Spherical Water Research Articles

Verification of mean dose in a tumor using 3D-printed tumor-model scintillators in anthropomorphic phantoms and a spherical phantom

To enhance treatment outcomes of radiotherapy, accurate verification of dosimetric parameters such as the mean, minimum, and maximum doses is essential. This study aimed to measure the mean absorbed dose in a tumor-shaped target and compare the results with the calculated value of the treatment planning system. Tumor model scintillators (TMSs) mimicking brain tumors were fabricated with a commercial 3D printer based on stereolithography files of tumors. The TMSs were irradiated following treatment plans made with the Leksell Gamma Plan® (Elekta AB, Stockholm, Sweden), and the mean dose in each TMS was measured three times and compared with the calculated value. Eleven TMSs were set at the center of a spherical solid water phantom. Two additional TMSs were fabricated according to images of vestibular schwannomas and were set at the tumor location in head model phantoms following each patient's head shape. The mean relative differences between the measured and calculated mean doses were less than one percent. This method provides an independent parameter for evaluating the accuracy of the treatment planning system.

Monte Carlo-based dosimetry of proposed bi-radionuclide (125I and 106Ru/106Rh) eye plaque: A feasibility study.

Combining the sharp dose fall off feature of beta-emitting 106Ru/106Rh radionuclide with larger penetration depth feature of photon-emitting125I radionuclide in a bi-radionuclide plaque, prescribed dose to the tumor apex can be delivered while maintaining the tumor dose uniformity and sparing the organs at risk. The potential advantages of bi-radionuclide plaque could be of interest in context of ocular brachytherapy. The aim of the study is to evaluate the dosimetric advantages of a proposed bi-radionuclide plaque for two different designs, consisting of indigenous 125I seeds and 106Ru/106Rh plaque, using Monte Carlo technique. The study also explores the influence of other commercial 125I seed models and presence or absence of silastic/acrylic seed carrier on the calculated dose distributions. The study further included the calculation of depth dose distributions for the bi-radionuclide eye plaque for which experimental data are available. The proposed bi-radionuclide plaque consists of a 1.2-mm-thick silver (Ag) spherical shell with radius of curvature of 12.5mm, 20µm-thick-106Ru/106Rh encapsulated between 0.2mm Ag disk, and a 0.1-mm-thick Ag window, and water-equivalent gel containing 12 symmetrically arranged 125I seeds. Two bi-radionuclide plaque models investigated in the present study are designated as Design I and Design II. In Design I, 125I seeds are placed on the top of the plaque, while in Design II 106Ru/106Rh source is positioned on the top of the plaque. In Monte Carlo calculations, the plaque is positioned in a spherical water phantom of 30cm diameter. The proposed bi-radionuclide eye plaque demonstrated superior dose distributions as compared to 125I or 106Ru plaque for tumor thicknesses ranges from 5 to 10mm. Amongst the designs, dose at a given voxel for Design I is higher as compared to the corresponding voxel dose for Design II. This difference is attributed to the higher degree of attenuation of 125I photons in Ag as compared to beta particles. Influence of different 125I seed models on the normalized lateral dose profiles of Design I (in the absence of carrier) is negligible and within 5% on the central axis depth dose distribution as compared to the corresponding values of the plaque that has indigenous 125I seeds. In the presence of a silastic/acrylic seed carrier, the normalized central axis dose distributions of Design I are smaller by 3%-12% as compared to the corresponding values in the absence of a seed carrier. For the published bi-radionuclide plaque model, good agreement is observed between the Monte Carlo-calculated and published measured depth dose distributions for clinically relevant depths. Regardless of the type of 125I seed model utilized and whether silastic/acrylic seed carrier is present or not, Design I bi-radionuclide plaque offers superior dose distributions in terms of tumor dose uniformity, rapid dose fall off and lesser dose to nearby critical organs at risk over the Design II plaque. This shows that Design I bi-radionuclide plaque could be a promising alternative to 125I plaque for treatment of tumor sizes in the range 5 to 10mm.

Mass Transfer during Boric Acid Dissolution

The process of mass transfer during the dissolution of boric acid spheres in water was investigated in the temperature range from 293 K to 323 K, and at stirring rotation rates from 1.67 to 6.67 s-1. The study aimed to determine the dependence of the dissolution rate on the stirring rotation rate and water temperature. The analysis of the experimentally obtained results revealed that the most significant factor affecting the intensification of the dissolution process is an increase in the solution temperature. The phenomena of external and internal diffusion during the dissolution of boric acid spheres in water under agitation were also examined. To evaluate the mass transfer process, a generalized criterion equation was used that takes into account all the factors under study. Comparison of experimental and theoretically calculated values showed that the maximum absolute relative error does not exceed 6%. The results obtained are valuable for further research and potential applications in the chemical industry, pharmacology, and cosmetology.

Small, Fluorinated Mn2+ Chelate as an Efficient 1H and 19F MRI Probe.

We explore the potential of fluorine-containing small Mn2+ chelates as alternatives to perfluorinated nanoparticles, widely used as 19F MRI probes. In MnL1, the cyclohexanediamine skeleton and two piperidine rings, involving each a metal-coordinating amide group and an appended CF3 moiety, provide high rigidity to the complex. This allows for good control of the Mn-F distance (rMnF=8.2±0.2 Å determined from 19F relaxation data), as well as for high kinetic inertness (a dissociation half-life of 1285 h is estimated for physiological conditions). The paramagnetic Mn2+ leads to a ~150-fold acceleration of the longitudinal 19F relaxation, with moderate line-broadening effect, resulting in T2/T1 ratios of 0.8 (9.4 T). Owing to its inner sphere water molecule, MnL1 is a good 1H relaxation agent as well (r1=5.36 mM-1 s-1 at 298 K, 20 MHz). MnL1 could be readily visualized in 19F MRI by using fast acquisition techniques, both in phantom images and living mice following intramuscular injection, with remarkable signal-to-noise ratios and short acquisition times. While applications in targeted imaging or cell therapy monitoring require further optimisation of the molecular structure, these results argue for the potential of such small, monohydrated and fluorinated Mn2+ complexes for combined 19F and 1H MRI detection.

Small, Fluorinated Mn2+ Chelate as an Efficient 1H and 19F MRI Probe

AbstractWe explore the potential of fluorine‐containing small Mn2+ chelates as alternatives to perfluorinated nanoparticles, widely used as 19F MRI probes. In MnL1, the cyclohexanediamine skeleton and two piperidine rings, involving each a metal‐coordinating amide group and an appended CF3 moiety, provide high rigidity to the complex. This allows for good control of the Mn−F distance (rMnF=8.2±0.2 Å determined from 19F relaxation data), as well as for high kinetic inertness (a dissociation half‐life of 1285 h is estimated for physiological conditions). The paramagnetic Mn2+ leads to a ~150‐fold acceleration of the longitudinal 19F relaxation, with moderate line‐broadening effect, resulting in T2/T1 ratios of 0.8 (9.4 T). Owing to its inner sphere water molecule, MnL1 is a good 1H relaxation agent as well (r1=5.36 mM−1 s−1 at 298 K, 20 MHz). MnL1 could be readily visualized in 19F MRI by using fast acquisition techniques, both in phantom images and living mice following intramuscular injection, with remarkable signal‐to‐noise ratios and short acquisition times. While applications in targeted imaging or cell therapy monitoring require further optimisation of the molecular structure, these results argue for the potential of such small, monohydrated and fluorinated Mn2+ complexes for combined 19F and 1H MRI detection.

Computational study on the impact of geometric parameters on the overall efficiency of multi-branch channel heat sink in the solar collector

Enhancing the thermal performance of electronic devices is a persistent challenge. Liquid-cooled Multi-branch-channel heat sinks (MBCHSs) offer a promising solution. The present study focuses on optimizing MBCHS hydrothermal efficiency and temperature uniformity. Various MBCHSs, including a foundational case and cases denoted as 1 through 4, have been developed to assess the impact of geometric parameters on performance. Using a performance evaluation criterion (PEC), it quantitatively assesses hydrothermal improvements in each model. Additionally, this study explores the use of a water-based ternary hybrid nanofluid (THNF) with GO-Al2O3-ZnO ternary hybrid nanoparticles in an optimized multi-branch channel. Furthermore, an analysis and generation of entropy were examined. The COMSOL software has been employed for the simulation of the problem in this study. This promising fluid replacement for pure water demonstrates superior performance and temperature control. The findings indicate that among the various cases, case 2 exhibits the highest PEC. At Reynolds number 500, the optimal MBCHS geometry (case 2) featuring THNF with a volumetric fraction of 0.06 exhibits a 16.63% higher Heat Transfer Coefficient (HTC) compared to pure water. In contrast, MBCHS, with the same volumetric fraction, demonstrates a 29.82% lower Nusselt number. Contrastingly, at a volumetric fraction of 0.06, MBCHS displays a pressure drop 70.27% higher than that of pure water. Overall, the PEC of MBCHS with a volumetric fraction of 0.06 has decreased by 41% compared to pure water. At Reynolds number 500, lamina-shaped nanoparticles exhibit a 50.34% and 56.56% higher HTC in comparison to spherical and pure water, respectively. Moreover, the PEC for lamina-shaped nanoparticles at Reynolds 500 undergoes a 49.58% and 62.37% reduction when compared to spherical and pure water, respectively.

Water entry of a sphere moving along a circular path at a constant speed

When a marine propeller rotates in partially submerged conditions, air is entrained from above the undisturbed free-surface, which is called the reference surface, and the ventilated air surrounds the propeller blades, causing thrust loss and excessive vibration, all of which seriously damage the durability of the propeller shaft system of a ship. In the present study, the entry of a propeller blade is simplified by the water entry problem of a sphere moving along a circular path at a constant speed. A high-speed camera was employed to capture the rapidly changing flow structures in detail. Above the reference surface, we focused on the free-surface disturbances, including splash and dome formation. Beneath the reference surface, the development and collapse of ventilated cavities, followed by the line-vortex cavity and cavity undulation, were observed. The ventilated cavity of the present study appears to be more elongated than those of the free-falling sphere's water entry experiments. Two parallel vortical structures appeared after the cavity pinch-off, and bubbles were entrained into these structures to form the line-vortex cavity. The sphere's drag was directly measured via the torque meter attached to the sphere's rotating axis. The relation between the measured drag and the flow around the sphere was identified.

Evaluating deposited radiation energy amount and collision quantities of small-molecule radiosensitizers through Monte Carlo simulations

This study investigates the photon interaction mechanism of various small molecule radiosensitizers, including Hydrogen Peroxide, Nimorazole, 5-Fluorouracil, NVX-108, and others, using the MCNP 6.3 Monte Carlo simulation code. The simulations focused on quantifying the linear attenuation coefficients, mean free path, and accumulation factors of these radiosensitizers, as well as their interactions in a simulated spherical water phantom irradiated with a 100 keV mono-energetic X-ray source. Our findings reveal significant variations in deposited energy, collision events, and mean free path among the radiosensitizers, indicating different efficacy levels in enhancing radiation therapy. Notably, NVX-108 demonstrated the highest energy deposition, suggesting its potential as a highly effective radiosensitizer. The study also examined the individual attenuation properties of these radiosensitizers against energetic photons, with NVX-108 showing the highest attenuation coefficient and a shorter mean free path, further supporting its superior potential in effective radiosensitization. It can be concluded that NVX-108 has higher interaction tendency with the energetic photons comparing other small-molecules under investigation.

Calculation method for novel upright CT scanner isodose curves.

A computational method based on Monte-Carlo calculations is presented and used to calculate isodose curves for a new upright and tilting CT scanner useful for radiation protection purposes. The TOPAS code platform with imported CAD files for key components was used to construct a calculation space for the scanner. A sphere of water acts as the patient would by creating scatter out of the bore. Maximum intensity dose maps are calculated for various possible tilt angles to make sure radiation protection for site planning uses the maximum possible dose everywhere. The resulting maximum intensity isodose lines are more rounded than ones for just a single tilt angle and so closer to isotropic. These maximum intensity curves are closer to the isotropic assumption used in CTDI or DLP based methods of site planning and radiation protection. The isodose lines are similar to those of a standard CT scanner, just tilted upwards. There is more metal above the beam that lessens the dose above versus below isocenter. Aside from the orientation, this upright scanner is very similar to a typical CT scanner, and nothing different for shielding needs to be done for this new upright tilting CT scanner, because an isotropic scatter source is often assumed for any CT scanner.

Evaluation of radiation detectors for the determination of field output factors in Leksell Gamma Knife dosimetry using 3D printed phantom inserts

The Leksell Gamma Knife® Perfexion™ and Icon™ have a unique geometry, containing 192 60Co sources with collimation for field sizes of 4 mm, 8 mm, and 16 mm. 4 mm and 8 mm collimated fields lack lateral charged particle equilibrium, so accurate field output factors are essential. This study performs field output factor measurements for the microDiamond, microSilicon, and RAZOR™ Nano detectors.3D printed inserts for the spherical Solid Water® Phantom were fabricated for microDiamond detector, the microSilicon unshielded diode and the RAZOR™ Nano micro-ionisation chamber. Detectors were moved iteratively to identify the peak detector signal for each collimator, representing the effective point of measurement of the chamber.In addition, field output correction factors were calculated for each detector relative to vendor supplied Monte Carlo simulated field output factors and field output factors measured with a W2 scintillator. All field output factors where within 1.1 % for the 4 mm collimator and within 2.3 % for the 8 mm collimator.The 3D printed phantom inserts were suitable for routine measurements if the user identifies the effective point of measurement, and ensures a reproducible setup by marking the rotational alignment of the cylindrical print. Measurements with the microDiamond and microSilicon can be performed faster compared to the RAZOR™ Nano due to differences in the signal to noise ratio. All detectors are suitable for field output factor measurements for the Leksell Gamma Knife® Perfexion™ and Icon™.

Scale-Resolving Simulation of Shock-Induced Aerobreakup of Water Droplet

Two different scale-resolving simulation (SRS) approaches to turbulence modeling and simulation are used to predict the breakup of a spherical water droplet in air, due to the impact of a traveling plane shock wave. The compressible flow governing equations are solved by means of a finite volume-based numerical method, with the volume-of-fluid technique being employed to track the air–water interface on the dynamically adaptive mesh. The three-dimensional analysis is performed in the shear stripping regime, examining the drift, deformation, and breakup of the droplet for a benchmark flow configuration. The comparison of the present SRS results against reference experimental and numerical data, in terms of both droplet morphology and breakup dynamics, provides evidence that the adopted computational methods have significant practical potential, being able to locally reproduce unsteady small-scale flow structures. These computational models offer viable alternatives to higher-fidelity, more costly methods for engineering simulations of complex two-phase turbulent compressible flows.

Dynamic Surface Tension of a Charged Spherical Water Droplet

Dynamic Surface Tension of a Charged Spherical Water Droplet

Structural analysis and optimal design of a spherical thin-walled stainless steel water tank without reinforced tie ribs

A spherical thin-walled stainless steel water tank without reinforced tie ribs has been designed to address the issues of easy fracture and corrosion of the ribs, difficulty in maintenance and cleaning, and short service life exposed during the use of thin-walled stainless steel water tanks with reinforced tie ribs. Firstly, an analytical model of a flat steel thin-walled water tank without reinforced tie ribs was established and subjected to static analysis under water pressure. The deformation and stress distribution patterns of the side molded plate of the flat box were obtained. Secondly, a spherical non ribbed thin-walled stainless steel water tank structure was designed with circular cross-section under different box bulge parameters, and its mechanical response characteristics under water pressure load were analyzed. A strengthening scheme was designed for the bottom box molded plate. Once again, optimize the combination design of the box scheme and the reinforcement scheme, and analyze their static, thermodynamic, and thermal solid coupling performance. Finally, the Latin Hypercube Sampling method was used to generate experimental design samples, and a response surface approximation model of a spherical thin-walled stainless steel water tank without reinforced tie ribs was constructed. The wall thickness of the box molded plate, skeleton, and reinforcement were used as design variables, and the maximum deformation and maximum equivalent stress were used as constraints. The lightweight design was carried out with the goal of minimizing mass. The research results indicate that the design program and parameter selection method for spherical thin-walled stainless steel water tanks without reinforced tie ribs proposed in the article are efficient and feasible, and can provide technical reference and theoretical support for the layout and overall optimization design of non ribbed thin-walled stainless steel water tank structures.

Absorption spectrum of magnetically structured emulsions in the centimeter range

The high degree of absorption of microwave radiation by composite materials with developed morphology can be significantly improved by directly changing the geometrical parameters of the subwavelength structure, which is difficult in the case of solid-state materials. In this work, a new composite liquid material with controlled absorption properties, a magnetodielectric emulsion, is investigated. The control of microgeometry parameters is accomplished through exposure to a magnetic field. The experimental studies have shown that the formation of chain structures from spherical water droplets in the composite leads to a significant change in the absorption coefficient. Thus, for an emulsion with 10% water content, exposure to a magnetic field of 25 kA m−1 increases the absorption coefficient by 400% at a radiation frequency of 10 GHz. It is noteworthy that the efficiency of the absorption properties control depends on the volume concentration of droplets in the sample and has a non-monotonic character. To interpret the obtained results, numerical modeling of the studied system in the effective medium approximation was carried out.

Treatment of tannery effluent: An effective biological enhancement approach

AbstractThe water pollution due to tannery industries that contaminate river water and other spheres, is a side effect of industry expansion. The research focused on the biological removal of synthetic azo dyes by using biological treatment under aerobic conditions. Through morphological observation, biochemical test, and 16S rRNA sequence analysis the isolated bacteria were determined to be Aeromonas caviae, Enterobacter sichuanensis. Reduction of the organic content present in the tannery effluent and removal of the nutrients that cause pollution or inactivate potential pathogenic microorganisms or parasites. Optimized the azo dye degradation conditions at the temperature of 37°C, at pH 7 in 10% inoculum concentration at the time of 48th hour where novel organism capable of performing effective degradation. The metabolite of an aliquot mixture of the optimized condition was analyzed using Fourier Transform Infrared (FTIR) and the results confirmed the reduction of azo dyes. These results indicate that A. caviae and E. sichuanensis can be utilized as a solution for the remediation of tannery industrial effluent containing azo dyes.

Isothermal compressibility, internal pressure studies of aqueous rare earth nitrate solutions at 298.15 K: An attempt to estimate ionic radii and understand inner– and outer–sphere exchange water structural interactions

In this communication, we report our analysis and results concerning the determination of ionic radii in aqueous solution phase for Lanthanum (La+3), Neodymium (Nd+3), Erbium (Er+3) and Ytterbium (Yb+3) ions in presence of nitrate (NO3-) anion at 298.15 K. The literature data for density, adiabatic compressibility, and specific heat capacity of solutions at constant pressure have been used to compute isothermal compressibility, internal pressure of solutions in limiting concentration range. The apparent molar isothermal compressibility of electrolytes and hydration numbers have been obtained. The electrostriction for rare earth cations and intrinsic volumes have been calculated using thermodynamic equations. The ionic radii of cations have been obtained using the ionic partial molar volume data of NO3- ions and the results are compared with those obtained for rare earth chlorides. The two series affect is also observed for ionic radii and internal pressure. The results have been explained on the basis of water structural effects due to electrostatic field and water dipole interaction between the inner– and outer–sphere water exchange reaction.

Optimal blade design of a spherical water turbine

The use of in-pipe water turbines for small-scale energy harvesting from pipe networks is starting to gain popularity. However, limited research have looked into whether adding helical blade turbines would be feasible with a spherical lift base in a water supply network. Three Naca airfoil (0012, 2412, 4412) were used to study the ratio of lift to drag force for each wing, Benefit from Qblade and ANSYS CFX software, and choosing the wing that has the highest ratio. The study investigates the feasibility of improving the design of spherical turbine blades by increasing the ratio of lift to drag. The results show that the Naca airfoil 4412 had the highest lift-to-drag force ratio, which was equal to 19.95. Through the improvement process for the Naca 4412 airfoil, the increase was made by 13.34 %, and the lift-to-drag ratio became 22.61. The study also dealt with the design of a turbine through the improved airfoil. 230 mm. It has the engineering characteristics of the number of helical blades, 5, The measurement of the blade's length chord 15 % of the turbine diameter, and the Angle of Attack, 9.5°

Effect of the Turbulence Model on the Computational Results of a Lucid Spherical Rotor

Due to the excessive increase in the energy demand, renewable energy has become an alternative for electricity production for industrial and domestic needs. Water energy has received significant investment as a sustainable and clean energy source. Lucid spherical rotors, a kind of hydro-power converter, are cross flow rotors designed to be mounted within a pipeline in order to gather excess energy available in gravity-fed water pipelines. This paper focuses on the effect of the numerical model parameters choice, namely the turbulence model, on the Lucid spherical rotor hydrodynamic characteristics. Numerical simulations were carried out through Ansys Fluent software 17.0 using the unsteady Reynolds-Averaged Navier-Stokes (URANS) equations. Four turbulence models: RNG k-ε, Realizable k-ε, SST k-ω and transition SST were tested. Performance characteristics in terms of torque and power coefficients in addition to hydrodynamic features of the flow around the considered rotor were analyzed. The adopted numerical model was validated based on previous experimental findings from the literature. It was found that the realizable k-ε model showed a good agreement with experimental results. Thus, it was adopted for the Lucid spherical rotor simulation. The obtained findings could provide further direction for researchers to use the Lucid spherical water turbine.

Decoration of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) with N-oxides increases the T1 relaxivity of Gd-complexes.

High complex stability and longitudinal relaxivity of Gd-based contrast agents are important requirements for magnetic resonance imaging (MRI) because they ensure patient safety and contribute to measurement sensitivity. Charged and zwitterionic Gd3+-complexes of the well-known chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) provide an excellent basis for the development of safe and sensitive contrast agents. In this report, we describe the synthesis of DOTA-NOx, a DOTA derivative with four N-oxide functionalities via "click" functionalization of the tetraazide DOTAZA. The resulting complexes Gd-DOTA-NOx and Eu-DOTA-NOx are stable compounds in aqueous solution. NMR-spectroscopic characterization revealed a high excess of the twisted square antiprismatic (TSAP) coordination geometry over square antiprismatic (SAP). The longitudinal relaxivity of Gd-DOTA-NOx was found to be r1=7.7 mm-1 s-1 (1.41 T, 37 °C), an unusually high value for DOTA complexes of comparable weight. We attribute this high relaxivity to the steric influence and an ordering effect on outer sphere water molecules surrounding the complex generated by the strongly hydrated N-oxide groups. Moreover, Gd-DOTA-NOx was found to be stable against transchelation with high excess of EDTA (200 eq) over a period of 36 h, and it has a similar in vitro cell toxicity as clinically used DOTA-based GBCAs.

Sustainable and clean water distillation by parabolic dish collector and different heat absorber and thermal storage materials: An experimental study

In this study, an integrated solar distillation unit with a parabolic dish collector and a spherical solar water distillation unit is designed. The use of parabolic dish collector increases the evaporation rate of the saltwater in the lower chamber (basin) of the spherical distillation unit considerably. The performance of solar water distillation system is investigated for different types of basin material, including copper, zinc, and iron. In the second part, the gravel is used in the copper basin of solar distillation system as the thermal energy storage material. The thermal efficiency, water productivity, exergy efficiency, and freshwater production cost of the integrated solar distillation system with different types of basin materials are studied. The thermal efficiency of the integrated solar distillation system with the copper, zinc, and iron basins was 13.97 %, 10.72 %, and 9.88 %%, respectively. The water productivity of the integrated solar distillation system with copper, zinc, and iron basins was 2.592 kg, 2.27 kg, and 1.825 kg, respectively during 9 h of experiment. The exergy efficiency of the integrated solar distillation system with the copper basin was better than the zinc and iron basins. The gravel can increase the productivity of solar distillation system up to three times in the sunset and night hours.