Effects Of High Electrical Conductivity Research Articles

Biochar production from the pyrolysis of food waste: Characterization and implications for its use

Food waste (FW) represents a large group of wastes that impose several issues on their management, especially in terms of microbiological and leaching pollution, and greenhouse gas emissions. According to the EU circular economy vision, finding a new way for FW valorisation to obtain reusable materials or compounds represents a priority. Thermal treatment represents one of the suitable ways for FW processing, and pyrolysis in particular presents many advantages in producing solid carbonaceous biochar, reusable oil and gas. This paper analyses biochar that was produced via thermal pyrolysis of FW. The influence of an organic additive (wooden sawdust) and a catalyst (zeolite) on the pyrolytic process at 600 °C was investigated. The results highlight how the initial composition of the feedstock (FS) influenced the characteristics of the obtained biochar. The addition of organic additives and catalyst did not change significantly the Brunauer–Emmett–Teller surface area and the calorific value. For all the analysed parameters, all tested FS respected the guidelines proposed by International Biochar Initiative (IBI) and the European Biochar Certificate (EBC) for possible reuse in agriculture and urban areas. The results suggest that biochar from FW could be potentially used in agriculture and urban green infrastructure, but the authors suggest further studies, especially on the effect of high electrical conductivity due to the typical high concentration of salts in FW.

Conductive fabrics based on carbon nanotube/Ti3C2Tx MXene/polyaniline/liquid metal quaternary composites with improved performance of EMI shielding and joule heating

Developing lightweight, flexible, conductive electromagnetic interference (EMI) shielding textiles with highly thermal conductivity and Joule heating performance is of great urgency in the field of next generation of wearable electronics, thermal management, communication, and artificial intelligence. In this work, an effective strategy to construct conductive fabrics based on carbon nanotube (CNT)/Ti3C2Tx MXene/polyaniline (PANI)/liquid metal (LM) quaternary composite with improved performance of EMI shielding and Joule heating is proposed. Conductive fabrics decorated with CNT/Ti3C2Tx/PANI/LM (CTPLM) as the conductive slurry by a simple solution dip-coating technique demonstrate a remarkable EMI shielding efficiency (EMI SE) of 78.9 dB at the thickness of 0.27 mm as well as absorbing shielding effectiveness (SEA) of 64.4 dB in the range of 8.2–12.4 GHz. The synergistic effect of high electrical conductivity and porous structure endow CTPLM-CF textiles with significantly higher EMI SE than pristine MXene film and pure CNT layer. Moreover, EMI shielding performance can be further improved to 104.3 dB when three layer conductive fabrics are combined. At the same time, conductive textiles present superior Joule heating performance with a saturation temperature of 34.5 °C @1V, 94.3 °C @2V, and 130.2 °C @3 V after 60 s, respectively. The combination of these components could comprehensively utilize the low density of carbon materials and excellent electrical conductivity from MXene and LM, thus providing a lightweight, flexible, multifunctional conductive textiles with superior EMI shielding and efficient Joule heating capability, which is highly desired for applications in aerospace, intelligent electronics, wearable electronics, thermotherapy, and personal self-heating system in harsh environment.

Aristate sphere Ni@Carbon fibers with advanced electromagnetic interference shielding performances

Increasingly serious electromagnetic wave pollution puts forward higher requirements for efficient and widely applicable electromagnetic interference (EMI) shielding materials. Herein, aristate sphere Ni@Carbon fibers were synthesized through an in-situ ultrasonic reduction method. The phase structure, morphology, magnetic, electrical conductivity and EMI shielding performances of the specimens were analyzed by various technologies. Experimental results revealed that the introduction of magnetic aristate sphere Ni endowed the carbon fibers with an outstanding EMI shielding effectiveness (SE) of 38.5 dB (99.9% attenuation) and specific shielding effectiveness (SSE/T) of 642 dB cm2/g. The advanced EMI shielding performances of aristate sphere Ni/Carbon fibers could originate from the synergistic effect of high electrical conductivity, well magnetic loss, and multiple electromagnetic reflection. Consequently, aristate sphere Ni@Carbon fibers would be an ideal candidate as light-weight, high-efficiency and widely applicable EMI shielding materials in electromagnetic shielding applications fields.

RhizobacteriumBacillus subtilisreduces toxic effects of high electrical conductivity in soilless culture of lettuce

Quality of irrigation water is a critical factor for greenhouse production. A high concentration of soluble salts is the main reason for high electrical conductivity (EC) of irrigation water. The low water quality available for agriculture is the main problem in many places of the world. Plant growth-promoting bacteria are free-living soil bacteria that can help plant growth without having pathogenic effects. In the current study, three concentrations of NaCl (0, 40 and 80 mM, which resulted in EC of 1, 4 and 8 mS, respectively) were added to the irrigation water. Half of the salt-treated plants were fed with the rhizobacterium Bacillus subtilis (OD=0.6) to test whether it can reduce the problems of medium and high EC of irrigation water on lettuce plants, cultivated in Perlite medium. Growth parameters, including fresh and dry weights, leaf area, leaf number and plant height of control plants, were considerably improved by application of B. subtilis in the root medium of lettuce plants. Furthermore, the growth of plants exposed to medium and high EC was improved by the presence of B. subtilis in their rhizosphere. Polyphasic chlorophyll fluorescence transient parameters such as absorption flux, trapping flux and quantum yield for energy dissipation were decreased in plants with B. subtilis in their rhizosphere, while electron transport flux per reaction center was increased in B. subtilis-treated plants. In conclusion, B. subtilis can be used in the root medium of greenhouse plants to prevent the toxic effects of high EC of irrigation water.

Hierarchical TiO2/C nanocomposite monoliths with a robust scaffolding architecture, mesopore-macropore network and TiO2-C heterostructure for high-performance lithium ion batteries.

Engineering hierarchical structures of electrode materials is a powerful strategy for optimizing the electrochemical performance of an anode material for lithium-ion batteries (LIBs). Herein, we report the fabrication of hierarchical TiO2/C nanocomposite monoliths by mediated mineralization and carbonization using bacterial cellulose (BC) as a scaffolding template as well as a carbon source. TiO2/C has a robust scaffolding architecture, a mesopore-macropore network and TiO2-C heterostructure. TiO2/C-500, obtained by calcination at 500 °C in nitrogen, contains an anatase TiO2-C heterostructure with a specific surface area of 66.5 m(2) g(-1). When evaluated as an anode material at 0.5 C, TiO2/C-500 exhibits a high and reversible lithium storage capacity of 188 mA h g(-1), an excellent initial capacity of 283 mA h g(-1), a long cycle life with a 94% coulombic efficiency preserved after 200 cycles, and a very low charge transfer resistance. The superior electrochemical performance of TiO2/C-500 is attributed to the synergistic effect of high electrical conductivity, anatase TiO2-C heterostructure, mesopore-macropore network and robust scaffolding architecture. The current material strategy affords a general approach for the design of complex inorganic nanocomposites with structural stability, and tunable and interconnected hierarchical porosity that may lead to the next generation of electrochemical supercapacitors with high energy efficiency and superior power density.

Effect of High Electrical Conductivity of Hydroponic Nutrient Solution on Vaccine Protein Content in Transgenic Tomato

Using greenhouse tomato (Solanum lycopersicum) as a model system to produce pharmaceutical proteins, electrical conductivity (EC) of hydroponic nutrient solution was examined as a possible factor that affects the protein concentration in fruit. Transgenic tomato plants, expressing F1-V protein, a plant-made candidate subunit vaccine against plague (Yersinia pestis), were grown hydroponically at high (5.4 dS·m−1) or conventional EC [2.7 dS·m−1 (control)] with a high-wire system in a temperature-controlled greenhouse. There was no significant difference in plant growth and development including final shoot dry weight (DW), leaf area, stem elongation rate, or leaf development rate between high EC and control. Net photosynthetic rate, transpiration rate, and stomatal conductance (gS) of leaves were also not significantly different between EC treatments. For both EC treatments, immature green fruit accumulated DW at a similar rate, but dynamics observed in fruit total soluble protein (TSP) and F1-V during the fruit growth were different between the two ECs. Fruit TSP concentration per unit DW decreased while TSP content per whole fruit increased as fruit grew, regardless of EC. However, TSPs were significantly lower in high EC than in control. Fruit F1-V concentration per unit DW and F1-V content per whole fruit were also lower in high EC than in control. Our results found that increasing EC of nutrient solution decreased TSP including the vaccine protein in fruit, suggesting that adjusting nutrient solution EC at an appropriate level is necessary to avoid salinity stress in this transgenic tomato.

Development of rapid oral bacteria detection apparatus based on dielectrophoretic impedance measurement method

In this study, a bacteria detection apparatus based on dielectrophoretic impedance measurement (DEPIM) method was demonstrated for rapid evaluation of oral hygiene. The authors integrated a micro electrode chip on which bacteria were captured by dielectrophoresis (DEP), an AC voltage source to induce DEP force, and an impedance measurement circuit to a portable instrument that enables rapid and automated oral bacterial inspection in hospitals and clinics. Special considerations have been made on effects of high electrical conductivity of oral samples on DEP force and DEPIM results. It was shown experimentally and theoretically that using a higher electric field frequency for the DEP bacteria trap and the impedance measurement could realise DEPIM application to bacteria inspection from oral samples with higher conductivity. Based on these investigations, the authors optimised the frequency condition of the DEPIM suitable for inspecting an oral sample along with the design and development of a portable DEPIM apparatus for on-site inspection of oral bacteria. Under the optimised frequency condition, DEPIM results were in good agreement with the conventional culture method showing significant applicability of the DEPIM apparatus for practical rapid oral bacteria inspection.

Effects of high electrical conductivity of nutrient solution and its application timing on lycopene, chlorophyll and sugar concentrations of hydroponic tomatoes during ripening

Tomato (cv. Durinta) plants were grown hydroponically under two electrical conductivities (EC, 2.3 and 4.5 dS m −1) of nutrient solution inside a greenhouse. The high EC treatment was initiated either immediately after anthesis (high EC treatment) or 4 weeks after anthesis (delayed high EC treatment). Fruits were harvested weekly beginning 2 weeks after anthesis, until all fruits reached the red stage (8 weeks after anthesis). Lycopene, chlorophyll, sugar and total soluble solid (TSS) concentrations of fruits were measured every week for all harvested tomatoes from the different ripeness stages. The results showed that lycopene concentration, fructose and glucose concentrations and TSS of red ripe tomato fruits were enhanced by both high EC and delayed high EC treatments compared to those in the low EC treatment. The lycopene concentration of red ripe tomato fruits in the high EC and the delayed high EC treatments showed an increase of 30–40% (1.29–1.39 mg g −1 dry matter) compared to those in the low EC treatment (0.99 mg g −1); however, there was no significant difference in the lycopene concentration between the high EC and delayed high EC treatments. TSS of red ripe tomato fruits grown in the high EC treatment was 6.1%, significantly greater than those grown in the delayed high EC treatment (5.7%). Weekly change in lycopene concentration indicated that lycopene synthesis was enhanced by the high EC treatment, regardless of the application timing. Regardless of EC treatment, chlorophyll concentration in fruit declined linearly during fruit development and ripening and reached non-detectable levels 7 weeks after anthesis. Our results indicated that: (1) accumulation of sugars and TSS in fruit was due to reduced water flux to the fruit under high EC as previously reported, and (2) lycopene synthesis was promoted by, but chlorophyll degradation was independent from, the osmotic and/or salt stress caused by the high EC.

A PHYSIOLOGICAL DISORDER OF SALINE STRESS RELEASED GREENHOUSE TOMATO PLANTS

A PHYSIOLOGICAL DISORDER OF SALINE STRESS RELEASED GREENHOUSE TOMATO PLANTS

Effects of high electrical conductivity in two-dimensional plasma flows

Der Einfluss endlicher elektrischer Leitfahigkeit auf die Kopplung zwischen Magnet-feld und Geschwindigkeitsvektor in einer ebenen, sonst dissipationsfreien Plasmastromung wird theoretisch untersucht. Die Stromungsgleichungen werden mittels Reihenentwicklung nach negativen Potenzen der (hohen) magnetischen Reynoldszahl linearisiert. Als Losung nullter Ordnung wird eine stationare, zweidimensionale, dissipationsfreie Stromung durcy einen parallelen Kanal verwendet, die zur Klasse der «aligned-flow» problems,v‖B0, gehort. Das linearisierte Gleichungssystem lasst sich mit Hilfe geeigneter Transformationen durch eine TRICOMISCHE Differentialgleichung samt Rand-und Anfangsbedingungen fur nur eine Stromungsvariable des gestorten Problems ersetzen, die der Diffusion des Magnet-felds aufgrund der endlichen Leitfahigkeit durch einen inhomogenen Term Rechnung tragt. Zur Losung dieser Gleichung wird ein Integraltransformationsverfahren angegeben, das fur eine grosse Klasse von uber den Kanal variablen Magnetfeldern nullter Ordnung anwendbar ist. Ein solcher Fall wird explizit behandelt und es wird gezeigt, dass durch die Losung alle anderen Stromungsvariablen 1. Ordnung eindeutig bestimmt sind. Fur den Fall konstanten Magnetfeldes in nullter Ordnung lasst sich der Kontakt mit bestehender einschlagiger Literatur herstellen.