scholarly journals Numerical Analysis for Predicting the Performance of Wave Observation Buoy: Dynamic Analysis under Regular Wave

2021 ◽  
Vol 8 (3) ◽  
pp. 127-139
Author(s):  
Insik Chun ◽  
In-Ki Min ◽  
Yongchim Min ◽  
Byungcheol Oh ◽  
Jaeseol Shim
Keyword(s):  
Single Point ◽  
Experimental Results ◽  
Mooring Line ◽  
Regular Wave ◽  
Experimental Conditions ◽  
Wave Observation ◽  
Exciting Forces ◽  
Set Up ◽  
Heave Motion

The prediction of the performance of a wave observation buoy is very important to acquire both in-situ security and good observation quality. In the present study, a numerical method was set up to analyze the dynamic interaction of a spherical buoy with its single point mooring line subject to regular wave conditions. The method was applied to the condition of an existing hydraulic experiment, producing results that are well compatible with experimental results within the limited accuracy of the available data. It was argued that some discrepancies between the numerical and experimental results might be due to the uncertainties of the wave exciting forces acting on the buoy and the experimental conditions of mooring line. The method was finally applied to demonstrate two practical issues related to in-situ wave height measurements; the effect of buoy size on resulting heave motion and the aspect of the numerical integration of heave acceleration to get wave profile.

Criteria for analysis of arterial and venous occlusion

1991 ◽  
Vol 70 (2) ◽  
pp. 665-675 ◽  
Author(s):  
T. S. Hakim
Keyword(s):  
Autologous Blood ◽  
Venous Pressure ◽  
Venous Occlusion ◽  
Pressure Gradients ◽  
Experimental Conditions ◽  
Pressure System ◽  
Arterial Inflow ◽  
Outflow Rate ◽  
Set Up

To provide a better understanding of analysis of arterial (AO) and venous occlusion (VO) tracings, using a constant and nonpulsatile perfusion pressure system, we set up an isolated in situ dog lobe preparation perfused with autologous blood. Four signals were recorded: arterial pressure, arterial inflow rate, venous pressure, and venous outflow rate. The four signals were recorded into the memory of a computer. When flow into the lobe was abruptly stopped (AO), flow out of the lung continued unchanged for approximately 150 ms and then decreased slowly to zero. Likewise, when flow out of the lung was abruptly stopped (VO), the flow into the lung continued unchanged for approximately 130 ms and then decreased slowly to zero. A monoexponential curve was fitted to different stretches of data between 0.1 and 5 s postocclusion and extrapolated to the instant of occlusion (defined here as the instant when flow at the site of occlusion becomes zero). The results indicate that 1) the first 150 ms postocclusion should be avoided because of the oscillatory artifacts generated by the occlusion maneuver, 2) use of a long segment of postocclusion data (5 s) tends to underestimate the middle pressure gradient and overestimate the arterial and venous pressure gradients, and 3) the changes in segmental vascular resistance under different experimental conditions were found to be unaffected by the criteria of analysis. Analysis of the postocclusion (AO and VO) tracings was found to be most compatible with the double-occlusion capillary pressure by fitting a stretch of data between 0.2 and 2.5 s postocclusion and extrapolating back to the instant when flow becomes zero at the site of occlusion but no earlier.

Effects of rotational speed on the leakage behavior, temperature increase, and swirl development of labyrinth seal in a compressor stator well

2016 ◽  
Vol 231 (13) ◽  
pp. 2362-2374 ◽  
Author(s):  
Gaowen Liu ◽  
Xiaozhi Kong ◽  
Yuxin Liu ◽  
Qing Feng
Keyword(s):  
Flow Characteristics ◽  
Internal Flow ◽  
Labyrinth Seal ◽  
Swirl Flow ◽  
Tip Clearance ◽  
Experimental Results ◽  
Test Rig ◽  
Experimental Conditions ◽  
Rotating Speed ◽  
Set Up

The stator well in a compressor is the space between the rotor and stator inside the mainstream annulus flow. Labyrinth seals are normally used to control the internal flow in the stator well. The upstream and downstream rotating cavities of the labyrinth seal can lead to substantial temperature rise and swirl development in this region. Additionally, due to the centrifugal expansion and thermal expansion, the tip clearance of labyrinth seal changes dramatically at different rotational speeds and temperatures in the stator well. A test rig capable to establish different rotational speeds and pressure ratios was designed according to the simplified model of the labyrinth seal in a compressor stator well (one stage). The leakage flow rate and change in total temperature across the stator well were measured. This paper also contains the experimental results of swirl ratios in the outlet rotating cavity to reveal the swirl development. Special emphasis in this work lies on acquiring the working tip clearance precisely. The set up tip clearance was measured with plug gauges, while the radial displacements of labyrinth ring and stator casing were measured separately with two high precision laser distance sensors. Two-dimensional, axisymmetric swirl flow numerical simulations were performed to get a further understanding about the basic flow characteristics and to evaluate their ability to predict the experimental results. The computational results of discharge coefficient, windage heating, and swirl ratio were compared to those obtained from test rig measurements. Particularly, when calculating, the tip clearance, the inlet parameters, and the outlet parameters of numerical model at a specific rotating speed were set to be the same with the experimental conditions.

Preliminary Study of Corrosion Mechanisms of Actinides Alloys: Calibration of FT-IR Spectroscopy

2008 ◽  
Vol 1104 ◽  
Author(s):  
Véronique Magnien ◽  
Marx Cadignan ◽  
Olivier Faivret ◽  
Gaelle Rosa
Keyword(s):  
Ir Spectroscopy ◽  
Accurate Estimation ◽  
Ir Absorption ◽  
Experimental Conditions ◽  
Ft Ir ◽  
Gaseous Atmospheres ◽  
Set Up ◽  
Corrosion Mechanisms ◽  
Ft Ir Spectroscopy

AbstractIn situ analyzes of gaseous atmospheres could be performed by FT-IR spectroscopy in order to study the corrosion reactions of actinides. Nevertheless experimental conditions and the nature of studied species have a strong effect on IR absorption laws. Thus a prior calibration of our set-up is required to obtain an accurate estimation of gas concentration. For this purpose, the behavior of several air pure gases has been investigated according to their concentration from IR spectra. Reproducible results revealed subsequent increases of the most significant peak areas with gas pressure and small deviations from Beer Lambert's law. This preliminary work allowed to determine precise absorption laws for each studied pure gas in our in situ experimental conditions. Besides our FT-IR set-up was well suitable to quantitative analysis of gaseous atmosphere during corrosion reactions. Finally the effect of foreign gas will be investigated through more complex air mixtures to obtain a complete calibration network.

Promoting Hydrogen Evolution of g-C3N4 Based Photocatalyst by Indium and Phosphorus Co-doping

2021 ◽  
Author(s):  
Xiao-Hang Yang ◽  
Chi Cao ◽  
Zilong Guo ◽  
Xiaoyu Zhang ◽  
Yaxin Wang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Post Treatment ◽  
Experimental Results ◽  
Indium Chloride ◽  
Co Doping ◽  
In Situ Copolymerization ◽  
Co Doped

Indium and phosphorus co-doped g-C3N4 photocatalyst (In,P-g-C3N4) was prepared by K2HPO4 post-treatment of indium doped g-C3N4 photocatalyst (In-g-C3N4) derived from in-situ copolymerization of dicyandiamide and indium chloride. The experimental results...

scholarly journals Comparison of Hydrocarbon-Degrading Consortia from Surface and Deep Waters of the Eastern Mediterranean Sea: Characterization and Degradation Potential

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2246
Author(s):  
Georgia Charalampous ◽  
Efsevia Fragkou ◽  
Konstantinos A. Kormas ◽  
Alexandre B. De Menezes ◽  
Paraskevi N. Polymenakou ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Oil Spills ◽  
Eastern Mediterranean ◽  
Sole Source ◽  
Eastern Mediterranean Sea ◽  
Deep Waters ◽  
Degradation Rates ◽  
Polycyclic Aromatic ◽  
Set Up

The diversity and degradation capacity of hydrocarbon-degrading consortia from surface and deep waters of the Eastern Mediterranean Sea were studied in time-series experiments. Microcosms were set up in ONR7a medium at in situ temperatures of 25 °C and 14 °C for the Surface and Deep consortia, respectively, and crude oil as the sole source of carbon. The Deep consortium was additionally investigated at 25 °C to allow the direct comparison of the degradation rates to the Surface consortium. In total, ~50% of the alkanes and ~15% of the polycyclic aromatic hydrocarbons were degraded in all treatments by Day 24. Approximately ~95% of the total biodegradation by the Deep consortium took place within 6 days regardless of temperature, whereas comparable levels of degradation were reached on Day 12 by the Surface consortium. Both consortia were dominated by well-known hydrocarbon-degrading taxa. Temperature played a significant role in shaping the Deep consortia communities with Pseudomonas and Pseudoalteromonas dominating at 25 °C and Alcanivorax at 14 °C. Overall, the Deep consortium showed a higher efficiency for hydrocarbon degradation within the first week following contamination, which is critical in the case of oil spills, and thus merits further investigation for its exploitation in bioremediation technologies tailored to the Eastern Mediterranean Sea.

The high enrichment of Geobacter by TiN nanoarray anode catalyst for efficient microbial fuel cells

2021 ◽  
Vol 9 (12) ◽  
pp. 7726-7735
Author(s):  
Da Liu ◽  
Weicheng Huang ◽  
Qinghuan Chang ◽  
Lu Zhang ◽  
Ruiwen Wang ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Hierarchical Structure ◽  
Microbial Fuel Cells ◽  
Dft Calculation ◽  
Experimental Results ◽  
Carbon Cloth ◽  
Anode Catalyst ◽  
High Enrichment

TiN nanoarrays, in situ grown on carbon cloth gather 97.2% of the model exoelectrogen Geobacter, greatly enhancing the MFCs' performance. The experimental results and DFT calculation certify the importance of the micro–nano-hierarchical structure.

In situ monitoring of isophorone diisocyanate-based flexible polyurethane foams formation

2016 ◽  
Vol 54 (1) ◽  
pp. 37-52 ◽  
Author(s):  
I Eceiza ◽  
L Irusta ◽  
A Barrio ◽  
MJ Fernández-Berridi
Keyword(s):  
Foam Height ◽  
Polyurethane Foams ◽  
In Situ Monitoring ◽  
Generation Process ◽  
Isophorone Diisocyanate ◽  
Experimental Conditions ◽  
Foaming Process ◽  
Foam Generation ◽  
Flexible Polyurethane

Novel isophorone diisocyanate-based flexible polyurethane foams were prepared by the one-step method in a computerized foam qualification system (FOAMAT). The experimental conditions to obtain this type of foams, in relation to the nature and concentration of catalysts as well as the reaction temperature, were established as no data were available in scientific literature. The chemical reactions occurring during the foam generation process were monitored in situ by attenuated total reflectance-FTIR spectroscopy. The kinetics of the foam generation was fitted to an nth order model and the data showed that the foaming process adjusted to a first-order kinetics. The physical changes as pressure, foam height, and dielectric polarization were monitored by the FOAM software (FOAMAT). According to these parameters, the foaming process was divided into four steps: bubble growth, bubble packing, cell opening, and final curing.

Use of a crystallization robot to set up sitting-drop vapor-diffusion crystallization andin situcrystallization screens

2000 ◽  
Vol 33 (2) ◽  
pp. 344-349 ◽  
Author(s):  
Christopher F. Snook ◽  
Michael D. Purdy ◽  
Michael C. Wiener
Keyword(s):  
Membrane Proteins ◽  
Protein Crystallization ◽  
Integral Membrane Proteins ◽  
Vapor Diffusion ◽  
Liquid Handling ◽  
General Utility ◽  
Crystallization Experiments ◽  
Automated Screening ◽  
Set Up

A commercial crystallization robot has been modified for use in setting up sitting-drop vapor-diffusion crystallization experiments, and for setting up protein crystallization screensin situ. The primary aim of this effort is the automated screening of crystallization of integral membrane proteins in detergent-containing solutions. However, the results of this work are of general utility to robotic liquid-handling systems. Sources of error that can prevent the accurate dispensing and mixing of solutions have been identified, and include local environmental, machine-specific and solution conditions. Solutions to each of these problems have been developed and implemented.

scholarly journals Biomass Combustion with in Situ CO2Capture by CaO. II. Experimental Results

2011 ◽  
Vol 50 (11) ◽  
pp. 6982-6989 ◽  
Author(s):  
Mónica Alonso ◽  
Nuria Rodríguez ◽  
Belén González ◽  
Borja Arias ◽  
Juan C. Abanades
Keyword(s):  
Experimental Results ◽  
Biomass Combustion
Sign in / Sign up

Export Citation Format

Share Document