Optimization of Filter Properties for Recirculating Etch Baths

2000 ◽  
Vol 43 (3) ◽  
pp. 30-40 ◽  
Author(s):  
Wayne Kelly ◽  
Donald Grant ◽  
Joseph Zahka
Keyword(s):  
High Efficiency ◽  
Polystyrene Latex ◽  
Capture Efficiency ◽  
Particle Capture ◽  
Membrane Filters ◽  
High Particle ◽  
Ideal Filter ◽  
Surface Modified ◽  
And Diffusion ◽  
The Ideal

Membrane filters are often used to remove small particles from liquids in recirculating etch baths (REBs). The ideal filter for this application would have both high particle capture efficiency and high flow permeability. Unfortunately, filters with high particle capture efficiency often have low permeability because the dominant particle capture mechanism is mechanical sieving. This paper describes more efficient capture mechanisms, interception and diffusion, and a filter with a surface modified to capture particles by these mechanisms. The filter has the same permeability as a conventional 0.45-μm filter and retains particles more efficiently than a conventional 0.05-μm filter. The filter is capable of removing multiple types of small (0.065-μm) particles (polystyrene latex, silicon nitride, alumina, etc.) with high efficiency (> 99.9 percent).

Particle Capture Mechanisms in Gases and Liquids: An Analysis of Operative Mechanisms in Membrane/Fibrous Filters

1989 ◽  
Vol 32 (4) ◽  
pp. 43-51
Author(s):  
Donald Grant ◽  
Benjamin Liu ◽  
Wayne Fisher ◽  
R. Bowling
Keyword(s):  
Relative Effectiveness ◽  
Particle Capture ◽  
Membrane Filters ◽  
Gas Streams ◽  
Media System ◽  
Fibrous Filters ◽  
Diffusion In Liquids ◽  
Low Levels ◽  
Chemical Conditions ◽  
And Diffusion

Membrane filters are capable of reducing particles in fluids to very low levels through the action of several capture mechanisms. However, the effectiveness of these mechanisms at removing particles is influenced by the properties of the fluid undergoing filtration. This article reviews the theories of particle capture mechanisms and discusses their relative effectiveness in various fluid types. Theory indicates that membrane filters remove essentially all particles from gas streams by interception and diffusion. In liquids, the operative particle capture mechanisms depend upon the physical chemistry of the particle-fluid-filter media system. Under favorable chemical conditions, the operative capture mechanisms are the same as in gases with essentially all particles removed. However, under unfavorable chemical conditions, only particle sieving occurs, and capture is greatly reduced. In addition, captured particles are less tightly held in liquids and shearing forces are larger, hence particle reentrainment is more likely.

scholarly journals A Numerical Study of the Effect of Particle Size on Particle Deposition on Turbine Vanes and Blades

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110178
Author(s):  
Zhengang Liu ◽  
Weinan Diao ◽  
Zhenxia Liu ◽  
Fei Zhang
Keyword(s):  
Particle Size ◽  
Particle Deposition ◽  
Numerical Study ◽  
Stokes Number ◽  
Capture Efficiency ◽  
Particle Capture ◽  
Factors Affecting ◽  
Pressure Surface ◽  
Deposition Area ◽  
Turbine Vanes

Particle deposition could decrease the aerodynamic performance and cooling efficiency of turbine vanes and blades. The particle motion in the flow and its temperature are two important factors affecting its deposition. The size of the particle influences both its motion and temperature. In this study, the motion of particles with the sizes from 1 to 20 μm in the first stage of a turbine are firstly numerically simulated with the steady method, then the particle deposition on the vanes and blades are numerically simulated with the unsteady method based on the critical viscosity model. It is discovered that the particle deposition on vanes mainly formed near the leading and trailing edge on the pressure surface, and the deposition area expands slowly to the whole pressure surface with the particle size increasing. For the particle deposition on blades, the deposition area moves from the entire pressure surface toward the tip with the particle size increasing due to the effect of rotation. For vanes, the particle capture efficiency increases with the particle size increasing since Stokes number and temperature of the particle both increase with its size. For blades, the particle capture efficiency increases firstly and then decreases with the particle size increasing.

scholarly journals Tannic acid-functionalized HEPA filter materials for influenza virus capture

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Subin Kim ◽  
Jinhyo Chung ◽  
Sang Hyun Lee ◽  
Jeong Hyeon Yoon ◽  
Dae-Hyuk Kweon ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Tannic Acid ◽  
High Efficiency ◽  
Influenza Viruses ◽  
Capture Efficiency ◽  
Protective Equipment ◽  
Filter Materials ◽  
Washing Process ◽  
Pathogenic Viruses ◽  
Cost Efficient

AbstractInfluenza, one of the most contagious and infectious diseases, is predominantly transmitted through aerosols, leading to the development of filter-based protective equipment. Though the currently available filters are effective at removing submicron-sized particulates, filter materials with enhanced virus-capture efficiency are still in demand. Coating or chemically modifying filters with molecules capable of binding influenza viruses has received attention as a promising approach for the production of virus-capturing filters. For this purpose, tannic acid (TA), a plant-derived polyphenol, is a promising molecule for filter functionalization because of its antiviral activities and ability to serve as a cost-efficient adhesive for various materials. This study demonstrates the facile preparation of TA-functionalized high-efficiency particulate air (HEPA) filter materials and their efficiency in influenza virus capture. Polypropylene HEPA filter fabrics were coated with TA via a dipping/washing process. The TA-functionalized HEPA filter (TA-HF) exhibits a high in-solution virus capture efficiency of up to 2,723 pfu/mm2 within 10 min, which is almost two orders of magnitude higher than that of non-functionalized filters. This result suggests that the TA-HF is a potent anti-influenza filter that can be used in protective equipment to prevent the spread of pathogenic viruses.

Corrosion Behaviours of Mo Modified Ti6Al4V Alloy in Hank’s Solution

2009 ◽  
Vol 610-613 ◽  
pp. 1150-1154
Author(s):  
Ai Lan Fan ◽  
Cheng Gang Zhi ◽  
Lin Hai Tian ◽  
Lin Qin ◽  
Bin Tang
Keyword(s):  
Electrochemical Corrosion ◽  
Optical Emission ◽  
Ti6al4v Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffusion Layers ◽  
Modified Layer ◽  
Surface Modified ◽  
Hank’S Solution ◽  
And Diffusion

The Mo surface modified layer on Ti6Al4V alloy was obtained by the plasma surface alloying technique. The structure and composition of the Mo modified Ti6Al4V alloy was investigated by X-ray diffraction (XRD) and glow discharge optical emission spectroscopy (GDOES). The Mo modified layer contains Mo coating on subsurface and diffusion layers between the subsurface and substrate. The X- ray diffraction analysis of the Mo modified Ti6Al4V alloy reveals that the outmost surface of the Mo modified Ti6Al4V alloy is composed of pure Mo. The electrochemical corrosion performance of the Mo modified Ti6Al4V alloy in 25°C Hank’s solution was investigated and compared with that of Ti6Al4V alloy. Results indicate that the self-corroding electric potential and the corrosion-rate of the Mo modified Ti6Al4V alloy are higher than that of Ti6Al4V alloy in 25°C Hank’s solution.

High-Efficiency Cut Blasting with Shell Radial Shaped Charge in Laboratory-Scale Blasting

2015 ◽  
Vol 1094 ◽  
pp. 445-450 ◽  
Author(s):  
Wei Chen ◽  
Hong Hao Ma ◽  
Zhao Wu Shen ◽  
De Bao Wang
Keyword(s):  
High Efficiency ◽  
Circular Tube ◽  
Rock Breaking ◽  
Shaped Charge ◽  
Axial Line ◽  
Rock Excavation ◽  
Crack Network ◽  
Utilization Ratio ◽  
The Cost ◽  
The Ideal

Due to the inefficiency problem of the cut blasting in rock excavation and rock breaking, a shell radial shaped charge device was proposed based of the ideal of ‘cutting to slotting’ and it was validated through experiments. For this device, the shell materials are used to be shaped materials and multiple shaped ring is designed on the circular tube. It can not only reduce charge quantity but also raise the utilization ratio of explosive energy. After explosion, multiple radial shaped charge jets can be formed along the axial line in sequence and then the surrounding rock mass would be cracked. The crack network will be formed along with the further extension of the fraction under the action of quasi static loading of detonation gas. The shell radial shaped charge device was tested through the cut blasting model experiment. Experimental results show that the utilization ratio of blasting hole nearly approaches 98% with this device. The blasting efficiency and cyclical footage can be improved effectively and the cost of drifting can also be reduced.

A multifunctional multi-walled carbon nanotubes/ceramic membrane composite filter for air purification

RSC Advances ◽  
2015 ◽  
Vol 5 (112) ◽  
pp. 91951-91959 ◽  
Author(s):  
Yang Zhao ◽  
Zhaoxiang Zhong ◽  
Ze-Xian Low ◽  
Zhong Yao
Keyword(s):  
Carbon Nanotubes ◽  
Ceramic Membrane ◽  
Small Diameter ◽  
Capture Efficiency ◽  
Air Purification ◽  
Particle Capture ◽  
Multi Walled Carbon Nanotubes ◽  
Composite Filter ◽  
Walled Carbon Nanotubes

Carbon nanotubes (CNTs) are very small diameter fibers that have the potential to be integrated into filters to further increase particle capture efficiency.

scholarly journals Methods to Form the Pedagogical Culture of Parents in the Educational System of the School

2020 ◽  
pp. 38-42
Author(s):  
Galina Veniaminovna Sorokoumova ◽  
Anastasiia Olegovna Bespalova
Keyword(s):  
Common Sense ◽  
Educational System ◽  
High Efficiency ◽  
Educational Institution ◽  
Parenting Skills ◽  
The Family ◽  
The Impact ◽  
The Ideal ◽  
Pedagogical Culture

The article deals with the concept of pedagogical culture of parents, the goals of development of pedagogical culture of parents and methods of formation and improvement of the level of pedagogical culture of parents. The paper focuses on the tasks of interaction between an educational institution and the family in the upbringing of children. Methods of study. To study the possibility of forming a pedagogical culture of parents, we used a questionnaire to survey the needs of parents to interact with the educational institution and the interest of teachers in working with the family, the «Ideas about the ideal parent» method by R. V. Ovcharova, Y.A. Degtyareva, «Family Biofield» inquirer by V. V. Boyko and «Determination of parenting skills» questionnaire by O.L. Zvereva. Results of the study. The article shows the results of the impact of the program, which includes a seminar using the case technology «pedagogical culture of parents» and parent training based on the program «education based on common sense» on the formation of the pedagogical culture of parents. Conclusion. The results of the study proved the possibility of purposeful formation of the pedagogical culture of parents in the educational system of the school and the high efficiency of practice – and personality-oriented methods of such work, and also showed greater competence and awareness among parents and kindergarten teachers in the education of children.

scholarly journals Hydrophobic Forces Are Relevant to Bacteria-Nanoparticle Interactions: Pseudomonas putida Capture Efficiency by Using Arginine, Cysteine or Oxalate Wrapped Magnetic Nanoparticles

2018 ◽  
Vol 2 (3) ◽  
pp. 29 ◽  
Author(s):  
Federico Figueredo ◽  
Albert Saavedra ◽  
Eduardo Cortón ◽  
Virginia Diz
Keyword(s):  
Amino Acid ◽  
Pseudomonas Putida ◽  
Surface Characteristics ◽  
Magnetic Core ◽  
Capture Efficiency ◽  
Homogeneous Distribution ◽  
Infrared Spectrometry ◽  
Ideal Situation ◽  
High Level ◽  
Surface Modified

Size, shape and surface characteristics strongly affect interfacial interactions, as the presented among iron oxide nanoparticles (NPs) aqueous colloids and bacteria. In other to find the forces among this interaction, we compare three types of surface modified NPs (exposing oxalate, arginine or cysteine residues), based on a simple synthesis and derivation procedure, that allows us to obtain very similar NPs (size and shape of the magnetic core). In this way, we assure that the main difference in the synthesized NPs are the oxalate or amino acid residue exposed, an ideal situation to compare their bacterial capture performance, and so too the interactions among them. Field emission scanning electron microscopy showed homogeneous distribution of particle sizes for all systems synthesized, close to 10 nm. Magnetization, zeta potential, Fourier transformed infrared spectrometry and other studies allow us further characterization. Capture experiments of Pseudomonas putida bacterial strain showed a high level of efficiency, independently of the amino acid used to wrap the NP, when compared with oxalate. We show that bacterial capture efficiency cannot be related mostly to the bacterial and NP superficial charge relationship (as determined by z potential), but instead capture can be correlated with hydrophobic and hydrophilic forces among them.

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