New damping materials by fabrication of ACM/PVC alloy into hollow fibers

The Automated Hollow Fiber Ultrafiltration (AHFU) method is proposed here as a simple, efficient and rapid virus concentration technique from tap and drinking water sources. The results reported here extend the testing of the AHFU method to include two Picornaviruses [Poliovirus 2 (vaccine) and Echovirus 1] and Reovirus 3. Their respective mean virus recoveries from between 3 and 100 l of tap water is 88 ± 26, 79 ± 60, and 104 ± 48%. Various approaches including membrane surface modification, changes in backwash hydrodynamics, modification of the feed and backwash composition, and the use of S35-methionine labelled Poliovirus 2, are used to study the recovery of sorbed Poliovirus 2 from the hollow fiber/solution interface. An increase in the backwash pH to between 9.5 and 10.5 significantly improved Poliovirus 2 recovery. This, together with the labelled experiments, indicates that the virus-membrane interactions are probably electrostatic in nature. Convective polarization during filtration probably brings the virus close enough to the surface for these interactions to occur since virus losses were not detected for a non-permeation recycle experiment. Because very low Reynold's numbers are used, the flow is in the creeping-flow-regime for both filtration and backwashing (axial and radial). Unless significantly higher Reynolds could be used, enhanced recovery due to purely hydrodynamic forces is unlikely. High Reynold's numbers, of course, are limited by the pressure constraints of the hollow fibers.

Download Full-text

Electrospun-based TiO2 nanofibers for organic pollutant photodegradation: a comprehensive review

Reviews in Chemical Engineering ◽

10.1515/revce-2020-0022 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Khee Chung Hui ◽

Hazwani Suhaimi ◽

Nonni Soraya Sambudi

Keyword(s):

Visible Light ◽

Organic Pollutants ◽

Organic Pollutant ◽

Hollow Fibers ◽

Promising Alternative ◽

Tio2 Nanofibers ◽

As Doping ◽

Secondary Pollutants ◽

Photocatalytic Reactors ◽

Light Area

Abstract Titanium dioxide (TiO2) is commonly used as a photocatalyst in the removal of organic pollutants. However, weaknesses of TiO2 such as fast charge recombination and low visible light usage limit its industrial application. Furthermore, photocatalysts that are lost during the treatment of pollutants create the problem of secondary pollutants. Electrospun-based TiO2 fiber is a promising alternative to immobilize TiO2 and to improve its performance in photodegradation. Some strategies have been employed in fabricating the photocatalytic fibers by producing hollow fibers, porous fibers, composite TiO2 with magnetic materials, graphene oxide, as well as doping TiO2 with metal. The modification of TiO2 can improve the absorption of TiO2 to the visible light area, act as an electron acceptor, provide large surface area, and promote the phase transformation of TiO2. The improvement of TiO2 properties can enhance carrier transfer rate which reduces the recombination and promotes the generation of radicals that potentially degrade organic pollutants. The recyclability of fibers, calcination effect, photocatalytic reactors used, operation parameters involved in photodegradation as well as the commercialization potential of TiO2 fibers are also discussed in this review.

Download Full-text

Polyvinyl butyral‐zirconia hybrid hollow fibers prepared by air gap spinning

Journal of Applied Polymer Science ◽

10.1002/app.50164 ◽

2020 ◽

Vol 138 (14) ◽

pp. 50164

Author(s):

Anamul Hoque Bhuiyan ◽

Takuma Nagakawa ◽

Koji Nakane

Keyword(s):

Polyvinyl Butyral ◽

Air Gap ◽

Hollow Fibers

Download Full-text

Topology Optimization of Hard-Coating Thin Plate for Maximizing Modal Loss Factors

Coatings ◽

10.3390/coatings11070774 ◽

2021 ◽

Vol 11 (7) ◽

pp. 774

Author(s):

Haitao Luo ◽

Rong Chen ◽

Siwei Guo ◽

Jia Fu

Keyword(s):

Topology Optimization ◽

Objective Function ◽

Composite Plates ◽

Optimization Method ◽

Hard Coating ◽

Design Variables ◽

Coating Composite ◽

Damping Materials ◽

Topology Optimization Method ◽

Loss Factors

At present, hard coating structures are widely studied as a new passive damping method. Generally, the hard coating material is completely covered on the surface of the thin-walled structure, but the local coverage cannot only achieve better vibration reduction effect, but also save the material and processing costs. In this paper, a topology optimization method for hard coated composite plates is proposed to maximize the modal loss factors. The finite element dynamic model of hard coating composite plate is established. The topology optimization model is established with the energy ratio of hard coating layer to base layer as the objective function and the amount of damping material as the constraint condition. The sensitivity expression of the objective function to the design variables is derived, and the iteration of the design variables is realized by the Method of Moving Asymptote (MMA). Several numerical examples are provided to demonstrate that this method can obtain the optimal layout of damping materials for hard coating composite plates. The results show that the damping materials are mainly distributed in the area where the stored modal strain energy is large, which is consistent with the traditional design method. Finally, based on the numerical results, the experimental study of local hard coating composites plate is carried out. The results show that the topology optimization method can significantly reduce the frequency response amplitude while reducing the amount of damping materials, which shows the feasibility and effectiveness of the method.

Download Full-text

Removal of CO2 from biogas by membrane contactor using PTFE hollow fibers with smaller diameter

Journal of Membrane Science ◽

10.1016/j.memsci.2021.119232 ◽

2021 ◽

Vol 627 ◽

pp. 119232

Author(s):

Mei Li ◽

Zhihao Zhu ◽

Meiqing Zhou ◽

Xingming Jie ◽

Lina Wang ◽

...

Keyword(s):

Hollow Fibers ◽

Membrane Contactor

Download Full-text