The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Sheekea Mah - One of the best experts on this subject based on the ideXlab platform.
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the study of reverse osmosis on glycerin solution Filtration dead end and crossflow Filtrations transport mechanism rejection and permeability investigations
Desalination, 2014Co-Authors: Sheekea Mah, Catherine Ching Ha Chang, Siangpiao ChaiAbstract:Abstract The utilization of recycled water from reverse osmosis (RO) Filtration within a production process can be one of the potential solutions to conserve fresh water. In this work, the effect of membrane physicochemical properties on glycerin rejection and water permeability were demonstrated in dead-end and crossflow Filtrations. The study showed that RO membrane with high surface roughness, high negative charge in glycerin solution, low water contact angle, high water affinity and small pore radius were favorable in glycerin separation. Crossflow Filtration provided better rejection and permeability than that of dead-end Filtration using the RO membranes studied in this work. The combination of fundamental knowledge on membrane physicochemical properties and boundary layer theory was used to speculate the molecular movement and transport mechanism across the membrane. The highest rejection of 99.81% was achieved by TFC-HR membrane, along with the permeate flux of 11.86 kg/m2·h in the crossflow Filtration while in the dead-end Filtration, only a rejection of 96.37% and permeate flux of 4.93 kg/m2·h were recorded. Lastly, it was found that the membrane surface pattern influenced the membrane performance significantly in terms of rejection and permeability.
Yusu Wang - One of the best experts on this subject based on the ideXlab platform.
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simba an efficient tool for approximating rips Filtration persistence via simplicial batch collapse
European Symposium on Algorithms, 2016Co-Authors: Yusu WangAbstract:In topological data analysis, a point cloud data P extracted from a metric space is often analyzed by computing the persistence diagram or barcodes of a sequence of Rips complexes built on P indexed by a scale parameter. Unfortunately, even for input of moderate size, the size of the Rips complex may become prohibitively large as the scale parameter increases. Starting with the Sparse Rips Filtration introduced by Sheehy, some existing methods aim to reduce the size of the complex so as to improve the time efficiency as well. However, as we demonstrate, existing approaches still fall short of scaling well, especially for high dimensional data. In this paper, we investigate the advantages and limitations of existing approaches. Based on insights gained from the experiments, we propose an efficient new algorithm, called SimBa, for approximating the persistent homology of Rips Filtrations with quality guarantees. Our new algorithm leverages a batch collapse strategy as well as a new sparse Rips-like Filtration. We experiment on a variety of low and high dimensional data sets. We show that our strategy presents a significant size reduction, and our algorithm for approximating Rips Filtration persistence is order of magnitude faster than existing methods in practice.
Siangpiao Chai - One of the best experts on this subject based on the ideXlab platform.
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the study of reverse osmosis on glycerin solution Filtration dead end and crossflow Filtrations transport mechanism rejection and permeability investigations
Desalination, 2014Co-Authors: Sheekea Mah, Catherine Ching Ha Chang, Siangpiao ChaiAbstract:Abstract The utilization of recycled water from reverse osmosis (RO) Filtration within a production process can be one of the potential solutions to conserve fresh water. In this work, the effect of membrane physicochemical properties on glycerin rejection and water permeability were demonstrated in dead-end and crossflow Filtrations. The study showed that RO membrane with high surface roughness, high negative charge in glycerin solution, low water contact angle, high water affinity and small pore radius were favorable in glycerin separation. Crossflow Filtration provided better rejection and permeability than that of dead-end Filtration using the RO membranes studied in this work. The combination of fundamental knowledge on membrane physicochemical properties and boundary layer theory was used to speculate the molecular movement and transport mechanism across the membrane. The highest rejection of 99.81% was achieved by TFC-HR membrane, along with the permeate flux of 11.86 kg/m2·h in the crossflow Filtration while in the dead-end Filtration, only a rejection of 96.37% and permeate flux of 4.93 kg/m2·h were recorded. Lastly, it was found that the membrane surface pattern influenced the membrane performance significantly in terms of rejection and permeability.
Gunnar Eigil Jonsso - One of the best experts on this subject based on the ideXlab platform.
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dynamic microFiltration with a vibrating hollow fiber membrane module Filtration of yeast suspensions
Journal of Membrane Science, 2006Co-Authors: Soren Prip Eie, Maria Guerra, Arvid Garde, Gunnar Eigil JonssoAbstract:Abstract A novel dynamic microFiltration system consisting of a vibrating hollow fiber membrane module is presented. The vibrations induce the shear rate at the membrane surface which makes it possible to filtrate at low feed cross-flow velocity and thus at a low transmembrane pressure. Results from test Filtrations of bakers yeast suspensions are presented and the critical flux concept is used to evaluate the Filtration data. The critical flux at the maximum degree of vibration is improved 325% compared to the critical flux at the minimum degree of vibration. An equation to calculate the membrane surface shear rate from the vibration frequency and amplitude is presented. The correlation between the critical flux and average surface shear rate is J p , crit = 8.22 ( γ ¯ s ) 0.26 . It is further shown that when operating below the critical flux in a 4.5 h test Filtration the permeability is kept constant. Above the critical flux, the transmembrane pressure increases resulting in a decrease in membrane permeability.
Mukter Zaman - One of the best experts on this subject based on the ideXlab platform.
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Recent advances in utilization of graphene for Filtration and desalination of water: A review
Desalination, 2015Co-Authors: Arash Aghigh, H.y. Wong, Md. Shabiul Islam, Vahid Alizadeh, Mukter ZamanAbstract:Water as a basic necessity is an influential factor in our everyday lives but water pollution, urbanization, and huge population growth has led humankind to the brink of water resource scarcity. To address this issue, water Filtration as well as desalination got enormous interest by the research community. Recently graphene, a new two dimensional material with exceptional capabilities and characteristics, has become apposite in the field of water Filtration and desalination. This paper reviews the recent progress in Graphene research for water desalination using novel methods such as Nanoporous Graphene (NG) sheets as well as Capacitive Deionization (CDI) method. Among which most promising uniform NG sheets can be used for water Filtration and desalination at a removal efficiency of 33-100% depending on the pore size as well as the applied pressure [1] and has a water flow rate of 10-100L/cm2/day/MPa [1] and by adjusting the pore size, different mineral Filtrations can take place [1]. The main drawback which limits the widespread utilization of NG is the mechanical stability of NG sheets as the pore number increases since water permeability is directly proportional to the number of pores, pore distribution as well as the mass production of graphene sheets which has not been solved [1,2]. Apart from this, in CDI method, Filtration is done by applying a certain potential difference between arrays of paired electrodes. The mentioned CDI method has moderate removal efficiency but has higher energy efficiency compared to the reverse osmosis method due to minimal energy requirement of only 0.1-2.03kWh/m3[3]. Graphene oxide based desalination is another emerging desalination method which is gaining popularity because of its ease of fabrication, industry scale production, and strong mechanical stability [4,5]. It uses the "ion sponging" effect and can block hydrated ions with a radius greater than 4.5A°. But still this method should be further improved as small seawater salts are able to pass from the GO sieve [6,7].