Experimental investigation of the ideal selectivity of MFI-ZSM-5 zeolite-type membranes for a first evaluation of the separation of hydrogen isotopologues from helium

This paper experimentally investigates the effect of pressure resistance distribution by using perforated grilles with different porosities ([Formula: see text]%, 58% and 35.4%) in a container data center. The inlet and outlet temperature distribution, rack cooling index (RCI) and supply heat index (SHI) are used to evaluate the cooling performance under semi-contained and fully contained configurations. As a result, the airflow reversal phenomenon at the top cabinets is found, which is especially conspicuous for the case without perforated grilles due to the extremely low pressure resistance in the cabinet. By implementing perforated grilles at lower three cabinets, the airflow reversal can be eliminated, however, it cannot be completely removed. By applying perforated grilles with [Formula: see text]% at the top three cabinets can increase the pressure resistance at the cabinets [Formula: see text] where the airflow reversal is eliminated thoroughly. Yet, the performance of cabinets at rack [Formula: see text] may degrade rapidly due to much stronger hot-exhaust recirculation. Hence, the fully contained configuration is applied. Note that the airflow reversal is more severe for the case without perforated grilles. By arranging the perforated grilles with [Formula: see text] = 35.4%, the corresponding RCI and SHI may reach the ideal values of 100% and zero, respectively. Therefore, the perforated grilles with [Formula: see text] = 35.4% are more reasonable for simulated racks under semi-contained and fully contained configurations when airflow reversal occurs.

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A Theoretical and Experimental Investigation of the Dynamic Response of Rolamite

Journal of Engineering for Industry ◽

10.1115/1.3591533 ◽

1969 ◽

Vol 91 (1) ◽

pp. 235-239

Author(s):

C. M. Percival ◽

F. R. Norwood

Keyword(s):

Experimental Investigation ◽

Dynamic Response ◽

Experimental System ◽

Equation Of Motion ◽

Bending Stiffness ◽

Force Generation ◽

Inertia Force ◽

Lagrange’S Equation ◽

The Ideal

In the following paper, Lagrange’s equation is used to derive an equation of motion for the rolamite mechanism in the ideal tight configuration; the effects of band inertia, force generation by bands of varying bending stiffness, and nonconservative forces are considered. An experimental system for investigating the dynamic response of rolamite is described. The effects of friction on the rolamite mechanism are discussed and experimentally determined values of coefficients of friction are presented.

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Preparation and Characterization of Metal Membranes for Gas Separation

Biointerface Research in Applied Chemistry ◽

10.33263/briac124.46494661 ◽

2021 ◽

Vol 12 (4) ◽

pp. 4649-4661

Keyword(s):

Sandwich Structure ◽

Structure Characterization ◽

Effect Of Temperature ◽

Structure And Properties ◽

Membrane Systems ◽

Gas Phases ◽

Ideal Selectivity ◽

Exogenous Factors ◽

The Ideal

The purpose of this article is the characterization of permeability and the ideal selectivity of new metallic brass membranes with a “sandwich” structure. Characterization is an important factor related to the morphology, structure, and properties of the membrane. The membranes were examined for simple gas phases, including various exogenous factors on their performance (temperature, pressure, durability). To evaluate their performance, permeate measurements were made at temperatures from -18 to 300°C and at various pressures from 1 to 10 bar. Results have shown that permeability is influenced by the molecular weight and exhibits ideal selectivity greater or equal by Knudsen’s ideal separation factor in a sequence of Η2>He>CH4>N2>O2>Ar≥CO2. The permeability is also a function of the thickness of the membrane, as it shows there’s a decrease in permeability and an increase in selectivity when the thickness is increased. The effect of temperature on these metal membranes is considered an important factor in the operation of membranes and membrane systems. The main feature is the reduction of permeability with the increase of temperature.

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Effects of 60Co-Irradiation on Gas Permeation Properties of Polyimide Membranes

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.912-914.123 ◽

2014 ◽

Vol 912-914 ◽

pp. 123-126

Author(s):

Yu Hua Qiao ◽

Huai Min Miao ◽

Yong Biao Xu ◽

Wei Jiang ◽

Yan Hong Zheng ◽

...

Keyword(s):

Gas Separation ◽

Radiation Effects ◽

Gas Permeability ◽

Gas Permeation ◽

Ideal Selectivity ◽

Tetracarboxylic Dianhydride ◽

Permeation Properties ◽

The Ideal ◽

Polyimide Membranes

Radiation effects on polyimide (PI) membranes were studied with different irradiation doses by60Co. The PI membrane were synthesized from 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane (Bis-AP-AF) with 3,3',4,4'-Benzophenone tetracarboxylic dianhydride (BTDA). The single gas permeability of He, H2, CO2, O2, N2and CH4were measured and compared in order to determine the effect of the the irradiation doses on the gas separation properties. The results showed that the ideal selectivity of He/CH4, H2/CH4, CO2/CH4and H2/N2of the irradiation PI membrane can be significantly improved by irradiation of60Co source. The optimum irradiation doses were 50 kGy. The highest ideal selectivity of He/CH4, H2/CH4, CO2/CH4and H2/N2is 3635.86, 2287.57, 282.00 and 205.29, respectively. In other word, the ideal selectivity of He/CH4, H2/CH4, CO2/CH4and H2/N2of the irradiation PI membrane with 50 kGy irradiation doses is 2.27, 2.11, 1.89 and 1.08 times higher than that of the PI membranes without irradiation.

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Experimental Investigation on Contaminated Friction of Hydraulic Spool Valve

Applied Sciences ◽

10.3390/app9235230 ◽

2019 ◽

Vol 9 (23) ◽

pp. 5230 ◽

Cited By ~ 2

Author(s):

Shuai Fan ◽

Rui Xu ◽

Hong Ji ◽

Shengqing Yang ◽

Qingyun Yuan

Keyword(s):

Experimental Investigation ◽

Surface Morphology ◽

Real Time ◽

Lower Limit ◽

Test Bench ◽

Size Range ◽

Valve Body ◽

Spool Valve ◽

The Ideal

This paper focuses on the contaminated friction of fit clearance between the spool and valve body to explore the influence principles of clamping stagnation phenomenon. From the perspective of surface morphology and size of particulates in the clearance, designing and manufacturing the valve body, rough spool, conical spool, and standard morphology spool, the test bench was built up and the curves of real-time contaminated friction in the movement of spools were obtained through experiments. The curves show that the contaminated frictions have a feature of pulsation; meanwhile, the stagnation-sensitive size of particulates is between 0.7 and 0.9 times that of clearance. Compared to the ideal morphology spool within the range of sensitive size, the contaminated fiction of rough spool is increased, whereas the lower limit of stagnation-sensitive size range of particulates on conical spool is decreased. The contaminated friction is gradually increased on cis-conical spool but increased first and then decreased on invert cone spool.

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Influence of Nonideaities on the Performance of a Self-Balancing Rotor System

Applied Mechanics ◽

10.1115/imece2005-82279 ◽

2005 ◽

Author(s):

Roland Horvath ◽

George T. Flowers ◽

Jerry Fausz

Keyword(s):

Experimental Investigation ◽

Dynamic Behavior ◽

Experimental Validation ◽

Research Study ◽

The Self ◽

Functional Capability ◽

Analytical Simulation ◽

Simulation Results ◽

Automatic Balancing ◽

The Ideal

An analytical, numerical and experimental investigation of the dynamic behavior of a four degree of freedom passive balancing system using pendulum balancers is presented. This work is an extension of previous studies which considered such automatic balancing systems and devices. It has previously been demonstrated analytically that a 4-DOF pendulum self-balancing system is capable, under idealized conditions, of exact radial balancing [10]. However, imperfections in the fabrication and assembly of such a system tend to compromise a number of the ideal modeling assumptions that were used to provide this result. The present research study examines the effects of a variety of such imperfections and their influence on the functional capability of the self-balancing system. Both analytical/simulation results and experimental validation are provided and discussed.

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A comparative experimental study on the deviation of the ideal selectivity in HDTMS-functionalized and untreated ceramic structures with pores in the upper mesoporous range

Microporous and Mesoporous Materials ◽

10.1016/j.micromeso.2015.06.042 ◽

2015 ◽

Vol 217 ◽

pp. 253-261 ◽

Cited By ~ 10

Author(s):

Benjamin Besser ◽

Thomas Veltzke ◽

Jochen A.H. Dreyer ◽

Julia Bartels ◽

Michael Baune ◽

...

Keyword(s):

Experimental Study ◽

Ideal Selectivity ◽

The Ideal

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Preparation and Characterization of Newly Developed Polysulfone/Polyethersulfone Blend Membrane for CO2 Separation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.699.325 ◽

2014 ◽

Vol 699 ◽

pp. 325-330 ◽

Cited By ~ 7

Author(s):

Hafiz Abdul Mannan ◽

Hilmi Mukhtar ◽

Thanabalan Murugesan

Keyword(s):

Polymeric Membranes ◽

Polymer Blending ◽

Blend Ratio ◽

Flat Sheet ◽

Ideal Selectivity ◽

Blend Membranes ◽

Physical Mixing ◽

Individual Polymer ◽

The Ideal

Polymeric membranes suffer from so called upper bound tradeoff between permeability and selectivity as described by Robeson. Polymer blending is a valuable technique to tune the properties of polymeric membranes by physical mixing of different polymers in a single mixture. In this study, preparation and characterization of newly developed polysulfone/polyethersulfone (PSF/PES) blend flat sheet dense membranes is described for CO2/CH4 separation. Blend membranes with different blending ratios were prepared and the developed membranes were characterized by FESEM, FTIR and TGA to see the effect of blend ratio on morphology, bonding and thermal stability respectively. Permeability of CO2 and CH4 gases in pressure range of 2-10 bar is recorded to find out the ideal selectivity of prepared membranes. The results are discussed and compared with individual polymer membranes.

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Mixed-Gas Selectivity Based on Pure Gas Permeation Measurements: An Approximate Model

Membranes ◽

10.3390/membranes11110833 ◽

2021 ◽

Vol 11 (11) ◽

pp. 833

Author(s):

Alexander O. Malakhov ◽

Vladimir V. Volkov

Keyword(s):

Gas Permeability ◽

Approximate Model ◽

Polymeric Membranes ◽

Mixture Component ◽

Mixed Gas ◽

Ideal Selectivity ◽

Local Permeability ◽

Input Parameters ◽

Gas Selectivity ◽

The Ideal

An approximate model based on friction-coefficient formalism is developed to predict the mixed-gas permeability and selectivity of polymeric membranes. More specifically, the model is a modification of Kedem’s approach to flux coupling. The crucial assumption of the developed model is the division of the inverse local permeability of the mixture component into two terms: the inverse local permeability of the corresponding pure gas and the term proportional to the friction between penetrants. Analytical expressions for permeability and selectivity of polymeric membranes in mixed-gas conditions were obtained within the model. The input parameters for the model are ideal selectivity and solubility coefficients for pure gases. Calculations have shown that, depending on the input parameters and the value of the membrane Peclét number (the measure of coupling), there can be both a reduction and an enhancement of selectivity compared to the ideal selectivity. The deviation between real and ideal selectivity increases at higher Peclét numbers; in the limit of large Peclét numbers, the mixed-gas selectivity tends to the value of the ideal solubility selectivity. The model has been validated using literature data on mixed-gas separation of n-butane/methane and propylene/propane through polymeric membranes.

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