Pseudocapacitance of MXene nanosheets for high-power sodium-ion hybrid capacitors

High-power Na-ion batteries have tremendous potential in various large-scale applications. However, conventional charge storage through ion intercalation or double-layer formation cannot satisfy the requirements of such applications owing to the slow kinetics of ion intercalation and the small capacitance of the double layer. The present work demonstrates that the pseudocapacitance of the nanosheet compound MXene Ti2C achieves a higher specific capacity relative to double-layer capacitor electrodes and a higher rate capability relative to ion intercalation electrodes. By utilizing the pseudocapacitance as a negative electrode, the prototype Na-ion full cell consisting of an alluaudite Na2Fe2(SO4)3 positive electrode and an MXene Ti2C negative electrode operates at a relatively high voltage of 2.4V and delivers 90 and 40mAhg-1 at 1.0 and 5.0Ag -1 (based on the weight of the negative electrode), respectively, which are not attainable by conventional electrochemical energy storage systems

Two-Dimensional Vanadium Carbide (MXene) as Positive Electrode for Sodium-Ion Capacitors

Ion capacitors store energy through intercalation of cations into an electrode at a faster rate than in batteries and within a larger potential window. These devices reach a higher energy density compared to electrochemical double layer capacitor. Li-ion capacitors are already produced commercially, but the development of Na-ion capacitors is hindered by lack of materials that would allow fast intercalation of Na-ions. Here we investigated the electrochemical behavior of 2D vanadium carbide, V2C, from the MXene family. We investigated the mechanism of Na intercalation by XRD and achieved capacitance of ∼100 F/g at 0.2 mV/s. We assembled a full cell with hard carbon as negative electrode, a known anode material for Na ion batteries, and achieved capacity of 50 mAh/g with a maximum cell voltage of 3.5 V

EVALUATION OF SUBLETHAL EFFECTS OF Ipomoea cairica LINN. EXTRACT ON LIFE HISTORY TRAITS OF DENGUE VECTORS

Plant derived insecticides have considerable potential for mosquito control because these products are safer than conventional insecticides. This study aimed to investigate sublethal activities of Ipomoea carica or railway creeper crude acethonilic extract against life history trait of dengue vectors, Aedes albopictus and Aedes aegypti. The late third instar larvae of Ae. albopictus and Ae. aegypti were exposed to a sublethal dose at LC50 and larvae that survived were further cultured. Overall, Ipomea cairica crude extracts affected the whole life history of both Aedes species. The study demonstrated significantly lower egg production (fecundity) and eggs hatchability (fertility) in Ae. albopictus. The sublethal dose of crude extracts reduced significantly the width of larval head capsule and the wing length of both sexes in both Aedes species. The significance of sublethal effects of I. cairica against Aedes mosquitoes was an additional hallmark to demonstrate further activity of this plant despite its direct toxicity to the larvae. The reduced reproductive capacity as well as morphological and physiological anomalies are some of the effects that make I. cairica a potential candidate to be used as a new plant-based insecticide to control dengue vectors

Control in Potatoes, 1988:

Abstract ‘Superior’ white potatoes were planted on 4 Apr in a Sassafras sandy loam soil field. Plots consisted of 3 rows of potatoes, each row 25 ft long and 3 ft wide, replicated 4 times in a randomized complete block design. Treatments were applied with a self-propelled, high-clearance sprayer with 1 drop nozzle on each side of the row and 1 over the center of each row calibrated to deliver 50 gal/acre at 40 psi. Treatments were applied on 10, 15, and 24 Jun and 7 and 15 Jul. Percentage of defoliation was recorded on 22 Jun and 13 Jul. The number of CPB larvae/5 hills was recorded on 30 Jun. Plots were harvested and yields were recorded (cwt/acre) on 10 Aug.</jats:p

Whorl Applications to Control Fall Armyworm in Sweet Corn, 1984

Abstract Sweet corn was planted 13 Jul to a Sassafras sandy loam field. Plots were 4 rows wide on 30-inch centers and 25 ft long. Treatments were replicated 4 times in a randomized complete block design. Granular whorl treatments were applied with a hand shaker in a 7-inch hand over the whorl; whorl sprays were applied with a self-propelled, high-clearance sprayer with 1 nozzle centered over each of the middle 2 rows calibrated to deliver 55 gal/acre at 200 psi. Treatments were applied on 10 and 16 Aug. Plant whorls were rated on fall armyworm damage on 23 Aug as follows: (0) no damage; (1) slight damage, 10% whorl feeding; (2) moderate damage, 10-25% whorl feeding; (3) heavy damage, 25-50% whorl feeding; (4) severe damage, 50-75% whorl feeding, tassel damaged and (5) whorl destroyed. Ten plant whorls were removed from the plants, unrolled, and all live fall armyworm and European corn borer (ECB) larvae were counted. In an attempt to determine benefits of whorl-stage applications, all plots were treated with a combination of Lannate 1.8L (.45 lb ai/acre) plus Parathon 8E (.33 lb ai/acre) after first silks appeared to control further insect damage. The silking applications were made on 11, 14, 18, 21 and 24 Sep. All ears within a 17.4-ft distance in each plot were harvested and weighed, sized and rated for insect damage.</jats:p

Control of Colorado Potato Beetle in Potatoes, 1984

Abstract Potatoes were planted on 12 Apr ’84, in a Sassafras sandy loam field. Plots were 20 ft long, 5 ft wide and replicated 4 times in a randomized complete block design; a guard row buffered each treated row. Treatments were applied with a self-propelled, high-clearance sprayer with 1 drop nozzle on each side of the row and 1 over the center calibrated to deliver 83 gal/acre at 200 psi. Treatments were applied on 13, 21, 29 Jim and 6 Jul. Plant percent defoliation was recorded on 26 Jun, 5 and 9 Jul. Number of Colorado potato beetle CPB larvae per 5 hills were recorded on 22 Jun. Number of stems/10 hills damaged by European corn borers (ECB) were recorded on 16 Jul. Yields (cwt/A) were recorded on 31 Jul. Plots were irrigated when moisture was below normal.</jats:p

Use of Entomogenous Fungi on Eggplant for Colorado Potato Beetle Control, 1981

Abstract ‘Special Hibush’ eggplant were transplanted to a Sassafras sandy loam field on May 20. Micrgplots consisted of screen cages 20 inches x 15 inches x 14 inches arranged with 2 plants/cage. Beauvariabassiana (WP, 80 x 108 spores/gm) and Metarhiziumanisopiiae (formulated on rice, spore concentration unknown) were formulated and supplied by BioControl International. Methods of application with B. bassiana were soil surface spray (1.5 g/100 ml), soil mix (1.5 g/100 ml/kg soil), foliar spray (25 g/500 ml with spreader sticker) and dilute foliar spray (same as foliar spray diluted 1:10); methods of application with M. anisopliae were soil mix broadcast (40 gm/kg soil) and soil broadcast (40 gm/2,000 sq. cm). All sprays were applied with a CO2-operated bicycle sprayer with 3 nozles/row calibrated to deliver 45 gal/acre at 40 psi. Twenty adult Colorado potato beetles were buried 2 inches below the soil surface in the center of the microplot and covered with soil just prior to treatment application (May 27); cages were than placed over each microplot. Experimental design was a randomized complete block with 2 replications.</jats:p