Orthogonal alignment of DNA using hexafluoroisopropanol as solvent for film castings

RSC Advances ◽  
2014 ◽  
Vol 4 (75) ◽  
pp. 39798-39801 ◽  
Author(s):  
Donna Marie D. Mamangun ◽  
Jose L. Santana ◽  
Fahima Ouchen ◽  
James G. Grote ◽  
Gregory A. Sotzing
Keyword(s):  
Dielectric Constant ◽  
Dissipation Factor ◽  
Low Frequencies ◽  
Surfactant Complex ◽  
Fluorinated Alcohol

The use of the fluorinated alcohol, 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as a processing solvent for orthogonal alignment of a DNA–surfactant complex is reported herein. 1-butanol (BuOH) was used as the control. At low frequencies, films of DNA–CTMA cast from HFIP exhibited a higher, more consistent dielectric constant and a lower dissipation factor compared to films cast from BuOH.

scholarly journals Performance Analysis Of Electrical Properties Of Resin Transfer Molded Banana Leaf Reinforced Polymer Composites

2021 ◽  
Vol 23 (10) ◽  
pp. 179-194
Author(s):  
T. Rajamanikandan ◽  
◽  
Dr.S. Banumathi ◽  
Dr.R. Asokan ◽  
◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Polymer Composites ◽  
Volume Resistivity ◽  
Dissipation Factor ◽  
Loading Frequency ◽  
Low Frequencies ◽  
High Frequencies ◽  
Reinforced Polymer ◽  
Fibre Loading ◽  
Banana Leaf

An investigation of the electrical characteristics of banana leaf reinforced Polymer composites made by resin transfer molding (RTM) has been carried out, with special emphasis on the effects of fibre loading, frequency and temperature. Every parameter, including the dielectric constant (ɛ0), dissipation factor (tan δ), loss factor (ɛ00), and conductivity, increases with increasing fibre concentration over the whole frequency range. A minimum fibre content of 50 % is required for composites to achieve excellent performance values. This increase is large at low frequencies, minimal at middle frequencies, and negligible at extremely high frequencies, according to the results of the study. At low frequencies, the volume resistivity fluctuates in response to fibre loading, while at high frequencies, the resistivity blends together. When the temperature rises, the dielectric constant values rise as well, however once the glass transition temperature is reached, the dielectric constant values fall. This fluctuates depending on the amount of fibre present. Finally, an attempt is made to establish a relationship between the experimental value of the dielectric constant and theoretical expectations.

Tuning the mechanical and dielectric properties of zinc incorporated hydroxyapatite

2020 ◽  
Vol 16 ◽  
Author(s):  
Alliya Qamar ◽  
Rehana Zia ◽  
Madeeha Riaz
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Bone Growth ◽  
Healing Process ◽  
Secondary Phase ◽  
Chemical Precipitation ◽  
Hexagonal Structure ◽  
Precipitation Method ◽  
Low Frequencies ◽  
A Minor

Background: Hydroxyapatite is similar to bone mineral in chemical composition, has good biocompatibility with host tissue and bone. Objective: This work aims to tailor the mechanical and dielectric properties of hydroxyapatite with zinc sudstitution, to improve wearability of implant and accelerate the healing process. Method: Pure and zinc incorporated hydroxyapatite Ca10(PO4)6(OH)2 samples have been successfully prepared by means of the chemical precipitation method. Results: The results showed that hydroxyapatite(Hap) having hexagonal structure was the major phase identified in all the samples. It was found that secondary phase of β-tricalcium phosphate (β-TCP) formed due to addition of Zinc resulting in biphasic structure BCP (Hap + β-TCP). A minor phase of ZnO also formed for higher concentration of Zn (Zn ≥ 2mol%) doping. It was found that the Zn incorporation to Hap enhanced both mechanical and dielectric properties without altering the bioactive properties. The microhardness increased upto 0.87 GPa for Zn concentration equal to 1.5mol%, which is comparable to the human bone ~0.3 - 0.9 GPa. The dielectric properties evaluated in the study showed that 1.5 mol% Zn doped hydroxyapatite had highest dielectric constant. Higher values of dielectric constant at low frequencies signifies its importance in healing processes and bone growth due to polarization of the material under the influence of electric field. Conclusion: Sample Z1.5 having 1.5 mol% Zn doping showed the most optimized properties suitable for bone regeneration applications.

ON THE DIELECTRIC BEHAVIOR OF LiCo3/5Fe2/5VO4 CERAMICS

2010 ◽  
Vol 24 (07) ◽  
pp. 665-670
Author(s):  
MOTI RAM
Keyword(s):  
Activation Energy ◽  
Dielectric Constant ◽  
Frequency Dependence ◽  
Chemical Method ◽  
Arrhenius Plot ◽  
Dielectric Behavior ◽  
Tangent Loss ◽  
Low Frequencies ◽  
Different Temperatures ◽  
Tan Δ

The LiCo 3/5 Fe 2/5 VO 4 ceramics has been fabricated by solution-based chemical method. Frequency dependence of the dielectric constant (εr) at different temperatures exhibits a dispersive behavior at low frequencies. Temperature dependence of εr at different frequencies indicates the dielectric anomalies in εr at Tc (transition temperature) = 190°C, 223°C, 263°C and 283°C with (εr) max ~ 5370, 1976, 690 and 429 for 1, 10, 50 and 100 kHz, respectively. Frequency dependence of tangent loss ( tan δ) at different temperatures indicates the presence of dielectric relaxation in the material. The value of activation energy estimated from the Arrhenius plot of log (τd) with 103/T is ~(0.396 ± 0.012) eV.

scholarly journals Electrical Capacitance Characteristics of Wood Chips at Low Frequency Ranges: A Cheap Tool for Quality Assessment

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3494
Author(s):  
Jakub Lev ◽  
Václav Křepčík ◽  
Egidijus Šarauskis ◽  
František Kumhála
Keyword(s):  
Moisture Content ◽  
Linear Models ◽  
Economic Value ◽  
Wood Chip ◽  
Principal Component ◽  
Dissipation Factor ◽  
Industrial Applications ◽  
Wood Chips ◽  
Electrical Capacitance ◽  
Low Frequencies

Moisture content is one of the most important parameters related to the quality of wood chips that affects both the calorific and economic value of fuel chips. For industrial applications, moisture content needs to be detected quickly. For this purpose, various indirect moisture content measurement methods (e.g., capacitance, NIR, microwave, ECT, X-ray CT, and nuclear MR) have been investigated with different results in the past. Nevertheless, determining wood chip moisture content in real time is still a challenge. The main aim of this article was therefore to analyze the dielectric properties of wood chips at low frequencies (10 kHz–5 MHz) and to examine the possibility of using these properties to predict wood chip moisture content and porosity. A container-type probe was developed for this purpose. The electrical capacitance and dissipation factor of wood chips with different moisture content was measured by an LCR meter at 10 kHz, 50 kHz, 100 kHz, 500 kHz, 1 MHz, and 5 MHz frequencies. Wood chip porosity was also measured using a gas displacement method. Linear models for moisture content and porosity prediction were determined by backward stepwise linear regression. Mathematical model was developed to better understand the physical relationships between moisture content, porosity, and electrical capacitance. These models were able to predict the moisture content of observed quantities of wood chips with the required accuracy (R2 = 0.9−0.99). This finding opens another path to measuring the moisture content and porosity of wood chips in a relatively cheap and fast way and with adequate precision. In addition, principal component analysis showed that it is also possible to distinguish between individual wood chip fraction sizes from the information obtained.

Investigation of the Properties of Alumina-Zirconia Ceramics

2014 ◽  
Vol 1040 ◽  
pp. 245-249
Author(s):  
Aleksander S. Ivashutenko ◽  
Alexandr V. Kabyshev ◽  
Nikita Martyushev ◽  
Igor G. Vidayev
Keyword(s):  
Dielectric Constant ◽  
Electric Conductivity ◽  
High Temperatures ◽  
Electrostatic Field ◽  
Mechanical Characteristics ◽  
Ferroelectric Properties ◽  
Dissipation Factor ◽  
Zirconia Ceramics ◽  
Measurement Results ◽  
Dielectric Dissipation Factor

The article focuses on the investigation of the properties of alumina-zirconia ceramics possessing high mechanical characteristics and good conductivity at high temperatures. Measurement results of the dielectric dissipation factor, dielectric constant, electric conductivity when using direct and alternating current for the ceramics samples of 80%(ZrO2-3%Y2O3)-20% Al2O3 composition are presented in the paper. Measurements were conducted simultaneously in the electrostatic field in vacuum while heating the samples to the temperatures ranging from 300 to 1700K. Investigations showed that alumina-zirconia ceramics at high temperatures obtains ferroelectric properties not typical of these structures.

scholarly journals The effects of additive on microstructure and electrical properties of batio3 ceramics

2004 ◽  
Vol 1 (3) ◽  
pp. 89-98 ◽  
Author(s):  
Vesna Paunovic ◽  
Ljiljana Zivkovic ◽  
Ljubomir Vracar ◽  
Vojislav Mitic ◽  
Miroslav Miljkovic
Keyword(s):  
Dielectric Constant ◽  
Curie Temperature ◽  
Room Temperature ◽  
Low Frequency ◽  
Dissipation Factor ◽  
The Other ◽  
Uniform Microstructure ◽  
Average Grain Size ◽  
Solid State Sintering ◽  
Curie Temperatures

In this paper comparative investigations of microstructure and dielectric properties of BaTiO3 ceramics doped with 1.0 wt% of Nb2O5, MnCO3 and CaZrO3 have been done. BaTiO3 samples were prepared using conventional method of solid state sintering at 13000C for two hours. Two distinguish micro structural regions can be observed in sample doped with Nb2O5. The first one, with a very small grained microstructure and the other one, with a rod like grains. In MnCO3 and CaZrO3 doped ceramics the uniform microstructure is formed with average grain size about 0.5- 2?m and 3-5?m respectively. The highest value of dielectric permittivity at room temperature and the greatest change of permittivity in function of temperature were observed in MnCO3/BaTiO3. In all investigated samples dielectric constant after initially large value at low frequency attains a constant value at f = 6kHz. A dissipation factor is independent of frequency greater than 10 kHz and, depending of systems, lies in the range from 0.035 to 0.25. At temperatures above Curie temperatures, the permittivity of all investigated samples follows a Curie- Weiss law. A slight shift of Curie temperature to the lower temperatures, in respect of Curie temperature for undoped BaTiO3, was observed in all investigated samples.

scholarly journals Electrical Dielectric Authorship of Polyvinyl-Acetate and Toluene Diisocyanate (PVA-TDI) with Manufactured Sulfonated Phenol-formaldehyde (SPF) Viscous Mass Material Composite

2017 ◽  
Vol 14 (2) ◽  
pp. 418-426
Author(s):  
Baghdad Science Journal
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Polyvinyl Acetate ◽  
Phenol Formaldehyde ◽  
Dissipation Factor ◽  
Toluene Diisocyanate ◽  
Total Conductivity ◽  
Viscous Mass ◽  
The Fourier Transform ◽  
Quality Factor Q

The electrical insulation of the manufacture sulfonated phenol-formaldehyde viscous material (product) has been studied with Polyvinyl-acetate (PVA) and toluene diisocyanate (TDI) blend has been prepared by fixing percentage by weight 3:1 and mixed with different percentages by weight of the product sulfonated phenol formaldehyde viscous mass (SPF). The Fourier transform infrared (FTIR) spectroscopy is done on (SPF) resin powder and prepared film of PVA-TDI-SPF viscous mass. The quality factor (Q), dissipation factor (D), parallel resistance (Rp), series resistance (Rs), parallel capacitance (Cp), series capacitance (Cs) and phase shift (?) are measured. The calculated maximum dielectric constant (??) is 3.49x107 at sample (1) wt.1% SPF viscous mass to the weight of (PVA-TDI), the minimum dielectric constant is 1.12x106 at sample (3) wt.3% of SPF viscous mass to PVA-TDI weight. The maximum dielectric loss factor (??) is 3.68x107 at sample (1) and the minimum dielectric loss is 2.04x106 for sample (3). The maximum conductance is 1.06x10-4 S at sample (1) and minimum conductance is 6.64x10-6 at sample (3). The maximum frequency dependent ac. conductivity (?ac) is 2.048 S m-1 for sample (1) and the minimum is 0.113 S m-1 at sample (3). The maximum total conductivity (?t) is 126.2 S m-1 for sample (1) and minimum (?t) is 1.129 S m-1 for sample (3). The maximum independent conductivity (?dc) is 124 S m-1 for sample (1) and minimum value is 1.015 S m-1 for sample (3). The maximum capacitive reactance (Xs) is 0.83 M? at sample (5) wt.5% SPF viscous mass to PVA-TDI weight and the minimum is 0.14 M? for sample (3).

Effect the Ratio and Particle Size of Glass Powder from Fluorescent Tubes Waste on Electrical Properties of PVA-Glass Composites

2021 ◽  
Vol 19 (10) ◽  
pp. 106-114
Author(s):  
Hani M Hussien
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Dielectric Constant ◽  
Glass Powder ◽  
Dissipation Factor ◽  
Powder Particle Size ◽  
Casting Method ◽  
Glass Composites ◽  
Mixing Ratios ◽  
Solution Casting Method

The polymer composites used in the present study were made of polyvinyl alcohol (PVA) as a matrix and glass powder as a filler. The glass powder was obtained from fluorescent tubes waste. The solution casting method was used to fabricate PVA/glass powder composite. Three groups of samples were prepared. The first was prepared by using PVA with the addition of glass powder (sieved less than 20 μm) in proportions 10, 20, 30, 40, and 50 %. The second: the mixing ratios of PVA and glass powder were 80% and 20%, respectively. The third: The mixing ratios of PVA and glass powder were 60% and 40%, respectively. In Both previous groups, the added glass powder used was sieved with sizes less than 20, 45, 105, and 125 μm. For all samples, the following properties were measured at room temperature: DC electrical conductivity, dielectric constant, electrical conductivity, and dissipation factor. The last three properties were measured with a range of frequencies from 1kHz to 5MHz. DC conductivity increases with increasing of glass powder. It was found that the highest conductivity values are for samples composed of glass powder with a particle size of less than 45 μm for both ratios of glass 20% and 40%. It is also noticed that within most frequencies, the sample with 30% glass has the largest dissipation factor. At 20% filler of glass powder, it is noted that the highest values of the dielectric constant are for samples composed of glass powder with a particle size of less than 45 μm and 125 μm. Below 1 MHz, the effect of glass powder particle size on the AC conductivity is minimal. It is found that the samples containing glass powder (less than 125 μm and 105 μm), have similar and lowest dissipation factor. At 40% filler of glass powder, it is noted that the lowest values of the dielectric constant are for samples composed of glass powder with a particle size little than 105 μm.

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