scholarly journals Automated Nanofiber Diameter Measurement in SEM Images Using a Robust Image Analysis Method

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ertan Öznergiz ◽  
Yasar Emre Kiyak ◽  
Mustafa E. Kamasak ◽  
Isa Yildirim
Keyword(s):  
Image Analysis ◽  
Fiber Diameter ◽  
High Surface ◽  
High Surface Area ◽  
Real Data ◽  
Average Fiber Diameter ◽  
Diameter Measurement ◽  
Sem Images ◽  
Human Errors ◽  
Nanofiber Diameter

Due to the high surface area, porosity, and rigidity, applications of nanofibers and nanosurfaces have developed in recent years. Nanofibers and nanosurfaces are typically produced by electrospinning method. In the production process, determination of average fiber diameter is crucial for quality assessment. Average fiber diameter is determined by manually measuring the diameters of randomly selected fibers on scanning electron microscopy (SEM) images. However, as the number of the images increases, manual fiber diameter determination becomes a tedious and time consuming task as well as being sensitive to human errors. Therefore, an automated fiber diameter measurement system is desired. In the literature, this task is achieved by using image analysis algorithms. Typically, these methods first isolate each fiber in the image and measure the diameter of each isolated fiber. Fiber isolation is an error-prone process. In this study, automated calculation of nanofiber diameter is achieved without fiber isolation using image processing and analysis algorithms. Performance of the proposed method was tested on real data. The effectiveness of the proposed method is shown by comparing automatically and manually measured nanofiber diameter values.

scholarly journals Amorphous Mo5O14-Type/Carbon Nanocomposite with Enhanced Electrochemical Capability for Lithium-Ion Batteries

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 8 ◽  
Author(s):  
Ahmed M. Hashem ◽  
Ashraf E. Abdel-Ghany ◽  
Rasha S. El-Tawil ◽  
Sylvio Indris ◽  
Helmut Ehrenberg ◽  
...  
Keyword(s):  
Oxygen Deficiency ◽  
High Surface ◽  
High Surface Area ◽  
Lithium Ion ◽  
Carbon Matrix ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Thermal Gravimetry ◽  
Type C ◽  
Carbon Nanocomposite

An amorphous MomO3m−1/carbon nanocomposite (m ≈ 5) is fabricated from a citrate–gel precursor heated at moderate temperature (500 °C) in inert (argon) atmosphere. The as-prepared Mo5O14-type/C material is compared to α-MoO3 synthesized from the same precursor in air. The morphology and microstructure of the as-prepared samples are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman scattering (RS) spectroscopy. Thermal gravimetry and elemental analysis indicate the presence of 25.8 ± 0.2% of carbon in the composite. The SEM images show that Mo5O14 is immersed inside a honeycomb-like carbon matrix providing high surface area. The RS spectrum of Mo5O14/C demonstrates an oxygen deficiency in the molybdenum oxide and the presence of a partially graphitized carbon. Outstanding improvement in electrochemical performance is obtained for the Mo5O14 encapsulated by carbon in comparison with the carbon-free MoO3.

Characterization of high density monolayers of the biofilm bacteriumCaulobacter crescentus: Evaluating prospects for developing immobilized cell bioreactors

2000 ◽  
Vol 46 (4) ◽  
pp. 339-349 ◽  
Author(s):  
John Smit ◽  
Christopher S Sherwood ◽  
Robin FB Turner
Keyword(s):  
Image Analysis ◽  
Phase Contrast ◽  
Caulobacter Crescentus ◽  
High Surface ◽  
High Surface Area ◽  
High Density ◽  
Immobilized Cell ◽  
Natural Flora ◽  
Vital Stains ◽  
Forming Characteristics

Caulobacters are biofilm-forming members of the natural flora of soil and aquatic environments, which exhibit several characteristics that make them attractive for development of high surface area microbial bioreactors or biosensors. Although caulobacters are well characterized genetically, little is known about their biofilm-forming characteristics as a monoculture, or their tolerance of bioreactor-like conditions. Here we investigated the ability of caulobacters to spontaneously form high-density monolayers on artificial surfaces under a variety of environmental conditions, using phase contrast image analysis to assess biofilm density, and epifluorescence with the vital stain DiBAC(tm) to assess viability. With adequate nutrition, extremely dense monolayers formed within 24-48 h, and maintained near 100% viability in experiments ranging up to 22 days. When areas were abraded to remove cells, repopulation occurred rapidly with characteristics similar to the population of a clean surface. When established monolayers were starved for nutrients, a significant fraction of the cells detached from the surface, and cells remaining on the surface no longer tested as viable. Within 4-6 h of nutrient restoration, however, cells in the monolayer again appeared normal and tested as 100% viable. This is the first demonstration that Caulobacter crescentus is stable and amenable to high density monolayer growth and resists starvation, though some cells may express a programmed response to detach from the surface under severe nutrient limitation.Key words: Caulobacter crescentus, biofilm characterization, image analysis, phase contrast, epifluorescence, vital stains.

Synthesis and Characterizations of MOF-199 Using PODFA as Porogen for CO2 Adsorption Applications

2016 ◽  
Vol 694 ◽  
pp. 44-49
Author(s):  
Nurfatihah Mahadi ◽  
Halina Misran ◽  
S.Z. Othman
Keyword(s):  
Fatty Alcohol ◽  
Palm Oil ◽  
Carbon Capture ◽  
Metal Organic Framework ◽  
High Surface ◽  
High Surface Area ◽  
Product Formation ◽  
Carbon Chain Length ◽  
Sem Images ◽  
Structure Directing Agent

Copper-based metal-organic framework (MOF-199, also known as Cu-BTC and HKUST-1) materials were successfully synthesized by hydrothermal method using renewable straight-chain fatty alcohol with eight carbon chain length (i.e. octyl alcohol). The addition of palm oil derived fatty alcohol (PODFA) was suggested to act as porogen (structure directing agent) that aided the particle formation and flexible porous structure. This synthesis approach was environmental-friendly and sustainable by utilizing the fatty alcohols originated from biomass such as palm oil. The resulting MOF-199 materials exhibited single crystalline octahedral morphology structure by X-ray diffraction analyses and SEM images. The optimum ratio of octyl alcohol exhibited well-defined single octahedral particles at size range of ca. 10-50 µm and reduced by-product formation of cuprous oxide at high temperature synthesis. The nature of MOF-199 having apparently high surface area, high pore volume and low density provided the possibility in carbon capture storage. The CO2 adsorption capacity of MOF-199 investigated using high pressure volumetric analyser (HPVA-II) at ambient temperature (i.e. 25 °C) was found to be at maximum working capacity.

scholarly journals Dielectric Behavior and Morphostructural Characteristics of Some HDPE Composites / Metal Nanopowders

2019 ◽  
Vol 56 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Alina-Ruxandra Caramitu ◽  
Sorina Mitrea ◽  
Virgil Marinescu ◽  
George-Andrei Ursan ◽  
Mihaela Aradoaie ◽  
...  
Keyword(s):  
Dielectric Spectroscopy ◽  
High Surface ◽  
High Surface Area ◽  
Dielectric Behavior ◽  
Sem Images ◽  
Low Frequencies ◽  
High Frequencies ◽  
Metal Filler ◽  
Powder Filler ◽  
Composite Samples

HDPE composite samples with aluminum and iron nanopowders were made by extrusion and injection. Samples of material obtained were characterized by comparative determinations of dielectric spectroscopy and SEM microscopy. SEM images have indicated that the agglomerations of the powders used are persistent, do not decompose during extrusion and injection processing. Determinations by dielectric spectroscopy indicated that HDPE composite materials with metal nanopowder filler have higher dielectric losses than pure HDPE (reference). The highest increases in tgd up to 2.6 times, were recorded for 50 nm nanopowders with specific high surface area (over 20 m2 / g). The electrical conductivity of the investigated samples increases with increasing frequency, both for pure HDPE and for HDPE with metal powder filler. As a result of the film effect in the HDPE case with metal filler, the increases in the high frequencies range are lower than in the extremely low frequencies range.

scholarly journals Experimental Investigation into the Structural and Functional Performance of Graphene Nano-Platelet (GNP)-Doped Asphalt

2019 ◽  
Vol 9 (4) ◽  
pp. 686 ◽  
Author(s):  
Murryam Hafeez ◽  
Naveed Ahmad ◽  
Mumtaz Kamal ◽  
Javaria Rafi ◽  
Muhammad Haq ◽  
...  
Keyword(s):  
Functional Performance ◽  
Permanent Deformation ◽  
High Surface ◽  
Asphalt Binder ◽  
High Surface Area ◽  
Adhesive Bond ◽  
Structural Performance ◽  
Complete Analysis ◽  
Skid Resistance ◽  
Sem Images

With the increase in the demand for bitumen, it has become essential for pavement engineers to ensure that construction of sustainable pavements occurs. For a complete analysis of the pavement, both its structural and functional performances are considered. In this study, a novel material (i.e., Graphene Nano-Platelets (GNPs)) has been used to enhance both of the types of pavements’ performances. Two percentages of GNPs (i.e., 2% and 4% by the weight of the binder) were used for the modification of asphalt binder in order to achieve the desired Performance Grade. GNPs were homogeneously dispersed in the asphalt binder, which was validated by Scanning Electron Microscope (SEM) images and a Hot Storage Stability Test. To analyze the structural performance of the GNPs-doped asphalt, its rheology, resistance to permanent deformation, resistance to moisture damage, and bitumen-aggregate adhesive bond strength were studied. For the analysis of the functional performance, the skid resistance and polishing effect were studied using a British Pendulum Skid Resistance Tester. The results showed that GNPs improved not only the rutting resistance of the pavement but also its durability. The high surface area of GNPs increases the pavement’s bonding strength and makes the asphalt binder stiffer. GNPs also provide nano-texture to the pavement, which enhances its skid resistance. Thus, we can recommend GNPs as an all-around modifier that could improve not only the structural performance but also the functional performance of asphalt pavements.

scholarly journals High Photocatalytic Activity under Visible Light for a New Morphology of Bi2WO6 Microcrystals

Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 667 ◽  
Author(s):  
Campos ◽  
Nobre ◽  
Filho ◽  
Ribeiro da Silva ◽  
Costa ◽  
...  
Keyword(s):  
Single Phase ◽  
High Surface ◽  
High Surface Area ◽  
Orthorhombic Phase ◽  
Xrd Analysis ◽  
High Photocatalytic Activity ◽  
Sem Images ◽  
Bismuth Tungstate ◽  
Adsorption Desorption ◽  
Dye Solutions

In this work, a new morphology was obtained for bismuth tungstate (Bi2WO6-glyc) using a hydrothermal method with the addition of glycerol as a surfactant. In order to compare, the bismuth tungstate without glycerol as the surfactant, i.e., Bi2WO6, was synthesized. Structural characterization by XRD and Rietveld refinement confirmed the orthorhombic structure as a single phase for all samples with high crystallinity. All active modes in Raman spectroscopy for the orthorhombic phase of bismuth tungstate were confirmed in agreement with XRD analysis. N2 adsorption/desorption and size pore distribution confirmed the high surface area (85.7 m2/g) for Bi2WO6-glyc when compared with Bi2WO6 (8.5 m2/g). The optical band gap by diffuse reflectance was 2.78 eV and 2.88 eV for Bi2WO6-glyc and Bi2WO6, respectively. SEM images confirmed the different morphology for these materials, and microstructures with cheese crisp were observed for Bi2WO6-glyc (cheese crisp). On the other hand, flower-like microcrystals were confirmed for Bi2WO6 sample. The photocatalytic performance of Bi2WO6-glyc (94.2%) in the photodegradation of rhodamine B (RhB) dye solutions at 60 min was more expressive than Bi2WO6 (81.3%) and photolysis (8.2%) at 90 min.

scholarly journals Manufacturing and Assessment of Electrospun PVP/TEOS Microfibres for Adsorptive Heat Transformers

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 443 ◽  
Author(s):  
Patrizia Frontera ◽  
Mikio Kumita ◽  
Angela Malara ◽  
Junya Nishizawa ◽  
Lucio Bonaccorsi
Keyword(s):  
Thermal Stability ◽  
High Surface ◽  
High Surface Area ◽  
High Permeability ◽  
Sem Images ◽  
Good Thermal Stability ◽  
Adsorption Heat Pump ◽  
High Flexibility ◽  
Woven Textile ◽  
Thermal Stability Of

A new adsorbent coating for the adsorber unit of an adsorption heat pump made of hybrid, organic–inorganic microfibres was prepared and characterized. Different coatings were obtained by the electrospinning of polyvinylpyrrolidone (PVP) solutions added with different quantities of tetraethyl orthosilicate (TEOS). PVP is a polymer with water adsorption capability and the TEOS addition allowed to increase the thermal stability of microfibres. The aim, indeed, was to preserve the polymeric structure of microfibres in order to obtain coatings with high flexibility and mechanical strength. The results demonstrated that TEOS concentrations in the range of 5–13 wt.% produced microfibre coatings of non-woven textile structure with both good water affinity and good thermal stability. SEM images of coatings showed that the deposited microfibre layers have both a high surface area and a high permeability representing a significant advantage in adsorption systems.

scholarly journals Biobased Dyes as Conductive Additives to Reduce the Diameter of Polylactic Acid Fibers during Melt Electrospinning

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1055 ◽  
Author(s):  
Kylie Koenig ◽  
Naveen Balakrishnan ◽  
Stefan Hermanns ◽  
Fabian Langensiepen ◽  
Gunnar Seide
Keyword(s):  
Polylactic Acid ◽  
Fiber Diameter ◽  
High Surface ◽  
High Surface Area ◽  
Degree Of Crystallinity ◽  
Environmentally Sustainable ◽  
Melt Electrospinning ◽  
Conductive Additives ◽  
Fiber Deposition ◽  
Environmentally Friendly Process

Electrospinning is widely used for the manufacture of fibers in the low-micrometer to nanometer range, allowing the fabrication of flexible materials with a high surface area. A distinction is made between solution and melt electrospinning. The former produces thinner fibers but requires hazardous solvents; whereas the latter is more environmentally sustainable because solvents are not required. However, the viscous melt requires high process temperatures and its low conductivity leads to thicker fibers. Here, we describe the first use of the biobased dyes alizarin; hematoxylin and quercetin as conductive additives to reduce the diameter of polylactic acid (PLA) fibers produced by melt electrospinning; combined with a biobased plasticizer to reduce the melt viscosity. The formation of a Taylor cone followed by continuous fiber deposition was observed for all PLA compounds; reducing the fiber diameter by up to 77% compared to pure PLA. The smallest average fiber diameter of 16.04 µm was achieved by adding 2% (w/w) hematoxylin. Comparative analysis revealed that the melt-electrospun fibers had a low degree of crystallinity compared to drawn filament controls—resembling partially oriented filaments. Our results form the basis of an economical and environmentally friendly process that could ultimately, provide an alternative to industrial solution electrospinning

scholarly journals Δ-FeOOH as Support for Immobilization Peroxidase: Optimization via a Chemometric Approach

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 259 ◽  
Author(s):  
Tássia Silva Tavares ◽  
Eduardo Pereira da Rocha ◽  
Francisco Guilherme Esteves Nogueira ◽  
Juliana Arriel Torres ◽  
Maria Cristina Silva ◽  
...  
Keyword(s):  
High Efficiency ◽  
Immobilized Enzyme ◽  
High Surface ◽  
High Surface Area ◽  
Sem Images ◽  
X Ray ◽  
Independent Variables ◽  
Surface Iron ◽  
Chemometric Approach ◽  
Optimized Conditions

Owing to their high surface area, stability, and functional groups on the surface, iron oxide hydroxide nanoparticles have attracted attention as enzymatic support. In this work, a chemometric approach was performed, aiming at the optimization of the horseradish peroxidase (HRP) immobilization process on Δ-FeOOH nanoparticles (NPs). The enzyme/NPs ratio (X1), pH (X2), temperature (X3), and time (X4) were the independent variables analyzed, and immobilized enzyme activity was the response variable (Y). The effects of the factors were studied using a factorial design at two levels (−1 and 1). The biocatalyst obtained was evaluated for the ferulic acid (FA) removal, a pollutant model. The materials were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The SEM images indicated changes in material morphology. The independent variables X1 (−0.57), X2 (0.71), and X4 (0.42) presented the significance effects estimate. The variable combinations resulted in two significance effects estimates, X1*X2 (−0.57) and X2*X4 (0.39). The immobilized HRP by optimized conditions (X1 = 1/63 (enzyme/NPs ratio, X2 = pH 8, X4 = 60 °C, and 30 min) showed high efficiency for FA oxidation (82%).

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