scholarly journals Floating Structure with Stabilised Buoyancy Control Device for Photovoltaic Application

2021 ◽  
Vol 945 (1) ◽  
pp. 012072
Author(s):  
Chee Sean Tan ◽  
Lai Wai Tan ◽  
Chee Wayne Tan
Keyword(s):  
Solar Energy ◽  
Focal Point ◽  
Anthropogenic Pollution ◽  
Control Device ◽  
Tidal Wave ◽  
Floating Structure ◽  
Wave Impact ◽  
Neutral Buoyancy ◽  
The Impact ◽  
Buoyancy Control

Abstract Conventional approach of energy derivation is causing anthropogenic pollution and climate change. Various sustainable alternatives of renewable energy particularly solar energy have been developed and implemented as a part of the global effort to gradually decommission usage of fossil fuel and in turn, reduce carbon footprint to overcome adverse environmental impacts. Nevertheless, it was reported that in 2019, only 0.85% of total energy used globally is powered by solar energy. Photovoltaic by itself is not feasible enough due to magnified requirement of land for its installation. Therefore, one of the solutions is floating photovoltaic. However, floating photovoltaic is also restraint by the impact of tidal wave. Characterisation of relationship between stability of large floating structures corresponding to volumetric displacement of the buoyancy control device is the focal point of this paper. Significance of tidal wave impact is empirically assessed based on a scaled-down model of buoyancy control device integrated large floating structure by manipulating the buoyancy of buoyancy control device assisted structure to structure without buoyancy control device under a controlled environment. Fluctuation of the buoyancy control device can be reduced by up to 99.65% when tested against highest configuration of wave transducer by displacing only 50% of air with water. Meanwhile, neutral buoyancy is achieved up to almost 100% when the buoyancy control device is completely filled with water and total submergence has been achieved.

Buoyancy Control Device Enabled by Reversible Proton Exchange Membrane Fuel Cells for Fine Depth Control

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Jalal Yazji ◽  
Alicia Li Jen Keow ◽  
Hamza Zaidi ◽  
Luke T. Torres ◽  
Christopher Leroy ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Dynamic Model ◽  
Proton Exchange Membrane ◽  
Water Electrolysis ◽  
Control Device ◽  
Proton Exchange ◽  
Underwater Robots ◽  
Neutral Buoyancy ◽  
Depth Control ◽  
Buoyancy Control

Abstract Fine buoyancy control is essential for underwater robots to maintain neutral buoyancy despite dynamic changes in environmental conditions. This paper introduces a novel buoyancy control system that uses reversible fuel cells (RFC) as a mass-to-volume engine to change the underwater robots' buoyancy. The RFC uses both the water electrolysis process and fuel cell reaction to produce and consume gases in a flexible bladder for volume change. Unlike conventional actuators such as motors and pistons used in buoyancy control, this mechanism is silent, compact, and energy-efficient. A dynamic model that described the dynamics of the RFC-enabled buoyancy change is presented. Then, a proportional-derivative (PD) controller is designed to position the device at any depth underwater. A prototype device is built to validate the dynamic model and the performance of the feedback controller. Experimental results demonstrate a fine depth control performance with 4 cm accuracy and 90 s settling time. The compact buoyancy design is readily integrable with small underwater robots for fine depth change allowing the robots to save actuation energy.

scholarly journals Prototype Pengontrolan Titik Fokus Panel Surya Terhadap Energi Matahari Secara Otomatis Pada STMIK Amik Riau

2018 ◽  
Vol 3 (1) ◽  
pp. 73
Author(s):  
Rometdo Muzawi ◽  
Ahmad Fauzan ◽  
Lusiana Lusiana
Keyword(s):  
Solar Energy ◽  
Temperature Sensor ◽  
Focal Point ◽  
Electrical Energy ◽  
Control Device ◽  
Solar Panel ◽  
The Sun ◽  
Solar Panels ◽  
Maximum Power Point ◽  
Power Point

A solar panel is a device that can convert solar energy into electricity. The use of solar energy sources can be utilized as street lighting and garden lights. Today many use of solar panels mounted in static (silent) positions in one direction at one focal point will not get the maximum power point of the sun and sunlight received by the solar panel slightly so that it is inefficient at the time of charging the battery.The amount of solar energy that can be absorbed depends on the absorption of sunlight. Absorption can be optimized by making solar panels can continue to face the sun. This system uses ATMEGA8535 microcontroller with one temperature sensor to detect high solar thermal temperature received by solar panels and four photodiode sensors as a detection of light reflection received. These sensors can be able to provide a dynamic solar panels that are automatic and optimal in absorbing sunlight. With the absence of the use of solar panels as the lighting of the garden lights in Stmik Amik Riau and still using electrical energy from PLN, the purpose of this study is to build a solar panel control device that is able to follow the movement of the direction of the arrival of sunlight so it will be optimal in absorbing sunlight.Keywords: Solar Panel, microcontroller, Temperature Sensor, Photodiode Sensor

scholarly journals PROTOTYPE PENGONTROLAN TITIK FOKUS PANEL SURYA TERHADAP ENERGI MATAHARI SECARA OTOMATIS PADA STMIK Amik Riau

2018 ◽  
Vol 8 (1) ◽  
pp. 117
Author(s):  
Rometdo - Muzawi ◽  
Ahmad - Fauzan ◽  
Lusiana - Lusiana
Keyword(s):  
Solar Energy ◽  
Temperature Sensor ◽  
Focal Point ◽  
Electrical Energy ◽  
Control Device ◽  
Solar Panel ◽  
The Sun ◽  
Solar Panels ◽  
Maximum Power Point ◽  
Power Point

A solar panel is a device that can convert solar energy into electricity. The use of solar energy sources can be utilized as street lighting and garden lights. Today many use of solar panels mounted in static (silent) positions in one direction at one focal point will not get the maximum power point of the sun and sunlight received by the solar panel slightly so that it is inefficient at the time of charging the battery.The amount of solar energy that can be absorbed depends on the absorption of sunlight. Absorption can be optimized by making solar panels can continue to face the sun. This system uses ATMEGA8535 microcontroller with one temperature sensor to detect high solar thermal temperature received by solar panels and four photodiode sensors as a detection of light reflection received. These sensors can be able to provide a dynamic solar panels that are automatic and optimal in absorbing sunlight. With the absence of the use of solar panels as the lighting of the garden lights in Stmik Amik Riau and still using electrical energy from PLN, the purpose of this study is to build a solar panel control device that is able to follow the movement of the direction of the arrival of sunlight so it will be optimal in absorbing sunlight.Keywords - Solar Panel, microcontroller, Temperature Sensor, Photodiode Sensor.

scholarly journals Influence of the Spatial Pressure Distribution of Breaking Wave Loading on the Dynamic Response of Wolf Rock Lighthouse

2021 ◽  
Vol 9 (1) ◽  
pp. 55
Author(s):  
Darshana T. Dassanayake ◽  
Alessandro Antonini ◽  
Athanasios Pappas ◽  
Alison Raby ◽  
James Mark William Brownjohn ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Pressure Distribution ◽  
Distinct Element ◽  
Breaking Waves ◽  
Breaking Wave ◽  
Wave Loading ◽  
Wave Impact ◽  
Pressure Distributions ◽  
Impact Area ◽  
The Impact

The survivability analysis of offshore rock lighthouses requires several assumptions of the pressure distribution due to the breaking wave loading (Raby et al. (2019), Antonini et al. (2019). Due to the peculiar bathymetries and topographies of rock pinnacles, there is no dedicated formula to properly quantify the loads induced by the breaking waves on offshore rock lighthouses. Wienke’s formula (Wienke and Oumeraci (2005) was used in this study to estimate the loads, even though it was not derived for breaking waves on offshore rock lighthouses, but rather for the breaking wave loading on offshore monopiles. However, a thorough sensitivity analysis of the effects of the assumed pressure distribution has never been performed. In this paper, by means of the Wolf Rock lighthouse distinct element model, we quantified the influence of the pressure distributions on the dynamic response of the lighthouse structure. Different pressure distributions were tested, while keeping the initial wave impact area and pressure integrated force unchanged, in order to quantify the effect of different pressure distribution patterns. The pressure distributions considered in this paper showed subtle differences in the overall dynamic structure responses; however, pressure distribution #3, based on published experimental data such as Tanimoto et al. (1986) and Zhou et al. (1991) gave the largest displacements. This scenario has a triangular pressure distribution with a peak at the centroid of the impact area, which then linearly decreases to zero at the top and bottom boundaries of the impact area. The azimuthal horizontal distribution was adopted from Wienke and Oumeraci’s work (2005). The main findings of this study will be of interest not only for the assessment of rock lighthouses but also for all the cylindrical structures built on rock pinnacles or rocky coastlines (with steep foreshore slopes) and exposed to harsh breaking wave loading.

scholarly journals The role of L/W in the solar radiation for Saharian cities

2019 ◽  
Vol 91 ◽  
pp. 05006
Author(s):  
Rami Qaoud ◽  
Alkama Djamal
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Energy Levels ◽  
Direct Solar Radiation ◽  
Test Field ◽  
Natural Lighting ◽  
The Difference ◽  
The Impact ◽  
The Relationship

The urban fabric of the desert cities is based on the principle of reducing the impact of urban canyons on direct solar radiation. Here comes this research, which is based on a comparative study of the periods of direct solarisation and values of the solar energy of urban canyons via two urban fabrics that have different building densities, where the ratio between L/W is different. In order to obtain the real values of the solar energy (thermal, lighting), the test field was examined every two hours, each three consecutive days. The measurement stations are positioned by the three types of the relationship between L/W, (L≥2w, L=w, L≤0.5w). According to the results, we noticed and recorded the difference in the periods of direct solarization between the types of urban engineering canyons, reaching 6 hours a day, the difference in thermal values of air, reaching 4 °C, and the difference in periods of direct natural lighting, reaching 6 hours. It should be noted that the role of the relationship between L/W is to protect the urban canyons by reducing the impact of direct solar radiation on urban canyons, providing longer hours of shading, and reducing solar energy levels (thermal, lighting) at the urban canyons. This research is classified under the research axis (the studies of external spaces in the urban environment according to the bioclimatic approach and geographic approach). But this research aims to focus on the tracking and studying the distribution of the solar radiation - thermal radiation and lighting radiation - in different types of street canyons by comparing the study of the direct solarization periods of each type and the quantity of solar energy collected during the solarization periods.

Active Noise Control Using Phase-Compensated, Damped Resonant Filters

2005 ◽  
Vol 128 (2) ◽  
pp. 148-155 ◽  
Author(s):  
Jesse B. Bisnette ◽  
Adam K. Smith ◽  
Jeffrey S. Vipperman ◽  
Daniel D. Budny
Keyword(s):  
Noise Control ◽  
Control Method ◽  
Active Noise Control ◽  
Control Device ◽  
Modal Control ◽  
Pass Filter ◽  
Acoustic Transducers ◽  
Active Noise ◽  
The Impact ◽  
Resonant Filters

An active noise control device called active noise absorber or ANA, which is based upon damped, resonant filters is developed and demonstrated. It is similar to structural positive position feedback (PPF) control, with two exceptions: (1) Acoustic transducers (microphone and speaker) cannot be truly collocated, and (2) the acoustic actuator (loudspeaker) has significant dynamics. The speaker dynamics can affect performance and stability and must be compensated. While acoustic modal control approaches are typically not sought, there are a number of applications where controlling a few room modes is adequate. A model of a duct with speakers at each end is developed and used to demonstrate the control method, including the impact of the speaker dynamics. An all-pass filter is used to provide phase compensation and improve controller performance and permits the control of nonminimum phase plants. A companion experimental study validated the simulation results and demonstrated nearly 8 dB of control in the first duct mode. A multi-modal control example was also demonstrated producing an average of 3 dB of control in the first four duct modes.

Disaster impacts in a port-city; learning from Beirut's  Port explosion

2021 ◽  
Author(s):  
Steluta topalov
Keyword(s):  
Large Scale ◽  
Focal Point ◽  
Transportation System ◽  
The Philippines ◽  
Lessons Learned ◽  
Social Dimension ◽  
Global Network ◽  
Port Cities ◽  
Residential Units ◽  
The Impact

<p>On 4 august 2020, one of the biggest non-nuclear explosions the world has seen in recent times took place in the Port of Beirut. Caused by the detonation of 2,750 tons of ammonium nitrate, inadequate stored in a warehouse in the port, the blast destroyed much of the city’s port and the surrounding infrastructure and severly  damaged the dense residential and commercial areas within 5 km of the explosion site. The impact of the explosion, which registered as a 3.3 magnitude earthquake according to the U.S. Geological Survey, was felt as far away as the island of Cyprus.</p><p>Athough the event was an technological hazard, the impact of the explosion is similar to a standardised natural disaster.</p><p>According to UNDP, a total of 200 000 residential units were affected with an estimated of 40 000 buildings damaged; 200 people lost their lives, around 6 000 individuals were injuried and around 300 000 people were displaced.</p><p>Such figure are comparable to other large-scale disasters such as Cyclone Vayu in India, which occured in June 2019 or the displacement caused by the Typhoon Vongfong, in the Philippines.</p><p>The frequent increase of the natural disasters  puts pressure on the critical infrastructure of the cities. The disruption of the transportation system,  which is vital for the sustainable daily operations, are having a big impact on the economical, enviromental and social dimension of a city system. Among the various types of transportation system, ports are a focal point because of its strategic role for the economic growth of cities,regions and  global network. In addition, they are nodal points for the social and economical activity of the inhabitants.</p><p>Although the ports have played a key role in the development of their host cities, they are also vulnerable to a broad range of risks and threats because of a particular spatial character: the location at the intersection of land and sea.  </p><p>The study of the Beirut’s Port explosion examines the impact of port failures on the host urban enviroment and the relationship between hazards, vulnerability and the impact. The vulnerability of the port to disasters results  to the vulnerability of its host city. A context –based understanding  of the impact of the disaster and the elements at risk is essential to identify appropriate risk management strategies. The location of the port within the urban environment, in densely populated area, as in case of Beirut are some of the characteristics of the port cities that can magnify the impact of disasters to which they are prone.  The study will focus on a collection of data that records the impact and allows visualisation of the complex patterns of the disaster risk reduction.</p><p>The impact caused by the Beirut’s port explosion reminds us about the important role of the ports in their host cities and how fundamental is to identify the port’s infrastructure  exposure to hazards and risks.  Lessons learned from such event may be useful to reduce disaster risks in the port cities.</p>

Wave Impact Loads on the Bottom of Flat Decks

2021 ◽  
Author(s):  
Daniel de Oliveira Costa ◽  
Julia Araújo Perim ◽  
Bruno Guedes Camargo ◽  
Joel Sena Sales Junior ◽  
Antonio Carlos Fernandes ◽  
...  
Keyword(s):  
Scale Effects ◽  
Offshore Structures ◽  
Model Tests ◽  
Analytical Models ◽  
Navier Stokes ◽  
Impact Loads ◽  
Wave Impact ◽  
Wave Channel ◽  
Waves And Currents ◽  
The Impact

Abstract Slamming events due to wave impact on the underside of decks might lead to severe and potentially harmful local and/or global loads in offshore structures. The strong nonlinearities during the impact require a robust method for accessing the loads and hinder the use of analytical models. The use of computation fluid dynamics (CFD) is an interesting alternative to estimate the impact loads, but validation through experimental data is still essential. The present work focuses on a flat-bottomed model fixed over the mean free surface level submitted to regular incoming waves. The proposal is to reproduce previous studies through CFD and model tests in a different reduced scale to provide extra validation and to identify possible non-potential scale effects such as air compressibility. Numerical simulations are performed in both experiments’ scales. The numerical analysis is performed with a marine dedicated flow solver, FINE™/Marine from NUMECA, which features an unsteady Reynolds-averaged Navier-Stokes (URANS) solver and a finite volume method to build spatial discretization. The multiphase flow is represented through the Volume of Fluid (VOF) method for incompressible and nonmiscible fluids. The new model tests were performed at the wave channel of the Laboratory of Waves and Currents (LOC/COPPE – UFRJ), at the Federal University of Rio de Janeiro.

Hydrodynamic Сonditions of the Bakalskaya Spit Degradation (Western Crimea) over the Past 30 Years

2021 ◽  
Vol 37 (3) ◽  
Author(s):  
B. V. Divinsky ◽  
R. D. Kosyan ◽  
◽  
Keyword(s):  
Discriminant Analysis ◽  
Coastal Zone ◽  
Satellite Images ◽  
Wind Waves ◽  
Total Duration ◽  
Wave Model ◽  
Statistical Characteristics ◽  
Wave Impact ◽  
Annual Variability ◽  
The Impact

Purpose. The paper is aimed at studying the morphodynamic features of the Bakalskaya Spit evolution being influenced by the sea wind waves and swell, namely assessment of inter-annual variations in the alluvial (erosion) areas of the Bakalskaya Spit coastline, analysis of inter-annual variability of the wind wave parameters, determination of the surface wave characteristics (or a combination of a few ones) responsible for the processes of the bottom material erosion or accumulation in the coastal zone. Methods and Results. Based on the analysis of satellite images for 1984–2016, the areas of the bottom material accumulation or erosion of the Bakalskaya Spit coastline were determined. Application of the spectral wave model permitted to obtain time series of the main parameters of wind waves and swell (significant wave heights and propagation directions) in the Bakalskaya Spit coastal zone with the 1 hr time resolution for the period from 1984 to 2016. The characteristics of surface waves responsible for the coastline deformation were revealed using the discriminant analysis. Conclusions. Analysis of satellite images of the spit made it possible to distinguish three periods in the history of the Bakalskaya Spit evolution: 1985–1997, 1998–2007 and 2007–2016. The first period was characterized by relative stability. The strongest erosion took place in 1998; after that the alluvial and erosion cases alternated for 10 years weakly tending to general erosion that constituted the second period. The third one that began in 2007 can be defined as the period of spit degradation accompanied by the irreversible loss of beach material. The basic parameters conditioning hydrodynamics of the Bakalskaya Spit water area are: total duration of storms; average and maximum values of significant heights of wind waves and swell. Statistical characteristics of the wind waves’ parameters are of a fairly strong inter-annual variability. According to the average and maximum indices, the wind waves directed close to the normal to the coastline (WSW and WNW) are the most developed. The applied discriminant analysis permitted to draw a statistically reliable conclusion that the direction of the final (average annual) wave impact on the coastal zone, conditioning the processes of sand accumulation or erosion was set by the waves directed to NNW, at that the swell contribution was dominant. The impact degree is conditioned by strong storms with the directions close to the normal to the coastline, namely, the WSW ones

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