scholarly journals Resistivity behavior of leather after electro-conductive treatment

2019 ◽  
Vol 2 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Aulon Shabani ◽  
Majlinda Hylli ◽  
Ilda Kazani ◽  
Pellumb Berberi
Keyword(s):  
Electrical Resistivity ◽  
Environmental Conditions ◽  
Electrical Resistance ◽  
Chemical Processes ◽  
Bulk Conductivity ◽  
Measuring Cell ◽  
Textile Materials ◽  
Multiple Factors ◽  
Conductive Properties ◽  
First Time

Measurement of electrical resistance of textile materials, fiber and fabrics included, remains always an engaging task due to sensitivities to interference of multiple factors. Difficulty stands on both finding a method of measurements that fits the requirements of samples to be tested and the most appropriate indicator describing this property. Numerous methods and indicators are used for different sample content and shape (fibers, roving, yarn or fabric, etc.), even when the material tested is the same. Different methods usually use indicators that produce results difficult to compare or to interpret, or do not express intrinsic qualities of their constituent materials. The situation is the same for leather materials. In this paper, we propose a new method, multiple steps method, and a new indicator, electrical resistivity, which takes into consideration compressional properties of leather sample and produce results independent from the amount and form of the sample. Electrical resistivity of conductive leather, as defined below, is shown to be an inherent indicator of bulk conductivity of leather assembly and is not influenced by sample form or the way it is placed within the measuring cell. The method is used for the first time to evaluate changes in electrical resistivity of leather after various chemical processes to make it electro-conductive. The data provide important information about the evolution of electro-conductive properties of leather at different stages of processing, as well as the influence of environmental conditions.

scholarly journals The Impact of Elongation on Change in Electrical Resistance of Electrically Conductive Yarns Woven into Fabric

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3390
Author(s):  
Željko Knezić ◽  
Željko Penava ◽  
Diana Šimić Penava ◽  
Dubravko Rogale
Keyword(s):  
Mathematical Model ◽  
Electrical Resistance ◽  
Electrically Conductive ◽  
Textile Materials ◽  
Measurement Results ◽  
Conductive Yarns ◽  
Yarn Count ◽  
As Relationship ◽  
The Impact ◽  
The Mathematical Model

Electrically conductive yarns (ECYs) are gaining increasing applications in woven textile materials, especially in woven sensors suitable for incorporation into clothing. In this paper, the effect of the yarn count of ECYs woven into fabric on values of electrical resistance is analyzed. We also observe how the direction of action of elongation force, considering the position of the woven ECY, effects the change in the electrical resistance of the electrically conductive fabric. The measurements were performed on nine different samples of fabric in a plain weave, into which were woven ECYs with three different yarn counts and three different directions. Relationship curves between values of elongation forces and elongation to break, as well as relationship curves between values of electrical resistance of fabrics with ECYs and elongation, were experimentally obtained. An analytical mathematical model was also established, and analysis was conducted, which determined the models of function of connection between force and elongation, and between electrical resistance and elongation. The connection between the measurement results and the mathematical model was confirmed. The connection between the mathematical model and the experimental results enables the design of ECY properties in woven materials, especially textile force and elongation sensors.

Study on Conductive Mechanism of Carbon Fiber Filled Cement-Based Composites

2011 ◽  
Vol 415-417 ◽  
pp. 1435-1438
Author(s):  
Xue Li Nan ◽  
Xiao Min Li
Keyword(s):  
Electrical Resistivity ◽  
Carbon Fiber ◽  
Cement Paste ◽  
Ionic Conduction ◽  
Strong Electrolyte ◽  
Pull Out ◽  
Fiber Bridging ◽  
Interface Contact ◽  
Conductive Mechanism ◽  
Conductive Properties

In order to investigate conductive mechanism of carbon fiber filled cement-based composites, the conductive properties of cement paste, carbon fiber filled cement-based composites containing different contents of carbon fibers or aggregates were studied. Experimental results indicate that the electrical resistance of the plain cement paste obviously increases with hydration time, which results from the ionic conduction in strong electrolyte solution. The electrical resistivity of the carbon fiber filled cement-based composites decreases with the increase of fiber content. Both contacting conduction and ionic conduction are in charge of the electrical conduction in these composites. The electrical resistivity of the carbon fiber filled cement-based composites decreases under compression, which is due to the improvement of interface contact between matrix and fibers and the increase of fiber bridging probability. The fiber pull-out and breaking under tension lead to an increase in electrical resistivity of these composites. Aggregates block fiber dispersion and contact. This causes an increase in electrical resistivity of the composites.

scholarly journals First report on cyanobacterial flora from Masirah Island, Sultanate of Oman

Algologia ◽  
2020 ◽  
Vol 30 (4) ◽  
pp. 440-451
Author(s):  
M. Shamina ◽  
Keyword(s):  
Environmental Conditions ◽  
Food Industry ◽  
Vital Role ◽  
Taxonomic Composition ◽  
Climatic Conditions ◽  
Taxonomic Classification ◽  
Biofuel Production ◽  
Sultanate Of Oman ◽  
First Report ◽  
First Time

Cyanobacteria are organisms which play a vital role in various molecular and biotechnological aspects in food industry, agriculture, pharmaceuticals, neutraceuticals, biofuel production, etc., it is necessary to understand its adaptability to various environmental conditions. Furthermore it is equally important to discover new cyanobacterial taxa and with it occasional changes in taxonomic classification, thus the author set out to study cyanobacteria in extreme climatic conditions of desert, where temperatures are mostly above 45 oC. The taxonomic composition of cyanobacteria of Masirah Island, Sultanate of Oman, was studied for the first time. The studied samples were collected during the period of 2017–2019. The ten samples belonged to two orders: Oscillatoriales Schaffner and Synechococcales L.Hoffmann, Komárek & J.Kastovsky. All of them were filamentous non-heterocyst forms. Three species belonged to the genus Leptolyngbya Anagn. & Komárek, the genera Oscillatoria Vaucher ex Gomont and Lyngbya C.Agardh ex Gomont were represented by two species each, while the genera Pseudanabena Lauterborn, Planktolyngbya Anagn. & Komárek and Geitlerinema (Anagn. & Komárek) Anagn. were one species.

scholarly journals Pressure-induced monotonic enhancement of Tc to over 30 K in the superconducting Pr0.82Sr0.18NiO2 thin films

2021 ◽  
Author(s):  
Ningning Wang ◽  
Mingwei Yang ◽  
Keyu Chen ◽  
Zhen Yang ◽  
Hua Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Pressure Effect ◽  
Ambient Pressure ◽  
Strain Engineering ◽  
Superconducting Properties ◽  
Liquid Pressure ◽  
Infinite Layer ◽  
Effect Of Pressure ◽  
First Time

Abstract The successful synthesis of superconducting nickelate thin films with the highest Tc ~ 15 K has reignited great enthusiasms on this class of potential analogue to high-Tc cuprates suggested decades ago. To pursue higher Tc is always an important task in studying new superconductors. Here we report for the first time the effect of pressure on the superconducting properties of infinite-layer Pr0.82Sr0.18NiO2 thin films by measuring electrical resistivity under various pressures in a cubic anvil cell apparatus. We find that the onset of superconductivity, Tconset, can be enhanced monotonically from ~ 18 K at ambient pressure to ~ 31 K without showing signatures of saturation upon increasing pressure to 12.1 GPa in the presence of liquid pressure transmitting medium. This encouraging result indicates that the Tc of infinite-layer nickelates superconductors can be further raised up by applying higher pressures or strain engineering in the heterostructure films. In addition to the pressure effect, we also discussed the influence of stress/strain on the superconducting properties of the nickelate thin films.

scholarly journals The usage of electroimpedancemetry in the diagnostics of acute sinusitis

2002 ◽  
Vol 1 (1) ◽  
pp. 101-107
Author(s):  
A. V. Davidov
Keyword(s):  
Nasal Cavity ◽  
Paranasal Sinus ◽  
Electrical Resistance ◽  
Inflammatory Diseases ◽  
Acute Sinusitis ◽  
Comparative Aspect ◽  
Methods Of Evaluation ◽  
First Time ◽  
High Credibility ◽  
Wide Usage

For the first time in the rhinological practice the methods of evaluation of the functional state of tissues of nasal cavity that were based on registration of their electrical features-electrical resistance (impedance) and potencial were worked out. In the comparative aspect there were researched the active and the passive electrical features of the tissues of nasal cavity which healthy people and those whose disease is acute sinusitis, have. For the first time the dynamic of electrical features was studied and the most informative electrical rates for the initial diagnostic of acute sinusitis and for evaluation of the effectiveness of appointed treatment were revealed. As a result of researches a new way of noninvasive diagnostic of inflammatory diseases of paranasal sinus was worked out, approved and inserted in practice. (Patent № 2157094, 10.10.2000 «The way of diagnostic of inflammatory diseases of paranasal sinus»). The suggested way is simple, reliable; it has high credibility value of revealing the pathologies of paranasal sinus and evaluation of its dynamic. This method may be recommended for the wide usage in hospitals and clinics for diagnostic of acute sinusitis and evaluation of effectiveness of treatment.

LOW TEMPERATURE RESISTIVITY OF TRANSITION ELEMENTS: VANADIUM, NIOBIUM, AND HAFNIUM

1957 ◽  
Vol 35 (8) ◽  
pp. 892-900 ◽  
Author(s):  
G. K. White ◽  
S. B. Woods
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Electrical Resistance ◽  
Thermal Resistivity ◽  
Superconducting Transition ◽  
Transition Elements ◽  
Pure Niobium ◽  
Temperature Resistivity ◽  
The Ideal

Measurements of the thermal conductivity from 2° to 90 ° K. and electrical conductivity from 2° to 300 ° K. are reported for vanadium, niobium, and hafnium. Although the vanadium and hafnium are not as pure as we might wish, measurements on these metals and on niobium allow a tabulation of the "ideal" electrical resistivity clue to thermal scattering for these elements from 300 ° K. down to about 20 ° K. Ice-point values of the "ideal" electrical resistivity are 18.3 μΩ-cm. for vanadium, 13.5 μΩ-cm. for niobium, and 29.4 μΩ-cm. for hafnium. Values for the "ideal" thermal resistivity of vanadium and niobium are deduced from the experimental results although for vanadium and more particularly for hafnium, higher purity specimens are required before a very reliable study of "ideal" thermal resistivity can be made. For the highly ductile pure niobium, the superconducting transition temperature, as determined from electrical resistance, appears to be close to 9.2 ° K.

Electrical resistivity of coal-bearing rocks under high temperature and the detection of coal fires using electrical resistance tomography

2015 ◽  
Vol 204 (2) ◽  
pp. 1316-1331 ◽  
Author(s):  
Zhenlu Shao ◽  
Deming Wang ◽  
Yanming Wang ◽  
Xiaoxing Zhong ◽  
Xiaofei Tang ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
High Temperature ◽  
Electrical Resistance ◽  
Electrical Resistance Tomography ◽  
Coal Fires

Organization and Compaction of Composite Filler Material Using Acoustic Focusing

2017 ◽  
Author(s):  
Lauren A. Chai ◽  
Brian W. Anthony
Keyword(s):  
Electrical Resistivity ◽  
Carbon Nanofibers ◽  
Electrical Resistance ◽  
Volume Fraction ◽  
Acoustic Radiation ◽  
Mineral Oil ◽  
Acoustic Focusing ◽  
Initial Drop ◽  
Light Mineral ◽  
External Face

Carbon nanofibers in polymer-based composites reduce the electrical resistivity of the composite but can be up to 100 times more expensive than the bulk polymer. This work uses acoustic focusing to organize and compact carbon nanofibers in a mineral oil mixture. The result is a decrease in the composite electrical resistivity without an increase in the global volume fraction of the fibers in the composite and associated material cost. The composite consisted of Pyrograf PR-19-LHT carbon nanofibers mixed in light mineral oil at 1.6% volume fraction carbon nanofibers. The mixture was contained in a 1 cm × 1 cm × 4 cm glass cuvette. A PZT-4 piezoelectric transducer, epoxied to the external face of one of the sidewalls, generated the acoustic radiation forces in the container. A 1.179 MHz sinusoidal signal powered the transducer, producing a standing wave with 27 nodes and 13 antinodes in the container. A digital multimeter performed the 2-wire resistance measurement before, during and after focusing. Settling of the filler due to gravity resulted in an initial drop in the electrical resistance. Once the mixture reached steady state, toggling the signal power off and on also toggled the approximate electrical resistance between the 19.2 MOhms and 11.5 MOhms respectively. This work also presents a simple volume fraction model, which predicted that the focused resistance would be 34% of the unfocused value. In the experiment, acoustic focusing reduced the electrical resistance to 60% of the resistance in the unfocused mixture, demonstrating acoustic focusing as a method for reducing electrical conductivity within a composite.

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