DESIGN OF A SAMPLE HOLDER FOR LOW TEMPERATURE ELECTRICAL CONDUCTIVITY MEASUREMENTS

2013 ◽  
Vol 22 ◽  
pp. 741-744 ◽  
Author(s):  
YADUNATH SINGH
Keyword(s):  
Electrical Conductivity ◽  
Low Temperature ◽  
Electric Fields ◽  
Low Cost ◽  
Ambient Pressure ◽  
Liquid Nitrogen Temperature ◽  
Sample Holder ◽  
Ac Electrical Conductivity ◽  
Switching Phenomenon ◽  
Wide Range

Both DC and AC electrical conductivity of materials provide a number of valuable informationon the nature of current carriers, 3-D effects, scattering by defects and impurities, formation of CDW, soliton propagation, non – linear and switching phenomenon and other characters pertaining to these compounds. These measurements are therefore carried out over a wide range of temperature, pressure, electric fields and impurity concentrations. Besides these, the low temperature studies of the materials are performed to determine Optical and Magnetic properties and etc. Therefore, a suitable sample holder is required to perform these studies with low temperature variations. In this paper, we report a design of such a suitable and simple sample holder, which can work up to liquid nitrogen temperature (77 K). This model is easy to fabricate, low cost, more efficient with less wastage in terms of liquid gases than other models. This model can be used for both low temperature dependent electrical conductivity at ambient pressure and clamped high pressure measurements within the given range

scholarly journals Novel Pressure Sensors Made from Nanocomposites (Biodegradable Polymers–Metal Oxide Nanoparticles): Fabrication and Characterization

2018 ◽  
Vol 63 (8) ◽  
pp. 754 ◽  
Author(s):  
A. Hashim ◽  
A. Hadi
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Properties ◽  
Low Cost ◽  
Metal Oxide Nanoparticles ◽  
Pressure Sensors ◽  
High Sensitivity ◽  
Oxide Nanoparticles ◽  
Ac Electrical Conductivity ◽  
Dc Electrical Conductivity ◽  
Pressure Sensitive

This paper aims to the preparation of novel pressure-sensitive nanocomposites with low cost, light weight, and good sensitivity. The nanocomposites of polyvinyl alcohol, polyacrylic acid, and lead oxide nanoparticles have been investigated. The dielectric properties and dc electrical conductivity of (PVA–PAA–PbO2) nanocomposites have been studied. The dielectric properties of nanocomposites were measured in the frequency range (100 Hz–5 MHz). The experimental results showed that the dielectric constant and dielectric loss of (PVA–PAA–PbO2) nanocomposites decrease, as the frequency increases, and they increase with the concentrations of PbO2 nanoparticles. The ac electrical conductivity of (PVA–PAA–PbO2) nanocomposites increases with the frequency and the concentrations of PbO2 nanoparticles. The dc electrical conductivity of (PVA–PAA–PbO2) nanocomposites also increases with the concentrations of PbO2 nanoparticles. The application of pressure-sensitive nanocomposites has been examined in the pressure interval (60–200) bar. The results showed that the electrical resistance of (PVA–PAA–PbO2) pressure-sensitive nanocomposites decreases, as the compressive stress increases. The (PVA–PAA–PbO2) nanocomposites have high sensitivity to pressure.

scholarly journals Lichtabsorption von oxidischen Silber(I)-Verbindungen / Light Absorption of Silver(I)-oxides

1984 ◽  
Vol 39 (6) ◽  
pp. 739-743 ◽  
Author(s):  
Claus Friebel ◽  
Martin Jansen
Keyword(s):  
High Pressure ◽  
Charge Transfer ◽  
Low Temperature ◽  
Absorption Edge ◽  
Diffuse Reflectance ◽  
Static Pressure ◽  
Ambient Pressure ◽  
Partial Structures ◽  
Wide Range ◽  
Charge Transfer Transitions

AbstractDiffuse reflectance spectra of Ag2SO4, Ag3PO4, Ag2CO3, Ag2Ge2O5, AgBO2, Ag3BO3-II, Ag6Si2O7, Ag10Si4O13 and Ag10Ge4O13 in the region ν̄ = 10000-40000 cm-1 and generally at 298 K and ambient pressure were measured. Additional spectra were recorded at 5 K for Ag3BO3 and Ag3PO4, and under application of a static pressure of 80 kbar for Ag10Si4O13. As a common feature all spectra show a steep absorption edge, which is only structured in singular cases. The edges appear in the remarkably wide range from 33100 cm-1 (Ag2SO4) to 13500 cm-1 (Ag10Ge4O13). As the shifts correlate with the dimensions of the cluster-like silver partial structures, the absorptions have been attributed to 4d→5s band-band transitions, an interpretation, which is in agreement with the low temperature and high pressure spectra. However, effects originating from charge-transfer transitions cannot be absolutely excluded.

scholarly journals (303) Performance of a New, Low-cost Soil Moisture, Temperature, and Electrical Conductivity Sensor

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1024A-1024
Author(s):  
Colin S. Campbell ◽  
Gaylon S. Campbell ◽  
Douglas R. Cobos ◽  
Brody Teare
Keyword(s):  
Electrical Conductivity ◽  
Low Cost ◽  
Considerable Improvement ◽  
Soil Types ◽  
Calibration Equation ◽  
Conductivity Sensor ◽  
Trade Name ◽  
Wide Range ◽  
Mineral Soils ◽  
Single Calibration

Knowledge of soil water, fertilizer, and temperature is important when growing plants in any type of growing media. Although instruments to measure these properties have been available for several years, they are often expensive, failure-prone, and require different calibration for individual soil types. Recently, a low-cost sensor (Trade name: ECH2O-TE) was released that measures volumetric water content, electrical conductivity (EC), and temperature. The objective of this study was to determine how the probe performed in various soil and soilless media, as well as various salinities. We found the probe performed very well over a wide range of soil types and salinities. From the data, it appears that a single calibration can be used for all mineral soils and organic potting soils. A second calibration equation may be required for substrates such as rockwool. The output of the probe was not affected by the salinity (EC) of the soil from 0.1 to greater than 10 dS/m and showed considerable improvement in temperature sensitivity compared to existing technology. These results suggest the sensor provides a low-cost, reliable, easier-to-use alternative to other sensors of its kind.

A Prototype Continuous Flow Polymerase Chain Reaction LTCC Device

2007 ◽  
Vol 539-543 ◽  
pp. 523-528 ◽  
Author(s):  
Korey Moeller ◽  
Jason Besecker ◽  
Greg Hampikian ◽  
A. Moll ◽  
D. Plumlee ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Low Temperature ◽  
Continuous Flow ◽  
Low Cost ◽  
Flow Characteristics ◽  
Chain Reaction ◽  
Wide Range ◽  
Polymerase Chain ◽  
Thermal Cycler ◽  
Biological Entities

There is a growing need for remote biological sensing in both laboratory and harsh field environments. Sensing and detection of biological entities such as anthrax, Ebola and other micro-organisms of interest involves sampling of the environment, amplification, analysis and identification of the target DNA. A key component of such a sensor is a low cost, portable, reusable, continuous flow polymerase chain reaction (PCR) thermal cycler. Fabrication with low temperature co-fired ceramics (LTCC) can provide a reusable low cost device capable of operating in a wide range of environments The design and manufacture of a prototype continuous flow micro-fluidic PCR device using low temperature co-fired ceramic is presented. Initial modeling of flow characteristics and heat transfer was carried out in SolidWorks™. The prototype device employs resistance heaters below the channels, buried and surface thermocouples for temperature monitoring, and air gaps for thermal isolation.

Electrokinetic instabilities of non-dilute colloidal suspensions

2009 ◽  
Vol 619 ◽  
pp. 331-365 ◽  
Author(s):  
GURU NAVANEETHAM ◽  
JONATHAN D. POSNER
Keyword(s):  
Electrical Conductivity ◽  
Electric Fields ◽  
Colloidal Particles ◽  
Volume Fraction ◽  
Flow Instability ◽  
Colloidal Suspensions ◽  
Critical Conditions ◽  
Scaling Analysis ◽  
Average Particle ◽  
Wide Range

An experimental investigation of electrokinetic instabilities (EKIs) of non-dilute colloidal suspensions in microchannels is presented. The addition of charged colloidal particles to a solution can alter the solution's electrical conductivity and permittivity as well as the average particle electrophoretic mobility. In this work, a colloidal (500 nm polystyrene) volume fraction gradient is achieved at the intersection of a Y-shaped polydimethylsiloxane (PDMS) microchannel. The flow becomes unstable when the electroviscous stretching and folding of the conductivity and permittivity interfaces exceed the dissipative effects of viscous forces and particle diffusion. The suspension conductivity as a function of the particle volume fraction is presented. The critical conditions required for flow instability are measured along with a scaling analysis which shows that the flow becomes unstable due to a coupling of applied electric fields and the electrical conductivity and permittivity gradients in the flow. The flow becomes unstable at a critical electric Rayleigh number of Rae = 1.8 × 105 for a wide range of applied electric fields spanning three orders of magnitude and colloid volume fractions varying two orders of magnitude. EKIs of non-dilute colloidal suspensions may be important for applications such as the electrophoretic deposition of micropatterned colloidal assemblies, electrorheological devices and on-chip electrokinetic (EK) manipulation of colloids.

Temperature Dependent Electrical Properties of Green Synthesized Silver Nanoparticles-Polyaniline Composite

2014 ◽  
Vol 938 ◽  
pp. 230-235 ◽  
Author(s):  
Mukundan Dorairajan ◽  
Vikram Srinivas ◽  
Vasanthakumari Raju ◽  
Gayathri Raghavan
Keyword(s):  
Electrical Conductivity ◽  
Silver Nanoparticles ◽  
Low Cost ◽  
Spectral Response ◽  
Dc Conductivity ◽  
Temperature Dependent ◽  
Thermal Alteration ◽  
Neem Extract ◽  
Wide Range ◽  
Green Synthesized Silver Nanoparticles

Polyaniline (PANI) Nanocomposites are potential materials for actuators, EMI shielding, Fuel cells and components in non volatile memory. Silver nanoparticles have wide range of applications such as catalysis, microelectronics, biotechnology and silver-oxide batteries. This work reports the effect of thermal alteration [lowhigh temperatur on the electrical conductivity of green synthesized silver (Ag) nanoparticles-polyaniline composite. A simple low cost green synthesis using Azadirachta indica [Neem] extract is employed for synthesis of silver nanoparticles; Polyaniline is prepared by redox polymerization of aniline using ammonium per sulphate. The silver nanoparticles are incorporated into Polyaniline during polymerization. PANI and PANI-Ag composites are characterized by FTIR, UV-Vis, TGA, XRD, TEM and DC conductivity. The DC conductivity and UV-Vis spectral response were recorded for the samples at low temperatures [263K, 273K, and 283 and high temperatures [353K, 433K, and 533. The effect of thermal alteration showed a significant change in both conductivity and UV-Vis spectral response. UV-visible spectra show the transition occurring in PANI Emeraldine salt phase to Pernigraniline with increase in temperature. TGA analysis confirms the improved thermal stability for PANI-Ag composite. The mechanism of electrical conductivity with temperature in the system is investigated and reported. Thus, this work deals with an approach to analyze the electrical behavior of green synthesized silver nanoparticles composited with a conducting polymer. The results show that these composites can be suitable for temperature dependent semiconductors, bio sensors and catalytic reactions.

scholarly journals RELaTED Project: New Developments on Ultra-Low Temperature District Heating Networks

Proceedings ◽  
2020 ◽  
Vol 65 (1) ◽  
pp. 25
Author(s):  
Antonio Garrido Marijuan ◽  
Roberto Garay ◽  
Mikel Lumbreras ◽  
Víctor Sánchez ◽  
Olga Macias ◽  
...  
Keyword(s):  
Low Temperature ◽  
High Performance ◽  
Waste Heat ◽  
District Heating ◽  
Hot Water ◽  
Thermal Systems ◽  
Heating Source ◽  
Wide Range ◽  
Thermal Sources ◽  
Heating Networks

District heating networks deliver around 13% of the heating energy in the EU, being considered as a key element of the progressive decarbonization of Europe. The H2020 REnewable Low TEmperature District project (RELaTED) seeks to contribute to the energy decarbonization of these infrastructures through the development and demonstration of the following concepts: reduction in network temperature down to 50 °C, integration of renewable energies and waste heat sources with a novel substation concept, and improvement on building-integrated solar thermal systems. The coupling of renewable thermal sources with ultra-low temperature district heating (DH) allows for a bidirectional energy flow, using the DH as both thermal storage in periods of production surplus and a back-up heating source during consumption peaks. The ultra-low temperature enables the integration of a wide range of energy sources such as waste heat from industry. Furthermore, RELaTED also develops concepts concerning district heating-connected reversible heat pump systems that allow to reach adequate thermal levels for domestic hot water as well as the use of the network for district cooling with high performance. These developments will be demonstrated in four locations: Estonia, Serbia, Denmark, and Spain.

scholarly journals Information and information resources in COVID-19: Awareness, control, and prevention

2021 ◽  
pp. 096100062110165
Author(s):  
Mohammadhiwa Abdekhoda ◽  
Fatemeh Ranjbaran ◽  
Asghar Sattari
Keyword(s):  
Low Cost ◽  
Information Resources ◽  
Age And Gender ◽  
Use Of Resources ◽  
Strategic Approach ◽  
Wide Range ◽  
Data Collection Instrument ◽  
Control And Prevention ◽  
And Gender ◽  
And Control

This study was conducted with the aim of evaluating the role of information and information resources in the awareness, control, and prevention of COVID-19. This study was a descriptive-analytical survey in which 450 participants were selected for the study. The data collection instrument was a researcher-made questionnaire. Descriptive and inferential statistics were used to analyze the data through SPSS. The findings show that a wide range of mass media has become well known as information resources for COVID-19. Other findings indicate a significant statistical difference in the rate of using information resources during COVID-19 based on age and gender; however, this difference is not significant regarding the reliability of information resources with regard to age and gender. Health information has an undisputable role in the prevention and control of pandemic diseases such as COVID-19. Providing accurate, reliable, and evidence-based information in a timely manner for the use of resources and information channels related to COVID-19 can be a fast and low-cost strategic approach in confronting this disease.

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