Elastic melt-blown nonwoven fabrication of styrene‐ethylene/butylene‐styrene copolymer and polypropylene blends: a study of morphology and properties

Fabrics produced by the melt-blown nonwoven process have the advantage over competing materials of possessing an ultrafine fibrous and porous structure. However, their brittleness and poor toughness restrict their wider application. There is increasing demand for nonwovens that have high stretchability and elasticity while maintaining a melt-blown structure. In this study, polypropylene (PP) and styrene‐ethylene/butylene‐styrene copolymer (SEBS) were blended at different ratios and subsequently used in the melt-blowing process. The morphology of the blends displayed a co-continuous structure when the ratio of SEBS to PP in blends was similar. Furthermore, it was found that all the blends had good spinnability from the melt-blowing process during rheological and thermal properties tests. All the elastic melt-blown nonwovens fabricated in this research had elongations higher than 400% and elastic recoveries higher than 50%, which was indicative of good elasticity. Meanwhile, the nonwovens maintained fine fiber diameters and good filtration properties, in keeping with traditional melt-blown nonwovens.

Characterization of cellulose acetate functional groups synthesized from corn husk (Zea mays)

The use of masks is very important to reduce transmission of the COVID 19 virus. Therefore, an innovation is needed from mask materials is that are environmentally friendly, have good filtration quality and have anti-virus agents. An alternative way to provide masks with good filterability using a raw material of cellulose acetate. Cellulose acetate has fibrils that are bonded together so that it can form dense fibers. Fiber is a semipermeable layer that functions as a particle filtration. Therefore, this study aims to get cellulose from corn husks via delignification. The research method consisted of extracting cellulose from corn husks and further synthesizing cellulose acetate. FTIR results showed an absorption peak at wave numbers 3349 cm-1, 1728 cm-1, 1252 cm-1, and 1031 cm-1. These peaks indicated the presence functional groups of OH, C=O, aryl ether, and C-O. This functional group indicates a cellulose acetate compound.

Filtration efficiency improvement of air filter paper for fine particles by electrospinning technology

Due to great advantages, such as simple operation, high porosity, and good fiber continuity, the working principle and research progress of electrospinning technology was studied and polyvinyl alcohol (PVOH) nanofibers were prepared via this process. Air filter paper was used as the receiving substrate to prepare electrospun nano air filter paper (NAFP). The PVOH concentration, static voltage, and receiving distance, were tested to explore the influence of spinning parameters on the filtration performance. Further, the microfiber morphology of the electrospun NAFP was observed. The performance of filter paper, including air permeability, pore size, initial resistance, filtration efficiency, and dust retention, were tested. The results showed that the electrospun NAFP had better filtration performance compared to the air filter paper, and simultaneously they had lower initial resistance and higher precision filtration efficiency. The nanofiber influenced the surface of the air filter paper, as it sharply reduced the pore size. When the spinning condition was 10%, 21 kV, and 15 cm, the pore size decreased approximately 0.6 times of the original, which meant the electrospun NAFP could capture particles ≥ 0.2 μm in size. Finally, after three repeated uses, the good filtration performance was maintained.

Application of Biopolymeric Electrospun Nanofibers in Biological Science

Biopolymers are those class of macromolecules which are found in nature or extracted from the living organisms. Various structures and properties of the biopolymers-based materials are well researched till to date. These mainly includes hydrogels, bio glasses, bio inks, biocomposites, fibers and others. These biopolymers-based structures have some limitations. However, Biopolymers have some common advantages (i.e., non-toxicity, easy availability, monodispersity, degradability, and better solubility etc.) and disadvantages (i.e., poor thermal and chemical stabilities, brittleness etc.). To overcome these disadvantages, it is necessary to tailor these polymers by few emerging techniques like “Electrospinning”. Electrospinning is one of the easiest techniques to prepare nanofibers from polymeric solutions by applying high voltage. Obtained nano/micro structural polymeric fibers have good properties like high surface area, porosity and low weights etc. The materials having high surface area and porosity can easily interact with cells and tissues, are better mobile vehicles for drugs, as well as possess good filtration and adsorption abilities. Thus, these one-dimensional structures of the biopolymers are very useful in various fields of biomedical especially water sanitation/desalination, tissue engineering, drug delivery and scaffolds. Various biopolymers like chitosan, chitin, sodium alginate, guar gum, polylactic acid and others are successfully fabricated as fibers and used in various fields of biomedical.

Preparation of different scale firous membranes and their filtration properties

In this work, the PAN monolayer/composite nanofibrous membranes were successfully fabricated at different processing parameters. As expected, compared with monolayer membranes, the composite membrane revealed high breaking strength, high breaking elongation, high porosity and good filtration performance. The composite method used in this article also provides new ideas for designing filter materials.

DEVELOPMENT OF MACHINE LEARNING METHOD WITH BIOMETRIC PROTECTION WITH NEW FILTRATION METHODS

Biometric images were processed and filtered by a newly developed Ateb-Gabor wavelet filter. Identification of biometric images was performed by machine learning methods. The Gabor filter based on Ateb functions is effective for filtering because it contains generalizations of trigonometric functions. Developed wavelet transform of Ateb-Gabor function. It is shown that the function depends on seven parameters, each of which makes significant changes in the results of filtering biometric images. A study of the wavelet Ateb-Gabor function was performed. The graphical dependences of the Gabor filter wavelet and the Ateb-Gabor filter wavelet are constructed. The introduction of wavelet transforms reduces the complexity of Ateb-Gabor filter calculations by simplifying function calculations and reducing filtering time. The complexity of the algorithms for calculating the Gabor filter wavelet and the Ateb-Gabor filter wavelet is evaluated. Ateb-Gabor filtering allows you to change the intensity of the entire image, and to change certain ranges, and thus change certain areas of the image. It is this property that biometric images should have, in which the minions should be contrasting and clear. Ateb functions have the ability to change two rational parameters, which, in turn, will allow more flexible control of filtering. The properties of the Ateb function are investigated, as well as the possibility of changing the amplitude of the function, the oscillation frequency to the numerical values ​​of the Ateb-Gabor filter. By using the parameters of the Ateb function, you can get a much wider range of shapes and sizes, which expands the number of possible filtering options. You can also implement once filtering, taking into account the direction of the minutes and reliably determine the sharpness of the edges, rather than filtering batocrates. The reliability results were tested on the basis of NIST Special Database 302, and good filtration results were shown. This was confirmed by a comparison experiment between the Wavelet-Gabor filtering and the Ateb-Gabor wavelet function based on the measurement of the PSNR signal-to-noise ratio.

Preparation of a Cu-BTC/pan electrospun film with a good air filtration performance

Copper-1,3,5-benzoic acid (Cu BTC) was synthesized by the hydrothermal method, which had regular octahedral morphology. Cu-BTC particles were used as additives in the polyacrylonitrile (PAN) solution to fabricate Cu-BTC/PAN membrane by the electrostatic spinning method, its good filtration performance was witnessed experimentally.

Buchsbaumness of the associated graded rings of filtration

Let [Formula: see text] be a Noetherian local ring of dimension [Formula: see text] and [Formula: see text] an [Formula: see text]-primary ideal of [Formula: see text]. In this paper, we discuss a sufficient condition, for the Buchsbaumness of the local ring [Formula: see text] to be passed onto the associated graded ring of filtration. Let [Formula: see text] denote an [Formula: see text]-good filtration. We prove that if [Formula: see text] is Buchsbaum and the [Formula: see text] -invariant, [Formula: see text] and [Formula: see text], coincide then the associated graded ring [Formula: see text] is Buchsbaum. As an application of our result, we indicate an alternative proof of a conjecture, of Corso on certain boundary conditions for Hilbert coefficients.

WAVELET TRANSFORMATION ATEB-GABOR FILTERS TO BIOMETRIC IMAGES

Biometric images were pre-processed and filtered in two ways, by wavelet- Gabor and wavelet Ateb-gabor filtration. Ateb-based Gabor filter is effective for filtration because it contains generalizations of trigonometric functions. The wavelet transform of Ateb-Gabor function was developed. The function dependence on seven parameters was shown, each of them significantly changes the filtering results of biometric images. The Ateb-Gabor wavelet research was performed. Graphic dependencies of the wavelet Gabor filter and the wavelet Ateb-Gabor filter were constructed. The appliance of wavelet transform makes it possible to reduce the complexity of calculating an Ateb-Gabor filter by simplifying function calculations and reducing filtering time. The complexities of algorithms for calculating the wavelet Gabor filter and the wavelet Ateb-Gabor filter have been evaluated. Ateb-Gabor filtration allows you to adjust the intensity of the entire image, and to change certain ranges, thereby changing certain areas of the image. Biometric images should have this property, on which the minucius should be contrasting and clear. Ateb functions have the property of changing two rational parameters, which will allow to make more flexible control of filtration. The properties of the Ateb function, as well as the possibility of changing the amplitude of the function, the oscillation frequency by the numerical values of the Ateb-Gabor filter, were investigated. By using the parameters of the Ateb function, you can get a much larger range of shapes and sizes, which expands the number of possible filtration options. You can also perform filtration once, taking into account the direction of the minucius and reliably determine the sharpness of the edges, rather than perform filtration many times. The reliability of results were tested using NIST Special Database 302 and good filtration results were shown. This is confirmed by the comparison experiment between the wavelet-Gabor filter and the wavelet Ateb-Gabor function based on the PSNR signal-to-noise ratio measurement.

Recent Patent on a Tree-type Cylindrical-shaped Nanoporous Filtering Membrane

Background: Nanoporous filtering membranes can be used for super purification including a liquid-liquid separation. It is the aim of engineers to design these membranes with good filtration capabilities, high fluxes and satisfying mechanical strengths. Realistic membranes need to have a balance among these performances to achieve satisfactory overall performances. Objective: The study aims to show a tree-type cylindrical-shaped nanoporous filtering membrane with good characteristics. Methods: According to the principle of the nanotube tree for transportation presented previously, here the design method of a tree-type cylindrical shaped nanoporous filtering membrane is presented and the flow resistances of this membrane have been calculated for varying operational parameter values. Results: It is shown that the invented membrane possesses nanoscale filtration pores and larger flow-resistance-reducing pores. These pores are densely evenly distributed on the membrane surface. The membrane practically has a low flow resistance and thus a high flux if its thickness is as small as possible. It can also be used for a liquid-liquid separation if the mixed liquids have largely different interactions with the pore walls of the membrane. Conclusion: By an appropriate design, the invented membrane has a good overall performance including the capabilities of super purification or a liquid-liquid separation, the high flux and a satisfactory mechanical strength.