The influence of polymer concentration, applied voltage, modulation depth and pulse frequency on DNA separation by pulsed field CE

Abstract In this work, machining of microchannel in silica glass was successfully carried out using electro chemical discharge machining (ECDM) process. The experiments were planned according to L27 orthogonal array with applied voltage, stand-off distance (SOD), electrolyte concentration, pulse frequency and pulse-on-time (TON) as control factors. The material removal rate (MRR), overcut (OC) and tool wear rate (TWR) were considered as response characteristics. In this study the effects of control parameters on MRR, OC and TWR have been investigated. The multi-objective optimization of ECDM was carried out through grey relational analysis (GRA) method. Optimal combination of process parameters achieved from GRA was 45V applied voltage, 25wt.% electrolyte concentration, 1.5mm SOD, 400Hz pulse frequency and 45μs TON. ANOVA for GRG study revealed that the applied voltage (70.33%) was most significant factor affecting output responses followed by electrolyte concentration (11.69%), pulse frequency (4.98%) and SOD (4.13%). Furthermore, the regression equations were formulated for the optimum combination to predict the collaboration and higher-order effects of the control parameters. In addition confirmation test was conducted for the optimal setting of process parameters and the comparison of experimental results exhibited a good agreement with predicted values. The microstructural observation of machined surface for the optimum combination was carried out.

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Artificial Neural Networks Modeling of Electrospun Polyurethane Nanofibers from Chloroform/Methanol Solution

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.41.18 ◽

2016 ◽

Vol 41 ◽

pp. 18-30 ◽

Cited By ~ 2

Author(s):

Saman Firoozi ◽

Amir Amani ◽

Mohammad Ali Derakhshan ◽

Hossein Ghanbari

Keyword(s):

Neural Networks ◽

Artificial Neural Networks ◽

Polymer Solution ◽

Flow Rate ◽

Applied Voltage ◽

Polymer Concentration ◽

Electrospun Nanofibers ◽

Dominant Factor ◽

Artificial Neural ◽

Chloroform Methanol

In this study, electrospun nanofibers of polyurethane were prepared utilizing a new solvent system made of chloroform/methanol. Also, we planned to assess effects of four important parameters on diameter of electrospun polyurethane nanofibers using Artificial Neural Networks (ANNs). The parameters investigated included flow rate of syringe pump, distance of spinneret to collector, applied voltage and concentration of polymer solution. Diameter of obtained electrospun nanofibers was measured using scanning electron microscopy (SEM). Results showed that flow rate and distance had reverse relation with fiber diameter, while applied voltage and concentration of polymer solution directly affected the diameter. Also, polymer concentration was shown to be the dominant factor here.

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Controlled Morphology of Porous Polyvinyl Butyral Nanofibers

Journal of Nanomaterials ◽

10.1155/2011/292516 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 42

Author(s):

Daniela Lubasova ◽

Lenka Martinova

Keyword(s):

Applied Voltage ◽

High Efficiency ◽

Polymer Concentration ◽

Polyvinyl Butyral ◽

Solution Concentration ◽

Solvent Mixture ◽

Electrospinning Process ◽

Filter Materials ◽

One Step ◽

Poor Solvent

A simple and effective method for the fabrication of porous nanofibers based on the solvent evaporation methods in one-step electrospinning process from the commercial polyvinyl butyral (PVB) is presented. The obtained nanofibers are prevalently amorphous with diameters ranging from 150 to 4350 nm and specific surface area of approximately 2–20 m2/g. Pore size with irregular shape of the porous PVB fibers ranged approximately from 50 to 200 nm. The effects of polymer solution concentration, composition of the solvents mixture, and applied voltage on fiber diameter and morphology were investigated. The theoretical approach for the choice of poor and good solvents for PVB was explained by the application Hansen solubility parameter (HSP) and two-dimensional graph. Three basic conditions for the production of porous PVB nanofibers were defined: (i) application of good/poor solvent mixture for spinning solution, (ii) differences of the evaporation rate between good/poor solvent, and (iii) correct ratios of good/poor solvent (v/v). The diameter of prepared porous PVB fibers decreased as the polymer concentration was lowered and with higher applied voltage. These nanofiber sheets with porous PVB fibers could be a good candidate for high-efficiency filter materials in comparison to smooth fibers without pores.

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Coaxial nanofibers from poly(caprolactone)/ poly(vinyl alcohol)/Thyme and their antibacterial properties

Journal of Industrial Textiles ◽

10.1177/1528083716674906 ◽

2016 ◽

Vol 47 (5) ◽

pp. 834-852 ◽

Cited By ~ 15

Author(s):

Pantea Koushki ◽

S Hajir Bahrami ◽

Marziyeh Ranjbar-Mohammadi

Keyword(s):

Flow Rate ◽

Applied Voltage ◽

Vinyl Alcohol ◽

Polymer Concentration ◽

Antibacterial Properties ◽

Poly Vinyl Alcohol ◽

Core Shell ◽

Operational Parameters ◽

The Core ◽

Poly Caprolactone

Today, with substantial global demand from patients suffering from wounds and burns, the wound care sector has gained great deal of interest in medical industry. Herein, coaxial electrospun poly(caprolactone)/poly(vinyl alcohol) core–shell nanofibers incorporated with Thyme extract in the core structure were prepared using coaxial electrospinning, and the effect of various operational parameters such as polymer concentration, applied voltage, flow rate, distance, and Thyme concentration on nanofiber diameter were studied. Physical and mechanical properties of the nanofibers were determined by analytical techniques. The results revealed that desired nanofibers with uniform surface morphology and acceptable tensile strength could be obtained at applied voltage of 15 kV, needle tip-target of 13 cm, core flow rate of 0.2 mL/h, and shell flow rate of l mL/h. Moreover, MTT assay shows that the nanofibers are highly biocompatible regardless of Thyme encapsulation. Antibacterial activities of the prepared core–shell nanofibers were also examined against two bacteria—gram-positive Staphylococcus and gram-negative Escherichia. Encapsulation of 5% (w/v) Thyme extract concentration in the core–shell poly(caprolactone)/poly(vinyl alcohol) nanofibers led to high antibacterial activity of the produced nanofibers.

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Size mapping of electric field-assisted production of polycaprolactone particles

Journal of The Royal Society Interface ◽

10.1098/rsif.2010.0099.focus ◽

2010 ◽

Vol 7 (suppl_4) ◽

Cited By ~ 30

Author(s):

M. Enayati ◽

Z. Ahmad ◽

E. Stride ◽

M. Edirisinghe

Keyword(s):

Particle Size ◽

Electric Field ◽

Size Distribution ◽

Flow Rate ◽

Applied Voltage ◽

Polymer Concentration ◽

Extensive Study ◽

Uv Spectrophotometry ◽

Polymeric Particles ◽

Stable Cone

In this investigation, biodegradable polycaprolactone polymeric particles (300–4500 nm in diameter) were prepared by jetting a solution in an electric field. An extensive study has been carried out to determine how the size and size distribution of the particles generated can be controlled by systematically varying the polymer concentration in solution (and thereby its viscosity and electrical conductivity), and also the selected flow rate (2–50 µl min −1 ) and applied voltage (0–15 kV) during particle generation. Change in these parameters affects the mode of jetting, and within the stable cone-jet mode window, an increase in the applied voltage (approx. 15 kV) resulted in a reduction in particle size and this was more pronounced at high flow rates (such as; 30, 40 and 50 µl min −1 ) in the same region. The carrier particles were more polydisperse at the peripheral regions of the stable cone-jet mode, as defined in the applied voltage-flow rate parametric map. The effect of loading a drug on the particle size, size distribution and encapsulation efficiency was also studied. Release from drug-loaded particles was investigated using UV spectrophotometry over 45 days. This work demonstrates a powerful method of generating drug-loaded polymeric particles, with the ability to control size and polydispersivity, which has great potential in several categories of biotechnology requiring carrier particles, such as drug delivery and gene therapy.

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Influence of Sieving Polymer Concentration and Applied Voltage on Separation Accuracy of the Capillary Gel Electrophoresis for Small DNA Fragments

Materials Science Forum ◽

10.4028/www.scientific.net/msf.990.101 ◽

2020 ◽

Vol 990 ◽

pp. 101-105

Author(s):

Tomoka Nakazumi ◽

Yusuke Hara

Keyword(s):

Applied Voltage ◽

Gel Electrophoresis ◽

Polymer Concentration ◽

Dna Fragments ◽

Dna Ladder ◽

Capillary Gel Electrophoresis ◽

Two Factors ◽

Sufficient Degree ◽

Separation Conditions

In this study, measurement conditions of Capillary gel electrophoresis (CGE) were optimized in order to increase the separation accuracy for small DNA fragments. We adopted a 20-bp DNA Ladder including 13 small double-stranded fragments (20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 300, 400, and 500-bp). The applied voltage and sieving polymer concentration were assessed because these two factors significantly affect the separation accuracy of DNA fragments. As a result, we succeeded in optimizing CGE separation conditions for small DNA fragments with a sufficient degree of accuracy.

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Characterization of Polydioxanone in Near-Field Electrospinning

Polymers ◽

10.3390/polym12010001 ◽

2019 ◽

Vol 12 (1) ◽

pp. 1

Author(s):

William E. King ◽

Yvonne Gillespie ◽

Keaton Gilbert ◽

Gary L. Bowlin

Keyword(s):

Applied Voltage ◽

Biomedical Applications ◽

Near Field ◽

Deposition Velocity ◽

Polymer Concentration ◽

Air Gap ◽

Translational Velocity ◽

Individual Fiber ◽

The Creation ◽

Fiber Deposition

Electrospinning is a popular method for creating random, non-woven fibrous templates for biomedical applications, and a subtype technique termed near-field electrospinning (NFES) was devised by reducing the air gap distance to millimeters. This decreased working distance paired with precise translational motion between the fiber source and collector allows for the direct writing of fibers. We demonstrate a near-field electrospinning device designed from a MakerFarm Prusa i3v three-dimensional (3D) printer to write polydioxanone (PDO) microfibers. PDO fiber diameters were characterized over the processing parameters: Air gap, polymer concentration, translational velocity, needle gauge, and applied voltage. Fiber crystallinity and individual fiber uniformity were evaluated for the polymer concentration and translational fiber deposition velocity. Fiber stacking was evaluated for the creation of 3D templates to guide the alignment of human gingival fibroblasts. The fiber diameters correlated positively with polymer concentration, applied voltage, and needle gauge; and inversely correlated with translational velocity and air gap distance. Individual fiber diameter variability decreases, and crystallinity increases with increasing translational fiber deposition velocity. These data resulted in the creation of tailored PDO 3D templates, which guided the alignment of primary human fibroblast cells. Together, these results suggest that NFES of PDO can be scaled to create precise geometries with tailored fiber diameters for biomedical applications.

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Effects of Applied Voltage and Fence Configurations on DNA Separation Based on Electrophoresis Using Nanostructured Fence Matrix

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C ◽

10.1299/kikaic.73.555 ◽

2007 ◽

Vol 73 (726) ◽

pp. 555-561 ◽

Cited By ~ 2

Author(s):

Yoichi TAGAYA ◽

Shingo YONEOKA ◽

Masakazu BABA ◽

Kenji FUKUZAWA ◽

Yasunaga MITSUYA

Keyword(s):

Applied Voltage ◽

Dna Separation

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Measurement and Time Response of Electrohydrodynamic Direct-Writing Current

Micromachines ◽

10.3390/mi10020090 ◽

2019 ◽

Vol 10 (2) ◽

pp. 90 ◽

Cited By ~ 3

Author(s):

Gaofeng Zheng ◽

Wendong Xue ◽

Huatan Chen ◽

Lingling Sun ◽

Jiaxin Jiang ◽

...

Keyword(s):

Applied Voltage ◽

Signal To Noise Ratio ◽

Polymer Concentration ◽

Processing Parameters ◽

High Signal ◽

Electrical Characteristics ◽

Direct Writing ◽

The Stability ◽

Impulse Current ◽

Stable Stage

The micro/nano current is an important characteristic to reflect the electrohydrodynamic direct-writing (EDW) process. In this paper, a direct-written current measurement system with a high signal to noise ratio was proposed to monitor the charged jets, providing the data basis for the promotion of stability and precision of the EDW jet. The electrical characteristics of the printing process were studied, the electrohydrodynamic direct-written current was associated with the stability of charged jet and the accuracy of direct-written patterns. There was an impulse current when the front end of the jet reached the collector and then a stable jet could be gained. With the increase of applied voltage, the severe fluctuation of measured current increased, the charged jet became more unstable and the accuracy of direct-written parallel lines was lower. The effects of processing parameters on direct-written current were also investigated. The average direct-written current at the stable stage increased as the applied voltage and polymer concentration increased, and it decreased as the distance from the nozzle to the collector increased. This research will promote the development and applications of EDW technology in the fields of micro/nano manufacturing.

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