Laboratory studies of suspended particle volume concentration in atmosphere using a smartphone

Abstract The article presents the results of laboratory studies of the effect of volume concentration of suspended particles in contrast to the luminous slits image obtained by smartphone cameras of SAMSUNG Galaxy A3 and Honor 8 Lite. Experimentally it was found that a pattern of change in contrast to the luminous slits image from the volumetric concentration of suspended particles appears under ambient light. The pattern of contrast change can be expressed by an exponential function. The correlation coefficient is 0.97. Cigarette smoke was used as suspended particles.

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Thermodynamics of Bidisperse Ferrofluids in Zero External Magnetic Field: Theory and Simulations

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.233-234.331 ◽

2015 ◽

Vol 233-234 ◽

pp. 331-334

Author(s):

Anna Yu. Solovyova ◽

Ekaterina A. Elfimova

Keyword(s):

Magnetic Field ◽

Field Theory ◽

Free Energy ◽

External Magnetic Field ◽

Volume Concentration ◽

Helmholtz Free Energy ◽

Hard Spheres ◽

Particle Volume ◽

Simulation Data ◽

Theoretical Predictions

The thermodynamic properties of a ferrofluid modeled by a bidisperse system of dipolar hard spheres in the absence of external magnetic field are investigated using theory and simulations. The theory is based on the virial expansion of the Helmholtz free energy in terms of particle volume concentration. Comparison between the theoretical predictions and simulation data shows a great agreement of the results.

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Assessment of Phytotoxic Potential of Potato Genotypes

Plant Breeding and Seed Science ◽

10.1515/plass-2017-0004 ◽

2017 ◽

Vol 75 (1) ◽

pp. 17-22

Author(s):

Dorota Sołtys-Kalina

Keyword(s):

Correlation Coefficient ◽

Negative Impact ◽

Biologically Active ◽

Test Plant ◽

Laboratory Studies ◽

Leaf Extracts ◽

Potato Leaf ◽

Active Compounds ◽

Step Procedure ◽

Total Glycoalkaloids

Abstract In the laboratory studies on allelopathy, phytotoxicity is defined as a negative impact of plant’s extracts or natural compounds derived from plants, on germination and/or growth of the tested (acceptor) plant. Glycoalkaloids are the main biologically active compounds of the potato and are involved in potato phytotoxicity (the correlation coefficient of the length of the test plant with the concentration of total glycoalkaloids present in the leaf extracts of forty potato genotypes was r = -0.41). The assessment of phytotoxic abilities of the potato is a two-step procedure which consists of determining glycoalkaloids in potato leaf extracts and analyzing the root and hypocotyl lengths of the test plant growing in potato leaf extracts.

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Wear Characteristics of Dense Fine Particles Solid-Liquid Two-Phase Fluid Centrifugal Pump with Open Impellers

Shock and Vibration ◽

10.1155/2021/6635630 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Yanping Wang ◽

Chuanfeng Han ◽

Ye Zhou ◽

Zhe Lin ◽

Jianfeng Ma ◽

...

Keyword(s):

Numerical Simulation ◽

Centrifugal Pump ◽

Volume Concentration ◽

Fine Particles ◽

Two Phase Flow ◽

Middle Part ◽

Phase Flow ◽

Particle Volume ◽

Two Phase ◽

Wear Characteristics

The demand for a centrifugal pump with open impellers for conveying dense fine particles in solid-liquid two-phase flow has increased significantly in actual engineering. The wear of dense fine particles on the centrifugal pump is also exceedingly prominent, which affects the engineering efficiency and economic benefits. The two-phase flow in the open centrifugal pump is three-dimensional and unsteady; the movement of high-volume concentration particles in the centrifugal pump and its mutual influence on the two-phase flow, which results in the calculation of wear, are very intricate. To study the wear characteristics of the centrifugal pump with open impeller with high-volume concentration particles more accurately, numerical simulation and experimental comparison are carried out for the impeller wear of dense fine particles transported by the centrifugal pump with open impellers. Considering the relationship between particles and walls, we used the Fluent 18.0 built-in rebound function and wear model. The RNG k-ε model and the DDPM model were adopted in the numerical simulation, and the numerical solution for centrifugal pump wear was performed under flow rate (9.6 m3·h−1, 12.8 m3·h−1, 16 m3·h−1, and 19.2 m3·h−1), different particle sizes (0.048 mm, 0.106 mm, 0.15 mm, 0.27 mm, and 0.425 mm), and different particle volume concentrations (10%, 15%, 20%, 25%, and 30%), respectively. By comparing the serious wear positions of the impeller, the experimental results correspond well with the numerical simulation, which can be used to predict and study the wear characteristics of the impeller. The results show that the most serious area of blade wear is the middle part of the pressure surface, followed by the middle part of the upper part of the blade. The wear of the impeller is greatly affected by relevant parameters, such as pump flow rate, particle diameter, and particle volume concentration. These results can provide some basis for the wear-resistant design of dense fine particle impeller.

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Nanoparticle Number Concentration in the Air in Relation to the Time of the Year and Time of the Day

Atmosphere ◽

10.3390/atmos11050523 ◽

2020 ◽

Vol 11 (5) ◽

pp. 523

Author(s):

Jáchym Brzezina ◽

Klaudia Köbölová ◽

Vladimír Adamec

Keyword(s):

Web Application ◽

Annual Variation ◽

Suspended Particle ◽

Relative Number ◽

Absolute Number ◽

Suspended Particles ◽

Number Concentration ◽

Size Fractions ◽

The Difference ◽

The Individual

The paper analyzes suspended particles number concentrations of 61 size fractions (184 nm to 17,165 nm) in the air at a traffic location. The average course of the individual fractions was analyzed at various intervals – daily, weekly, monthly and annually, in the period between 2017 and 2019. The data was then used to calculate the arithmetic mean for all the fractions (MS Excel, R) and then using a proprietary web application, heatmaps were constructed. The obtained results showed significant differences in both the annual and daily variation of number concentrations between the individual fractions differing in particle size. In the case of the annual variation, one can see a greater variability of smaller particles, which is most likely due to the source of the actual suspended particles. Meteorological and dispersion conditions are found as important factors for suspended particle concentrations. These can lead to significant differences from year to year. However, a comparison between 2018 and 2019 showed that even though the average absolute number concentrations can differ between years, the actual relative number concentrations, i.e., the ratios between the individual fractions remain very similar. In conclusion it can be said that the difference between the number concentration variation of the size fractions depends on both the actual pollution sources (especially in the long-term, i.e., the annual variation) and the actual size of the particles, which plays a role especially in the short-term (daily, weekly variation).

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Energy and Exergy Analysis of Shell and Coil Heat Exchanger Using Water Based Al2O3 Nanofluid Including Diverse Coil Geometries: An Experimental Study

Journal of Nanofluids ◽

10.1166/jon.2020.1727 ◽

2020 ◽

Vol 9 (1) ◽

pp. 13-23

Author(s):

Samir M. Elshamy ◽

Mohamed T. Abdelghany ◽

M. R. Salem ◽

O. E. Abdellatif

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Transfer Coefficient ◽

Exergy Analysis ◽

Volume Concentration ◽

Pure Water ◽

Cone Angle ◽

Particle Volume ◽

Water Based ◽

Coil Heat

The aim of this research is to investigate experimentally the characteristics of the convective heat transfer and exergy analysis of pure water and water based Al2O3 nanofluid through helical coiled tubes (HCTs) and conical coiled tubes (CCTs) inside shell and coil heat exchangers. HCT and CCT fabricated with different coil torsions (λ) ranges from 0.0202 to 0.052 with different two angles (0° and 45°) while have the same curvature ratio (δ = 0.0564). The effects of mean coil torsion, the cone angle and nanoparticles volume concentration on the thermal performance were investigated. Results indicated that the overall heat transfer coefficient (Uov), convection heat transfer coefficient (ht), the tube side Nusselt number (Nut), effectiveness (ɛ) and exergy efficiency (ηex) of nanofluids are higher than those of the pure water at same flow condition, and this increase goes up with the increase in particle volume concentration (ϕ). The results also showed that Uov, ht, Nut, ɛ and ηex increases by decreasing the coil torsion from 0.052 to 0.0202. Correlations for Nut as a function of the investigated parameters are obtained.

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Heat transfer intensification of Zirconia/water nanofluid

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v13i1.4530 ◽

2017 ◽

Vol 13 ◽

pp. 01-08

Author(s):

Mohamed Iqbal Shajahan ◽

Chockalingam Sundar Raj ◽

Sambandan Arul ◽

Palanisamy Rathnakumar

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Laminar Flow ◽

Friction Factor ◽

Volume Concentration ◽

Constant Heat Flux ◽

Particle Volume ◽

Heat Transfer Intensification ◽

Nusselt Numbers ◽

Thermal Analyser

This paper investigated convective heat transfer and friction factor of ZrO2/H2O nanofluid through a circular pipe under laminar flow condition with constant heat flux. Nanofluid is prepared for 0.5, 0.75 and 1% volume concentrations with yttrium oxide surfactant. Nanofluid’s thermal conductivity and viscosity is measured by KD2 Pro thermal analyser and Brookfield viscometer respectively. Results showed that the thermal conductivity and viscosity increased with increase in particle volume concentration. These nanofluids are experimented in a forced convection system, first heat transfer characteristics of DI (Deionised) water under laminar flow in a copper tube measured, then three nanofluids are carried out the tests, results revealed that the enhanced Nusselt numbers of 21.09,28.05 and 35.73% at the 0.5, 0.75 and 1% volume concentrations, There is no excess penalty in pumping power and results showed less variations in friction factor for nanofluids comparatively with the base fluid DIWater.

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Analysis of the effect of ultrasonic vibration on nanofluid as coolant in engine radiator

Eastern-European Journal of Enterprise Technologies ◽

10.15587/1729-4061.2021.241694 ◽

2021 ◽

Vol 5 (5 (113)) ◽

pp. 6-13

Author(s):

Sudarmadji Sudarmadji ◽

Santoso Santoso ◽

Sugeng Hadi Susilo

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Fluid Flow ◽

Transfer Coefficient ◽

Ultrasonic Vibration ◽

Flow Rate ◽

Volume Concentration ◽

Aluminum Oxide Nanoparticles ◽

Particle Volume ◽

Overall Heat Transfer Coefficient

The paper discusses the combined methods of increasing heat transfer, effects of adding nanofluids and ultrasonic vibration in the radiator using radiator coolant (RC) as a base fluid. The aim of the study is to determine the effect of nanoparticles in fluids (nanofluid) and ultrasonic vibration on the overall heat transfer coefficient in the radiator. Aluminum oxide nanoparticles of 20–50 nm in size produced by Zhejiang Ultrafine powder & Chemical Co, Ltd China were used, and the volume concentration of the nanoparticles varied from 0.25 %, 0.30 % and 0.35 %. By adjusting the fluid flow temperature of the radiator from 60 °C to 80 °C, the fluid flow rate varies from 7 to 11 lpm. The results showed that the addition of nanoparticles and ultrasonic vibration to the radiator coolant increases the overall heat transfer coefficient by 62.7 % at a flow rate of 10 liter per minute and temperature of 80 °C for 0.30 % particles volume concentration compared to pure RC without vibration. The effect of ultrasonic vibration on pure radiator coolant without vibration increases the overall heat transfer coefficient by 9.8 % from 385.3 W/m2·°C to 423.3 W/m2·°C at a flow rate of 9 liter per minute at a temperature of 70 °C. The presence of particles in the cooling fluid improves the overall heat transfer coefficient due to the effect of ultrasonic vibrations, nanofluids with a volume concentration of 0.25 % and 0.30 % increased about 10.1 % and 15.7 %, respectively, compared to no vibration. While, the effect of nanoparticles on pure radiator coolant at 70 °C enhanced the overall heat transfer coefficient by about 39.6 % at a particle volume concentration of 0.35 % compared to RC, which is 390.4 W/m2·°C to 545.1 W/m2·°C at 70 °C at a flow rate of 10 liter per minute

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Variation of Suspended Particles in the Bottom Layer of the East China Sea with Data from Seafloor Observatory

Sensors ◽

10.3390/s19235156 ◽

2019 ◽

Vol 19 (23) ◽

pp. 5156 ◽

Cited By ~ 2

Author(s):

Dinghui Shang ◽

Rufu Qin ◽

Huiping Xu ◽

Changwei Xu ◽

Kelin Sun ◽

...

Keyword(s):

Particle Size ◽

East China Sea ◽

Power Law ◽

Volume Concentration ◽

Maximum Velocity ◽

Bottom Layer ◽

Suspended Particles ◽

East China ◽

The East China Sea ◽

China Sea

The in situ scattering and transmissometry laser (LISST-100X), equipped with an acoustic wave and current (AWAC) meter and conductivity, temperature, and depth (CTD) instruments over the seabed in the East China Sea, was used to monitor the variation in suspended particles in the bottom sea layer, including particle size distribution (PSD) and volume concentration. The power law approximation was tested to describe the variability in PSD based on the field data. The results show that the power law was robust in processing continuous data, accompanied with the same optimal reference particle size (~63 μm) and little change in the corresponding exponent (~3.4) in both periods. Suspended particles were divided into three types: macroflocs (>133 μm), microflocs (36–133 μm), and single grains (<36 μm). Particle sizes were coarse during the two seasons, with macroflocs representing more than 60% of all the suspended particles, especially in February, when the particle size spectra were usually open-ended. Results from the harmonic analysis method indicate that tidal-induced resuspension and advection are the major reasons for the diurnal dynamics of sediments. Due to the tidal asymmetry in the region, we only found one mode in volume concentration at the moment of maximum velocity. However, the ratios of macroflocs were bimodal, with maximum floods and ebbs in one tidal cycle in February, when the higher mode at the maximum ebbs may be contributed to by the flocculation of finer particles considering the decreasing ratios of finer particles. Due to the enhanced stratification and the clean barrier built up by the Taiwan Warm Current in the southeast corner, the significant daily variation in suspended particles observed in February weakened in September. The influence of waves was uncertain, although the correlation coefficient between significant wave height and volume concentration was about 64% in February.

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Investigation of Airborne Molecular Contamination in Cleanroom Air Environment through Portable Soft X-Ray Radiolysis Detector

Applied Sciences ◽

10.3390/app10030978 ◽

2020 ◽

Vol 10 (3) ◽

pp. 978 ◽

Cited By ~ 1

Author(s):

Changhyuk Kim ◽

Kyungil Cho ◽

David Y. H. Pui

Keyword(s):

Calibration Curve ◽

Volume Concentration ◽

University Of Minnesota ◽

Air Concentration ◽

Scanning Mobility Particle Sizer ◽

Particle Volume ◽

X Ray ◽

Condensation Particle Counter ◽

Wide Range ◽

Total Particle

Airborne molecular contamination (AMC) represents a wide range of gaseous contaminants in the cleanroom air environment. It is difficult to monitor AMC in the cleanroom air using conventional methods in real-time due to its ultra-low concentrations, such as part-per-billion or -trillion (ppb or ppt). In this study, AMC in the real university cleanroom air environment was investigated to figure out hot spots through portable soft X-ray radiolysis detector, which converts gaseous AMC into nanoparticles (gas-to-particle conversion) under the soft X-ray irradiation. A soft X-ray was connected to a clean stainless steel chamber to convert the introduced AMC into nanoparticles, and the size distributions of nanoparticles were measured through a scanning mobility particle sizer, which consists of a differential mobility analyzer and a condensation particle counter. By converting the size distribution information into total particle volume concentrations, equivalent AMC concentrations can be calculated using an appropriate calibration curve between AMC and the total particle volume concentration. The volume concentration of nanoparticles were converted into an equivalent sulfur dioxide (SO2, a major acidic AMC in the cleanroom air) concentration by a calibration curve between SO2 and the particle volume concentrations. AMC levels at different locations in the cleanroom at the University of Minnesota were measured by the soft X-ray-assisted AMC detector, and revealed that several tenth-order of pptV (lower than 15 pptV) in terms of the equivalent SO2 concentration existed in the cleanroom air environment.

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