scholarly journals An Investigation on the Sound Absorption Performance of Granular Molecular Sieves under Room Temperature and Pressure

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1936
Author(s):  
Bing Zhou ◽  
Jiangong Zhang ◽  
Xin Li ◽  
Bilong Liu
Keyword(s):  
Layer Thickness ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Sound Absorption ◽  
Room Temperature ◽  
Acoustical Parameters ◽  
Pellet Size ◽  
Impedance Tubes ◽  
Absorption Performance ◽  
Temperature And Pressure

The sound absorption of granular silica-aluminate molecular sieve pellets was investigated in this paper. The absorption coefficients of molecular sieve pellets with different pore sizes, pellet sizes, and layer thicknesses were measured through impedance tubes under room temperature and pressure conditions. The effects of pore size, pellet size, layer thickness were compared and explained. The comparisons show that at room temperature and pressure, the sound absorption of molecular sieve pellets is not a result of the crystalline structure, but rather it mainly changes with the pellet size and layer thickness. In addition, the five non-acoustical parameters of molecular sieve pellets were obtained by an inverse characterization method based on impedance tube measurements. The measurement by impedance tubes is in good agreement with the calculation of Johnson-Champoux-Allard (JCA) model, proving that the JCA model can be effectively used to predict the sound absorption of molecular sieve pellets.

Improvement of Adsorption Performance Based on Metal Ion Modified ETS-4 Molecular Sieves

2013 ◽  
Vol 815 ◽  
pp. 437-442 ◽  
Author(s):  
Li Yun Song ◽  
Xiao Jun Liu ◽  
Zong Cheng Zhan ◽  
Hong He ◽  
Xue Hong Zi ◽  
...  
Keyword(s):  
Molecular Sieves ◽  
Molecular Sieve ◽  
Metal Ion ◽  
Room Temperature ◽  
Raw Materials ◽  
Ni Doping ◽  
Adsorption Performance ◽  
Adsorption Capacities ◽  
Titanium Trichloride ◽  
Significant Change

Titanosilicate ETS-4 with the Sr and Ni cations modification were prepared by hydrotherrmal method using titanium trichloride and tetraethoxysilane as raw materials. The properties and morphology of the materials were characterized by XRD, SEM techniques, Sr and Ni introduced to the molecular sieve affected the frame contraction when they were heated, and did little effect on the crystallization and morphology. N2and CH4isotherms of each sample were measured at room temperature. The Sr and Ni doping could improve the N2and CH4adsorption capacities of ETS-4. The capacities of the two gases increased in the pressurization process for ETS-4-Sr and ETS-4-Ni, with the pressure increasing, no significant change in capacities of N2and CH4was observed over the ETS-4 sample. Compared to ETS-4 molecular sieves, the capacity for N2of ETS-4-Sr and ETS-4-Ni at the pressure of 1200 mmHg increased 4.2 and 3.9 times, respectively. At last, the results indicated that the cations doping (Sr2+and Ni2+) can improve the adsorption performance of ETS-4 greatly.

Comparison of HZSM-5 Zeolite and SAPO-5 Molecular Sieve in 1-Hexanol Conversion

1992 ◽  
Vol 57 (4) ◽  
pp. 739-744 ◽  
Author(s):  
Yuri A. Kalvachev ◽  
Cvetana P. Bezouhanova ◽  
Hans Lechert
Keyword(s):  
Ir Spectra ◽  
Carbonyl Compound ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Room Temperature ◽  
Olefin Isomerization ◽  
Positional Isomerization

The IR spectra of 1-hexanol adsorbed on SAPO-5 molecular sieves and on HZSM-5 zeolite were compared. It has been found, that both types of catalysts activate at 423 K the dehydration of 1-hexanol. In the IR spectra bands at 670 cm-1 (Z-isomer), 889 cm-1 (CH2=C< fragment), 911 cm-1 (CH2=CH-) and 965 cm-1 (E-isomer) have been observed, indicating that the skeletal and positional isomerization took place. A carbonyl compound (1730 cm-1) was formed at room temperature on all the investigated catalysts and disappeared upon heating. The activity of HZSM-5 in olefin isomerization and in dehydrogenation was greater than that of SAPO-5.

Catalytic decomposition and mechanism of formaldehyde over Pt–Al2O3 molecular sieves at room temperature

2017 ◽  
Vol 19 (10) ◽  
pp. 6957-6963 ◽  
Author(s):  
Xiaofeng Zhu ◽  
Jiaguo Yu ◽  
Chuanjia Jiang ◽  
Bei Cheng
Keyword(s):  
Molecular Sieves ◽  
Molecular Sieve ◽  
Room Temperature ◽  
Catalytic Decomposition ◽  
Formaldehyde Oxidation

Al2O3 molecular sieve supported Pt was prepared for catalytic formaldehyde oxidation at room temperature.

scholarly journals Design of a Dehydration Tower for the Obtaining of Alcohol Anhídro

2019 ◽  
Vol 7 (4) ◽  
pp. 1-6
Author(s):  
Flores Linda Coba Raquel ◽  
Arellano Alberto Riofrío Luis ◽  
Brito Hanníbal
Keyword(s):  
Ethyl Alcohol ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Laboratory Tests ◽  
Process Variables ◽  
Anhydrous Alcohol ◽  
Anhydrous Ethyl Alcohol ◽  
Temperature And Pressure ◽  
High Degree

The design of a dehydration tower was carried out in order to obtain anhydrous ethyl alcohol of high degree of purity by adsorption with molecular sieves, for which, we proceeded to identify the process variables by laboratory tests varying the temperature and pressure in the feeding to the molecular sieve, with these data and the flow of feeding proceeded with the design of the dehydrator, determining the variables of the equipment (diameter, volume, internal bed, flow of feeding), as well as additional devices such as a preheater that works with a temperature of 120 ºC, which is essential to increase the enthalpy of the steam, and a condenser fed with water at a temperature of 25 ºC, which makes it possible to transform the anhydrous alcohol from vapor to liquid, having a yield of 86.6% and an efficiency of 92,9%, values that help to have an alcohol of 99,5% by weight in a time of 20 minutes.

ESEM - A multipurpose surface Electron Microscope

1986 ◽  
Vol 44 ◽  
pp. 632-633 ◽  
Author(s):  
G.D. Danilatos
Keyword(s):  
Electron Microscope ◽  
Room Temperature ◽  
Environmental Scanning ◽  
Gas Composition ◽  
Saturated Water Vapor ◽  
Surface Electron ◽  
Current State ◽  
Saturated Water ◽  
New Type ◽  
Temperature And Pressure

Over recent years a new type of electron microscope - the environmental scanning electron microscope (ESEM) - has been developed for the examination of specimen surfaces in the presence of gases. A detailed series of reports on the system has appeared elsewhere. A review summary of the current state and potential of the system is presented here.The gas composition, temperature and pressure can be varied in the specimen chamber of the ESEM. With air, the pressure can be up to one atmosphere (about 1000 mbar). Environments with fully saturated water vapor only at room temperature (20-30 mbar) can be easily maintained whilst liquid water or other solutions, together with uncoated specimens, can be imaged routinely during various applications.

Fibrillin molecules aggregate to form an extendible beaded structure which is a major component of “Elastin Associated” microfibrils

1989 ◽  
Vol 47 ◽  
pp. 246-247
Author(s):  
Douglas R. Keene ◽  
B. Kerry Maddox ◽  
Marie B. Spurgin ◽  
Lynn Y. Sakai ◽  
Robert W. Glanville
Keyword(s):  
Molecular Sieve ◽  
Room Temperature ◽  
Culture Medium ◽  
Weight Fraction ◽  
Ammonium Bicarbonate ◽  
High Molecular Weight Fraction ◽  
Bicarbonate Buffer ◽  
Human Amnion ◽  
Gold Conjugate ◽  
Ammonium Bicarbonate Buffer

A mouse monoclonal antibody was used to identify beaded aggregates found in guanidine extracts of human amnion as assemblies of fibrillin molecules. These aggregates were also shown to be a major component of extracellular matrix microfibrils. We further demonstrated that the periodicity of these aggregates can be increased when subjected to mechanical stress.Human amnion was extracted with guanidine and the extracted material purified using ion exchange and molecular sieve chromatography. A high molecular weight fraction was precipitated by dialyzing against dilute acetic acid. Part of the precipitate was suspended in 0.2 M ammonium bicarbonate buffer and rotary shadowed. A second portion was resuspended in culture medium containing antibody which recognizes matrix microfibrils, diluted 1:5 in ammonium bicarbonate and reacted for 120 minutes at room temperature. Antibody labeled precipitate was washed by repeated pelleting and resuspension in buffer and then incubated in Janssen GAM 5 nm gold conjugate for 60 minutes at room temperature.

scholarly journals Temperature and Pressure Variation of the Cl-NQR in A2PbCl6-Crystals

1986 ◽  
Vol 41 (1-2) ◽  
pp. 311-314 ◽  
Author(s):  
Y. M. Seo ◽  
J. Pelzl ◽  
C. Dimitropoulos
Keyword(s):  
Relaxation Rate ◽  
Room Temperature ◽  
Lattice Relaxation ◽  
Pressure Variation ◽  
Mixed Crystals ◽  
Spin Lattice Relaxation ◽  
Structural Transitions ◽  
Spin Lattice Relaxation Rate ◽  
Spin Lattice ◽  
Temperature And Pressure

The 35Cl NQR frequency and spin-lattice relaxation rate in the compounds A2PbCl6 (A = Cs, Rb, NH4, K) have been investigated in the range 4.2 K to 500 K, and as a function of pressure at room temperature. NQR experiments conducted on (K: NH4)2PbCl6 mixed crystals have been used to complete the NQR-frequency versus temperature diagram of K2PbCl6, revealing two structural transitions at Tc1 ≅ 358 K and at TC2 ≅ 333 K.

Sound absorption performance of flexible polyurethane/silicon dioxide perforated coating composites

2021 ◽  
pp. 004051752110155
Author(s):  
Min Peng ◽  
Xiaoming Zhao ◽  
Weibin Li
Keyword(s):  
Silicon Dioxide ◽  
Sound Absorption ◽  
Woven Fabric ◽  
Perforation Rate ◽  
Cavity Depth ◽  
Resonant Frequencies ◽  
The Matrix ◽  
Absorption Performance ◽  
Traditional Sense ◽  
Flexible Polyurethane

Perforated materials in the traditional sense are rigid, usually dense, costly and inflexible. For this study, polyester/cotton blended woven fabric as the base fabric, nano-SiO2 (silicon dioxide) as the functional particles and PU (polyurethane) as the matrix were selected. Accordingly, flexible PU/SiO2 perforated coating composites with different process parameters were developed. The influence of the nano-SiO2 content, perforation diameter, perforation rate, number of fiber felt layers and cavity depth on the sound absorption coefficient were investigated. The resonant frequencies of materials with different cavity depths were evaluated by both theoretical calculation and experimental method. It was found that the flexible perforated composite has good sound absorption and mechanical properties, and has great potential for applications requiring soft and lightweight sound absorption materials.

scholarly journals Diffuse Sound Absorptive Properties of Parallel-Arranged Perforated Plates with Extended Tubes and Porous Materials

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1091 ◽  
Author(s):  
Dengke Li ◽  
Daoqing Chang ◽  
Bilong Liu
Keyword(s):  
Boundary Condition ◽  
Porous Material ◽  
Porous Materials ◽  
Sound Absorption ◽  
Azimuthal Angle ◽  
Octave Band ◽  
Frequency Range ◽  
Absorption Coefficients ◽  
Perforated Plates ◽  
Absorption Performance

The diffuse sound absorption was investigated theoretically and experimentally for a periodically arranged sound absorber composed of perforated plates with extended tubes (PPETs) and porous materials. The calculation formulae related to the boundary condition are derived for the periodic absorbers, and then the equations are solved numerically. The influences of the incidence and azimuthal angle, and the period of absorber arrangement are investigated on the sound absorption. The sound-absorption coefficients are tested in a standard reverberation room for a periodic absorber composed of units of three parallel-arranged PPETs and porous material. The measured 1/3-octave band sound-absorption coefficients agree well with the theoretical prediction. Both theoretical and measured results suggest that the periodic PPET absorbers have good sound-absorption performance in the low- to mid-frequency range in diffuse field.

Preparation and Characterization of Ni-Containing Aluminophosphate Molecular Sieves

2011 ◽  
Vol 418-420 ◽  
pp. 617-620
Author(s):  
Ying Sun ◽  
Lan Ying Ge
Keyword(s):  
Oxidation State ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Crystalline Form ◽  
Spectroscopic Techniques ◽  
Tetrahedral Coordination ◽  
Tetrahedral Geometry ◽  
Nickel Ions ◽  
Aluminophosphate Molecular Sieves

Aluminophosphate molecular sieve and Ni(II)-containing APO-5 materials were synthesized hydrothermally and characterized by various analytical and spectroscopic techniques. It indicates that the nickel ions with a divalent oxidation state can incorporate into the tetrahedral coordination in mesoporous aluminophosphate very well. The better crystallizing temperature is explored. A stronger crystalline form is obtained with the addition of HF. Further, microporous aluminophosphate molecular sieves and Ni(II) ions remain in a tetrahedral geometry even after calcination at 550 °C.

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