Academic literature on the topic 'Submerged'

An experimental investigation on laboratory simulation of reinforced concrete beams submerged in sea water was carried out. The research aimed to analyze the beam flexural behavior cause by submersion effect in the marine environment and simulation pool. Flexural testing was conducted by using two point loading up to beams ruptured. Total 18 reinforced concrete beams of 10 cm x 12 cm x 60 cm in dimension with GFRP-S bonded on the bottom side. Nine beams were submerged in the marine environment and 9 beams were submerged in the simulation pool. Exposure period is 1, 3 and 6 months after 28 days cured in fresh water. The result indicate that the ultimate load and bonding capacity of beam specimens submersed in the marine environment were relatively lower than the specimens submersed in simulation pool. Based on this experimental study, submerging of specimens in simulation pool (Pp ) could be used to predict specimens submersed in marine (Ps) by using equation

This article proposes semi-empirical equations to estimate wave transmission coefficient through submerged complex with solid pile breakwater based on theories of random wave energy conservation of perpendicular wave transmission incorporated with physical hydraulic experiments in wave flume applied on both types of submerged breakwater with and without piles. These equations are able to describe interactions and energy dissipation process for each element of this complex structure which are foundation block and pile rows. Energy dissipation process depends on three major factors which are [relative submerge depth (Rc/Hm0), relative crest width (B/Hm0), wave slope at construction location (sm=Hm0/Lm)] and wave energy dissipation process through pile rows is determined by two major factors [relative submerged depth or submerged length of piles (Rc/Hm0), relative pile row width (Xb/Lm)].

The probability distribution of buoyancy amplitude of vortex-induced vibration for a submerged floating tunnel with single span under steady flow is studied by means of Monte-Calor method in this paper. The probability response of bending moment and displacement in the central span of submersed floating tunnel, including shear response at its buttress are also analyzed. Meanwhile, the reliability of a submerged floating tunnel with single span is also calculated in terms of the structural limit state equation under vortex-induced vibration.

Introduction: Tooth restoration and implant-supported was one of the methods to overcome the free end cases. Abutment and implant are two components that are fused together by a screw. Therefore, the main problem to solve are loosened screw and implant or abutment fracture because of increasing unpredictable potential force on the implant, abutment, and screw. The purpose of this research was to describe the distribution stress between the connection of the body of implant and abutment on the submerged and non-submerged design of the implant supported bridge. Method: The submerged and non-submerged design implant have been analyzed using the Finite Element Method under lateral and vertical static load for 180 N. The numeric model for lower jaw posterior segmented bone was determined by computed tomography, and the load measurement was performed to observe the distribution at the connection between the body of implant and the abutment of the implant supported bridge submerge and non-submerged design. Results: At the lateral load, the distribution strength value was 1.562x107 Pa, whilst for the non-submerged was 9.63x107Pa. At the vertical load, the distribution strength value was 1.038x107 Pa, whilst for the non-submerged was 3.342x107Pa. At the load of 180 N towards the vertical and lateral on the supported implant bridge, the distribution strength value had a smaller scale compared to the ultimate tensile strength (UTS), which was 1040 MPa (1.04 x 109 Pa). Conclusion: Both of the design including the secondary component (abutment) was safe to used as the supporting implant bridge.

AbstractTethered submerged buoy is used extensively in the field of marine engineering. In this paper considering the effect of wave, the nonlinear dynamics behavior of tethered submerged buoy is debated under wave loadings. According to Newton’s second law, the dynamic of the system is built. The coupling factor of the system is neglected, the natural frequency is calculated. The dynamic responses of the system are analyzed using Runge–Kutta method. Considering the variety of the steepness kA, the phenomenon of dynamic behavior can be periodic, double periodic and quasi-periodic and so on. The bifurcation diagram and the largest Lyapunov exponent are applied to judge the nonlinear characteristic. It is helpful to understand the dynamic behavior of tethered submerged buoy and design the mooring line of tethered submerge buoy.

ABSTRACT Bituminous fuels (in the form of water-based emulsions) are increasingly being used as fuel sources in many countries. When spilled in a marine environment, these emulsified fuels initially disperse and then, under certain circumstances, coalesce to become highly adhesive to beaches and shorelines. These fuels may either float or submerge, depending on the salinity of the water into which the spill occurs. Similar situations are known to occur with some conventional heavy fuels, as was the case with the Erika incident off the coast of France. Technologies to detect these neutrally buoyant and/or submerged fuels are urgently needed. The remote detection of submerged oil is a daunting task. The majority of sensors commonly used for the detection of surface oil slicks are of no use for the detection of submerged oil. Environment Canada and the Canadian Coast Guard have recently undertaken a series of bench-scale studies to develop technologies for the real-time remote detection of neutrally buoyant and/or submerged fuels in the marine environment. The unique capabilities of “active sensors” such as laser fluorosensors are being evaluated for the subsurface detection of heavy petroleum products. The detection of submerged Orimulsion by laser-induced fluorescence has been demonstrated at a distance of 81 m (265 feet) in a small test tank. Further experiments are underway to confirm the real-time detection of submerged Orimulsion, initially on the ground, and then through airborne tests.

This paper presents a general solution for wave scattering by stationary objects, which consist of a submerged rectangular plate and a floating rectangular dock. The objects can be either permeable or solid. The general solution is capable to cover all the existing single rectangular objects, such as a surface-piercing breakwater, a bottom-mounted submerge breakwater and a submerged plate. Furthermore, this general solution can also yield new analytical solutions for different combinations of objects, i.e. a single floating breakwater, and a combination of a floating and a bottom-mounted breakwater. Based on the general theory, a MATLAB computer program has been developed. It can be used to further explore different breakwater configurations with different properties.

Submersion occurs when a previously erupted tooth becomes embedded in the oral tissues. The purpose of this paper is to examine the distribution, the degree of re-impaction, the rate of congenital absence of the successor buds and the treatment in 28 submerged teeth in 17 patients.

The objective of this work is to better understand the operation of Submerged Flame Burners, commonly known as Submerged Combustion Burners. Two main aspects require consideration, namely: practical applications of the technology in industry; secondly, theoretical modelling of the flame behaviour within the Submerged Combustion Burner in order to ensure flame stability in the burner and hence heat transfer efficiency and reliable operation. The current status of the Submerged Combustion Technology has been reviewed, detailing the separation equipment items that, overall, make up an industrial Submerged Combustion package. The functionality of the different items has been considered in the context of the primary objective of the equipment, i.e. the establishment of a stable flame within the Submerged Burner. Cases detailing specific instances of the application of Submerged Combustion technology in industry are presented in order that practical aspects of the operation of such units can be better appreciated. The flame system within the Submerged Burner has been modelled using a commercially available Computational Fluid Dynamic Package. A simplified model was used in order to represent the processes occurring within the burner for the combustion of methane with air as the oxidant. The K- turbulence model was used for the prediction of turbulence behaviour within the system. The results of the Computational Fluid Dynamic modelling cover a range of operating parameter values that might be expected to be encountered in industrial applications of Submerged Combustion. The results of the theoretical analysis have been considered in terms of the significance to the design and operation of industrial Submerged Combustion units. The discussions of the practical application of the technology have also led to recommendations being made in respect of the design of the ancillary equipment associated with the Submerged Combustion Burners. The observations made and conclusions drawn in this work provide a better understanding of the processes involved with the production of a stable flame within a Submerged Combustion Burner. Recommendations have been made for future work building on the work reported here.

Experimental study was conducted to analyze the physical flow turbulence and sediment distribution with submerged vane. The objectives behind the investigation were verified and compare results with the Odgaard theory, also; achieved to measure vertical pressures acting on both sides of submerged vane, calculate lift and drag forces, lift and drag coefficients experimentally, that the theory of Odgaard was fails to predict satisfactorily. Other motivation of the study was investigates experimentally the hydrodynamic characterization of submerged vanes as; velocities fields, circulation, vorticity, bed topography, pressures, drag and lift forces with its coefficients, study physical fluid turbulence of submerged vanes as; Reynolds normal and shear stresses, turbulent kinetic energy and rate of dissipation, turbulence intensities, Kolmogorov scales, kinetic energy spectrum, turbulent velocities fields, fluctuating velocities and finally Reynolds stresses histograms. Tests were conducted with clear water was transported throughout the re-circulated rectangular channel with cross-section 7.5 m long, 2.52 m wide channel with a bed consisting of 50 cm thick layer of sand with a median diameter of 1.6-mm and a geometric standard deviation of 1.36. Velocities were measured with a 7 Acoustic Doppler Velocimeter ADV, which were calibrated and checked periodically, depths and water surface elevations were measured with a gauge that could be read with an error of less than 0.3 mm. The current meter, gauges were mounted on a movable instrument sliding carriage, which rode on rails a top of the channel walls, on a traversing mechanism, which enabled them to be positioned at any desired location in the channel. Positioning and data sampling were controlled from a computer program. The water surface elevations were used to determine water surface slope S and Darcy-Weisbach friction factor f=8gRS/u_o^2, where uo = undisturbed (pre-vane) cross-sectional-averaged velocity. In all tests, uo=0.2867 m/s, and the discharge Q=116,62 l/s =0.11662 m^3/s. The vanes were made of 14 mm-thick PVC sheet, they were rectangular in shape, with height H = 7 cm = 0.4337d, and length L = 25 cm = 3.571H. In all tests, the vanes were placed at an angle of attack of 20 degrees with the channel centerline. Water depth was 0.1614 m, pre-vane water surface slope, friction factor and geometric standard deviation, sg, were 1.6×10^(-3), 0.045 and 1.36 respectively. The Vectrinos were been calibrated to work at 25Hz and for each position taken data for 4 minutes, a sample volume that is located approximately 4.3 mm of the device. For each position there are seven Vectrinos 10 cm distance from one to other taking data, so data recorded 7 points at the same time. Data recorded were taking on about 24.080 points on whole the sectional cross channel, with the aim to measure the velocities once the channel-bed has reached to the permanent regime or steady state (equilibrium), during the measurements of velocities, we has taken the bed topography (bathymetry) of the channel-bed by using ADV. In the current dissertation, we installed 30 piezometers in each side of Vane. Once obtained the experimental pressures measured at the laboratory on both sides of vane, the pressure difference between vane sides (¿P), and the perpendicular resultant force (FR¿) acting on the vane, first calculated the resultant force between drag and lift components (FR), then we used this force to calculate drag force FD and lift force FL, also calculated Drag coefficient CD, and finally we calculated the Lift coefficient CL. Results, includes submerged vanes turbulence statistics as; Probability distribution of the velocity field, Reynolds stresses, Turbulence intensity, Kinetic and Dissipation energy, and finally, Kolmogorov turbulence scales. Other results contain energy spectrum, turbulent velocities fields, fluctuating velocities and Reynolds stresses histograms.
El estudio experimental se ha llevado a cabo para analizar el funcionamiento, la turbulencia del flujo y el transporte de sedimentos con paneles sumergidos. Los objetivos tras la investigación fueron verificados y comparados con los resultados de la teoría de Odgaard, también; se han medido las presiones verticales que actúan sobre ambos lados de los paneles sumergidos, se han calculado las fuerzas de drag y lift y, sus coeficientes experimentalmente, ya que la teoría de Odgaard no pudo predecirlas satisfactoriamente. Otra motivación del estudio, fue investigar experimentalmente la caracterización hidrodinámica de los paneles sumergidos como; distribución de velocidades, circulación, vorticidad, topografía del fondo, presiones, fuerzas de drag y lift y sus coeficientes, tensiones de Reynolds, energía cinética turbulenta y disipación turbulenta, intensidades de turbulencia, escalas de Kolmogorov, espectro de energía cinética, campos de velocidades turbulentas, velocidades fluctuantes y finalmente, histogramas de las tensiones de Reynolds. Se realizaron pruebas en aguas claras, a lo largo de un canal rectangular con una sección de 7.5 m de largo, 2.52 m de ancho y un espesor de 50 cm de arena de 1.6 mm de diámetro medio y una desviación geométrica de 1.36. Las velocidades fueron medidas con 7 Acoustic Doppler velocímeter ADV, las que fueron calibradas y revisadas periódicamente, las profundidades y las alturas de superficie de agua fueron medidas con un limnímetro que puede leerse con un error de menos de 0.3 mm. Los paneles fueron construidos con placas de PVC de 14 mm de espesor, de forma rectangular, con altura H = 7 cm = 0.4337d y longitud L = 25 cm = 3.571H. En todos los ensayos, los paneles se colocaron con un ángulo de ataque al flujo de 20 grados con la línea central del canal. El calado del agua es de 0.1614 m, la pendiente superficie, el factor de fricción y la desviación geométrica, fueron, 0.045 y 1.36 respectivamente. Los Vectrinos se han calibrado para trabajar a 25Hz y con un volumen de control de 4.3 mm, para cada posición se tomaron datos durante 4 minutos. Para cada posición hay siete Vectrinos con una distancia de 10 cm entre ellos, registrando por lo tanto 7 puntos al mismo tiempo. Los datos registrados fueron alrededor de 24,080 puntos en toda la sección del canal, con el objetivo de medir las velocidades una vez los sedimentos en el canal han alcanzado el régimen permanente o estacionario (equilibrio), durante las mediciones de las velocidades, se ha medido la topografía del fondo (batimetría) mediante el uso de los sensores ADV. La tesis actual, ha desarrollado un sistema para medir la presión vertical que actúa sobre ambas caras del panel, se instalaron 30 piezómetros de plástico en cada lado del panel. Una vez obtenida la presión experimental medida en el laboratorio a ambos lados del panel, se halla la diferencia de presión entre los dos lados, y la fuerza perpendicular resultante actuando sobre el panel, primero se calculó la fuerza resultante entre los dos componentes de drag y lift, para utilizarla después en el cálculo de la fuerza del drag FD y lift FL, así como el coeficiente de arrastre CD, y finalmente se calculó el coeficiente de lift CL. Los resultados de turbulencia incluyen; Distribución de probabilidad de la distribución de velocidades, tensiones de Reynolds, intensidad turbulenta, energía cinética y disipación. Finalmente, escalas de turbulencia de Kolmogorov. Otros resultados contienen el espectro de energía, campos de velocidades turbulentas, velocidades fluctuantes y los histogramas de las tensiones de Reynolds.

Shoreline response to submerged breakwaters is particularly influenced by the wave field behind the structure driven by coastal processes. The 2D aspects of wave transmission behind submerged breakwaters have been extensively studied by researchers. However, available 2D engineering design tools are inefficient in breakwater design due to not being able to provide any information on the spatial distribution of the nearshore wave field around the breakwater. There are very few studies considering 3D effects in the literature and consequently no reliable guidance for engineers. This encouraged the author to investigate this subject experimentally and numeri¬cally, with the aim of contributing to this important research topic. A comprehensive set of 2D and 3D experiments has been conducted in three wave tanks with different scales. A method has been prepared for predicting the waves transmitted behind the breakwaters based on the data-driven algorithms called Artificial Neural Networks (ANN) and using some of the experimental data collected. Multi-layer perceptron (MLP) and Radial basis function (RBF) models were designed and trained by the Levenberg-Marquardt learning algorithm (LM) and a derivative- based algorithm of gradient descent (GD) respectively. To verify the numerical model, wave simulation was also carried out using DHI MIKE 21 BW (2DH Boussinesq Wave module) based on the numerical solution of the time domain formulations of Boussinesq type equations. The spatial variations of wave energy and wave pattern around the breakwater were generally found to depend on incident wave climate and whether or not wave breaking occurred over the breakwater as well as degree of breaking, with different wave patterns observed for different wave conditions. In cases with waves breaking over the breakwater the lower wave heights were observed behind the breakwater crown on the shorewardside; for nonbreaking wave conditions passing over the submerged breakwater lower wave heights were observed in the gap between the end of the breakwater and the flume wall. Investigations illustrated that the dimensionless Cartesian coordinates x/L₀ and y/L₀ were the most significant parameter in the 3D wave field around the breakwater, with wave height and energy varying spatially around the structure. This confirms the importance of 3D effects on wave height prediction and highlights the inadequacy of 2D models that are unable to deal with spatial variation of wave height behind the breakwater. The RBF model trained by non-dimensional parameters was determined as the most appropriate tool and was proven to be more capable of handling wave transmission prediction comparing with other ANN models. Predictions from the proposed ANN model were found to be in very good agreement with new laboratory data never seen by the model before. The ANN model predictions have also been compared with results from the MIKE 21 BW model. The proposed ANN model was validated in three distinct cases of interpolation, extrapolation and larger scale tests. The model gave the most reliable and convincing predictions within a specific range of input parameters (interpolation) while outside this range (extrapolation) to some extent, reasonable results were still achieved. The proposed model was assessed under larger scale conditions with data collected in another wave tank with different laboratory facilities. Outputs under these conditions also showed good agreement. This shows that the performance of the model is not affected significantly by scale changes and the model has the potential to be used in real applications. The Boussinesq wave model was found to overestimate wave-induced breaking dissipation over the crest of the submerged breakwater leading to underprediction of wave transmission. The evaluations showed more consistency between the measured experimental data and predictions from the ANN model in comparison to those from the Boussinesq wave model. These demonstrate the accuracy and reliability of the model and its capability in predicting the wave field around submerged breakwaters. A simplified version of the numerical model and wave prediction scheme is provided in this thesis for practical applications. The proposed ANN model is a significant advance in that it can be used to predict 3D wave pattern around submerged breakwaters in the range of dimensionless Cartesian coordinate -0.26