The effects of column height and diameter on the effectiveness of a continuous bubble fractionation system

The objective of our study was to identify blood pressure (BP) and pulse wave velocity (PWV) changes during orthostatic loading, using a new the head-up tilt test (HUTT), which incorporates the usage of a standardized hydrostatic column height. Methods: 40 healthy subjects 20–32 years performed HUTT, which was standardized to a height of the hydrostatic column at 133 cm. Exposure time was 10 min in each of 3 positions: horizontal supine 1, HUTT, and horizontal supine 2. The individual tilt up angle made it possible to set the standard value of the hydrostatic column. Hemodynamic parameters were recorded beat to beat using “Task Force Monitor 3040 i”, pulse-wave velocity (PWV) was measured with a sphygmograph–sphygmomanometer VaSera VS1500N. Results: Orthostatic loading caused a significant increase in heart rate (HR) and a decrease in stroke volume (SV) (p < 0.05) but no significant reductions in cardiac output, changes in total vascular resistance (TVR), or BP. An analysis of personalized data on systolic blood pressure (SBP) changes in tilt up position as compared to horizontal position (ΔSBP) revealed non-significant changes in this index in 48% of subjects (orthostatic normotension group), in 32% there was a significant decrease in it (orthostatic hypotension group) and in 20% there was a significant increase in it (orthostatic hypertension group). These orthostatic changes were not accompanied by any clinical symptoms and/or syncope. During HUTT, all subjects had in the PWV a significant increase of approximately 27% (p < 0.001). Conclusion: The new test protocol involving HUTT standardized to a height of hydrostatic column at 133 cm causes typical hemodynamics responses during orthostatic loading. Individual analysis of the subjects revealed subclinical orthostatic disorders (OSD) in up to 52% of the test persons. During HUTT, all test subjects showed a significant increase in PWV. The new innovative HUTT protocol can be applied in multi-center studies in healthy subjects to detect preclinical forms of orthostatic disorders under standard gravity load conditions.

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Investigation of the transport characteristics of Pb(II) in sand-bone char columns

Science Progress ◽

10.1177/00368504211023665 ◽

2021 ◽

Vol 104 (2) ◽

pp. 003685042110236

Author(s):

Gang Li ◽

Jinli Zhang ◽

Jia Liu ◽

Tao Luo ◽

Yu Xi

Keyword(s):

Adsorption Capacity ◽

Flow Rate ◽

Dose Response ◽

Construction Materials ◽

Column Height ◽

Maximum Adsorption Capacity ◽

Complexation Reaction ◽

Bone Char ◽

Inlet Flow ◽

Inlet Flow Rate

Pb(II) leakage from batteries, dyes, construction materials, and gasoline threaten human health and environmental safety, and suitable adsorption materials are vitally important for Pb(II) removal. Bone char is an outstanding adsorbent material for water treatment, and the effectiveness in Pb(II) removing need to be verified. In this paper, the transport characteristics of Pb(II) in columns filled with a sand and bone char mixture were studied at the laboratory scale, and the influences of the initial concentration, column height, inlet flow rate, and competing ion Cu(II) on Pb(II) adsorption and transport were analyzed. The Thomas and Dose-Response models were used to predict the test results, and the mechanisms of Pb(II) adsorption on bone char were investigated. The results showed that the adsorption capacity of the bone char increased with increasing column height and decreased with increasing initial Pb(II) concentration, flow rate, and Cu(II) concentration. The maximum adsorption capacity reached 38.466 mg/g and the saturation rate was 95.8% at an initial Pb(II) concentration of 200 mg/L, inlet flow rate of 4 mL/min, and column height of 30 cm. In the competitive binary system, the higher the Cu(II) concentration was, the greater the decreases in the breakthrough and termination times, and the faster the decrease in the Pb(II) adsorption capacity of the bone char. The predicted results of the Dose-Response model agreed well with the experimental results and were significantly better than those of the Thomas model. The main mechanisms of Pb(II) adsorption on bone char include a surface complexation reaction and the decomposition-replacement-precipitation of calcium hydroxyapatite (CaHA). Based on selectivity, sensitivity, and cost analyses, it can be concluded that bone char is a potential adsorbent for Pb(II)-containing wastewater treatment.

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Determination of gas bubble fractionation rates in the deep ocean by laser Raman spectroscopy

Marine Chemistry ◽

10.1016/j.marchem.2004.10.006 ◽

2006 ◽

Vol 99 (1-4) ◽

pp. 12-23 ◽

Cited By ~ 31

Author(s):

S.N. White ◽

P.G. Brewer ◽

E.T. Peltzer

Keyword(s):

Raman Spectroscopy ◽

Deep Ocean ◽

Laser Raman Spectroscopy ◽

Gas Bubble ◽

Laser Raman ◽

Bubble Fractionation

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ChemInform Abstract: Bubble Fractionation of Enantiomers from Solution Using Molecularly Imprinted Polymers as Collectors.

ChemInform ◽

10.1002/chin.199850290 ◽

2010 ◽

Vol 29 (50) ◽

pp. no-no

Author(s):

D. W. ARMSTRONG ◽

J. M. SCHNEIDERHEINZE ◽

Y.-S. HWANG ◽

B. SELLERGREN

Keyword(s):

Molecularly Imprinted Polymers ◽

Molecularly Imprinted ◽

Imprinted Polymers ◽

Bubble Fractionation

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Ensemble-based data assimilation of volcanic aerosols using FALL3D+PDAF

10.5194/egusphere-egu21-6774 ◽

2021 ◽

Author(s):

Leonardo Mingari ◽

Andrew Prata ◽

Federica Pardini

Keyword(s):

Data Assimilation ◽

Information Transfer ◽

High Performance ◽

Volcanic Ash ◽

Numerical Models ◽

Volcanic Eruptions ◽

Column Height ◽

Eruption Column ◽

Operational Environment ◽

Assimilation System

<p>Modelling atmospheric dispersion and deposition of volcanic ash is becoming increasingly valuable for understanding the potential impacts of explosive volcanic eruptions on infrastructures, air quality and aviation. The generation of high-resolution forecasts depends on the accuracy and reliability of the input data for models. Uncertainties in key parameters such as eruption column height injection, physical properties of particles or meteorological fields, represent a major source of error in forecasting airborne volcanic ash. The availability of nearly real time geostationary satellite observations with high spatial and temporal resolutions provides the opportunity to improve forecasts in an operational context. Data assimilation (DA) is one of the most effective ways to reduce the error associated with the forecasts through the incorporation of available observations into numerical models. Here we present a new implementation of an ensemble-based data assimilation system based on the coupling between the FALL3D dispersal model and the Parallel Data Assimilation Framework (PDAF). The implementation is based on the last version release of FALL3D (versions 8.x) tailored to the extreme-scale computing requirements, which has been redesigned and rewritten from scratch in the framework of the EU Center of Excellence for Exascale in Solid Earth (ChEESE). The proposed methodology can be efficiently implemented in an operational environment by exploiting high-performance computing (HPC) resources. The FALL3D+PDAF system can be run in parallel and supports online-coupled DA, which allows an efficient information transfer through parallel communication. Satellite-retrieved data from recent volcanic eruptions were considered as input observations for the assimilation system.</p>

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Performance of a Three-Phase, Spray-Column, Direct-Contact Heat Exchanger

Journal of Heat Transfer ◽

10.1115/1.3250639 ◽

1989 ◽

Vol 111 (1) ◽

pp. 166-172 ◽

Cited By ~ 12

Author(s):

T. C¸oban ◽

R. Boehm

Keyword(s):

Heat Exchanger ◽

Direct Contact ◽

Local Heat Transfer ◽

Local Heat ◽

Column Height ◽

Contact Heat ◽

Factors Affecting ◽

Spray Column ◽

Three Phase ◽

New Formulation

A numerical model of a three-phase, direct-contact, spray-column heat exchanger has been developed. This model has been used to calculate performance information about this type of device and to compare, where possible, to experiments. General equations are defined for distance up the column using a physically based model for the local heat transfer. This model has been used to investigate a number of characteristics of these devices, such as temperature and holdup distributions through the column. A new formulation is given for a mixed, time-averaged temperature that may be representative of measurements taken with temperature transducers in direct-contact heat exchangers. Little has been given in the literature about quantitative variations of performance as a function of the key independent variables, and information on these aspects is presented here. Although the results presented are for a specific geometry (0.61 m diameter, 3 m active column height, evaporating pentane in 85°C water), the variations shown can give insights generally into the factors affecting performance in these devices. In virtually all cases examined here, extremely good comparisons are shown between predictions and measurements. Conclusions are drawn about the applicability of the model and the important effects demonstrated.

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Adsorption of Methylene Blue from Solution by Natural Zeolite in Fixed-Bed Column: Effect of Bed Depth

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.3115 ◽

2012 ◽

Vol 518-523 ◽

pp. 3115-3119

Author(s):

Yan Qiang Li ◽

Xiao Feng Ren ◽

Shao Hua Chen ◽

Xiu Rong Zhao ◽

Run Ping Han

Keyword(s):

Methylene Blue ◽

Natural Zeolite ◽

Fixed Bed ◽

Breakthrough Curves ◽

Form Solution ◽

Column Height ◽

Nonlinear Regression Analysis ◽

Adsorption Ability ◽

Fixed Bed Column ◽

Linear And Nonlinear

The effect of bed depth on adsorption ability of natural zeolite to removal methylene blue (MB) from aqueous solution in the fixed-bed column was studied. The results showed that the increase in column height favored the MB removal form solution. The equilibrium uptake of MB onto unit mass zeolite increased with the bed depth growth. The experimental data were fitted to Yan model using linear and nonlinear regression analysis, respectively. The experimental points and the predicted curves using the Yan model were compared and the error analysis was performed. The results indicated that Yan model were good to predict the breakthrough curves and both two methods can be used to obtain the parameters of Yan model and to predict the breakthrough curves.

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