scholarly journals Mechanistic insight on the sonolytic degradation of phenol at interface and bulk using additives

2017 ◽  
Vol 20 (2) ◽  
Author(s):  
Sarjerao Bapu Doltade ◽  
Vitthal L. Gole
Keyword(s):  
Liquid Medium ◽  
Experimental Studies ◽  
Theoretical Knowledge ◽  
Bubble Dynamic ◽  
Medium Temperature ◽  
Optimum Parameters ◽  
Mechanistic Insight ◽  
Effect Of Particle Size ◽  
Chloride Effect ◽  
Sonolytic Degradation

AbstractPresent work investigated the degradation of phenol based on theoretical knowledge of bubble dynamic and experimental studies. Optimum parameters of theoretical knowledge such as initial concentration of phenol: 1.1 mole/L; concentration of additive: 2 g/L; liquid medium temperature: 35°C and pressure of liquid medium: 101325 Pa were considered for the experimental study. The degradation was further explored in the presence of zinc oxide (effect of particle size), hydrogen peroxide (effect on hydroxyl radical concentration), and sodium chloride (effect of a change in liquid properties) and its effect on degradation of phenol. The degradation of phenol increased in the presence catalyst such as 0.61±0.013 moles L

scholarly journals A new method for determining allowable medium temperature during transient operation of thick-walled elements in a supercritical power plant

2010 ◽  
Vol 31 (3) ◽  
pp. 55-72
Author(s):  
Piotr Duda ◽  
Dariusz Rząsa
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
New Method ◽  
Optimum Operating ◽  
Transient Operation ◽  
Medium Temperature ◽  
Heating And Cooling ◽  
Optimum Parameters ◽  
Start Up ◽  
Working Parameters

A new method for determining allowable medium temperature during transient operation of thick-walled elements in a supercritical power plantConstruction elements of supercritical power plants are subjected to high working pressures and high temperatures while operating. Under these conditions high stresses in the construction are created. In order to operate safely, it is important to monitor stresses, especially during start-up and shut-down processes. The maximum stresses in the construction elements should not exceed the allowable stress limit. The goal is to find optimum operating parameters that can assure safe heating and cooling processes [1-5]. The optimum parameters should guarantee that the allowable stresses are not exceeded and the entire process is conducted in the shortest time. In this work new numerical method for determining optimum working parameters is presented. Based on these parameters heating operations were conducted. Stresses were monitored during the entire processes. The results obtained were compared with the German boiler regulations - Technische Regeln für Dampfkessel 301.

Fabrication of Efficient Electrodes for Dye-Sensitized Solar Cells Using Additive Manufacturing

2018 ◽  
Author(s):  
Sagil James ◽  
Rinkesh Contractor ◽  
Chris Veyna ◽  
Galen Jiang
Keyword(s):  
Solar Cells ◽  
Additive Manufacturing ◽  
Liquid Medium ◽  
Experimental Studies ◽  
Dye Sensitized Solar Cells ◽  
Light Condition ◽  
Small Scale ◽  
Dye Sensitized ◽  
Si Solar Cells ◽  
Sensitized Solar Cells

Dye-Sensitized Solar Cells (DSSC) are third generation solar cells used as an alternative to c-Si solar cells. DSSC are mostly flexible, easier to handle and are less susceptible to damage compared to c-Si solar cells. Additionally, DSSC is an excellent choice for indoor application as they perform better under diverse light condition. Most DSSCs are made of liquid medium sandwiched between two conductive polymer layers. However, DSSCs have significantly lower efficiencies compared to silicon solar cells. Also, use of liquid medium resulting in leaking of liquid, and occasional freezing during cold weather, and thermal expansion during hot weather conditions. DSSC can be manufactured in small quantities using relatively inexpensive solution-phase techniques such as roll-to-roll processing and screen printing technology. However, scaling-up the DSSC manufacturing from small-scale laboratory tests to sizeable industrial production requires better and efficient manufacturing processes. This research studies the feasibility of using additive manufacturing technique to fabricate electrodes of DSSC. The study aims to overcome the limitations of DSSCs including preventing leakage and providing more customized design. Experimental studies are performed to evaluate the effects of critical process parameters affecting the quality of electrodes for DSSC. Volume resistivity test is performed to evaluate the efficiency of the electrodes. In this study, the electrodes of DSSC are successfully fabricated using Fused Disposition Modeling (FDM) 3D printing technique. The results of this study would enable additive manufacturing technology towards rapid commercialization of DSSC technology.

scholarly journals Numerical Analysis and Experimental Studies on the Residual Stress of W/2024Al Composites

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2746 ◽  
Author(s):  
Guosong Zhang ◽  
Changhui Mao ◽  
Jian Wang ◽  
Ning Fan ◽  
Tiantian Guo
Keyword(s):  
Residual Stress ◽  
Numerical Analysis ◽  
Residual Stresses ◽  
Experimental Studies ◽  
High Strength ◽  
Radiation Shielding ◽  
X Ray Diffraction ◽  
Transfer Coefficients ◽  
Medium Temperature ◽  
Heat Transfer Coefficients

W/2024Al composites can be used for radiation shielding with desirable mechanical properties such as high strength, excellent corrosion resistance, and low density. The quench-induced residual stresses in W/2024Al composites were studied by experimental measurements and numerical analysis using ABAQUS software. Due to the accurate calculation of heat transfer coefficients and the established constitutive equation for description of the variation of yield stress at elevated temperature with different strain rates, the prediction of residual stresses in as-quenched composite blocks achieved by finite element method (FEM) is reliable. Moreover, X-ray diffraction and crack-compliance method were carried out to measure the stresses that developed at the surface and interior of the composites to validate the simulation results. Quenching residual stresses of composite blocks were investigated by taking the influence of quenching medium temperature into consideration. In addition, a comparative study on residual stress magnitudes of as-quenched 2024Al and W/2024Al composites was conducted, and the results show that stress magnitudes of W/2024Al composites are lower than that of 2024Al due to lower thermal gradients during the quenching process.

Comparative tests of quality of bacteriological investigation with Corynebacterium diphtheriae isolation

2021 ◽  
Vol 66 (8) ◽  
pp. 509-512
Author(s):  
O. Yu. Borisova ◽  
N. T. Gadua ◽  
A. S. Pimenova ◽  
A. P. Shepelin ◽  
L. V. Domotenko ◽  
...  
Keyword(s):  
Liquid Medium ◽  
Causative Agent ◽  
Bacterial Culture ◽  
Experimental Studies ◽  
Well Being ◽  
Corynebacterium Diphtheriae ◽  
Comparative Tests ◽  
The Third ◽  
Bacteriological Investigation

The results of comparative experimental studies of identification of nontoxigenic C. diphtheriae strain by three different commercial laboratories are presented. A typical nontoxigenic strain of C. diphtheriae biovar mitis was used. For the studies, three lines of ten-fold dilutions of bacterial culture were prepared, followed by control planting on the medium and counting CFU/ml. In the experiment, tampons were pooled with a 24-hour bacterial culture of a nontoxigenic C. diphtheriae strain. Tampons were provided from three different laboratories - ∑-Transwab® with Ames liquid medium (from the first and second laboratories) and a viscose tampon with coal medium (from the third laboratory). After pooled, tampons were delivered to commercial laboratories. And as a result of the experiment, Corynebacterium spp. was identified in first laboratory (103 CFU/tamp), S. epidermidis (102 CFU/ml) - in second laboratory and nontoxigenic C. diphtheriae biovar gravis - in third laboratory. The study indicates that there is a need to the supervision of bacteriological investigations conducted in various laboratories. This will improve the quality of investigations on diphtheria infection and identify of diphtheria carrier, which is a reservoir of the causative agent of diphtheria, and will contribute to the maintenance of sanitary and epidemiological well-being in our country.

Hyperfine interaction effects on the (1s2p)3P1–(1s2s)1S0 energy splitting in He-like ions for parity nonconservation studiesThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.

2011 ◽  
Vol 89 (1) ◽  
pp. 73-77 ◽  
Author(s):  
Fabrizio Ferro ◽  
Anton Artemyev ◽  
Andrey Surzhykov ◽  
Thomas Stöhlker
Keyword(s):  
Hyperfine Interaction ◽  
Hyperfine Structure ◽  
Nuclear Spin ◽  
Experimental Studies ◽  
Theoretical Knowledge ◽  
Energy Splitting ◽  
Parity Nonconservation ◽  
Opposite Parity ◽  
Atomic Systems ◽  
Dependent Part

Accurate theoretical knowledge of the (1s2p)3P1–(1s2s)1S0 splitting in He-like ions is demanded for future experimental studies of the nuclear spin-dependent part of the weak interaction. In this paper we perform a calculation of the hyperfine structure of (1s2p)3P1–(1s2s)1S0 within 3 ≤ Z ≤ 35, Z being the atomic number. In this Z range parity nonconservation (PNC) effects are amplified by the close energy proximity of the opposite parity levels (1s2p)3P1 and (1s2s)1S0. We find that the hyperfine structure is relevant for Z > 12, and produces splitting among the hyperfine sublevels as large as 150 meV for medium Z He-like ions (Z ∼ 35).

scholarly journals Plasma-electrolyte discharges in a gas-liquid medium for the production of hydrogen

2021 ◽  
Vol 23 (2) ◽  
pp. 27-35
Author(s):  
A. F. Gaysin ◽  
F. M. Gaysin ◽  
L. N. Bagautdinova ◽  
A. A. Khafizov ◽  
R. I. Valiev ◽  
...  
Keyword(s):  
Liquid Medium ◽  
Electric Discharge ◽  
Discharge Current ◽  
Experimental Studies ◽  
Gaseous Hydrogen ◽  
Constant Current ◽  
Industrial Plant ◽  
Dielectric Tube ◽  
Discharge Ignition ◽  
Production Of Hydrogen

THE PURPOSE. Comprehensive study of the effect of direct current electric discharge plasma in a gas-liquid medium of inorganic mixtures in order to obtain gaseous hydrogen. Obtain volt-ampere, volt-second and ampere-second characteristics of the discharge at various concentrations of electrolyte. Study the process of electrolysis, breakdown, discharge ignition and discharge flow in a dielectric tube at a constant current. METHODS. To solve this problem, experimental studies were carried out on a model installation, which consists of a power supply system, a discharge chamber, equipment for monitoring and controlling the operation of the installation and measuring the characteristics of an electric discharge. To analyze the stability of the discharge, the time dependences of the voltage ripple and the discharge current were obtained. RESULTS. Experimental studies were carried out between the electrolytic cathode and the electrolytic anode at constant current and at atmospheric pressure with the following parameters: discharge voltage U = 0.1-1.5 kV, discharge current I = 0.02-2.3 A, interelectrode distance l = 100 mm , 1%, 3% and 5% solutions of sodium chloride in tap water were used as electrolytes. CONCLUSION. It is shown that electrical breakdown and ignition of a discharge that is stable in time depends on the conductivity of the gas-liquid medium of the electrolyte. The nature of the current-voltage characteristics depends on the random processes occurring in the gas-liquid medium, which is associated with numerous breakdowns occurring in the gas-liquid medium of the electrolyte, combustion and attenuation of microdischarges, the appearance of bubbles, and the movement of the electrolyte inside the dielectric tube. It is shown that the generation of hydrogen and hydrogen-containing components can occur both at the stage of electrolysis and during discharge combustion. A feature of this method is that electrical discharges in the tube increase the release of hydrogen. In this installation, inorganic and organic liquids of a certain composition and concentration can be used. The results of experimental studies made it possible to develop and create a small-sized installation for producing gaseous hydrogen. Tests have shown that a small-sized plant can be taken as the basis for a industrial plant for the production of hydrogen gas.

scholarly journals Study of diffusion processes in pumpkin particles during candied fruits production

2017 ◽  
Vol 11 (4) ◽  
Author(s):  
V. Atamanyuk ◽  
I. Huzova ◽  
Z. Gnativ
Keyword(s):  
Diffusion Processes ◽  
Sucrose Concentration ◽  
Experimental Studies ◽  
Equilibrium Concentration ◽  
Raw Material ◽  
Transfer Coefficients ◽  
Medium Temperature ◽  
Sugar Syrup ◽  
Different Temperatures ◽  
Time Required

The production of candied fruits is a priority development area of the food industry. The basic process in candied fruits production is diffusion of sugar syrup into vegetable raw material. Kinetics of the diffusion processes depends on sucrose concentration, medium temperature, particles size and internal structure of the fruits.The experiments to determine the factors influencing the diffusion processes were carried out using the installation designed by the authors; the experimental dependences of sucrose concentration change in pumpkin candied fruits on time have been determined at temperatures of 20, 40, 60 and 80°C. Cell sizes and diameter of pores between the cells in raw and blanched pumpkin have been determined. This makes it possible to determine the internal porosity of the pumpkin particle, the value of which determines the coefficient of mass transfer.On the basis of the experiments we derived the dependence, allowing to determine the mass transfer coefficients for sucrose molecules in blanched pumpkin fruits within the temperatures corresponding to the quality of the finished product. The experimental studies and the chosen mathematical model allow us to calculate the change in sucrose concentration in the pumpkin fruits in time at different temperatures and to determine the time required for the candied fruits to reach the equilibrium concentration. Also, the coefficients not depending on temperature, but depending only on the shape of the particles being saturated with sugar syrup, have been determined using the kinetic model of diffusion processes. The obtained theoretical dependences are in good agreement with the experimental data and substantiate the expediency of the chosen temperature and concentration ranges. The designed installation, the obtained experimental and theoretical dependences, and the calculated coefficients allow to create an intensive sucrose diffusion process in pumpkin particles during pumpkin candied fruits production.

Experimental Studies on the Isothermal and Heat Transfer Performance of Trough Solar Power Collectors

2014 ◽  
Vol 1044-1045 ◽  
pp. 320-326 ◽  
Author(s):  
Yun Liu ◽  
Hong Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Thermal Power ◽  
Experimental Studies ◽  
Power Input ◽  
Working Fluid ◽  
Transfer Performance ◽  
Medium Temperature ◽  
Temperature Heat

The medium temperature heat pipe is a highly effective heat transfer element through heat exchange due to phase change of the liquid organic working fluid. A medium temperature heat pipe used in solar energy receiver of parabolic trough thermal power generating system has been analysed, and a medium temperature heat pipe with liquid organic working fluid has been designed. The isothermal performance and heat transfer performance of the medium temperature heat pipe with liquid organic working fluid have been tested under various power input and different inclined angles. Test proves that axial temperature difference of half circle heated medium temperature heat pipe is smaller, and the half circle heated heat pipe with inclined angle is 4°and 8°can work stably, having good axial isothermal performance and heat transfer performance, the influence on isothermal performance and heat transfer performance of the medium temperature heat pipe can be neglected.

Theoretical and Experimental Investigation on Rotor Dynamic Behavior of Bladeless Turbine for Innovative Cycles

2019 ◽  
Author(s):  
Paolo Silvestri ◽  
Alberto Traverso ◽  
Federico Reggio ◽  
Theofilos Efstathiadis
Keyword(s):  
Dynamic Behaviour ◽  
Waste Heat ◽  
Structural Characteristics ◽  
Low Cost ◽  
Experimental Studies ◽  
Small Scale ◽  
Momentum Exchange ◽  
Medium Temperature ◽  
Static Conditions ◽  
Rotor Dynamic

Abstract This paper focuses on rotor dynamic investigation of a bladeless turbine, or Tesla turbine, for application to innovative small scale cycles. Tesla rotor consists of a shaft with several co-rotating disks with small gaps between each other. The flow through the disks creates a momentum exchange by viscous effect, motoring the shaft. Thanks to its simplicity and low cost, the Tesla expander is attractive for energy harvesting and waste heat recovery from low/medium temperature in small and micro scale applications. Rotor assembly and its parts may present dynamic criticalities, due to their structural characteristics: to predict and ensure low vibrations during operations, numerical and experimental studies have been carried out on some prototypes. The activity started considering a non-rotating single Tesla disk both in free and real constrained configuration: an experimental modal analysis was performed, whose results were used to validate a disk numerical model. In this case, an analytical approach with a simplified geometry assumption was considered. All methods results were correlated each other and discrepancies have been identified and analysed. Furthermore, the investigation of a single disk rotor vibrational behaviour has been extended from static conditions to rotating conditions. Numerical analysis has been carried on taking into account the effect of gyroscopic couples and centrifugal field generated by disk rotation. In parallel, a corresponding experimental activity has been done using a dedicated test rig which allowed to perform vibrational operational measurement while the disk was in motion. Campbell diagram of the single rotating disk on the shaft has been obtained from numerical and experimental analysis allowing to identify system dynamic behaviour and to deepen aspects related to critical speeds. Finally, a whole rotor model has been developed, allowing the characterization of the dynamic behaviour of a fully assembled turbine rotor. The developed models, validated with experiments, are powerful tools that can predict the bladeless expander vibrational behaviour at the early phase of design.

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