scholarly journals Empirical modelling and optimization of pressure-coupled infusion gyration parameters for the nanofibre fabrication

2019 ◽  
Vol 475 (2225) ◽  
pp. 20190008 ◽  
Author(s):  
Xianze Hong ◽  
Anthony Harker ◽  
Mohan Edirisinghe
Keyword(s):  
Applied Pressure ◽  
Fibre Diameter ◽  
Morphological Characteristics ◽  
Average Diameter ◽  
Solution Concentration ◽  
Optimal Conditions ◽  
Empirical Modelling ◽  
Average Fibre Diameter ◽  
Poly Ethylene ◽  
Oxide Fibres

Pressure-coupled infusion gyration (PCIG) is a novel promising technique for economical and effective mass production of nanofibres with desirable geometrical characteristics. The average diameter of spun fibres significantly influences the structural, mechanical and physical properties of the produced fibre mats. Having a comprehensive understanding of the significant effects of PCIG experimental variables on the spun fibres is beneficial. In this work, response surface methodology was used to explore the interaction effects and the optimal PCIG experimental variables for achieving the desired morphological characteristics of fibres. The effect of experimental variables, namely solution concentration, infusion (flow) rate, applied pressure and rotational speed, was studied on the average fibre diameter and standard deviations. A numerical model for the interactional influences of experimental variables was developed and optimized with a nonlinear interior point method that can be used as a framework for selecting the optimal conditions to obtain poly-ethylene oxide fibres with desired morphology (targeted average diameter and narrow standard deviation). The adequacy of the models was verified by a set of validation experiments. The results proved that the predicted optimal conditions were able to achieve the average diameter that matched the pre-set desired value with less than 10% of difference.

OPTIMIZATION OF ELECROSPINNING OF PVDF SCAFFOLDS FABRICATION USING RESPONSE SURFACE METHOD

2015 ◽  
Vol 75 (6) ◽  
Author(s):  
Madana Leela Nallappan ◽  
Mohamad Mahmoud Nasef
Keyword(s):  
Experimental Design ◽  
Response Surface ◽  
Vinylidene Fluoride ◽  
Fibre Diameter ◽  
Solution Concentration ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Statistical Validation ◽  
Electric Voltage ◽  
Average Fibre Diameter

Poly(vinylidene fluoride) (PVDF) scaffolds were prepared via electrospinning. The response surface methodology (RSM) was used to optimize the parameters that influence the average fibre diameter. The objective is to produce fibres with small diameters. The factors considered for experimental design were the applied electric voltage, the PVDF solution concentration, and the distance between the needle tip and the collecting drum. The Central Composite Design (CCD) was used to generate the experimental design whilst the analysis of variance (ANOVA) was performed to obtain statistical validation of regression models and to study the interaction between input parameters. The optimum operating conditions that guaranteed PVDF scaffolds with small nanofibre diameter were in the voltage and concentration range of 16-20 kV and 10-14wt%.

scholarly journals Experimental Validation of Upward Electrospinning Process

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Faissal Abdel-Hady ◽  
Abdulrahim Alzahrany ◽  
Mostafa Hamed
Keyword(s):  
Gravitational Force ◽  
Vacuum Chamber ◽  
Fibre Diameter ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Needle Size ◽  
Average Fibre Diameter ◽  
Jet Stability ◽  
Average Fibre

An experimental investigation has been carried out to validate the concept of a new upward electrospinning process in producing polymer nanofibres. The role of gravitational force in this concept is reversed from the conventional downward electrospinning. This inversion results in more stretching of the fibre, less bead formation, and jet stability. An experimental setup is built inside a vacuum chamber in order to eliminate the ambient effects. The effect of various parameters such as applied voltage, needle-collector distance, solution concentration, flow rate, and needle size, on average fibre diameter and beads formation, was investigated using scanning electron microscopy (SEM).

Molecular Imprinted Poly(Ethyleneco-Vinyl Alcohol) Nanofibers Electrospun on Gold Electrodes for Impedimetric Creatinine Sensing

2013 ◽  
Vol 543 ◽  
pp. 84-88 ◽  
Author(s):  
Amina Betatache ◽  
Mohamed Braiek ◽  
Jean François Chateaux ◽  
Florence Lagarde ◽  
Nicole Jaffrezic-Renault
Keyword(s):  
Vinyl Alcohol ◽  
Sensor Response ◽  
Gold Electrodes ◽  
Optimal Conditions ◽  
Imprinted Polymer ◽  
Electrical Voltage ◽  
Poly Ethylene ◽  
Biomimetic Sensor ◽  
Polymer Solvent

In this work, a biomimetic sensor elaborated by direct electrospinning of molecular imprinted poly (ethylene co-vinyl alcohol) (EVOH) onto gold electrodes was proposed for impedimetric creatinine detection. Dimethylsulfoxyde (DMSO) was selected as polymer solvent and creatinine (1% wt) was used as template. In the optimal conditions of fabrication (20% wt EVOH, electrical voltage: 20 kV, collection distance: 30 cm), the sensor response was proportional to log [creatinine concentratio in the 1 fg.L-1-1 μg.L-1 range. We also showed that the sensor could be reused at least three times and that the response of the non imprinted polymer control sensor, prepared the same way but in absence of creatinine, was very low.

scholarly journals Fabrication and Properties of High-Content Keratin/Poly (Ethylene Oxide) Blend Nanofibers Using Two-Step Cross-Linking Process

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yong Liu ◽  
Xia Yu ◽  
Jia Li ◽  
Jie Fan ◽  
Meng Wang ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Average Diameter ◽  
Diglycidyl Ether ◽  
Cross Linking ◽  
Electrospun Fibers ◽  
Hydrophobic Property ◽  
Poly Ethylene Oxide ◽  
Cross Linker ◽  
Poly Ethylene ◽  
Nanofiber Mats

High-content keratin/poly (ethylene oxide) (PEO) (90/10) blend nanofibers were prepared by electrospinning combined with a two-step cross-linking process. The keratin/PEO aqueous solution was firstly mixed with ethylene glycol diglycidyl ether (EGDE) as cross-linker and then electrospun into nanofibers. The resulting nanofibrous mats were cross-linked with EGDE vapor to decrease the solubility of nanofibers in water. The morphologies and properties of electrospun fibers were investigated by SEM, FTIR, TG, XRD, and contact angle testing, respectively. The results showed that the morphologies of nanofibers were uniform at the fiber average diameter of 300 nm with negligible bead defects by adding EGDE to keratin/PEO solutions. The cross-linking results showed that EGDE vapor could improve the hydrophobic property of blended nanofibers. The crystallinity of the keratin/PEO blend nanofiber mat increased from 13.14% for the uncross-linked sample to 21.54% and 35.15% for the first cross-linked and second cross-linked samples, respectively. Free defect nanofiber mats with high keratin content producing from this two-step cross-linking process are particularly promising for tissue engineering and cell-seeded scaffold.

Some wool characteristics of Karadi sheep in northern Iraq

1974 ◽  
Vol 83 (1) ◽  
pp. 171-174 ◽  
Author(s):  
K. E. Ghoneim ◽  
N. T. Kazzal ◽  
R. Kh. Abdallah
Keyword(s):  
Fibre Diameter ◽  
Fibre Length ◽  
Fibre Strength ◽  
Northern Iraq ◽  
Phenotypic Correlations ◽  
Average Fibre Diameter ◽  
Average Fibre

SUMMARYOne hundred and sixty-eight wool samples were collected from commercial flocks of Karadi sheep raised in the five provinces of northern Iraq. The wool characteristics dealt with were staple and fibre length, crimps, fibre diameter, medullation, fibre strength and elongation.The results showed that the Karadi wool is a long type of carpet fleece with average staple and fibre lengths of 19·3 and 23·5 cm, respectively. It had an average fibre diameter of 48·1 μ and contained 19·45 % medullated fibres. The number of crimps per 2 cm was 2·4. Average fibre strength and elongation were 24·8 g/5 cm and 31·8 % respectively. Phenotypic correlations between wool traits were studied.

Preparation of Pd/Ag Film on Porous Ceramic Tube by Osmosis Pressure–Assisted Electroless Plating

2011 ◽  
Vol 199-200 ◽  
pp. 426-430
Author(s):  
Bo Quan Jiang ◽  
Jiang Nan Zhang ◽  
Yu De Liu ◽  
Jian Guo Zou
Keyword(s):  
Electroless Plating ◽  
Hydrogen Permeation ◽  
Sucrose Solution ◽  
Porous Ceramic ◽  
Film Surface ◽  
Solution Concentration ◽  
Alloy Film ◽  
Molar Ratio ◽  
Optimal Conditions ◽  
Permeation Properties

The osmosis pressure was introduced to improve the conventional electroless plating process for preparing porous ceramic supported Pd/Ag inorganic composite membrane. The effects of temperature (t), molar ratio of hydrazine to total metal ions(y), molar ratio of silver ions to palladium ions(x), concentrations of ethylene diamine tetraacetic acid (EDTA) and sucrose solution on the metal deposition rate, silver content in alloy film, surface morphology of film and permeation properties of the membrane were investigated and their optimal conditions were determined to be: [MET]=5mM, x = 20%, y = 1, [EDTA] = 40g•L-1, t = 40 °C, pH =11 and sucrose solution concentration of 6 M. Under these optimal conditions, the prepared Pd/Ag alloy film with thickness of 7.9 μm demonstrated good permeation properties with nitrogen free and hydrogen permeation rate of 8.8×10-3m3•m-2•s-1at 0.3 MPa and 473 K.

Studies on Western Australian Merino sheep. 1. Stud, strain and environmental effects on hogget performance

1992 ◽  
Vol 43 (6) ◽  
pp. 1381 ◽  
Author(s):  
RP Lewer ◽  
RR Woolaston ◽  
RR Howe
Keyword(s):  
Fibre Diameter ◽  
Strain Differences ◽  
Average Fibre Diameter ◽  
Weaning Age ◽  
Average Fibre ◽  
Males And Females ◽  
Wool Yield ◽  
Fleece Weight ◽  
Western Australian ◽  
Australian Merino

A 6 year study is reported of Merino studs and strains (Peppin, Collinsville and Bungaree) in Western Australia. Wool and body traits of males and females were measured, with additional subjective traits assessed on females. The effects of strain, stud (within strain), birth year, dam age, birth rearing rank, weaning age and their interactions were estimated using least squares procedures. When tested against studs, strain differences were significant for fibre diameter (both sexes), clean wool yield and about half of the subjective traits (females) but for none of the liveweights. Stud and year effects were significant for all traits, as was their interaction for most traits. Some studs were more stable between years than others in both clean fleece weight and average fibre diameter. Of the remaining effects, birth rearing rank influenced the greatest number of traits, while dam age only affected yield in ewes and some early liveweights. Peppins produced wool 2.0-2.3 microns finer than Bungarees, but not significantly different from Collinsvilles. Peppins also had the best subjective wool scores, but had the highest wrinkle scores and scored poorly on other subjective body traits. Twin-born hoggets produced 0.05-0.15 kg less clean wool than their single-born contemporaries, and their fleeces were about 0.4 microns coarser with poorer subjective qualities. Twins were also lighter from birth (by 23%) up to 17 months (by 5%) in females. Late-born lambs had higher birth weights, but lower subsequent weights, persisting until 12 months in females.

Toughening Modification of Poly(butylene terephthalate)/Polycarbonate Blends by Poly(ethylene-co-octene)

2005 ◽  
Vol 13 (4) ◽  
pp. 385-394
Author(s):  
Huiyu Bai ◽  
Yong Zhang ◽  
Yinxi Zhang ◽  
Xiangfu Zhang ◽  
Wen Zhou
Keyword(s):  
Average Diameter ◽  
Melt Blending ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Bisphenol A Polycarbonate ◽  
Elongation At Break ◽  
Butylene Terephthalate ◽  
Twin Screw ◽  
Poly Ethylene ◽  
The Impact

New toughened poly(butylene terephthalate) (PBT)/bisphenol A polycarbonate (PC) blends were obtained by melt blending with commercial poly(ethylene-co-octene) copolymer (POE), varying the POE content up to 10 wt%, in a twin screw extruder, followed by injection moulding. The influence of POE on the properties of the PBT/PC blends was investigated in terms of mechanical testing, dynamic mechanical thermal (DMTA) analysis, differential scanning calorimetry (DSC), and scanning electronic microscopy (SEM). The results showed that addition of POE led to remarkable increases in the impact strength, elongation at break and Vicat temperature, and a reduction in the tensile strength and flexural properties of PBT/PC blends. The morphology of the blends was observed using SEM and the average diameter of the dispersed phase was determined by image analysis. The critical inter-particle distance for PBT/PC was determined.

scholarly journals Adsorption Study for the Removal of Nitrate from Water Using Local Clay

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
A. Battas ◽  
A. El Gaidoumi ◽  
A. Ksakas ◽  
A. Kherbeche
Keyword(s):  
Solution Concentration ◽  
Optimal Conditions ◽  
Batch Experiments ◽  
X Ray Diffraction ◽  
Local Clay ◽  
Initial Concentration ◽  
X Ray ◽  
Rate Of Reaction ◽  
Pseudo Second Order ◽  
Adsorbent Dose

Our research aimed at the removal of nitrate ions through adsorption by local clay. A series of batch experiments were conducted to examine the effects of contact time, adsorbent characteristics, initial concentration of nitrate, pH of the solution, concentration, and granulometry of adsorbent. Adsorption isotherms studies indicated that local clay satisfies Freundlich’s model. The rate of reaction follows pseudo-second-order kinetics. Local clay successfully adsorbs nitrates at pH acid. The adsorption capacity under optimal conditions was found to be 5.1 mg/g. The adsorption yield increases with adsorbent dose and decrease with initial concentration of nitrate. The local clay was characterized by the X-ray fluorescence method (XRF), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), scanning electronics microscopy (SEM), and measurement of specific surface area (BET). The results of the study indicated that local clay is useful materials for the removal of nitrates from aqueous solutions which can be used in water treatment without any chemical modification.

The fibre diameter profile of wool staples from individual sheep

1979 ◽  
Vol 30 (1) ◽  
pp. 163 ◽  
Author(s):  
N Jackson ◽  
AM Downes
Keyword(s):  
Coefficient Of Variation ◽  
Fibre Diameter ◽  
Average Diameter ◽  
Seasonal Effects ◽  
Genetic Studies ◽  
Phenotypic Differences ◽  
Mean Diameter ◽  
Local Areas ◽  
Mean Variance ◽  
Staple Length

Variation in fibre diameter along the staple was measured on duplicate staples from five sheep from each of four lines selected for high and low staple length and high and low fibre diameter. It was found that the high and low fibre diameter lines differed in mean diameter and in variance along the staple, but did not differ in coefficient of variation along the staple. The high and low staple length lines also differed in mean diameter, but did not differ in variance or coefficient of variation along the staple. Individual sheep within selection lines differed in mean, variance along the staple, and coefficient of variation along the staple. The measurement technique was found to be highly repeatable between duplicate staples sampled from the same animal. Susceptibility to seasonal effects at particular positions along the staple was tested by analysing the interaction between staple segments and other factors, and was described by regressing the diameter at a position on the average diameter of all sheep at that position. It was found that the high and low fibre diameter lines differed in susceptibility (thus described) while the high and low staple length lines did not so differ. Individual sheep within selection lines also differed in susceptibility. The application of measured variation in diameter along the staple to sheep breeding must await more extensive genetic studies. The present study simply unmasks some previously unnoticed genetic and phenotypic differences and checks on the accuracy of the measurement method. It shows that there are non-susceptible individual animals and selection lines for which the variance of diameter along the staple is very low, and hence there exists the potential to reduce this variation on a nation-wide basis, or in local areas, if such a reduction be thought desirable from a woolprocessing viewpoint.

Sign in / Sign up

Export Citation Format

Share Document