Tank Depth Research Articles

Influence of Tank Water Depths on Reproductive Performance of Catfish (Heterobranchus longifilis) Valenciennes, 1840

Aims: To determine the optimum water depth required for catfish spawning in hatcheries. Study Design: Treatments were assigned using complete randomized design. Place and Duration of Study: Fish Farm Complex of the Akwa Ibom State University (AKSU), Nigeria. Methodology: Eighteen (18) similarly-sized H. longifilis broodstock (2.51-2.53 kg, 64 – 66 cm): comprising six broodstock of three males and three females, were held for six months at 0.50 m, 0.75 m and 1.0 m pond water depth. All males were sacrificed for milt extraction without hormonal inducement; with milt from each treatment diluted with normal saline solution. Female broodstock from each treatment were separately induced with ovaprim hormones at a single dosage of 0.5ml/kg body weight of fish and allowed for 16 hours before manual stripping; 3g of egg from each broodstock and mixed with the diluted milt and activated with 100 ml of normal saline. The fertilized eggs were incubated and thereafter assessed for percentage fertilization, hatchability, survival and fry production success. Results: broodstock reproductive parameters significantly increased (P = 0.00) with water depth of broodstock culture tank. Percentage fertilizations were: 49.50±0.78, 68.17±0.93, and 82.50±1.44; respectively. Percentage hatchability of broodstock eggs were: 91.37±1.65 significantly higher for 1.0 m water depth group than 67.79±4.58 from 0.75 m water depth treatment while the least value of hatchability 50.31± 0.78 was recorded for broodstock raised at 0.50 m water depth. The fish group raised at 1.0 m water depth also exhibited highest percentage survival value of 97.02 ± 1.09 and fry production success value of 73.08 ± 0.53 while broodstock raised at 0.50 m water depth indicated the least values: % survival, 8.38 ± 0.48 and fry production success of 2.07 ± 0.07. Conclusion: In times or places of water scarcity, H. longifilis broodstock may be raised at pond water of 0.5 m to 1.0 m. But the water depth that would afford the best breeding and reproductive performance is at 1.0 m depth.

Design and Realization of Intelligent Fish Tank System based on STM32 Microcontroller

With the improvement of people's living standards, people's pursuit of quality of life is also increasing, enthusiast groups are growing, the demand for environmental control of the fish tank is increasingly refined and intelligent, and the ornamental fish industry has come into being. In this paper, we study a system based on STM32 microcontroller for detecting and controlling parameters such as temperature, light, PH, and water depth of the fish tank, and real-time displaying and controlling using the 2.8-inch LCD screen. In addition, the system supports remote control through the cell phone APP, and users can set up timed tasks or perform real-time operations as needed. Eventually, this project has researched and designed a smart fish tank system that can be remotely controlled, integrated with various functions and operated conveniently.

Converting rectangular and circular primary tanks into the AAA biologically enhanced clarification settler.

The frequent design challenge for existing water resource recovery facilities targets the accommodation of an ~50% load increase within the existing infrastructure and footprint. Off-loading this organic load at the top-end of the plant and redirection toward the digesters has proven the most efficient way of process intensification. The Triple A settler is an "activated primary treatment," stands for alternating activated adsorption, and can be retrofitted into existing rectangular or circular (mostly) primary tanks at a hydraulic retention time of 2 h and a sludge retention time of about 0.5days. Several technology implementations demonstrate flexible designs adjusting to existing tank geometries and depths of 2.5 to 5.0m. Different implementation scales from dry-weather flow rates ranging from 0.1 to 10mgd show generic applicability of the functional principles at any scale: Biosorption, bioflocculation, and assimilation provide the key added value in pretreatment efficiencies of ~60/25/33 in %COD/%N/%P removal compared with application of pure physics in primary settling with typical 33%/9%/11% removal, respectively. PRACTITIONERS POINTS: Triple A is a hybrid form of A-stage and contact stabilizer for advanced primary treatment. Besides COD and TSS, also, P and N can be removed via Triple A. Triple A can be retrofitted in existing rectangular or circular tanks. This high-rate process does not worsen the conditions for enhanced biological phosphorus removal. Energy efficiency, capacity increase, and operational benefits are the main goals of Triple A.

Plume Spreading Due to Floor Conditions of a Plunging Liquid Jet Using Stereographic Backlit Imaging

Abstract Plunging liquid jets are a multiphase flow studied to understand how gas is entrained in a liquid and the resulting mixing capabilities. From existing literature, it has been hypothesized that rising bubbles play a noticeable role in the multiphase hydrodynamics of the plunging liquid jet bubble plume and that separating the rising bubbles from the incoming liquid jet can result in a significant increase in the depth of the bubble plume. This study explores the effects of separating the incoming liquid jet from the rising bubble plume through floor interactions and compression effects due to a finite tank depth. This configuration is found in many natural and industrial systems, but not within published literature. Using existing theoretical models of infinite depth plunging liquid jet systems, which align reasonably well with captured baseline data, two models are developed for when floor interactions are present, one theoretical and one empirical. The models show a correlation between plume spread and floor interaction with the incoming plunging liquid jet bubble plume. Data acquired through stereographic backlit imaging over a range of flow rates show a reasonable agreement with the proposed models.

Ensuring the safety of maritime transportation of drilling fluids by platform supply-class vessel

The technology of drilling fluids transportation on the offshore Platform Supply-class Vessel has been considered. It has been established that density stratification of drilling fluid by depth of a cargo tank in the interval of its transportation time of 6–48 h is 4.03–46.29%. The research was carried out in the onboard mud system of a specialized Platform Supply Vessel 5750 tons deadweight offshore vessel. The objective was to improve the drilling fluid transportation system by developing technology to ensure that the density of drilling fluid is maintained at a constant value along the height of the tank while they are being transported by Platform Supply Vessel-class vessels. Using of an additional X-circulation of the drilling fluid in the volume of adjacent cargo tanks has been proposed as such method. Samples for drilling fluid density were taken at different points of the tank.

Underwater Acoustic Intensity Analysis using Noise Assisted-MEMD with Varying Distances

With current developments, underwater communication using acoustic signals is widely used. Many things need to be prepared to support a reliable underwater communication system, such as taking measurements in a test tank to find out the correct measurement configuration. Underwater acoustic intensity measurements, which are detailed in this paper, are performed in the test tank using distance variation schemes. Measurements were made at various distances of 4, 10, 20, and 50 meters from the signal source. The hydrophone that was used has a sensitivity of -180 dB re 1V/µPa. The hydrophone was placed at a depth of 2 meters below the surface of the water in the test tank, which divided the test tank depth in half to ensure that reflections from the bottom and the surface were kept to a minimum. However, the problem is that there are noisy signals at different frequencies. This paper proposes a method using Noise Assisted - Multivariate Empirical Mode Decomposition (NA-MEMD) to decompose the signal and then calculate the sound intensity. The result shows that an increase in the distance between the transmitter and receiver, also causes a change in the intensity with an average change of 0.467 dB/meter. It is concluded that the NA-MEMD approach was shown to be successful in decomposing the intended signal from the noise to equalize the quality of the signal received at different distances, and the correlation between intensity value and change in distance is resilient, with a correlation value of 0.98, indicating a very strong correlation.

Hydrodynamic Tests of Innovative Tourist Submarine

This paper deals with the resistance, towing, seakeeping, and open water propeller tests of an innovative tourist submarine model. Tests were performed in a 276 m long towing tank. As the submarine model is a complex structure composed of various parts attached to the pressure hull, the largest possible model, in the scale of 1:5.0, was produced, considering the towing tank depth and the capabilities of the measurement equipment. Resistance tests were performed in deep water and on the surface in calm water. The tested speed range in both cases was up to 5.5 knots. To ensure the avoidance of free surface effects, resistance tests in deep water were performed for different draughts and then extrapolated to infinite water depth. Smaller effective powers were found for the surface condition. The results are compared to an independently performed computational fluid dynamics (CFD) analysis using OpenFOAM. A fair agreement between the experimentally and numerically predicted effective power is found, while the reasons for the differences found are explained. The free submarine model was towed with a rope performed for the speed range 1.7 kn–3.5 kn, and the towing force in the rope was measured. Seakeeping tests in irregular beam waves at zero speed were performed to check the flooding risk on open hatches. Open water tests of the main thrusters for propelling the submarine were conducted, indicating that both power demand and propeller thrust are slightly larger compared to the initial estimates.

Design and implementation of microcirculation cooling device for microelectronic devices based on electrostatic force

This paper presents the design of a cooling device for microelectronic device applications. The proposed device uses parallel plate capacitor electrical bias to generate an electrostatic force that acts on the coolant to enable control of the coolant flow in the radiator. Through a combination of the structural design of the device and the application of an electrical bias on both sides of multiple parallel plate capacitor electrodes, the generation of a radiator coolant eddy current is realized, and the functions of cooling and heat transfer are realized for microelectronic devices placed on the surface of the base platform. Based on this principle, a finite element multi-physical field simulation was used to simulate the flow heat transfer function of the coolant in the device under the action of the electrostatic force and the effects of the channel diameter, channel spacing, voltage, and liquid storage tank depth on the peak coolant velocity were studied. In addition, 3D printing technology was used to fabricate the heat dissipation device. The heat dissipation device was tested by charging, with a basic realization of the function of controlling the cooling liquid flow in the heat dissipation device demonstrated. The device realizes radiator coolant flow rate control through voltage control and has characteristics that include low energy consumption and a convenient and compact structure.

PLUME ANALYSIS OF PLUNGING LIQUID JETS WITH FLOOR INTERACTIONS USING STEREOGRAPHIC BACKLIT IMAGING

Plunging liquid jets occur when a liquid jet travels through a gas and enters a liquid pool. They are studied in order to understand and model the highly efficient gas-liquid mixing in the resulting bubble plume. Among the aspects of plunging jets studied, compression effects at the bottom or within the pool, while relatively common in application, remain less understood in current literature. The presence of a tank floor spreads the resultant bubble plume which reduces the flow resistance between the rising bubble plume and the incoming liquid jet. The effect of the tank floor on the overall entrainment and mixing is unknown. In order to understand the compression effects of the plume-floor interaction, a liquid-filled tank was designed to simulate multiple tank depths. This work describes the apparatus used to produce a plunging jet with floor effects, as well as the image analysis methodology for identifying and comparing plume formations. Data were collected for multiple liquid flow rates encompassing different entrainment regimes as well as multiple plate positions, varying the level of plume and base interaction. Stereographic backlit images were acquired and several different identification methods are described to better define and compare bubble plume features. Limitations in the image analysis procedures are also described.

Enhancing tunability of liquid storage tanks to function as deep tuned liquid dampers by use of a submerged stretched membrane

This is a study on a deep, liquid-containing tank, such as an overhead water tank on a building, with a vertically submerged stretched membrane (SSM). Here, instead of the sloshing mode, which can become detuned and also affords a low damper mass ratio, the impulsive liquid–membrane interacting system is designed to serve as a dynamic vibration absorber. The requirement of tuning the frequency of the impulsive liquid–membrane interacting system to the structural frequency can be achieved without any imposition on the tank dimensions, which are generally fixed from the tank's functional requirements. The system frequency would remain unchanged so long the membrane would remain submerged below a minimum liquid depth, thereby allowing fluctuation of liquid level within a prescribed range of the tank depth. The formulation for obtaining the frequency of the impulsive liquid–membrane interacting system is derived, using the sub-domain partition approach. It is seen that through suitable adjustment of the design parameters of the membrane, the proposed tank damper can be tuned to both short-period and to long-period structures. Further, the impulsive liquid mass, which otherwise has no role to play in the damping mechanism of a tuned liquid damper (TLD), is here utilized to absorb and dissipate the vibrational energy. Through a time-domain study considering recorded seismic accelerograms, the significant control effectiveness of the proposed damper system is illustrated. Further, the results obtained from the equivalent mechanical model of the structure–damper system are compared with those from a finite element analysis of the fluid–structure system in the ANSYS Workbench environment.

RETRACTED: Transient heat transfer analysis of serially connected array of phase change material in the thermal battery units with Al2O3 working Nano fluids

This study is focused on heat transfer analysis of a serially connected PCM thermal battery units where Al2O3 based Nano fluid is circulated inside u-tube at every battery storage tank. The most stable Crank-Nicolson numerical shame is applied to set of equations which are derived based on energy balance governing equation and a thermal capacitance network from borehole heat exchanger concept. Transient thermal performance of the PCM material such as hourly variation in mean temperature of the PCM material inside the thermal storage batteries as well as temperature profile of the PCM material along the depth of the tanks are determined at different time period. Additionally, temperature profile of the working fluid along the depth of the storage tank as well as hourly temperature variation of the Nano fluid at exit of different tanks are presented in the study.

Control and regulation of the density of technical fluids during their transportation by sea specialized vessels

The object of research is the process of transporting drilling slurry through specialized marine vessels of the Platform Supply Vessels class. The subject of research is the sedimentation stability of the drilling slurry along the height of the cargo tank, which is proposed to be defined as a relative change in vertical density near the surface and bottom of the cargo tank. The studies were carried out on a specialized sea vessel with a displacement of 7320 tons. The design of the vessel provided for the reception and transportation of drilling slurry in four cargo tanks located on the port and starboard sides of the vessel. It has been experimentally established that during the 48-hour transportation, the density of the drilling slurry in the bottom part increases to 19.7 %; decrease in density on the surface – up to 7.8 %; decrease in the sedimentation resistance of the drilling slurry along the depth of the cargo tank – up to 29.85 %. A variant of modernization of the drilling slurry transportation system by installing additional circulation pumps providing forced circulation of the drilling slurry between cargo tanks is proposed. By using programmable microcontrollers (performing turning on/off the circulation pumps), it is possible to provide the following conditions for transporting the drilling fluid: an increase in the density of the drilling fluid in the bottom part up to 0.3 %; decrease in density on the surface – up to 0.25 %; decrease in the sedimentation resistance of the drilling slurry along the depth of the cargo tank – up to 8.01 %. It has been experimentally established that the creation of additional circulation and automatic support of the sedimentation resistance of the drilling fluid in the range of 2–7 % contributes to: – increasing the relative performance of cargo pumps from 38–55 % to 92–96 %; – reducing the time of pumping drilling slurry from cargo tanks to the drilling platform from 7.1 to 3.2 hours; – maintaining the technical condition of equipment, pipelines and elements of the drilling slurry transportation and pumping system.

Effect of Hydrostatic Pressure on the Propagation of Partial Discharge Acoustic Signals in Transformer Oil

In this research article an attempt is made to investigate the effect of hydrostatic pressure on the propagation behavior of Partial Discharge (PD) Acoustic Emission (AE) signals in a simple experimental tank. A mathematical model has been developed in the form of Partial Differential Equations (PDEs) for PD acoustic wave propagation in transformer oil in a steel tank. A Finite Element Analysis tool (FEMLAB), has been used to simulate the propagation of the acoustic waves. The simulation results show that the speed of the acoustic signal varies with the depth of the source location demonstrating hydrostatic pressure affects AE wave propagation. Furthermore, the effect of hydrostatic pressure was investigated and conformed experimentally. It is concluded that the propagation speed is not constant within the tank and increases with tank depth. If the effect of increased acoustic velocities due to hydrostatic pressure is ignored then the possibility of practical PD location algorithms inferring the incorrect location in high voltage assets, such as oil filled transformers, will be increased significantly.

Регулирование плотности бурильной суспензии при её транспортировке судами класса Platform Supply Vessels

Annotation – The issues of maintaining the drilling fluid density during its transportation from shore to the oil drilling platform by the Platform Supply Vessels were considered. The research was carried out on the vessel of 5650 deadweight tons, which made 2 ... 2.5 day voyages from port to drilling platform with possible waiting for direct approach to the platform for 1 ... 1.5 days. The drilling fluid was transported in four tanks of equal-size, arranged in pairs on each side of the vessel. It was found that during this period of time there is a latent stratification of drilling fluid along the depth of cargo tank, causing stratification of its density. The density of the drilling fluid was measured at depths corresponding to 10, 50 and 90 % of the total tank depth. The drilling fluid density stratification is defined as the relative density change in the upper (at 10 % depth) and lower (at 90 % depth) parts of the cargo tank. The hydrometer was used to measure density, allowing measurements in the range of 650 ... 1630 kg/m3 with an accuracy of 1 kg/m3 while controlling the temperature. Density measurements were taken at 6-hour intervals. It has been experimentally proved that during the 48-hour transportation of the drilling fluid with the density of 1295 kg/m3, the density value at the indicated depths is 1163 and 1524 kg/m3 respectively, while the density stratification reaches 31 %. It is offered to prevent the density stratification by creating a forced X-shaped circulation of the drilling fluid between cargo tanks which stand side by side. It is offered to regulate and maintain automatically the drilling fluid density in the range of 2 ... 7 % by using programmable controllers. When the density stratification reaches 7 %, the controller switches on the circulation pumps and circulates the drilling fluid between tanks which stand side by side. This increases the drilling fluid uniformity and helps to reduce the density stratification along the depth of the cargo tank. The process of additional circulation of the drilling fluid is rationally ensured until the density stratification reaches a value of 2 %. Fulfilment of the above-mentioned conditions will ensure that the drilling fluid maintains its operational properties and the energy consumption associated with the additional operation of the circulation pumps is minimised.

УДОСКОНАЛЕННЯ СИСТЕМИ ЗБЕРІГАННЯ ТА ЦИРКУЛЯЦІЇ БУРИЛЬНОЇ СУСПЕНЗІЇ НА СУДНАХ ТИПУ PLATFORM SUPPLY VESSEL

The system of storage and circulation of drilling fluid on Platform Supply Vessel class vessels is considered. It was experimentally established that for the transport time of 6 … 36 hours the stratification of the density of the drilling fluid by the depth of the cargo tank is 3.04 … 32.04 %. As a method that ensures minimal stratification of the density of the drilling fluid during its transportation, it is proposed to use additional X-shaped circulation of the drill slurry in the volume of adjacent cargo tanks. Studies have confirmed that the density stratification for the time period of 6 … 36 hours decreases to the range of 2.30 … 9.01 %. The integrated use of additional X-shaped circulation and simultaneous air supply to the bottom of the cargo tank provides a value of density stratification of 0.73 … 2.93 %.

포기조에서 산기관의 설치위치가 용존산소에 미치는 영향 연구

Currently, countries worldwide are trying to reduce greenhouse gases, and Korea also attempts to decrease industrial greenhouse gas emissions. Aeration is the most energy-demanding process in a sewage treatment facility. Improvements in the aeration process''s efficiency will significantly contribute to national goals and climate change response. We conduct the aeration performance test to derive the optimum conditions for the diffuser arrangement and its installation depth in the aeration tank. The ball-type diffusers are installed at about 1/3 level (900 mm below the water surface) and 2/3 level (1,800 mm below the water level) of the water tank. We observed the change in aeration tank dissolved oxygen (DO) concentration with the blown air volume and time. The average increase in DO concentration ranged from 1.13 mg/L to 1.73 mg/L when aeration was conducted at the middle of the aeration tank. In contrast, the average increase in DO concentration ranged from 0.52 mg/L to 1.04 mg/L when aeration devices were installed at the bottom of the aeration tank. These results indicated that installing diffusers in the middle depth of the aeration tank was more effective for oxygen delivery and power requirement. The average air power required to drive the DO between 0.5 mg/L and 3.0 mg/L for an hour is found as 0.42 kWh and 0.38 kWh for the bottom and middle part of the tank, respectively. The results show 9.5% energy saving for aeration in the middle. The results reveal that the lower the depth of the aeration diffuser installation, the better the oxygen delivery. Therefore, it will be possible to construct an aeration system with better energy efficiency when aeration diffusers are installed at low-water-depths.

Round Robin Testing: Exploring Experimental Uncertainties through a Multifacility Comparison of a Hinged Raft Wave Energy Converter

The EU H2020 MaRINET2 project has a goal to improve the quality, robustness and accuracy of physical modelling and associated testing practices for the offshore renewable energy sector. To support this aim, a round robin scale physical modelling test programme was conducted to deploy a common wave energy converter at four wave basins operated by MaRINET2 partners. Test campaigns were conducted at each facility to a common specification and test matrix, providing the unique opportunity for intercomparison between facilities and working practices. A nonproprietary hinged raft, with a nominal scale of 1:25, was tested under a set of 12 irregular sea states. This allowed for an assessment of power output, hinge angles, mooring loads, and six-degree-of-freedom motions. The key outcome to be concluded from the results is that the facilities performed consistently, with the majority of variation linked to differences in sea state calibration. A variation of 5–10% in mean power was typical and was consistent with the variability observed in the measured significant wave heights. The tank depth (which varied from 2–5 m) showed remarkably little influence on the results, although it is noted that these tests used an aerial mooring system with the geometry unaffected by the tank depth. Similar good agreement was seen in the heave, surge, pitch and hinge angle responses. In order to maintain and improve the consistency across laboratories, we make recommendations on characterising and calibrating the tank environment and stress the importance of the device–facility physical interface (the aerial mooring in this case).

Evaluating the performance of fine bubble diffused aeration systems in cylindrical aeration tanks by fuzzy c-means algorithm.

In order to make a comprehensive evaluation of the performance of fine bubble diffused aeration systems in cylindrical aeration tanks, the following parameters are considered: distribution of DO concentration in the horizontal direction of the different water depth of an aeration tank, distribution of DO concentration in the vertical direction of the aeration tank, distribution of DO concentration in all the points of the aeration tank and ratio of total mass increment of DO in the aeration tank to total mass of oxygen in aeration air. The aeration characteristic criterion (ACC) is proposed to synthesize these parameters, and weighted sums of the similarity degrees derived from the extensions of fuzzy c-means (FCM) are used to construct ACC. The results show that compared with total volumetric oxygen transfer coefficient (KLα) and specific standard oxygen transfer efficiency (SSOTE), ACC is demonstrated to be more marked and sensitive for the performance evaluation of the fine bubble diffused aeration systems equipped with fine-pore aeration tubes. Moreover the performance of aeration systems equipped with different layouts of fine-pore aeration tubes is comparatively studied, and their performance from best to worst is ring-type diffuser > square-type diffuser > parallel-lines-type diffuser > cross-type diffuser.

An experimental sedimentation tank for enhancing the settling of solid particles

Sedimentation tanks have a vital role in the overall efficiency of solid particles removal in treatment units. Therefore, an in-depth study these tanks is necessary to ensure high quality of water and increasing the system efficiency. In this work, an experimental rectangular sedimentation tank has been operated with and without a baffle to investigate the system behaviour and effectiveness for the reduction of solid particles. Turbid water was prepared using clay, which was collected from the water treatment plant of Al Maqal Port (Iraq), mixed with clear water in a plastic supply tank. Raw and outflow samples were tested against turbidity after plotting a calibration curve between inflow suspended solids versus their corresponding turbidity values. The key objective was to assess the impact of different flow rates, particle concentrations, heights and positions of the baffle on the system efficiency. Findings showed that the tank performance was enhanced significantly (p < 0.05) with the use of a baffle placed at a distance of 0.15 of tank length with height equal to 0.2 of tank depth. Higher removal efficiency (91%) was recorded at a lower flow rate (0.015 dm3∙s–1) and higher concentration (1250 mg∙dm–3), as the treatment efficiency enhanced by 34% compared with the operation without a baffle. Placing the baffle in the middle of the sedimentation tank produced the worst results. System efficiency for solids removal reduced with increasing baffle height. Further research is required to evaluate the efficiency of an inclined baffle.

An efficient new assay for measuring zebrafish anxiety: Tall tanks that better characterize between-individual differences

BackgroundZebrafish (Danio rerio) are increasingly being used to model anxiety. A common behavioral assay employed for assessing anxiety-like behaviors in zebrafish is the “novel tank test”. We hypothesized that using deeper tanks in this test would result in greater between-individual variation in behavioral responses and a more ‘repeatable’ assay. New methodsAfter mapping the literature and identifying common behavioral parameters used in analysis, we performed novel tank anxiety tests in both custom-designed ‘tall’ tanks with increased depth and ‘short’ trapezoidal tanks. We compared the repeatability of the behavioral parameters between tall and short tanks and also investigated sex differences. ResultsOverall, regardless of tank depth, almost all behavioral parameters associated with anxiety in zebrafish were significantly repeatable (R = 0.24 to 0.60). Importantly, our tall tanks better captured between-individual differences, resulting in higher repeatability estimates (average repeatability tall tanks: R = 0.46; average repeatability short tanks: R = 0.36) and clearer sex differences. ConclusionsOur assay using tall tanks has advantages over tests based on short tanks which underestimate repeatability. We argue that use of deeper tanks will improve the reliability of behavioral data across studies using novel tank tests for zebrafish. Our results also call for increased attention in designing the most appropriate assay in biomedical and behavioral sciences as current methods may lack the sensitivity to detect subtle, yet important, information, such as between-individual variation, an important component in assessing the reliability of behavioral data.