ELASTİK MODÜL YAKLAŞIMI İLE SES HIZLARININ HESAPLANARAK TUNGSTENİN AKUSTİK EMPEDANS ÜZERİNDEKİ ETKİLERİNİN ARAŞTIRILMASI

2021 ◽  
Vol 8 (17) ◽  
pp. 150-159
Author(s):  
Hüseyin Okan DURMUŞ ◽  
Bülent AYDEMİR ◽  
Emel ÇETİN ARI ◽  
Baki KARABÖCE
Keyword(s):  
Elastic Modulus ◽  
Acoustic Impedance ◽  
Ultrasonic Transducers ◽  
Support Material ◽  
Mechanical Method ◽  
Support Materials ◽  
Mixing Ratios ◽  
Metal Filler ◽  
Epoxy Material ◽  
Sound Velocities

Some metal filler powders, such as tungsten, are available as support materials in the bodies of ultrasonic transducers. The backing materials consist of two types of epoxy material, mainly hardener and adhesive, and filler powders. One of the reasons why these filler powders are incorporated into epoxy materials is the desire to achieve high acoustic impedance in ultrasonic probes. In this context, samples with different epoxy mixing ratios of tungsten added in amounts of 1, 2, 5 and 10 grams were prepared for the measurement, and the sound velocities used in the calculation of acoustic impedance were calculated over elastic modulus and densities measured by mechanical method. Thus, the effects of tungsten used in the support material in the probes of ultrasound devices were investigated. As a result, the increasing effect of tungsten on acoustic impedance was also determined with the calculations made by mechanical method.

Employing Exfoliated Graphite as Novel Support Material for Heterogeneous Model Catalysts

2019 ◽  
Author(s):  
Moritz Wolf ◽  
Nico Fischer ◽  
Michael Claeys
Keyword(s):  
Surface Area ◽  
Graphite Powder ◽  
Model Catalysts ◽  
Model Systems ◽  
Exfoliated Graphite ◽  
Support Material ◽  
Heterogeneous Model ◽  
Support Materials ◽  
Metal Support Interaction ◽  
Catalyst Systems

<p>The inert nature of graphitic samples allows for characterisation of rather isolated supported nanoparticles in model catalysts, as long as sufficiently large inter-particle distances are obtained. However, the low surface area of graphite and the little interaction with nanoparticles result in a challenging application of conventional preparation routes in practice. In the present study, a set of graphitic carbon materials was characterised in order to identify potential support materials for the preparation of model catalyst systems. Various sizes of well-defined Co<sub>3</sub>O<sub>4</sub> nanoparticles were synthesised separately and supported onto exfoliated graphite powder, that is graphite after solvent-assisted exfoliation <i>via</i> ultrasonication resulting in thinner flakes with increased specific surface area. The developed model catalysts are ideally suited for sintering studies of isolated nano-sized cobaltous particles as the graphitic support material does not provide distinct metal-support interaction. Furthermore, the differently sized cobaltous particles in the various model systems render possible studies on structural dependencies of activity, selectivity, and deactivation in cobalt oxide or cobalt catalysed reactions.</p>

Theoretical exploration of novel catalyst support materials for fuel cell applications

2016 ◽  
Vol 4 (39) ◽  
pp. 15181-15188 ◽  
Author(s):  
Xin Xia ◽  
Jane L. R. Yates ◽  
Glenn Jones ◽  
Misbah Sarwar ◽  
Ian Harkness ◽  
...  
Keyword(s):  
Material Selection ◽  
Catalyst Support ◽  
Oxygen Adsorption ◽  
Oxygen Binding ◽  
Support Material ◽  
Support Materials ◽  
Wetting Ability ◽  
Orr Activity ◽  
Novel Catalyst ◽  
Ability Parameter

(Left) The atomic model of oxygen adsorption on the MX supported Pt overlayer film. (Right) Support material selection through the Pt wetting ability parameter δ and oxygen binding energy, ΔE*[O]. The dashed line corresponds to the wetting parameter δ0 of the unsupported Pt(111) surface. The red line denotes the apex of ORR activity.

Batch experiment on H2S degradation by bacteria immobilised on activated carbons

2004 ◽  
Vol 50 (4) ◽  
pp. 299-308 ◽  
Author(s):  
R. Yan ◽  
Y.L. Ng ◽  
X.G. Chen ◽  
A.L. Geng ◽  
W.D. Gould ◽  
...  
Keyword(s):  
Activated Carbons ◽  
Enrichment Culture ◽  
Future Research ◽  
Support Material ◽  
Support Materials ◽  
Biological Treatments ◽  
Pore Blockage ◽  
The Media ◽  
Biofilm Development ◽  
Optimum Balance

Biological treatments of odorous compounds, as compared to chemical or physical technologies, are in general ecologically and environmentally favourable. However, there are some inefficiencies relative to the media used in biofiltration processes, such as the need for an adequate residence time; the limited lifetime, and pore blockage of media, which at present render the technology economically non-viable. The aim of the study is to develop novel active media to be used in performance-enhanced biofiltration processes, by achieving an optimum balance and combination of the media adsorption capacity with the biodegradation of H2S through the bacteria immobilised on the media. An enrichment culture was obtained from activated sludges in order to metabolise thiosulphate. Batch-wise experiments were conducted to optimise the bacteria immobilisation on activated carbon, so as to develop a novel “biocarbon”. Biofilm was mostly developed through culturing the bacteria with the presence of carbons in mineral media. SEM and BET tests of the carbon along with the culturing process were used to identify, respectively, the biofilm development and biocarbon porosity. Breakthrough tests evaluated the biocarbon performance with varying gas resistance time, inlet H2S concentration, and type of support materials. Fundamental issues were discussed, including type of support material, mode of bacteria immobilisation, pore blockages, and biodegradation kinetics, etc. This batch-wise study provides a basis for our future research on optimisation of the biofiltration process using a bio-trickling reactor.

scholarly journals Clay Hybrid Membranes in Wastewater Treatment

2021 ◽  
Author(s):  
Tanushree Choudhury
Keyword(s):  
Active Layer ◽  
Ceramic Membrane ◽  
Low Cost ◽  
Composite Membranes ◽  
High Price ◽  
Manufacturing Cost ◽  
Support Material ◽  
Support Materials ◽  
Micro Particles ◽  
Ceramic Support

Most of NF membranes which are developed recently are composite membranes, whose support layer is covered with an active layer. Among different ceramic support materials that are currently used as support layer, α-alumina supports are integral part of the membrane which is made of artificial materials like alumina and thus adds to the high price of the membrane. This draws our attention in making low cost support material of natural clay which aims to be an excellent membrane support as it possesses high mechanical strength, high permeability, narrow pore size distribution and low manufacturing cost. Titania as active layer for ceramic membrane is preferred over Al2O3 membranes. One of the problems encountered when photocatalysts are immobilized on support is the detachment of the micro particles from the support for high flow rates of liquid effluent. This can be overcome by using Montmorillonite clay as support material as it is a great binder.

Evaluation of Thermal Gelation of F-127 in a Non-Aqueous Solvent and its Suitability as a Support Material for Additive Manufacturing

2014 ◽  
Vol 911 ◽  
pp. 226-231 ◽  
Author(s):  
Muhammad Fahad ◽  
Maqsood Ahmed Khan ◽  
Marianne Gilbert
Keyword(s):  
Additive Manufacturing ◽  
Elevated Temperatures ◽  
Industrial Applications ◽  
Manufacturing Processes ◽  
Support Material ◽  
Support Materials ◽  
Thermal Gelation ◽  
Aqueous Solvent ◽  
Reverse Thermal Gel ◽  
Am Processes

Pluronics are well known for their reverse thermal gel (RTG) formation in aqueous solutions and have been used in a variety of industrial applications. Additive Manufacturing processes that utilize jetting technology require support materials for building parts that comprise holes, cavities and/or overhangs. Currently available support materials include waxes which due to their brittleness, are weak and can lead to accuracy issues during part building via jetting technology. Pluronic F-127 in a non-aqueous solvent (Formamide) have been investigated in this paper for thermal gelation at elevated temperatures and the suitability of this composition as support material for jetting based AM processes have been evaluated.

Properties of Films Characterized by Scanning Acoustic Microscope

2014 ◽  
Vol 1061-1062 ◽  
pp. 961-965
Author(s):  
Hong Juan Yan ◽  
Chun Guang Xu ◽  
Ding Guo Xiao ◽  
Qi Lin
Keyword(s):  
Elastic Modulus ◽  
Sound Velocity ◽  
Ultrasonic Wave ◽  
Acoustic Impedance ◽  
Extreme Values ◽  
Amplitude Spectrum ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
Acoustic Microscope ◽  
Scanning Acoustic Microscope

The scanning acoustic microscope is used to detect the properties of films. The ultrasonic wave propagates in the films with thickness h, acoustic impedance Z2 between medium with acoustic impedance Z1. The echoes from upper and lower interfaces overlap and interfere. The echoes are transformed by FFT. The interference phenomena are observed in amplitude spectrum of echoes. The spectrum has periodic extreme values at fn, fn=nc/2h. When thickness h is known, sound velocity c2 of film can be calculated. According to the principle, the properties of films such as thickness, acoustic impendence and elastic modulus are evaluated by scanning acoustic microscopy. The experimental results are good accorded with the actual properties of specimens.

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