To investigate the interactions among geomorphology, hydrodynamics, and sediment dynamics on the inner shelf offshore Louisiana, multiple acoustic and optical sensors were deployed during a 58-day ...intermediate-energy period from May 23 to July 22, 2016. Time series results show that an elongated bathymetric “trough” between Ship Shoal and Isles Dernieres partially confines flow in the E-W (shore-parallel) direction. Warm water with lower salinity was observed in the mid to upper water column with cool water with higher salinity in the lower water column. High sediment concentrations of 1–10 g/L were observed in the bottom boundary layer during intermediate-energy conditions in response to sustained winds of up to 11 m/s, significant waves heights of up to 1.5 m, occasional 8 s period swells, and a spring tidal range of 0.6 m. The dominant current and sediment transport directions were westward during the study period. About 77% of the sediment flux occurred during three 2-day-long periods (only 10% of the observation period), revealing the nonlinear and episodic nature of sediment transport in this study area. Although intermediate-energy conditions are less energetic than hurricanes and storms, they occur more often and contribute greatly to the long-term net sediment transport. Based on preliminary estimates, ~51.0 million tons of sediment passes along the Louisiana inner shelf annually, comparable with the annual sediment exiting the Mississippi Delta and sourced from marsh edge erosion in coastal Louisiana combined. The inner shelf sediment flux is an integral part of the coastal sediment budget and may provide important mineral sediment for wetland accretion if transported onshore during storms.
Benign prostatic hyperplasia (BPH) is a non-malignant enlargement of the prostate gland that is common in older men. The clinical manifestations of BPH are frequent urination, urgency, incomplete ...dribbling of urine, and urinary retention. Moxibustion, as a convenient, safe and effective method, has been widely applied in the clinical treatment of BPH. The study aim to assess the efficacy and safety of moxibustion for BPH.
The following electronic databases will be searched regardless of language and publication status: Pubmed, MEDLINE, EMBASE, China Biomedical Database, China National Knowledge Infrastructure, VIP Database, and Wanfang Database, to select studies that meet the requirements. The study will consist of a prospective randomised controlled clinical trials (RCTs) of moxibustion in the treatment of BPH, language of publication does not have barrier of blinding or restrictions, adverse events will be assessed and reported for safety assessment. Two reviewers will independently conduct and screen all included studies and the meta-analysis will be performed with RevMan V5.3.
The study will provide a high-quality convincing assessment of efficacy and safety of moxibustion for BPH.
The conclusion of this study will provide the latest evidence for judging whether moxibustion is effective and safe in the treatment of BPH.
INPLASY2021120021.
Generally, the combination of semiconductor nanomaterials and an inert matrix could form a new material with enhanced optical property and corrosion resistance. Herein, 2D mesoporous sheet-like ZnSe ...nanostructure assembled from lots of 0D nanoparticles was first fabricated, the possible growth mechanism was proposed. Due to the presence of two different dimensions in ZnSe nanosheets (NSs), two absorption peaks around 421 and 480 nm were observed in the UV–Vis absorption spectrum. The violet, blue and green emissions were observed in the room-temperature PL spectrum of ZnSe NSs. Then, ZnSe NSs@SiO
2
nanocomposites were synthesized by a modified Stöber method. After coated with SiO
2
, the LO phonon peak of ZnSe was asymmetrically broadened and weakened. When the adding amount of TEOS was 0.2 ml, the blue emission intensity of ZnSe NSs@SiO
2
was more than eleven times that of bare ZnSe NSs, the corrosion resistance was enhanced. Different emission peaks were observed in the violet-blue and visible region of ZnSe NSs@SiO
2
. The optical properties of ZnSe NSs have been effectively regulated by adjusting the adding amount of TEOS, indicating the effective surface passivation by SiO
2
.
The stratigraphic architecture of Plaquemines sub-delta lobe is identified from sedimentary cores and sub-bottom seismic data collected at Lower Breton Sound, Louisiana, USA. Four lithofacies were ...identified in cores from bottom to top: (1) organic-poor mud; (2) organic-poor silty sand; (3) massive mud; (4) organic-rich peat and root-rich soft mud. Overall, the lithofacies displays a typical progradational deltaic deposit at bottom with upward-coarsening feature, and then an upward-fining deposit overlying on top. Stratigraphic position of the organic-rich peat facies indicates that it is formed after the fluvial sediment source moves away from this region, and it is recognized as a termination of progradation of the Plaquemines sub-delta. Dated peat samples show that sub-delta progradation stops between 876 and 1384 yr AD, during which a 20–70 cm relative sea-level rise is detected. The geological framework reported in this study provides critical information for future modeling on river diversions. The stratigraphic architecture underlying Lower Breton Sound implicates that top three facies of root-rich soft mud, organic-rich peat and massive mud are likely to be eroded away before the development of new crevasse-splay or sub-delta, when sediment diversion is in operation. The deeper organic-poor silty sand lithofacies, however, can serve as a firm foundation to build new land.
•High resolution stratigraphy of the Plaquemines sub-delta lobe is reported.•Progradation of the Plaquemines sub-delta lobe stops during 876–1384 yr AD.•A 20–70 cm relative sea-level rise is detected at Lower Breton Sound during 876–1384 yr AD.
The application of elliptical injector will not only increase the atomization quality, but also reduce spray tip penetration, which has the potential to avoid wall wetting. However, so far the ...research on the effect of elliptical GDI nozzle on impinging spray is seldom reported. In this study, A GDI nozzle with circular and elliptical cross section shapes was employed to study the spray impingement characteristics through VOF-spray one way coupling method. The results revealed that the elliptical spray has shorter penetration as compared to circular spray, and the circular spray impingement time is earlier than the elliptical spray. Additionally, the spray rebound height of the circular spray was larger than that of the elliptical spray at the initial injection progress, while the elliptical spray rebound height became higher at the end of the injection. Furthermore, the elliptical spray impingement wall film mass and area were always smaller as compared with circular spray, and the injection pressure showed a negative influence on wall film mass. Finally, the average film thickness of the spray-wall impingement for an elliptical nozzle is observed to be reduced by 10.3% compared to that of a circular nozzle. Increasing the injection pressure is helpful to decrease the average wall film thickness.
Zeolites are an important class of tetrahedrally coordinated inorganic materials that have been widely used in many chemical industries as catalysts, adsorbents, and ion-exchangers. To date, over 200 ...types of zeolite framework have been discovered. Predicting not-yet-discovered zeolite frameworks is of great importance not only for zeolite structure determination but also for the identification of promising synthetic candidates with desirable functions. However, owing to the complexity and diversity of zeolite framework topologies, zeolite structure prediction has been a challenging task for several decades. Many efforts have been devoted towards this end, among which the computer-aided assembly of zeolite framework constituent atoms (T atoms) in predefined Wyckoff positions (WPs) is a promising approach because of its high efficiency in configuration space searching. However, this approach suffers from high computational overheads caused by the large number of possible WP combinations. On the basis of the analysis of known zeolite structures, we find that the site symmetries of many WPs are incompatible with the tetrahedral coordination of T atoms. Moreover, to avoid the formation of chemically unfeasible distorted tetrahedral coordination, T atoms cannot be too "crowded" in some WPs. We define, for the first time, the T atom distribution (TAD) densities for special site symmetries as the numbers of T atoms per special point, per unit length of rotation axes, or per unit area of mirror planes, respectively. By restricting the number of T atoms in every WP so as not to exceed the highest allowed TAD density, WP combinations for zeolite structure prediction can be reduced by 1-4 orders of magnitude. Taking advantage of this discovery, the efficiency of zeolite structure prediction based on the enumeration of WP combinations can be significantly improved.
Based on the characteristic analysis of tomato, the performance requirements of the flexible end-effector are determined. And the flexible end-effector of the harvesting robot is designed on this ...basis. The end-effector is driven by the sixth joint module of the robot. Through the drive screw and sliding nut, the rotation movement of the drive module is transformed into the opening and closing movement of the fingers, so as to realize the harvesting of tomato. The parts and components of the designed end-effector are introduced. Through the motion analysis of the flexible end-effector, the relationship between the harvesting diameter and the driving rotation angle of the joint is obtained. Performance tests and experiments were conducted to verify that the flexible end effector can harvest tomatoes of different heights and diameters without causing damage to them. Moreover, the success rate of robot harvesting tomatoes is relatively high.
To investigate bay hydrodynamics and its impacts on the adjacent micro-tidal wetland sustainability, hourly measurements of wave, tidal current, and benthic suspended sediment concentration in ...summer, winter, and spring of 2015–2016 were conducted in Fourleague Bay, Louisiana, USA. High-temporal resolution data indicate that benthic suspended sediment resuspension had a dominant periodicity of 4.8-d, which was mainly caused by wind-driven waves. Sediment flux reached 28 g·m−2·s−1 during events. Net sediment flux direction is northwestward in summer, and southeastward in winter and spring. Potential depth-integrated sediment flux to surrounding wetland varied within 0–500 g·m−1·s−1. Seasonal variations of river discharge and wind direction (particularly speed >3 m·s−1) dominated potential sediment contribution from the bay to the surrounding wetland. Three sediment transport regimes were delineated: ‘bypassing’ season, resuspension-accumulation season, and combined ‘bypassing’ and resuspension-accumulation season. This study couples bay hydrodynamics to the sediment transport processes and sustainability of adjacent wetlands in a micro tidal environment. It sheds light on the understanding of natural feedback mechanisms and how estuarine-marsh system survive high relative sea level rising scenario in micro tidal environment, which could aid in the design of future ecological engineering restoration strategies.
Energy efficiency as well as fast data transmission is vital to green communications-based applications for Internet of Things (IoT). Wireless sensors, which constitute one of the important parts of ...IoT, adopt duty cycle operating mode to save energy. Although duty cycle operating mode will decrease the energy consumption of sensor nodes, it leads to a larger communication delay. In this paper, a utility-based adaptive duty cycle (UADC) routing algorithm is proposed to increase energy efficiency, reduce transmission delay, and keep long lifetime at the same time. First, UADC routing algorithm adopts a comprehensive performance evaluation function to evaluate the utility of choosing different relay nodes. Then it selects the node which maximizes the utility of the system to perform data relay. The utility function synthesizes comprehensive indexes like the reliability, energy consumption, and delay of the node. UADC routing algorithm adopts a high-duty cycle operating mode in the areas which have more remaining energy to decrease the delay. And a low-duty cycle operating mode in the energy-strained areas is adopted to ensure a long lifetime. The simulation results also prove the significant performances of our proposed algorithms.
Hurricanes can greatly modify the sedimentary record, but our coastal scientific community has rather limited capability to predict hurricane-induced sediment deposition. A three-dimensional sediment ...transport model was developed in the Regional Ocean Modeling System (ROMS) to study seabed erosion and deposition on the Louisiana shelf in response to Hurricanes Katrina and Rita in the year 2005. Sensitivity tests were performed on both erosional and depositional processes for a wide range of erosional rates and settling velocities, and uncertainty analysis was done on critical shear stresses using the polynomial chaos approximation method. A total of 22 model runs were performed in sensitivity and uncertainty tests. Estimated maximum erosional depths were sensitive to the inputs, but horizontal erosional patterns seemed to be controlled mainly by hurricane tracks, wave–current combined shear stresses, seabed grain sizes, and shelf bathymetry. During the passage of two hurricanes, local resuspension and deposition dominated the sediment transport mechanisms. Hurricane Katrina followed a shelf-perpendicular track before making landfall and its energy dissipated rapidly within about 48h along the eastern Louisiana coast. In contrast, Hurricane Rita followed a more shelf-oblique track and disturbed the seabed extensively during its 84-h passage from the Alabama–Mississippi border to the Louisiana–Texas border. Conditions to either side of Hurricane Rita’s storm track differed substantially, with the region to the east having stronger winds, taller waves and thus deeper erosions. This study indicated that major hurricanes can disturb the shelf at centimeter to meter levels. Each of these two hurricanes suspended seabed sediment mass that far exceeded the annual sediment inputs from the Mississippi and Atchafalaya Rivers, but the net transport from shelves to estuaries is yet to be determined. Future studies should focus on the modeling of sediment exchange between estuaries and shelves and the field measurement of erosional rates and settling velocities.
•Erosional depths were sensitive to both erosional rates and settling velocities.•Local resuspension and deposition dominated the sediment transport mechanisms.•East of hurricane tracks has stronger winds, taller waves and deeper erosions.•Hurricanes suspended seabed sediment mass far exceeding the annual river inputs.
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