the longshore sand movement. The results show that the coastline evolution of sand beaches in the southern Bohai Strait has spatial and temporal variations and the coast can be divided into four typical regions. Region (I), the north coast of Qimudao, is a slightly eroded and dissipative beach with a large sediment transport rate; Region (II), the southwest coast of Gangluan Port, is a slightly deposited and dissipative beach with moderate sediment transport rate; Region (III), in the central area, is a beach that is gradually transformed from a slightly eroded dissipative beach to a moderately or slightly strong eroded bar-trough beach from west to east with a relatively moderate sediment transport rate. Region (IV), on the east coast, is a strongly eroded and reflective beach with a weak sediment transport rate. The wave conditions exhibit an increasing trend from west to east in the offshore area. The distribution of the wave-induced current inside the wave breaking region and the littoral sediment transport in the nearshore region exhibit a gradual weakening tendency from west to east, which is opposite to the trend of the wave conditions outside the breaking region. The presence of submerged shoal (Dengzhou Shoal), deep trough (Dengzhou Channel), islands and irregular topography influnces the wave climate, beach types, wave-induced current features, littoral sediment transport trends and coastline evolution patterns in the southern Bohai Strait. Human activities, such as the sand exploitation of Dengzhou Shoal and other coastal engineering projects, also influence the beach morphology and coastline evolution.

Origin, evolution and structure of meso-α-scale lows associated with cloud clusters and heavy rainfall over the Korean peninsula

An investigation was conducted to describe the locations of initial occurrence, evolution and structure of meso-α-scale lows (MLs) associated with cloud clusters and heavy rainfall over the Korean Peninsula using observation and reanalysis data. We selected 29 heavy rainfall events associated with MLs during the 10-year period of 2001-2010. The locations of initial ML occurrence are widely spread from the eastern flank of the Tibetan Plateau to the Yellow Sea. These locations are grouped into 3 regions: 1) the eastern flank of the Tibetan Plateau (R1, 6 cases), 2) central and eastern China (R2, 16 cases), and 3) the Yellow Sea (R3, 7 cases). Initial MLs tend to occur within a deep trough over the eastern flank of the Tibetan Plateau (R1 cases) or a long trough extended northeastward from the southeast of the Tibetan Plateau along the northwestern rim of the western Pacific subtropical high (a majority of R2 cases and two R3 cases). Horizontal temperature gradients are weak over the areas of initial MLs. Meso-α-scale lows tend to develop in the lower troposphere (e.g., below 700 hPa) in an environment of existing cyclonic vorticity. And they are accompanied by anticyclonic vorticity in the upper troposphere. The speed of ML movement varies with each case and with the location of ML. The average speeds of ML movement are 32.4, 37.2 and 40.4 km h-1 for the R1, R2 and R3 groups, respectively. Meso-α-scale lows are shown to have a warm-core structure in general. They are tilted toward various directions with a majority of them (14 of 29 MLs) tilting northward with height.

The Catastrophe over Jammu and Kashmir in September 2014: A Meteorological Observational Analysis

An observational analysis of the catastrophic rainstorm during 4-6 September 2014 over Jammu and Kashmir (J&K) presented in this study shows that the event was unprecedented in terms of the 24, 48 and 72 h accumulated rainfall. The 24 h accumulated rainfall exceeded the previously determined one-day severe rainstorm limits of 20 cm for a number of stations on 5 and 6 September 2014. Weekly cumulative rainfall (4-10 September 2014) exceeded the average rainfall of the entire monsoon season (June-September) in 6 out 18 districts of the state. A number of stations recorded all-time highest 24, 48 and 72 h accumulated rainfall during the week. Analysis of short-duration intensity of rainfall shows that the heaviest rain-rate (35 mm/h) was recorded over Kawa (Udhampur district). The rain-rate remained less than 20 mm/h at other stations. As Kawa is on the windward side of the Pir Panjal Range, orography seems to have played a significant role. The analysis of synoptic conditions leading to unprecedented rainfall shows that the rains were caused by the interaction of the westwardmoving monsoon low pressure area across central and northwest India and a eastward-moving deep trough in the mid-tropospheric westerlies. The additional low pressure areas that formed over Saurashtra and Kutch on 3 September 2014 and over head Bay of Bengal on 5 September 2014, ensured the vigour of the event was maintained through strong wind and moisture flux in J&K. NWP models could capture heavy rains over J&K only in day 1 forecast.

Is the oceanic heat flux on the central Amundsen sea shelf caused by barotropic or baroclinic currents?

The glaciers that drain the West Antarctic Ice Sheet into the Amundsen Sea are accelerating and experiencing increased basal melt of the floating ice shelves. Warm and salty deep water has been observed to flow southward in deep troughs leading from the shelf break to the inner shelf area where the glaciers terminate. It has been suggested that the melting induced by this warm water is responsible for the acceleration of the glaciers. Here we investigate the structure of the currents and the associated heat flow on the shelf using in-situ observations from 2008 to 2014 in Dotson Trough, the main channel in the western part of the Amundsen Sea shelf, together with output from a numerical model. The model is generally able to reproduce the observed velocities and temperatures in the trough, albeit with a thicker warm bottom layer. In the absence of measurements of sea surface height we define the barotropic component of the flow as the vertical average of the velocity. It is shown that the flow is dominated by warm barotropic inflows on the eastern side and colder and fresher barotropic outflows on the western side. The transport of heat appears to be primarily induced by this clockwise barotropic circulation in the trough, contrary to earlier studies emphasizing a bottom-intensified baroclinic inflow as the main contributor.

Hydrophysical features of deep water troughs in the western Kara Sea

In the 59th cruise of the RV Akademik Mstislav Keldysh (September–October, 2011) a large amount of hydrophysical data was obtained with the help of various measuring systems. The data allowed us to study the dynamics and hydrological structure of deep-sea troughs of the western part of the Kara Sea at a high spatial resolution. In particular, the analysis of this material showed that a cyclonic jet exists in the central spur of the St. Anna Trough at depths of 150–300 m and penetrates down to the bottom. The jet is able to play a role of a dynamic barrier that prevents the penetration of water from the southwestern part of the Kara Sea to higher latitudes. In the eastern spur of the St. Anna Trough, the jet weakens, becomes less barotropic, and can no longer inhibit the northward spreading of the shelf waters of the Kara Sea. The weakest and least coherent currents were recorded in the Novaya Zemlya trough, in the southern part of which we traced waters of a Barents Sea origin.

High mixing effectiveness lobed nozzles and mixing mechanisms

For a circular lobed nozzle with the exit plane displaced from the center body, adding a central plug at exit or replacing the nozzle with an alternating-lobe nozzle can improve the mixing effectiveness. In this study, numerical investigations of jet mixing in the lobed nozzles with a central plug and alternating-lobe nozzles in pumping operation were conducted. The effects of the central plugs with the wake ranging from attached to separated flow on the mixing were analyzed, along with the mechanism of improving the mixing performance in a “sword” alternating-lobe nozzle. The simulation results reveal that the large-scale mixing rate, which is dominated by streamwise vortices, is related to the intensity of the attainable heat and mass transfer in the streamwise vortices. The effects of the streamwise vortices on the normal vortex ring are virtually a manifestation of the heat and mass transfer/mixing process of the streamwise vortices. The simulation results also show that the central plug with the attached rear-flow performs better in improving the mixing effectiveness and pumping performance; on the contrary, if the rear-flow is separated, more pressure loss will be induced. In particular, a completely separated flow over the rear of the central plug will severely degrade the attainable heat and mass transfer in the streamwise vortices. For the sword alternating-lobe nozzle, wider sword deep troughs help to increase the flux of the secondary stream around the core region and delay the confluence of the primary stream in the region between the deep and shallow troughs. Thus, the mixing is improved in the middle and posterior segments. Compared to the lobed nozzle with a central plug, the improved sword alternating-lobe nozzle can achieve a higher mixing effectiveness with much less pressure loss, which is preferred in situations when the power loss of the engine is restricted.

Wind Engineering Analysis of Parabolic Trough Collectors to Optimise Wind Loads and Heat Loss

Abstract Concentrating Solar Power (CSP) plants tend to be located in open areas. This leads to the power plant usually being subjected to high wind speeds without much shelter or protection. In parabolic trough plants the solar field, the collectors and receiver tubes, are affected by the wind on both the structural, as well as the performance level. The collectors must resist the aerodynamic forces caused by the wind, and the airflow around the receiver tube has a cooling effect on it. The effects of the wind on Parabolic Trough Collectors (PTC) were investigated in a parametric study over a large range of pitch and yaw angles. Three different trough geometries were analysed varying the focal length of the parabola, i.e. the depth of the trough. The data were obtained using the Computational Fluid Dynamics (CFD) package ANSYS CFX 15.0 and validated against experimental data. An increase of the depth of the parabolic trough increases the maximum aerodynamic forces on the trough. However, a deeper trough has a sheltering effect on the receiver tube, thus reducing the thermal losses due to forced convection. This effect becomes more important the higher the temperature difference between the receiver and ambient air, and it can also reduce the requirements for highly insulated evacuated receiver tubes, which are a significant cost factor in PTC plants. The highest force coefficients on the PTC are observed at high positive pitch angles and a yaw angle of 0°. While the aerodynamic loads on the trough reduce significantly with an increase in the yaw angle of the approaching wind, the heat flux around the receiver tube only shows a slight decrease in most cases. At some negative pitch angles an increasing yaw angle leads to higher thermal losses, as a vortex, forming at the leading edge of the trough, causes high air velocities around the receiver.

Band bending and alignment at the spinel/perovskiteγ−Al2O3/SrTiO3heterointerface

We present a comprehensive study of the band bending and alignment at the interface of $\ensuremath{\gamma}\text{\ensuremath{-}}{\text{Al}}_{2}{\text{O}}_{3}/{\text{SrTiO}}_{3}$ heterostructures by hard x-ray photoelectron spectroscopy. Our measurements find no signs for a potential gradient within the polar $\ensuremath{\gamma}\text{\ensuremath{-}}{\text{Al}}_{2}{\text{O}}_{3}$ film as predicted by the basic electronic reconstruction scenario. We present evidence for a band bending on the ${\text{SrTiO}}_{3}$ side of the interface, yielding a roughly 600 meV deep potential trough, which reaches below the chemical potential and has a spatial expansion of 3--5 unit cells. The band offset between the bulk valence bands is determined to be also approximately 600 meV, corresponding to aligned bands at the interface. Finally, the spatial confinement of the interfacial two-dimensional electron system is derived from the chemically shifted ${\text{Ti}}^{3+}$ photoemission signal in the Ti $2p$ core level spectra, measured at various photoelectron detection angles. It is found to be in excellent agreement with the spatial depth of the potential trough.

Effect of continental shelf canyons on phytoplankton biomass and community composition along the western Antarctic Peninsula

The western Antarctic Peninsula is experiencing dramatic climate change as warm, wet conditions expand poleward and interact with local physics and topography, causing differen- tial regional effects on the marine ecosystem. At local scales, deep troughs (or canyons) bisect the continental shelf and act as conduits for warm Upper Circumpolar Deep Water, with reduced sea- sonal sea ice coverage, and provide a reservoir of macro- and micronutrients. Shoreward of many canyon heads are Adelie penguin breeding colonies; it is hypothesized that these locations reflect improved or more predictable access to higher biological productivity overlying the canyons. To synoptically assess the potential impacts of regional bathymetry on the marine ecosystem, 4 major canyons were identified along a latitudinal gradient west of the Antarctic Peninsula using a high- resolution bathymetric database. Biologicalphysical dynamics above and adjacent to canyons were compared using in situ pigments and satellite-derived sea surface temperature, sea ice and ocean color variables, including chlorophyll a (chl a) and fucoxanthin derived semi-empirically from remote sensing reflectance. Canyons exhibited higher sea surface temperature and reduced sea ice coverage relative to adjacent shelf areas. In situ and satellite-derived pigment patterns indicated increased total phytoplankton and diatom biomass over the canyons (by up to 22 and 35%, respectively), as well as increases in diatom relative abundance (fucoxanthin:chl a). While regional heterogeneity is apparent, canyons appear to support a phytoplankton community that is conducive to both grazing by krill and enhanced vertical export, although it cannot compensate for decreased biomass and diatom relative abundance during low sea ice conditions.

Seismic model of the crust and upper mantle in the Scythian Platform: the DOBRE-5 profile across the north western Black Sea and the Crimean Peninsula

The Scythian Platform (ScP) with a heterogeneous basement of Baikalian–Variscan–Cimmerian age is located between the East European Craton (EEC) on the north and the Crimean–Caucasus orogenic belt and the Black Sea (BS) Basin on the south. In order to get new constrains on the basin architecture and crustal structure of the ScP and a better understanding of the tectonic processes and evolution of the southern margin of the EEC during Mesozoic and Cenozoic time, a 630-km-long seismic wide-angle refraction and reflection (WARR) profile DOBRE-5 was acquired in 2011 October. It crosses in a W–E direction the Fore-Dobrudja Trough, the Odessa Shelf of the BS and the Crimean Plain. The field acquisition included eight chemical shot points located every 50 km and recorded by 215 stations placed every ∼2.0 km on the land. In addition, the offshore data from existing profile 26, placed in the Odessa Shelf, were used. The obtained seismic model shows clear lateral segmentation of the crust within the study region on four domains: the Fore-Dobrudja Domain (km 20–160), an offshore domain of the Karkinit Trough at the Odessa Shelf of the BS (km 160–360), an onshore domain of the Central Crimean Uplift (Crimean Plain, km 360–520) and the Indolo-Kuban Trough at the Kerch Peninsula (km 520–620) that is the easternmost part of the Crimea. Two contrasting domains of the ScP within the central part of the DOBRE-5 profile, the Karkinit Trough and the Central Crimean Uplift, may represent different stages of the ScP formation. A deep Karkinit Trough with an underlying high-velocity (>7.16 km s−1) lower crust body suggests its rifting-related origin during Early Cretaceous time. The Central Crimean Uplift represents a thick (up to 47 km) crustal domain consisting of three layers with velocities 5.8–6.4, 6.5–6.6 and 6.7–7.0 km s−1, which could be evidence of this part of the ScP originating on the crust of Precambrian craton (EEC). The thick heterogeneous basement of the Central Crimean Uplift shows inclusions of granitic bodies associated with magmatic activity related with Variscan orogeny within the ScP. General bending and crustal scale buckling of the Central Crimean Uplift with a wavelength of 230 km could be an effect of the Alpine compressional tectonics in the adjacent Crimean Mountains. The extended/rifted continental margin of the ScP (EEC) at the Odessa Shelf and buckling/uplifted domain of the Central Crimean Uplift affected by compressional tectonics, are separated by the N–S oriented Western Crimean Fault. The crust of the southern margin of the EEC is separated from the ScP, which originated on the EEC crust tectonised and reworked during the Palaeozoic–Mesozoic, by the crustal fault of ∼W–E orientation, which corresponds with the Golitsyn Fault observed at the surface between the EEC and the ScP. The Fore-Dobrudja Domain with a thick (>10 km) heterogeneous basement and two subhorizontal layers in the crystalline crust (with velocities 6.2–6.3 and 6.4–6.65 km s−1) differs from the ScP crust and its origin could be very similar to that of the Trans-European Suture Zone and Palaeozoic West European Platform.

An ultraluminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30.

So far, roughly 40 quasars with redshifts greater than z = 6 have been discovered. Each quasar contains a black hole with a mass of about one billion solar masses (10(9) M Sun symbol). The existence of such black holes when the Universe was less than one billion years old presents substantial challenges to theories of the formation and growth of black holes and the coevolution of black holes and galaxies. Here we report the discovery of an ultraluminous quasar, SDSS J010013.02+280225.8, at redshift z = 6.30. It has an optical and near-infrared luminosity a few times greater than those of previously known z > 6 quasars. On the basis of the deep absorption trough on the blue side of the Lyman-α emission line in the spectrum, we estimate the proper size of the ionized proximity zone associated with the quasar to be about 26 million light years, larger than found with other z > 6.1 quasars with lower luminosities. We estimate (on the basis of a near-infrared spectrum) that the black hole has a mass of ∼1.2 × 10(10) M Sun symbol, which is consistent with the 1.3 × 10(10) M Sun symbol derived by assuming an Eddington-limited accretion rate.

Freshwater distributions and water mass structure in the Amundsen Sea Polynya region, Antarctica

Abstract We present the first densely-sampled hydrographic survey of the Amundsen Sea Polynya (ASP) region, including a detailed characterization of its freshwater distributions. Multiple components contribute to the freshwater budget, including precipitation, sea ice melt, basal ice shelf melt, and iceberg melt, from local and non-local sources. We used stable oxygen isotope ratios in seawater (δ18O) to distinguish quantitatively the contributions from sea ice and meteoric-derived sources. Meteoric fractions were high throughout the winter mixed layer (WML), with maximum values of 2–3% (±0.5%). Because the ASP region is characterized by deep WMLs, column inventories of total meteoric water were also high, ranging from 10–13 m (±2 m) adjacent to the Dotson Ice Shelf (DIS) and in the deep trough to 7–9 m (±2 m) in shallower areas. These inventories are at least twice those reported for continental shelf waters near the western Antarctic Peninsula. Sea ice melt fractions were mostly negative, indicating net (annual) sea ice formation, consistent with this area being an active polynya. Independently determined fractions of subsurface glacial meltwater (as one component of the total meteoric inventory) had maximum values of 1–2% (±0.5%), with highest and shallowest maximum values at the DIS outflow (80–90 m) and in iceberg-stirred waters (150–200 m). In addition to these upwelling sites, contributions of subsurface glacial meltwater could be traced at depth along the ∼ 27.6 isopycnal, from which it mixes into the WML through various processes. Our results suggest a quasi-continuous supply of melt-laden iron-enriched seawater to the euphotic zone of the ASP and help to explain why the ASP is Antarctica’s most biologically productive polynya per unit area.

Using Principle Component Analysis in Identifying Synoptic Patterns of Wet Periods in Central Iran

Atmosphere circulation patterns have an important role in appearance of natural events. For this purpose, in the present study in order to identify the atmosphere circulation patterns which cause humid periods, the principle components analysis method and cluster analysis were used. Therefore by emphasis on peripheral circulation approach, wet periods during a 30 years statistic period (1982-2011) in 6 synoptic stations in Kerman, Yazd and Isfahan province which have long term common statistic period were calculated using standard precipitation index. The findings of principle component analysis showed that by eight components it is possible to explain 94 percent of the variations in geo-potential height data. Therefore, the first component with 62.3 percent appearance shows the dominance of polar and Siberia high pressure in cold period of the year, and the remaining components show atmosphere instabilities which penetrate the region from Mediterranean sea, Black sea and Red sea. The results of cluster inspections show that there are two patterns with 28 percent frequency and 15 percent probability of precipitation in the region. Therefore, the circulation pattern of middle level of the atmosphere shows that by establishment of a deep trough at the east of Mediterranean sea and red sea and locating the east of trough on the researched area, and simultaneously a low pressure centre become dominant at the sea level on the region which cause precipitation event. This arrangement of circulation pattern causes Iran to exit from drought.

Effect of the atmospheric heat source on the development and eastward movement of the Tibetan Plateau vortices

Based on the final analyses data (FNL) of the Global Forecasting System of the National Centers for Environment Prediction (NCEP) and the radiosonde data over the Tibetan Plateau, evolutions of two types of the Tibetan Plateau vortices, moving-off the plateau (Type A) and dying-out on the plateau (Type B), are investigated respectively. Compared to Type B vortices, the large-scale circulations associated with Type A vortices show stronger ridge to the north of the plateau and deeper trough near the Bay of Bengal at 500 hPa, and the southwesterly flow from the trough and the northwesterly flow from the ridge converge more intensively to the east of Type A vortices. Meanwhile, at 200 hPa the divergence on the right-hand side of the upper westerly jet is just over the vortices. The convergence at 500 hPa and divergence at 200 hPa provide favourable conditions for the development and eastward motion of the vortices. The diagnoses of the potential vorticity (PV) budgets reveal that in the developing stages of the two types of vortices, the vertical distribution of the atmospheric heat source determines both their intensity and the moving direction. In the decaying stage, the maintenance and eastward movement for Type A vortices mainly depend on the convergence of the strong northwesterly and southwesterly to the east of the vortices. For Type B vortices, the vertical PV flux divergence caused by the ascending motion around the vortices reduces the intensity of the vortices and is unfavourable for their eastward motion.

The Sytykanskaya kimberlite pipe: Evidence from deep-seated xenoliths and xenocrysts for the evolution of the mantle beneath Alakit, Yakutia, Russia

Mantle xenoliths (>150) and concentrates from late autolithic breccia and porphyritic kimberlite from the Sytykanskaya pipe of the Alakit field (Yakutia) were analyzed by EPMA and LAM ICP methods. In P-T-X-f(O2) diagrams minerals from xenoliths show widest variations, the trends P-Fe#-CaO, f(O2) for minerals from porphyric kimberlites are more stepped than for xenocrysts from breccia. Ilmenite PTX points mark moving for protokimberlites from the lithosphere base (7.5 GPa) to pyroxenite lens (5–3.5 GPa) accompanied by Cr increase by AFC and creation of two trends P-Fe#Ol ∼10–12% and 13–15%. The Opx-Gar-based mantle geotherm in Alakit field is close to 35 mW/m2 at 65 GPa and 600 °C near Moho was determined. The oxidation state for the megacrystalline ilmenites is lower for the metasomatic associations due to reduction of protokimberlites on peridotites than for uncontaminated varieties at the lithosphere base. Highly inclined linear REE patterns with deep HFSE troughs for the parental melts of clinopyroxene and garnet xenocrysts from breccia were influenced by differentiated protokimberlite. Melts for metasomatic xenoliths reveal less inclined slopes without deep troughs in spider diagrams. Garnets reveal S-shaped REE patterns. The clinopyroxenes from graphite bearing Cr-websterites show inclined and inflected in Gd spectrums with LREE variations due to AFC differentiation. Melts for garnets display less inclined patterns and Ba-Sr troughs but enrichment in Nb-Ta-U. The 40Ar/39Ar ages for micas from the Alakit mantle xenoliths for disseminated phlogopites reveal Proterozoic (1154 Ma) age of metasomatism in early Rodinia mantle. Veined glimmerites with richterite – like amphiboles mark ∼1015 Ma plume event in Rodinia mantle. The ∼600–550 Ma stage manifests final Rodinia break-up. The last 385 Ma metasomatism is protokimberlite-related.

Wind engineering analysis of parabolic trough solar collectors: The effects of varying the trough depth

Wind affects parabolic trough solar collectors on both the structural and performance levels. With the need for higher temperatures, larger apertures of the troughs are required to increase the concentration ratio, however, this also increases the wind loads on the structure. Additionally, airflow around the receiver tube adversely affects the performance of the plant by increasing convective heat losses.This paper presents the results of research into the effects of the wind on parabolic trough solar collectors. The airflow is investigated in a parametric study aiming at a reduction of the wind loads and thermal losses in the receiver tubes to provide a basis for higher concentration ratios and thus higher efficiencies of parabolic trough power plants. Validated against experimental data from wind tunnel tests and previous studies on the wind effects on parabolic troughs, a series of three-dimensional simulations was conducted using the commercial CFD program ANSYS ® CFX 14.5. The parameter that was varied is the depth of the trough, i.e. the focal length of the paraboloid. Simulations were performed over a large range of pitch angles for three different trough geometries as periodic simulations of an individual trough, representing a single collector row. Time-averaged data on aerodynamic loads and heat transfer are presented.While a deep trough leads to higher forces than a shallow trough, when facing the wind, due to increased curvature, the wind speed around the receiver is significantly lower with a lower focal length, which can minimise the heat loss in the receiver tube leading to overall higher efficiencies due to higher possible temperatures in the solar field.

Fat transposition with a single subdermal stitch for the treatment of deep tear trough

Goal: To describe a fixation technique of the medial and central fat pads in the subperiosteal pocket for transconjunctival fat transposition, using a single subdermal, non-removable, non-absorbable stitch.Materials and methods: Retrospective study of 19 patients with bilateral deep tear through treated by means of transconjunctival fat transposition. Charts and photographic records were reviewed.Results: Photographical and clinical improvement of the deep tear through and fat prolapse was observed in all patients in variable degrees. There were no intraoperative complications. Significant periocular hematoma occurred in 1 patient and solved without complications. Two patients presented transitory fat pedicle hardening and one patient presented a conjunctival inferior fornix granuloma, surgically removed. All patients were satisfied.Conclusions: Transconjunctival subperiosteal fat transposition with single subdermal stitch to fix the medial and central fat pads, for the treatment of deep tear trough and fat prolapse demonstrated high patient satisfaction, good aesthetic results with no significant or permanent complications.

PHARMACOKINETIC STUDIES ON OXIMES IN ORGANOPHOSPHATE POISONING: A MINI REVIEW

Organophosphate (OP) poisoning is one of the most common causes of poisoning in developing countries especially in Southeastern Asia. Poisoning with phosphorus-containing organic chemicals or OP compounds can be managed with antidotes like oximes which are potential reactivators of acetylcholinesterase (AChE). The efficacy of oxime therapy in OP poisoned patients mainly depends upon various factors such as different dose plans, infusion rate of oximes, genetic differences of patients, type of oxime used and chemical nature of the OP compound ingested. Studies on pralidoxime kinetics in OP poisoned patients have shown that reactivation of AChE depends on the plasma concentration of oximes as well as OP compounds. The plasma concentration of oximes mainly depends on the dose plan from intermittent injection to continuous infusion after a loading dose. The incontrovertible fact is that the intermittent dosing of oximes results in deep troughs in blood pralidoxime/oxime levels (BPL) whereas continuous infusion of oximes maintains steady state plasma concentrations. Many published literature also highlighted pralidoxime via continuous infusion results in better outcomes with minimum fluctuation in BPL compared to intermittent dosing. At therapeutic doses, adverse effects of oximes are reported to be minimal. But high BPL is associated with some common adverse effects including dizziness, blurred vision and diastolic hypertension. Considering all the facts, it is important to note that kinetic studies of oximes are useful not only in deciding the dose regimen, but also in predicting the possible side-effects.

Composite Characterization of Engineering Ceramics Ground Surface

Traditional methods of roughness characterization cannot properly reflect the characteristics of engineering ceramics surface topography. Therefore, the composite characterization using combined fractal method and wavelet method is introduced in this paper. And they are used to describe the global and local characteristics of engineering ceramics ground surface, respectively. Furthermore, a concept called topography damage ratio is proposed to describe characteristic of the deep wave trough. Finally, 3-D measurement is used to verify this method.

A model of oceanic development by ridge jumping: Opening of the Scotia Sea

Ona Basin is a small intra-oceanic basin located in the southwestern corner of the Scotia Sea. This region is crucial for an understanding of the early phases of opening of Drake Passage, since it may contain the oldest oceanic crust of the entire western Scotia Sea, where conflicting age differences from Eocene to Oligocene have been proposed to date. The precise timing of the gateway opening between the Pacific and Atlantic oceans, moreover, has significant paleoceanographic and global implications. Two sub-basins are identified in this region, the eastern and western Ona basins, separated by the submarine relief of the Ona High. A dense geophysical data set collected during the last two decades is analyzed here. The data include multichannel seismic reflection profiles, and magnetic and gravimetric data.The oceanic basement is highly deformed by normal, reverse and transcurrent faults, as well as affected by deep intrusions from the mantle. The initial extension and continental thinning, with subsequent oceanic spreading, were followed by compression and thrusting. Several elongated troughs, bounded by faults, depict a thick sequence of depositional units in the basin. Eight seismic units are identified in a deep trough of the eastern Ona Basin. The deposits reach a thickness of 5km, a consistent value not previously reported from the Scotia Sea. A body of chaotic seismic facies is also observed above the thinned continental crust of the Ona High. Magnetic seafloor anomalies older than C10 (~28.5Ma) may be present in the region. The anomalies could include up to chron C12r (~32Ma), although their identification is difficult, since the amplitude is subdued and the original oceanic crust was highly deformed by later faulting and thrusting. The magnetic anomaly distribution is not congruent with seafloor spreading from a single ridge. The basin plain is tilted and subducted southwestward below the South Shetland Islands Block, particularly in the western part, where an accretionary prism is identified. Such tectonics, locally affecting up to the most recent deposits, imply that a portion of the primitive oceanic crust is absent. Based on the stratigraphy of the deposits and the magnetic anomalies, an age of 44Ma is postulated for the initiation of oceanic spreading in the eastern Ona basin, while spreading in the western Ona Basin would have occurred during the early Oligocene.The tectonics, depositional units and the age of the oceanic crust provide additional evidence regarding the Eocene opening of Drake Passage. The initial tectonic fragmentation of the South America–Antarctic Bridge, followed by oceanic spreading, was characterized by jumping of the spreading centers. An Eocene spreading center in the eastern Ona Basin was the precursor of the Scotia Sea. A model comprising four tectonic evolutionary phases is proposed: Phase I, Pacific subduction — Paleocene to middle Eocene; Phase II, eastern Ona back-arc spreading — middle to late Eocene; Phase III, ridge jumping and western Ona back-arc spreading — early Oligocene; and Phase IV, ridge jumping and West Scotia Ridge spreading — early Oligocene to late Miocene.The development of shallow gateways allowed for an initial connection between the Pacific and Atlantic oceans and, hence, initiated the thermal isolation of Antarctica during the middle and late Eocene. Deep gateways that enhanced the full isolation of Antarctica developed in Drake Passage from the Eocene/Oligocene transition onward. A significant correlation is observed between the tectonics, stratigraphic units and major climate events, thereby indicating the influence of the local tectonic and paleoceanographic events of the Southern Ocean on global evolution.