Electronic Conductivity Values Research Articles

A Facile Two-Step Thermal Process for Producing a Dense, Phase-Pure, Cubic Ta-Doped Lithium Lanthanum Zirconium Oxide Electrolyte for Upscaling

An inorganic solid electrolyte is the most favorable candidate for replacing flammable liquid electrolytes in lithium batteries. Lithium lanthanum zirconium oxide (LLZO) is considered a promising solid electrolyte due to its safe operating potential window (0–5 V) combined with its good electrochemical stability. In this work, 250 g batches of pre-sintered Ta-doped LLZO (Li7La3Zr1.6Ta0.4O12, Ta-LLZO) were synthesized for bulk production of a dense LLZO electrolyte. A simple two-step thermal treatment process was developed. The first thermal step at 950 °C initiates nucleation of LLZO, with carefully controlled process parameters such as heating atmosphere, temperature, and dopant concentration. In the second thermal step at 1150 °C, sintered discs were obtained as solid electrolytes, with relative densities of 96%. X-ray diffraction analysis confirmed the phase purity of the sintered Ta-LLZO disc, and refined data were used to calculate the lattice parameter (12.944 Å). Furthermore, the presence of the Ta dopant in the disc was confirmed through X-ray photoelectron spectroscopy (XPS) analysis. The ionic and electronic conductivity values of the Ta-LLZO disc were 10−4 S cm−1 and 10−10 S cm−1, respectively. These values confirm that the prepared (Ta-LLZO) discs exhibit ionic conductivity while being electronically insulating, being suitable for use as solid electrolytes with the requisite electrical properties.

A Rapid Synthesis of Zeolitic Imidazolate Framework-14 Cobalt (ZIF-14 Co) for Surface Modification of LiFePO<sub>4</sub> as Lithium‑Ion Battery Cathode Material

The main limitation of LiFePO4 (LFP) as a cathode material for lithium-ion battery (LIB) is its poor rate performance due to its low electronic conductivity values. At present, there are three main efforts being intensively carried out to overcome this: cation doping, crystal morphology adjustment, and LFP surface modification. Surface modification of LFPs has become a major concern in efforts to improve battery performance. The use of zeolitic imidazolate frameworks 8 (ZIF-8) and 67 (ZIF 67) as N-doped C sources for surface modification of LIB cathodes carried out in several studies has shown an improvement in the electrochemical performance of LIB. However, the thermal, solvothermal and chemical stability of ZIF-8 and ZIF-67, which adopt the sodalite (SOD) topology, is still not enough for this purpose. Zeolitic imidazolate frameworks 14 (ZIF-14), which is homologous to ZIF-8 and ZIF-67 with its crystals adopting analcime (ANA) topology, has better thermal, solvothermal, and chemical stability than ZIF-8 and ZIF-67. Apart from its topology, ZIF-14 cobalt (ZIF-14 Co) can be synthesized rapidly in a water-based system at room temperature, so that its use becomes more effective and efficient. This paper will describe the synthesis and characterization procedure of ZIF-14 Co for use as a modification material for the cathode surface of LIB.

A New Family of Layered Metal-Organic Semiconductors: Cu/V-Organophosphonates.

Herein, wereport the design and synthesis of a layered redox-active, antiferromagnetic metal organic semiconductor crystals with the chemical formula [Cu(H2 O)2 V(µ-O)(PPA)2 ] (where PPA is phenylphosphonate). The crystal structure of [Cu(H2 O)2 V(µ-O)(PPA)2 ] shows that the metal phosphonate layers are separated by phenyl groups of the phenyl phosphonate linker. Tauc plotting of diffuse reflectance spectra indicates that [Cu(H2 O)2 V(µ-O)(PPA)2 ] has an indirect band gap of 2.19eV. Photoluminescence (PL) spectra indicate a complex landscape of energy states with PL peaks at 1.8 and 2.2eV. [Cu(H2 O)2 V(µ-O)(PPA)2 ] has estimated hybrid ionic and electronic conductivity values between 0.13 and 0.6Sm-1 . Temperature-dependent magnetization measurements show that [Cu(H2 O)2 V(µ-O)(PPA)2 ] exhibits short range antiferromagnetic order between Cu(II) and V(IV) ions. [Cu(H2 O)2 V(µ-O)(PPA)2 ] is also photoluminescent with photoluminescence quantum yield of 0.02%. [Cu(H2 O)2 V(µ-O)(PPA)2 ] shows high electrochemical, and thermal stability.

Ionic–Electronic Conductivity in Ternary Polymer/Reduced Graphene Oxide/Polyelectrolyte Nanocomposite Coatings for Potential Application in Energy Storage

Polymeric mixed ionic–electronic conductors are desired for a range of applications. The growing interest in the shift from liquid to solid polymer electrolytes further fueled research interest in this domain. However, the predominant research in the field has been limited to binary systems where components are selected for their electronic and ionic conduction. Here, in a systematic study, we have developed ternary nanocomposites comprising an insulating polymer poly(benzyl methacrylate-stat-n-butyl acrylate) used as a binder, reduced graphene oxide as an electronic conductor nanofiller, and different concentrations of polyelectrolytes lignosulfonate (LS) and polystyrene sulfonate as ionic conductors. The developed ternary nanocomposite can be simply coated to obtain a uniform film at ambient temperature, exhibiting mixed ionic–electronic conduction. Scanning electron microscopy–energy-dispersive spectroscopy mapping revealed the distribution of polyelectrolytes throughout the film surface. The nanocomposite coatings exhibited the highest ionic conductivity of ∼54 S m–1 (30 wt % LS relative to monomer) and electronic conductivity of ∼40 S m–1 (7 wt % LS relative to monomer). The obtained ionic–electronic conductivity values were some of the highest reported in the literature (compared against binary systems), despite comprising an insulating binder as a majority component. The present work provides the important fundamental understanding behind the design and fabrication of ternary polymeric mixed ionic–electronic conductive coatings and paves the way for further research in the field. The developed nanocomposite coatings are anticipated to find application in a range of fields including energy storage, biomedical engineering, and sensors.

The Effect of Sintering Time on Electronic Conductivity of LiFeGdPO4/C as a Lithium-Ion Battery Cathode

Lithium iron phosphate (LiFePO4) is an alternative cathode material choice in lithium-ion batteries because of its non-toxic nature, high voltage (3.45 V), the high theoretical capacity of LiFePO4 (170 mAh/g), low cost, non-reactive and has good structural properties stability. However, LiFePO4 has a low electronic conductivity (10-9-10-10 S/cm) and a low diffusion coefficient of Li+ ions (10-12-10-14 cm2/s), so it affects electrochemical performance. There are several ways to increase the conductivity. These are namely carbon coating, metal ion doping and optimizing the sintering time. Optimal sintering time will increase crystallinity, thereby increasing the value of electronic conductivity. Then using the right sintering time will get a lot of the desired phase content. This study aims to determine the effect of the sintering time variation 6 hours, 8 hours, 10 hours, 20 hours and 30 hours to increase the electronic conductivity of LiFeGdPO4/C. The synthesis method used is the carbothermal reduction method with the precursors used are LiH2PO4, Fe2O3, Gd2O3 and carbon graphite. LCR meter and XRD are used to characterize samples. The results obtained indicate that the effect of sintering time can increase the value of the electronic conductivity of LiFeGdPO4/C, with the highest conductivity value at a sintering time of 30 hours of 1.5296 x 10-7 S/cm.

Design and Development of High-Loading Carbon-Sulfur Nanocomposite Cathodes with Drop-Casting Method

Advanced rechargeable batteries that can be widely applied in different energy-storage systems require a high energy density, a stable cyclability, and low costs in materials and fabrications. The commercial lithium-ion batteries exhibit high discharge capacity with a long cycle life, which allows them to dominate the current rechargeable battery markets. With the continuous development, the lithium-ion battery chemistry would soon encounter the theoretical material limitations. The mature fabrication technique and materials science have promoted the lithium-ion battery cathodes to meet their theoretical charge-storage capacity values. Moreover, the lithium insertion compounds have to maintain a stable crystal structure by limiting the full electrochemical utilization of the active material during cycling. Furthermore, with an increasing demand for lithium-ion battery products, the high prices and limited availability of the raw materials impact the market and the development of future lithium-ion batteries.To address these issues, a conversion-reaction cathode bypasses the limitation of low theoretical charge-storage capacity and limited electrochemical utilization garner significant attention. Among various conversion-reaction cathodes, the lithium-sulfur system is the most promising candidate for developing the post-lithium-ion technology with higher energy density at an affordable cost. This is primarily due to its naturally-abundant and low-cost sulfur cathode possesses a high charge-storage capacity of 1,672 mA∙h g-1, which makes the lithium-sulfur cells to approach a high energy density of about two to three times higher than that of current lithium-ion batteries. However, many obstacles limit the fast commercialization of lithium-sulfur technology. The low electronic conductivity values of sulfur and its end-discharged sulfides affect the electrochemical utilization of the active material and the development of a high-loading sulfur cathode for demonstrating a high energy density. In between sulfur and sulfides, the polysulfide intermediates generated during charge and discharge states are liquid-state active materials and have high solubility toward the liquid electrolyte. The dissolution of polysulfides would irreversibly diffuse out from the cathode and uncontrollably migrate in the cell, which causes the loss of active material from the cathode, the contamination of electrolyte, and the corrosion of the lithium metal anode. Consequently, the polysulfide issues result in poor electrochemical stability and further impact the high-loading cathode performance.This presentation will focus on the use of a drop-casting method to fabricate a high-loading carbon-sulfur nanocomposite cathode. Subsequently, we apply the developed high-loading nanocomposite cathode for exploring the effect of carbons’ nanopore sizes toward the electrochemical performance of sulfur cathodes. First, the drop-casted carbon-sulfur nanocomposite cathodes are fabricated with various carbon-sulfur nanocomposites. Super P-Sulfur, Ketjenblack-Sulfur, Black Pearl-Sulfur, and Vulcan Black-Sulfur nanocomposites featuring the nonporous Super P carbon, the mixed micro/mesoporous Ketjenblack carbon, the microporous Black Pearl carbon, and the macroporous Vulcan Black carbon are synthesized by the melt-sulfur diffusion method. The carbon-sulfur nanocomposites are mixed with liquid electrolyte to form a paste, followed by drop-casting on the current collector. These carbon-sulfur nanocomposite cathodes attain and are fixed at a high sulfur loading and sulfur content of 4 mg cm-2 and 60 wt%, respectively. Our findings indicate that the Black Pearl-sulfur nanocomposite cathode exhibits the best overall electrochemical performances featuring the high rate capability from C/20 to C/3 rates, stable long-term cyclability, and high capacity retention of above 80% after 100 cycles. The Ketjenblack-sulfur nanocomposite cathode with mixed micro/mesoporous carbon shows similar performances, while relatively lower than those obtained by Black Pearl-sulfur nanocomposite. With no nanopores and with macropores, Super P-Sulfur and Vulcan Black-sulfur nanocomposites display short cycle life in 40 cycles and low electrochemical utilization of sulfur, respectively. As a result, a carbon-sulfur nanocomposite with microporous carbon as the host would give the excellent polysulfide retention and the active-material utilization. With a nonporous carbon substrate, the carbon-sulfur nanocomposite might encounter the diffusion of polysulfides from the cathode electrode during cycling. With a macroporous carbon, the carbon-sulfur nanocomposite might also face the polysulfide diffusion issue, while mainly the diffusion of polysulfides from the composite. All these results demonstrate that the drop-casting method is a promising solution to develop high-loading sulfur cathode. Moreover, the further optimization of the nanocomposite might improve the electrochemical performance of the resulting high-loading nanocomposite sulfur cathode.

Spatial variation in major water quality types and its relationships with land cover in the middle and lower reaches of Aral Sea Basin

Water resources and environmental issues in the Aral Sea Basin of Central Asia are global concerns. In this study, the water quality variables (i.e., basic physical and chemical attributes, different forms of nutrients, other elements, cations, and anions) from 21 sampling sites in the middle and lower reaches of Aral Sea Basin were measured in 2019 to explore water environmental variations and their causes. Spatial variation in 20 water quality variables was investigated, and the representative water quality types, spatial differences, and their causes were identified via multivariate analysis methods (i.e., principal component analysis and cluster analysis). Furthermore, the effects of land cover on the spatial variation in water quality types were explored. The results showed that: 1) the values of electronic conductivity (EC) and total dissolved solids (TDS) increased from the middle to the lower reaches, and the highest values were in the Aral Sea. This indicates that the concentrations of anions and cations increased from the middle to the lower reaches. For the nutrient variables, high phosphorous concentrations were in the middle reaches of Amu Darya, and high nitrate-nitrogen concentrations were in the Syr Darya. For the different forms of carbon, the highest concentrations were in the Amu Darya, particularly in the delta area of lower reaches. 2) The water quality at all sampling sites can be divided into three water quality types according to the similarity classification of water quality variables. The first type had low concentrations for most water quality variables, which were distributed in the middle reaches of Syr Darya and the Aral Sea. The second type had high concentrations of different forms of nitrogen and phosphorus, which were distributed in the middle and lower reaches of Amu Darya. The third type had high concentrations of carbon, anions, and cations, which were distributed in the Aral Sea. The water quality concentrations of the first and second types were mainly due to rock weathering processes on bare land, and the anions and cations were mainly derived from the weathering of silicates and evaporites. The concentrations of the third type were mainly due to the evaporation and crystallization processes of a dry climate, and the anions and cations were mainly derived from the weathering of silicates and evaporites, which may also be affected by carbonate weathering. 3) With an increase in the buffer zone radius for each sampling point (0.5 km to 10 km), the significant land cover changed from bare land to water, shrubland, grassland, mixed farmland, and vegetation for the first water quality type; the most significant land cover was water. There were no significant relationships between the second water quality type and land cover. For the third water quality type, the significant land cover changed from water to water, mixed farmland, and vegetation - the most significant land cover was water. Therefore, spatial variation in the water quality variables was mainly affected by the local climate conditions (i.e., climatic drought and intensive evapotranspiration) and the mainland cover types (i.e., bare land, water, farmland, grassland, and urban). To improve the water environmental conditions in the middle and lower reaches of Aral Sea Basin, stream flow should be increased to recharge the Aral Sea and weaken the evaporation and crystallization processes in the lower reaches of Aral Sea. Vegetation restoration and a return of farmland to forest and grassland should also be strengthened in the riparian zone, particularly in the middle and lower reaches of Amu Darya and Syr Darya and the Aral Sea.

Vanadium substituted Li+-NASICON systems: Tailoring electronic conductivity for electrode applications

Mixed ionic-electronic NASICON structured systems namely, LiTi2(PO4)3-x(VO4)x and Li1.3Al0.3Ti1.7(PO4)3-x(VO4)x, for x = 0.1–0.4 have been prepared by partial substitution of V5+ in place of P5+ in LiTi2(PO4)3 (LTP) and Li1.3Al0.3Ti1.7(PO4)3 (LATP), respectively. A systematic investigation has been carried out to understand the mechanism of mixed electrical transport by varying the amount of Vanadium in subsequent steps. The structural features of these systems have been studied using XRD and FESEM that suggest Vanadium acceptability in the NASICON type network structure atleast up to x = 0.4 without any notable precipitation. High temperature in situ XRD studies suggest stability of the structure at least up to ∼500 °C. The electronic conductivity in these composites have been attributed to polaron hopping that could be tailored systematically as suggested by dc conductivity studies. The highest total conductivity and electronic conductivity values have been found to be 2 × 10−4 Ω−1cm−1 and 9 × 10−5 Ω−1cm−1, respectively for LTP with x = 0.4 at 100 °C. In order to test their potential as electrodes, symmetric cells of the type MIE|LiPF6/Li2SO4|MIE have been fabricated and charged/discharged at different current densities. These materials exhibit appreciable capacity and have been found to be suitable for EDLC/pseudo supercapacitor electrode applications.

Mixed Ionic-Electronic Conductors Based on PEDOT:PolyDADMA and Organic Ionic Plastic Crystals.

Mixed ionic-electronic conductors, such as poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) are postulated to be the next generation materials in energy storage and electronic devices. Although many studies have aimed to enhance the electronic conductivity and mechanical properties of these materials, there has been little focus on ionic conductivity. In this work, blends based on PEDOT stabilized by the polyelectrolyte poly(diallyldimethylammonium) (PolyDADMA X) are reported, where the X anion is either chloride (Cl), bis(fluorosulfonyl)imide (FSI), bis(trifluoromethylsulfonyl)imide (TFSI), triflate (CF3SO3) or tosylate (Tos). Electronic conductivity values of 0.6 S cm−1 were achieved in films of PEDOT:PolyDADMA FSI (without any post-treatment), with an ionic conductivity of 5 × 10−6 S cm−1 at 70 °C. Organic ionic plastic crystals (OIPCs) based on the cation N-ethyl-N-methylpyrrolidinium (C2mpyr+) with similar anions were added to synergistically enhance both electronic and ionic conductivities. PEDOT:PolyDADMA X / [C2mpyr][X] composites (80/20 wt%) resulted in higher ionic conductivity values (e.g., 2 × 10−5 S cm−1 at 70 °C for PEDOT:PolyDADMA FSI/[C2mpyr][FSI]) and improved electrochemical performance versus the neat PEDOT:PolyDADMA X with no OIPC. Herein, new materials are presented and discussed including new PEDOT:PolyDADMA and organic ionic plastic crystal blends highlighting their promising properties for energy storage applications.

Evaluation of Three Kinds of Nutshell with Respect to Utilization as Culture Media

The material basis of nutshells was explored in this study for Camellia oleifera Abel, Castanea mollissima Blume, and Carya cathayensis Sarg., The authors measured the moisture content, pH, electronic conductivity (EC), seed germination index (GI), and tannin content of the fresh shells of these three species. The contents of cellulose, hemicellulose, lignin, organic extracts, ash, saponin, cellulose crystallinity, organic carbon, and mineral elements of the dried shells was also measured. The results showed that the total mass fractions of cellulose, hemicellulose, and lignin in the shells of the three species were all above 80% of dry weight; the content of organic matter was higher than 66%, and the pH values were in the range of 5.5 to 8.5. The shells of the three species are good raw materials for the growth of plants and edible fungi. There were some shortcomings if used as fertilizers or substrates. However, the C/N and C/P ratios were high, the EC values were low, and the GI was < 100%. Additionally, the shells all contained tannin, saponin, and alkaloids, which were not conducive to the growth of plants and mycelia of edible fungi. Therefore, they can be used as culture media only after being processed.

An electron transfer in CuCl-CuCl2 melt at different Cl2 partial pressures

Electron and ion transference numbers, conductivity, and Cu+/Cu2+ concentration ratio in the CuCl-CuCl2 melt are measured at temperature of 560 °C and partial pressure of chlorine from 0.1 to 1 atm. The electron transference numbers and the total conductivity grow with chlorine partial pressure; that is accompanied by decreasing of ionic conductivity both in contribution and absolute values. The total conductivity changes from ∼6 to ∼8 S cm−1 while pCl2 increases from 0.1 to 1 atm. The electron transference numbers increase from 67 to 95% in the same chlorine partial pressure range. The electronic conductivity is evaluated by two independent methods. Values of electronic conductivity obtained from the concentrations of Cu2+ ions are close to that obtained by Faraday efficiency measurements.

Responses of Substrates and Salt Stress on Dracaena braunii to High Chloride Ions Concentrations in Ornamental Hydro-culture

In order to determine the short-term impact induced by chloride ionic, CaCl2 was used to study the chloride ionic effects of salinity on substrate and growth of Dracacena braunii grown in ornamental hydro-culture. A distilled water (control) was enriched with 10, 20, 50, 100, and 150 g･L -1 of CaCl2, respectively. Before planting, acidity and electronic conductivity values remarkably increased with increasing concentration of CaCl2. However, 4 weeks after planting, acidity values decreased to a slightly acidic pH, while there were not significant differences among electronic conductivity values obtained. Number of root, fresh weight, and total chlorophyll content were significantly decreased in response to CaCl2 concentration in comparison with control, whereas dry weight, water content, and color of stem were no significant effect of CaCl2 concentration less than 20 g･L -1 . These results showed that initial CaCl2 concentrations above 20 g･L -1 is considered to be the threshold value that will sustain the Dracacena braunii in the growth condition and above which plant growth will be retarded.

Improved ceramic and electrical properties of CaZrO3-based proton-conducting materials prepared by a new convenient combustion synthesis method

The present work emphasizes the features of a new combustion synthesis method suitable for easy synthesis and sintering of CaZrO3-based materials as promising proton-conducting electrolytes for electrochemical applications in solid oxide electrochemical devices. Sc- and In-doped CaZrO3 compounds are selected to be the objects of investigation and their crystal structure properties as well as microstructural, thermal and electrical characteristics are studied by the means of X-ray diffraction analysis, high-temperature dilatometry, scanning electron spectroscopy, impedance and 4-probe DC conductivity techniques. The established properties are critically compared with previously obtained data to confirm the prospects of the proposed method synthesis for the preparation of Zr-based proton-conducting ceramic materials. It is found that CaZr0.95Sc0.05O3–δ exhibits predominantly protonic conductivity under wet air atmospheres below 700°C; while, CaZr0.9In0.1O3–δ demonstrates a certain value of electronic conductivity along with ionic one.

Influence of long-range transboundary transport on atmospheric water vapor mercury collected at the largest city of Tibet

Monsoon circulation is an important process that affects long-range transboundary transport of anthropogenic contaminants such as mercury (Hg). During the Indian monsoon season of 2013, a total of 92 and 26 atmospheric water vapor samples were collected at Lhasa, the largest city of the Tibet, for Hg and major ions analysis, respectively. The relatively low pH/high electronic conductivity values, together with the fact that NH4+ in atmospheric water vapor was even higher than that determined in precipitation of Lhasa, indicated the effects of anthropogenic perturbations through long-range transboundary atmospheric transport. Concentrations of Hg in atmospheric water vapor ranged from 2.5 to 73.7ngL−1, with an average of 12.5ngL−1. The elevated Hg and major ions concentrations, and electronic conductivity values were generally associated with weak acidic samples, and Hg mainly loaded with anthropogenic ions such as NH4+. The results of principal component analysis and trajectory analysis suggested that anthropogenic emissions from the Indian subcontinent may have largely contributed to the determined Hg in atmospheric water vapor. Furthermore, our study reconfirmed that below-cloud scavenging contribution was significant for precipitation Hg in Lhasa, and evaluated that on average 74.1% of the Hg in precipitation could be accounted for by below-cloud scavenging.

Effect of synthesis conditions on electrical and catalytical properties of perovskites with high value of A-site cation size mismatch

The perovskite La0.15Sm0.35Sr0.08Ba0.42FeO3−δ has been prepared by the glycine nitrate route, varying the calcination temperature, fuel/oxidizer ratio and cooling rate, in order to study the sample preparation influence on the properties in the context of their application as a electrode material for SOFCs. The obtained materials have been characterized by X-ray diffraction, scanning electron microscopy, electrical and BET surface area measurements, and also the reaction between oxygen and CO, which can occur in SOFCs during the conversion of chemical energy into electrical energy. As overall results, all the samples present a phase segregation showing two perovskites with rhombohedral structure. SEM images show a well-necked morphology of the powders which are composed of nanosized particles and agglomerations of grains. The BET specific surface area of the samples decreases as calcination temperature increases, as well as for the quenched sample. The measured electronic conductivity values (<50 S/cm) are characteristic for samples with these high values of σ2(rA) (A cation size disorder). The catalytic activity tests for the CO oxidation reaction showed a T50% (“light-off temperature”, defined as the temperature at which 50% conversion of CO is achieved) value about 440°C–450 °C, CO conversion reaching 100% at approximately 600 °C for all the prepared perovskites. Then, for the La0.15Sm0.35Sr0.08Ba0.42FeO3−δ perovskite, CO conversion temperature is lower than usual SOFCs operating temperature. This points out to the technological interest of these materials in the framework of reducing the operating temperature of SOFCs.

Synthesis and Characterization of PVA/GO Nanocomposite Films

SummaryNanocomposite films of PVA (polyvinyl alcohol) with GO (graphene oxide) as organic filler have been synthesized successfully. GO was prepared through modified Hummers method and confirmed by SEM and XRD. Nanocomposites were prepared containing various weight amount of GO (0.1, 0.2 and 0.5%) within PVA matrix. Filmss are casted on clean glass plate through solution casting method and dried followed by. Further the investigation of thermal and mechanical as well as physicochemical properties of nanocomposites are done using respective analysis techniques. Electronic conductivity of the prepared Films are also measured. The value of electronic conductivity enhances as the GO content increases within polymer matrix. Thermal and mechanical analysis shows increment in stability with increasing GO content. Maximum electronic conductivity e.g. 1.95 × 10−2 Scm−1 was found for G‐5 (0.5%) films.

Impacts of Pig Manure-Based Liquid Fertilizer Agricultural Application on the Water Quality of Agricultural Catchment

This study was conducted to understand the effect of the livestock liquid fertilizer treatment at field-scale up to catchment-scale on the water quality properties. Cultivated paddy rice and upland plots located in Gyeonggi province, Korea were treated with two different liquid fertilizers, SP (Liquid fertilizer with storage process) and SCB (Liquid fertilizer with slurry composting and bio-filtration process). Plots with no fertilizer (control A) and chemical fertilizer (control B) were also prepared for comparison. Water quantity and quality were monitored at the catchment outlet for assessing the effect on water quality of stream water. As a result, the losses of N and P and the values of EC (Electronic Conductivity) in the surface drainage water from paddy rice plots treated with SP and SCB were higher than those from the control plots (A and B). In addition, the losses of N and P by the runoff water from upland plots with SP and SCB treatment were higher than those from control plots (A and B). The nutrient outflow from paddy rice fields and uplands with application of liquid pig manure was higher than those from the control plots (A and B). Particularly, the outflow from uplands may directly affect the water quality in neighboring streams. This caused the major eutrophication problem in stream water. In conclusion, it is necessary to establish the proper management practices to prevent the nutrient losses from agricultural fields and the pollutants against water environments.

Using electronic conductivity and hardness data for rapid assessment of stream water quality

A graphical screening method was previously developed by Kney and Brandes (2007) for assessing stream water quality data using electronic conductivity (EC) and alkalinity data. The method was aimed at providing citizen scientists involved in stream monitoring programs with a relatively simple way to interpret EC data. The method utilizes a plot of EC against concurrent alkalinity data, and is used to distinguish EC values for impacted or degraded streams from those that can be considered background values in a particular geologic setting. The method performs well in areas underlain by carbonate bedrock, as streams in those areas characteristically have EC values that are strongly correlated with alkalinity. However, in areas of low stream alkalinity (less than approximately 50 mg/L as CaCO(3)), the Kney and Brandes (2007) method was found to be much less effective in identifying impacted streams. This paper extends the graphical screening approach to streams with low alkalinity, specifically regions underlain by clastic sedimentary or crystalline bedrock, by using the strong correlation between EC and total hardness (TH). A baseline relationship of EC vs. TH is developed using surface water chemistry data from Hydrologic Benchmark Network streams (deemed as having minimal anthropogenic impacts) and regional groundwater quality data. The usefulness of the method is demonstrated by application to publicly available stream chemistry data and to field data collected from streams of eastern Pennsylvania under baseflow conditions. Results demonstrate that for streams with alkalinity <75 mg/L as CaCO(3), the TH-based graphical screening method should be used rather than the alkalinity-based method of Kney and Brandes (2007).

Improved microwave absorption and electrostatic charge dissipation efficiencies of conducting polymer grafted fabrics prepared via in situ polymerization

AbstractPolyaniline (PANI) and polypyrrole (PPY) were grafted over cotton fabrics by in situ polymerization. FTIR spectra show systematic shifting of bands corroborating surface grafting of conducting polymers on cotton fabric. SEM images revealed that the surface coating of PANI was smoother than PPY. However, better control over coating thickness and uniformity was achieved in PPY fabric. The probable formation mechanism of grated fabrics has also been proposed. The good thermal stability and acceptable electronic conductivity values indicate that these fabrics could be used for electrostatic charge dissipation and microwave absorption. The antistatic studies have shown complete charge dissipation (decay time &lt;0.01 sec). The microwave absorption studies of the conducting fabrics in X‐band (8.2–12.4 GHz) show absorption dominated total shielding effectiveness in the range −11.3 to −11.7 dB (&gt;92% attenuation) and −9.2 to −9.6 dB (&gt;88% attenuation) for fabrics grafted with PPY and PANI, respectively. Copyright © 2011 John Wiley &amp; Sons, Ltd.

Modelling electrode material utilization in the trench model 3D-microbattery by finite element analysis

A mathematical model for ionic transport in 3D-microbattery (3D-MB) using finite element analysis is presented here, based on concentrated solution theory, ionic and atomic diffusion and the Butler–Volmer equation. The model is used to study electrochemical processes taking place in the electrodes and electrolyte of a 3D-MB in the trench architecture, with a 10 μm thick electrolyte layer separating 10 μm thick graphite anode and LiCoO 2 cathode plates. The effect of changing conductivity of the positive electrode and the electrode plate height is also studied. Qualitative and quantitative data describing battery performance in terms of concentration gradient development and discharge curves points out the range for the most favourable electronic conductivity values of the electrodes: the values should not differ by more than order of magnitude. Furthermore, it is shown that also with optimal electrode conductivity values for electrodes, the Li ion diffusion in the electrodes during discharge is limiting the performance of the battery due to inhomogeneous lithiation and delithiation. Changing electrode height can be used to fine tune surface area usage, but has a limited effect on the overall battery performance.