End Of Tank Research Articles

Field flattening concepts for linac cavities of the cross-bar H type

The development of cross-bar H-type cavities (CH-DTL, H21 mode) is ongoing to improve the technology of this attractive type of drift tube linac (DTL). In comparison with the conventional DTL, the H-type cavities can reach a higher effective field gradient and are competitive in shunt impedance at an energy range up to 100 A MeV. H-mode DTL’s profit in shunt impedance additionally when applying the KONUS beam dynamics. They are in use at research laboratories as well as at hospitals. This paper describes a new concept to approach the zero mode in CH-type cavities, by extending the cavity diameter at the tank ends in combination with tilted drift tube stems. RFQs of the four-vane type are operated as well in the H210 mode and the strategy for voltage flattening can be partly applied there too if conventional vane undercuts are causing problems. Up to around 35 MeV, it is attractive to integrate one or more triplet lenses into each cavity, as one KONUS section is relatively short and would not exploit the full rf power of 3 MW klystrons which are available above 300 MHz. Such a cavity is denoted as a coupled CH-cavity CCH. Three possible arrangements of those internal triplet lenses are discussed and are compared to each other. The operating modes as well as higher modes are then compared with a lens-free CH cavity, where the lens position was filled by ordinary drift tubes. As a result, it is shown that the rf behavior and resonance frequency for the higher harmonics of the frequency band are very similar for all four investigated arrays. This means, that the tuning behavior of the CCH cavity can be simply deduced from the lens-free CH cavity by replacing an even number of ordinary drift tubes (nβλ) with a lens-containing drift tube with adequate length and large outer diameter. This large drift tube itself oscillates like an Alvarez-type drift tube. rf simulations on a 30-gap CH cavity show that the reduction in shunt impedance is about 10% when installing a lens with length 2 beta lambda. Published by the American Physical Society 2024

Nonlinear Multimodal Model for Tuned Sloshing Dampers With Nonflat Bottoms

Abstract A third-order nonlinear multimodal model is developed for tanks with nonflat bottoms. A six-node finite element model is used to determine the mode shapes of the velocity potential and the associated natural sloshing frequencies. Using this modal information, equations of motion are developed that accommodate the nonlinear coupling among the first three sloshing modes. Damping arising from screens is incorporated into the model using the principle of virtual work. The equations of motion are ordinary differential equations that are solved using the Runge–Kutta–Gill numerical time-stepping method. The model is evaluated with an existing third-order nonlinear multimodal model for a flat-bottom tank and is found to be in excellent agreement. Demonstrative simulations are conducted for tanks with sloped-, boxed-, and ramped-bottoms. The resulting sloshing forces and wave heights at the tank end wall are calculated and presented using time series plots and frequency response plots. The excitation of higher-order sloshing modes through modal coupling results in larger wave heights, and shallower wave troughs. The sloshing forces are less impacted by the responses of higher modes. Secondary resonances are clearly visible in several frequency response plots at frequencies that correspond to the natural sloshing frequency of a higher-order mode divided by an integer. The model is applicable to tanks that are of intermediate water depth with moderate excitation amplitudes, where the response of the second- and third-order sloshing modes are less than the fundamental mode.

Compensation of longitudinal entrance and exit gap field effects in RFQ’s of the 4-ROD type

Abstract In case of 4-Rod-type RFQ’s the quadrupole electrodes are excited by a series of coupled RF oscillators. As the contact planes between both electrode pairs differ, there remains an oscillating electric potential along the beam axis. This results in remarkably high longitudinal field components between the electrode ends and the RFQ tank end walls. In contrast, the electrodes of a 4-Vane RFQ are equally charged to ± | V 0 ∕ 2 | and only feature a quadrupole on-axis field. The entrance gap fields were investigated to serve as a longitudinal prebuncher instead of causing additional longitudinal emittance growth. The effects of the entrance gap field have been validated in beam dynamics simulations. The exit fields have to be taken into consideration for a calculation of the exact RFQ output energy.

Irregular wave transmission on bottom bumps using fully nonlinear NURBS numerical wave tank

In this study, a fully nonlinear three-dimensional numerical wave tank (NWT) is developed to simulate propagation of nonlinear random sea wave over the bottom ripple patches. Evolution of the free surface is performed by the non-uniform rational B-spline formulation (NURBS) and the mixed Eulerian–Lagrangian method (MEL). A high-order boundary integral equation is used to solve the Laplace equation in the Eulerian frame. The free surface is updated by the material node method and the fourth-order Runge–Kutta time integration scheme. Appropriate numerical solutions are obtained by deploying damping zones at the both tank end walls. Also, the NURBS approximation is applied to compute the kinematics of the free surface particles. Propagation of the irregular waves in an NWT is conducted and compared with the available experimental and numerical data. Bragg reflection of the random sea wave due to bottom ripple patches are compared with the prior numerical studies. The fully nonlinear free surface evolution of transmitted spectrum due to presence of the hemispherical bumps is modeled successfully. Also fifth-order Stokes wave is applied as a strong nonlinear incident wave to interact with the hemispherical bottom bumps.

Vibration Analysis of Composite Horizontal Cylindrical Tank with Different Layering Using the Finite Element Method

This paper focuses on the vibration analysis of composite cylindrical tank. The purpose of this study is comparison of natural frequencies with different layering and different fiber angle along the x-axis of the tank. The boundary conditions of the tank are located at the beginning and the end of tank. The tank fixed along the coordinate system (y, z) and is free in x-axis. Stability equations derived using the first-order shear deformation theory. The effect of layering and fiber angle has evaluated by using the finite element package ANSYS. The angle considered between -90 to 90 degrees also 0 to 90 degrees for position of fibers along the thickness, which distributed in the form of symmetrical and asymmetric. Finally, the natural frequencies of the tank under the effect of layering of composite in radial direction compared. The results shown that the number of layers and fiber orientation affected on the natural frequencies.

Isotopic analysis of N2O produced in a conventional wastewater treatment system operated under different aeration conditions.

Dissolved oxygen (DO) concentration is a key parameter of nitrous oxide (N2O), a greenhouse gas, emitted from wastewater treatment systems. No study of stable isotopes has described N2O production during conventional activated sludge (CAS) treatment under different DO concentrations. Concentrations and isotope ratios, including intramolecular site preference of (15)N in NNO (SP), of N2O were measured using gas chromatography/isotope ratio mass spectrometry (GC/IRMS) for samples from seven points in a wastewater treatment plant (WWTP) operated with three aeration conditions. The δ(15)N values of NH4(+) and the δ(15)N and δ(18)O values of NO3(-) were measured using IRMS. Aeration tank water was supersaturated with N2O. The highest value, 3700 nmol kg(-1), was observed at the aeration tank end and in settled sludge under the lowest aeration condition. About 0.03% of the influent NH4(+) was emitted as gaseous N2O at the lowest aeration condition. The conversion rate was 0.14% under the highest aeration condition. The SP values were significantly higher at the middle and end of the aeration tanks under the highest aeration condition, but were nearly zero or slightly negative under lower aeration conditions. Under the highest aeration condition, NH2OH oxidation (nitrification) was the main contributor to N2O production at about 90% and 57%, respectively, at the aeration tank middle and end. At other sampling points, 55-63% of the N2O was produced by bacterial NO2(-) reduction (nitrifier-denitrification) with a lower nitrification contribution. For all sampling points in the lower aeration experiments, NO2(-) reduction was a major N2O production pathway.

A Study on Acclimation and Culture of Salt Tolerant Sludge

The inoculated sludge in this experimental system is from the end of aeration tank of the wastewater treatment plant. Under stable operation, the system’s treatments of COD and NH4+-N are all in line with Level One Urban Sewage Discharge stipulated by Pollutant Discharge Standards for Urban Sewage Treatment Plants (GB 18918-2002). The removal rates of COD and NH4+-N are 94.27% and 91.03%. By gradually improving the method of salinity acclimation, the salt tolerant sludge with outstanding performance can be successfully acclimated, and each gradual increase in salinity scope is controlled at around 4 g/L. When the salinity is 1%, the removal rates of COD and NH4+-N reach to 92.09% and 70.13%. The salinity has significant impacts on microbial activity. With the increase in salinity, the dehydrogenase activity gradually decreases. Salinity has significant effects on protozoa. Paramecia and nematodes can be taken as the biological indicator of outflow water quality of brine waste.

Water and energy nexus of residential rainwater tanks at an end use level: Case of Australia

Internationally, rain water tank systems have experienced a renaissance in urban areas in recent times as they are perceived to be a low cost source substitution option for many end uses or micro-components (e.g. toilet, clothes washer, irrigation, etc.) of water demand. While there are many studies that have been conducted investigating rainwater tank performance, none have explored their water-energy nexus at a micro-component level. Through a high resolution (i.e. 5 s, 0.014 L/pulse, 1 W/pulse) smart metering study, this research was able to reveal the energy intensity of three rainwater tank end uses in 19 residential homes located in Gold Coast City, Queensland, Australia. Half flush toilet cistern events were found to have the highest variability of energy intensity values between homes (1.05 to 3.32 Wh/L) and also the highest energy intensity at 1.88 Wh/L. Full flush toilet events had a tighter range (1.02 to 2.30 Wh/L) and slightly lower energy intensity than half flush events at 1.61 Wh/L. Clothes washer energy intensity values were quite variable (0.90 to 2.73 Wh/L) but on average were lower than toilet flushing at 1.28 Wh/L. Lastly, irrigation events had the tightest range (0.83 to

A comparison of patient specific dosimetric calculations obtained by planar images and Monte Carlo simulation in 111In octreotide therapy

s / Physica Medica 30 (2014) e16ee44 e29 phase, as a function of the mean value of administered activity per patient treated each week was also acquired. Results: 675 patients were treated through 2011-2013. Mean administered activity 113,5±31.8mCi. Tank’s filling phase:42±4days.Rest decay duration:63±3days. I-131 activity,T, at the end of tank’s filling phase is given by the formula: T1⁄45.6*Aavg,[mCi] whereas Aavg[mCi] is the average amount of administered activity during tank’s filling time period. Tvalues:560-835 mCi and average monthly concentration 0.13mCi/lt. In accordance with Greek legislation, maximum limit of discharge is 110MBq /day. Liquid samples collected at releasing time documented radioactive releases of I-131, equal to those derived from estimations, much below recommended levels of once release. During the above time period a tank’s operation was interrupted twice as a consequence of clogging. Graphs that depict the measurements beyond are also provided. Conclusions: Above real practice data may be useful for further studies of environmental radiation protection from liquid waste of patients undergoing I-131 therapy for thyroid cancer. Physicists, taking into consideration ALARA principle, economic and social factors, must design in advance, emergency plan assuring that, any individual’s exposure is kept to the minimum practicable, in case of system’s mulfunction. A COMPARISON OF PATIENT SPECIFIC DOSIMETRIC CALCULATIONS OBTAINED BY PLANAR IMAGES AND MONTE CARLO SIMULATION IN 111IN OCTREOTIDE THERAPY Maria Argyrou , Maria Andreou , Nefeli Lagopati , Irini Baka , Ioannis Vamvakas , Maria Lyra . Radiation Physics Unit, A’ Radiology Department, Kapodistrian University of Athens, Aretaieion Hospital, 76 Vas. Sophias Ave, Athens, Greece; Medical Physics Department, Iaso Hospital,

An Experimental Study on the Ballistic Impact Behavior of Non-Filled Tank against Fragment Simulating Projectile (FSP)

This paper presents the ballistic impact study for the non-filled aluminum tank. The objective was to determine the ballistic limit for front tank wall and rear tank wall. The tank was impacted with fragment simulating projectile (FSP) with various velocities range from 239 m/s up to 556 m/s. The aluminum tank was 3 mm thick, 150 mm wide and 750 mm long. The ends of tank were closed with two Polymethyl methacrylate (PMMA) windows which fixed to the tank with four steel bars. The test was conducted at the Science and Technology Research Institute for Defense (STRIDE) Batu Arang, Selangor. The results showed that the ballistic limit for the front tank wall and rear tank wall was 257.7 m/s and 481 m/s, respectively.

Effect of Ferric Chloride on the Properties of Biological Sludge in Co-precipitation Phosphorus Removal Process

This paper studied the effect of ferric chloride on waste sludge digestion, dewatering and sedimentation under the optimized doses in co-precipitation phosphorus removal process. The experimental results showed that the concentration of mixed liquid suspended solid (MLSS) was 2436 mg·L−1 and 2385 mg·L−1 in co-precipitation phosphorus removal process (CPR) and biological phosphorous removal process (BPR), respectively. The sludge reduction ratio for each process was 22.6% and 24.6% in aerobic digestion, and 27.6% and 29.9% in anaerobic digestion, respectively. Due to the addition of chemical to the end of aeration tank, the sludge content of CPR was slightly higher than that of BPR, but the sludge reduction rate for both processes had no distinct difference. The sludge volume index (SVI) and sludge specific resistance of BPR were 126 ml·g−1 and 11.7×1012 m·kg−1, respectively, while those of CPR were only 98 ml·g−1 and 7.1×1012 m·kg−1, indicating that CPR chemical could improve sludge settling and dewatering.

Numerical analysis of the hydroelastic behavior of a vertical plate due to solitary waves

Interactions of a vertical elastic plate with fully nonlinear water waves were simulated. Utilizing the mixed Eulerian Lagrangian method for the free-surface flow and the finite element method for the deflection of an elastic plate, a fully coupled scheme for accurately determining fluid–plate motions was developed. Using this scheme, some modifications to the solvers for both fluid and plate were made. A hybrid wave-absorbing beach was installed to prevent wave reflection from the end of the wave tank. A fourth-order Runge–Kutta time-marching scheme with a uniform time step was applied to achieve numerical stability. The method was validated by simulating the wave generated by the initial deformation of a vertical plate and comparing the result with the corresponding analytical solution. For further validation, the hydroelastic behavior of a vertical plate induced by a pulse-type wave (where the initial pulse-type elevation of the free surface is specified) was computed, and the result was compared with another numerical result from a mode-expansion method. The interaction of a surface-piercing plate with nonzero initial free surface was then simulated, and the result was compared with the corresponding linear analytical solution. Finally, the hydroelastic response of a surface-piercing vertical plate due to a solitary wave (generated by actuating the vertical plate at the right end of the tank only at the beginning) was computed and investigated systematically.

Inelastic impact dynamics of ships with one-sided barriers. Part II: experimental validation

This paper is the second part of a two-part study of impact interaction of a ship roll motion with one-sided ice barrier. The first part was devoted to analytical and numerical simulations for the case of inelastic impact. The analytical approach was based on Zhuravlev and Ivanov non-smooth coordinate transformations. Extensive numerical simulations were carried out for all initial conditions covered by the ship grazing orbit for different values of excitation amplitude and frequency of external wave-induced roll moment. The basins of attraction of safe operation revealed the coexistence of different response regimes such as non-impact periodic oscillations, modulated impact motion, period added impact oscillations, chaotic impact motion and roll-over dynamics. This part presents an experimental investigation conducted on a small ship model in a tow tank. In particular, the experimental tests reveal complex dynamic response characteristics such as multi-frequency wave motion caused by the wave reflection from the tank end wall. Measured results show a good agreement with the predicted results by for small angles of the barrier relative to the ship unbiased position. However, deviation becomes significant as the angle increases. This deviation is mainly attributed to the uncertainty of the coefficient of restitution, which is found to depend on the velocity of impact in addition to the geometry and material properties of the model and barrier.

Nonlinear analysis on wave-plate interaction due to disturbed vertical elastic plate

Hydroelastic behavior of wave-plate interaction due to an initial deflection of a vertical elastic plate is simulated by using a Mixed Eulerian Lagrangian method for the fluid and a Finite Element Method for the plate. An implicit boundary-condition method is developed to solve the coupled motions of fluid and plate. A hybrid wave absorbing beach is installed to prevent the wave reflection from a vertical wall at the end of the wave tank. The 4th order Runge-Kutta scheme with uniform time step is used for time marching. First, numerical results of the elastic vibration of a vertical plate induced by deformation of itself at initial time are validated by comparing with corresponding analytical solution. Then, further comparison between the results from mode-expansion method and FEM is made. Finally, the influences of the edge condition at the top of plate and the plate stiffness on the wave-plate interaction are investigated systematically.

LED 색광에 대한 살오징어의 행동반응

To study the behavioral reaction of common squid Todarodes pacificus, to different colors of LED light, individual distribution in the dark condition without LED light stimuli, individual distribution when four colors of light stimuli were at the sections of end and middle of water tank and the changes of gathering rates as the elapse of illuminating time were examined. When it was dark, the distribution of the fish in each section of the tank was U-shape regardless of the investigating time intervals, which means that Todarodes pacificus gathered at the both ends of the tank. The individual distribution when light stimuli were at the one end of the tank showed the tendency of gathering at the illuminated section and decreasing at the opposite section. There were 448 of them at the end of the tank when the light was blue, 352 when white, 302 when green and 132 when red. Thus the fish liked blue light the most, followed by white light. The variations of gathering rate at the both ends of tank as illuminating time elapsed showed the tendency of increasing at the light section (A section), however, it showed the tendency of decreasing at the darkest section (F section). The individual distribution showed the tendency of letter <TEX>$\wedge$</TEX> of gathering at the center and decreasing at the both ends mostly when the light stimuli were at the middle section of tank. The gathering rates at the lighting section were 80.4% when red, 76.4% when white, 69.6% when green and 56.7% when blue. The fishes showed the affinity for the red light mostly, followed by the white light source. The red light and blue light showed the opposite when the light stimuli were at the one end of water tank. The variations of gathering rates as the elapse of time at the lighted section showed the tendency of gradual increasing in the four light sources. The color of light source showing the highest gathering rate within 25-30 minutes of light stimuli was the white, followed by the red.

발광다이오드 빛에 대한 살오징어의 행동 특성

Squid jigging fishery is very important in that there are about 1,000 jigging vessels more than 10 tonnage and about 5,000 ones less than 10 tonnage in Korea. But the cost of oil which is used to light fishing lamps, goes significantly up to almost one hundred million won for 50 tonnage vessels and forty million won in case of vessels less than 10 tonnage. This cost has almost taken 40% of total fishing costs. That is, the fishing business condition of squid jigging fishery is recently in the very difficult situation. As oil price increases, the business condition of the fishery gets worse and worse. Therefore it is very urgent to develop an economical fishing lamp, to solve this problem of fishery`s business difficulty. This research aims at developing a fishing lamp for squid jigging fishery using the light emitting diode which has very excellent efficiency and durability. We made a water tank with 20 meters width which is a shape of raceway to research behavioral characteristics of Japanese flying squid to LED light, and made an experiment to investigate optimum wave of LED light to lure squid. The method is to establish LED lamps on both ends of water tank and to observe squid`s behavior. Colors and wave lengths of LED lamps, used in experiment, are red(634nm), yellow(596nm), green(523nm), blue(454nm) and white(454nm+560nm). In experiment for attractive capability of LED lamp to squids, Japanese flying squid are highly attracted to blue lamp and white lamp. However, they are dispersed to red and yellow lamps. In addition, Japanese flying squid have moved and stayed in both dark ends of water tank. When compared intermittent lamp with continuous lamp, Japanese flying squid are highly attracted to intermittent lamp when intermittent interval is 0.25 second.

Fundamental Characteristics of Electromagnetic Wave Propagation in Non-reflection Coaxial Waveguide (2) -Output Characteristics of UHF Sensor above Cut-off Frequency-

It is necessary to consider the TEM-mode, the higher TE and TM-mode and resonance phenomena in GIS to describe the propagation and detection characteristics for partial discharge measured with the UHF-method. Measurements on the non-reflection coaxial wave-guide simulating GIS were carried out with changing installation and shape of UHF sensor and wave-guide length. This paper describes the output characteristics of UHF sensor above cut-off frequencies, when reflection and resonance phenomena are taken into account. In the frequency region above the cut-off frequencies of the TE11 mode, the output characteristics of UHF sensor shows resonant by reason of the electromagnetic reflection of TE mode at the both ends of wave-guide. At the resonant frequency, the output characteristics of UHF sensor are different by wave-guide length, shape of sensor and sensor installation, distance from end of tank, angle at circumference. The resonant frequencies are function of tank-length and cut-off frequency of tank, and expressed with equation of cylindrical cavity resonator.

Determination of the Shape of the Ends of Steel Horizontal Cylindrical Tanks from Measurements of Their Geometric Parameters

The algorithm considered here determines the shape of a tank end from the measured values of its perimeter, diameter, and height. The results of calculations reported are used to choose the shape of a real tank end.

SECOND-ORDER WAVES IN A THREE-DIMENSIONAL WAVE BASIN WITH PERFECTLY REFLECTING SIDEWALLS

A complete second-order solution is presented for the three-dimensional wave field produced by the snake-like motion of an array of wave generators located at one end of a semi-infinite rectangular tank. The solutions to the boundary-value problems at first and second order are obtained by the method of eigenfunction expansions and are correct to second order in wave-maker stroke (wave amplitude). This frequency-domain solution may be considered as an extension of the earlier (1991) two-dimensional (narrow flume) solution of Hudspeth & Sulisz. Numerical results are presented that illustrate the influence of the various wave maker and basin parameters on the generated wave field.

EFFECTS OF A SEA FLOOR STEP ON WAVE DRIFT FORCE

A linear and a fully nonlinear numerical wave tanks (NWTs) were applied to study wave drift force acts on a two-dimensional Lewis form body in finite depth wave flume. These NWTs are based on potential theory and the fluid and floating body motions are directly simulated in time domain. Boundary value problems both on the velocity potential φ and its time derivative ∂φ/∂t are solved at each time step. The coupling condition between fluid and floating body is imposed as the implicit boundary condition of ∂φ/∂t on wetted body surface. The radiation condition at both tank ends are satisfied by artificial damping technique. Using these NWTs, effects of the floor step of the flume on wave drift force were studied. Measurement of wave drift force was also conducted in our two dimensional wave flume. In this report, the results of simulations and measurements are presented and the effect of the floor step on wave drift force is discussed.