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Biosynthesis of Carbon Spheres for Supercapacitor Electrode Application

Biosynthesis of Carbon Spheres for Supercapacitor Electrode Application

The CV profiles of carbon spheres-2600 in KOH aqueous solution (6 M) at varying scanning rates are shown in Fig. 4A. The data show that the CV profiles retain a quasi-rectangular shape for the voltammogram even at high scan rates of 100 and 500 mV/s, which suggests an exceptionally fast charge/discharge capacity of the carbon spheres-2600 used as a supercapacitor electrode [38]. By controlling the film thickness of carbon spheres-2600, we fully utilize the advantages of the ionic layer adsorption and reaction process to enable precise control of the charge storage capacity of the electrodes [39]. Other factors contributing to the remarkable electrochemical features observed include the short diffusion length for electrolyte ions (mesopores – micropores), ample sites for adsorption within each micropore, and fast ionic transfer within the mesopores [40]. In addition, the carbon spheres-600 exhibits a relatively wider quasi-rectangular CV area compared to other samples, which indicates carbon sphere-600 has higher specific capacitance due to the higher specific micropore surface and mesopore surface areas [41, 42].
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EFFECT OF ELECTROLYTE CONCENTRATION ON SUPERCAPACITOR PERFORMANCE OF GRAPHENE- NIO COMPOSITE

EFFECT OF ELECTROLYTE CONCENTRATION ON SUPERCAPACITOR PERFORMANCE OF GRAPHENE- NIO COMPOSITE

611 | P a g e 80:10:10.The mixture was dispersed in acetone to form a slurry and coated on graphite sheets (~1cm 2 ). The fabricated electrodes were then dried in vacuum oven at 80 °C for 24 h. Electrolyte used for measurement was 1, 5 and 6 M KOH aqueous solution. CV and EIS analysis were carried out with a CHI660D electrochemical workstation, and charge-discharge tests were done on Arbin instruments.

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Synthesis of ammonia directly from air and water at ambient temperature and pressure

Synthesis of ammonia directly from air and water at ambient temperature and pressure

reported the synthesis of ammonia from N2 and H2O based on a Ru/C cathode, Pt anode, 2 M KOH aqueous solution as the electrolyte using Nafion as a separation membrane not electrolyte and[r]

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Sonochemical degradation of azithromycin in aqueous solution

Sonochemical degradation of azithromycin in aqueous solution

The basis of AOPs is hydroxyl radical production. But at higher pHs, H 2 O 2 decomposes quickly and reduces radical formation (7,22). The effect of pH on azithromycin degradation depends on the structure and properties of the agent and also on its PKa value. The pKa value of azithromycin is 8.74. Accordingly, in acidic solutions, it will usually be molecular. The molecular forms mainly directed to the liquid bubble transfer region, where there is a high OH concentration. According to the studies, the accumulation of catalyst particles in the acidic solution decreases, resulting in an increase in the effective surface of the catalyst, which leads to an increase in the sonocatalytic degradation in acidic conditions (15,23-25). Villaroel et al reported that in the degradation of acetaminophen by ultrasonic method, acidic medium (pH = 3-5.6) is more
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Electropolymerization and Characterization of Poly-N-methylpyrrole Coatings on AZ91D Magnesium Alloy

Electropolymerization and Characterization of Poly-N-methylpyrrole Coatings on AZ91D Magnesium Alloy

As a promising coating technology, various conducting polymers (CPs) have been applied to different metal surfaces [8]. Although the application of CP coatings can be seen critically [9, 10], CPs enhance the corrosion resistance of the coated surface [11]. Amongst these CPs, pyrrole and its derivatives are promising candidates for corrosion protection of biomedical metallic devices, due to their biocompatibility, stable oxidized state and the release of dopant ions. Polypyrrole coatings have been electropolymerized on various substrates such as copper [12], iron [13], aluminum [14], zinc [15, 16] and magnesium [17-19]. Most coating methods of reactive metals, if carried out in aqueous solutions, need a pretreatment to hinder corrosion during the initiation and growth of the protection layer. By using an aqueous sodium salicylate solution, Hermelin et al. [20] introduced a direct electropolymerization of a polypyrrole layer on zinc. Using the advantage of sodium salicylate, Turhan et al. [17] successfully coated AZ91D with polypyrrole in a one step process utilizing cyclic voltammetry. Despite promising results such as the improved corrosion resistance and the release of corrosion inhibiting salicylate for polypyrrole coated AZ91D in simulated body fluid [18], the adhesion of the layer needs improvement. One possible way to modify the properties of the coating, especially the adhesion, is to change the monomer, for instance to explore N-methylpyrrole as biocompatible coating. Although the nucleation and growth of poly-N-methylpyrrole layers on substrates such as copper [21], platinum [22] and various steels [23-27] already provided adherent layers and improvement of the corrosion properties, no research has been published for poly-N- methylpyrrole coatings on magnesium yet.
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Polyorganosiloxanes as electronic device encapsulants

Polyorganosiloxanes as electronic device encapsulants

The standard application route 4.7, characterised by the cohydrolysis and cocondensation of chlorosilanes, with system neutralisation by aqueous KOH solution, has been shown to be unsuit[r]

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The anodic behaviour of aluminium in aqueous solution

The anodic behaviour of aluminium in aqueous solution

object of the eXperimental work was to determine the origin and mechanism of the excess metal dissolution, the anode gas evolution, the nature of the steady electrode potential, and the [r]

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Synthesis and in Silico Analysis of Novel 1,2,4-Triazolylamides as Potential Antifungals

Synthesis and in Silico Analysis of Novel 1,2,4-Triazolylamides as Potential Antifungals

These three component inorganic ion-exchanger was synthesized under different condition. The most thermal and chemical properties of this material is prepared by intermixing solutions of sodium molybdate (0.1 M), sodium arsenate (0.1 M) and antimony(III) chloride (0.1 M) solution in different volume ratios at pH-1. The Ion-exchange capacity of all the samples was determined by column process. The selected sample was synthesized in bulk for detailed studies. Its ion-exchange capacity of synthesized material for Na + has been found to be 2.30 meq/g. Characterization of the

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Synthesis of Commercial Scale Tungsten Carbide Cobalt (WC/Co) Nanocomposite Using Aqueous Solutions of Tungsten (W), Cobalt (Co), and Carbon (C) Precursors

Synthesis of Commercial Scale Tungsten Carbide Cobalt (WC/Co) Nanocomposite Using Aqueous Solutions of Tungsten (W), Cobalt (Co), and Carbon (C) Precursors

Nanostrucrued 94 WC/6 Co and 88 WC/12 Co powder is made by dissolving selected ratio of AMT, cobalt nitrate, and water soluble carbon source such as polyvinyl alcohol (PVA), corn starch or glucose. The selected ratio of W to C being 1:4 by atomic ratio, with Co to WC ratio being 6 and 12 weight percent for the 94WC/6Co and 88 WC/12 Co composite powders, respectively. The solid precursor chemicals, tungsten source of AMT, cobalt source of nitrate, and carbon source of PVA or starch are then dissolved into DI water with the solid to water ratio being 2:1 by weight. The solution is under vigorous mechanical stirring until a clear liquid without obvious precipitates can be seen by naked eyes. Next, the dissolved aqueous solution is fed into an industrial spray drier, Model No. ACEM 100K (Denli Corp., P.R. China), to form a powder like precursor. This spray dryer has the capability of evaporating 100 kg water per hour. Next, the spray dried precursor powder is fed into a belt furnace, Model No. GTH 1500/100-14 (Denli Corp., P.R. China), with a 200 kg per hour feeding capacity, under a stream of argon or nitrogen atmosphere, to keep a positive pressure inside the furnace to prevent possi- ble moisture re-precipitation and powder oxidation during conversion. This operation is desired to remove resi- dual moisture and crystalline water, dissociation of ammonia N-H groups into hydrogen and nitrogen, dissocia- tion of C-H groups into carbon source and hydrogen, and finally convert the precursor ingredients into a W-Co-C-O complex oxide structure, here referring to a pre-composite powder. The temperature of this process is between 500 ˚C to 600˚C with a scheduled temperature profile. Subsequently, the obtained pre-composite powder is then converted to a WC/Co nanocomposite powder, with particle size being 30 to 100 nanometers in a rotary furnace (Model No. HHC- Φ400 × 7600, Denli Corp.) under nitrogen. If in some case, extra free carbon is presented in the powder, the powder is then again fed into a rotary furnace under stream of hydrogen to remove extra carbon species.
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Mercury Removal from Aqueous Solution Using Natural, Synthetic, and Modified Zeolites

Mercury Removal from Aqueous Solution Using Natural, Synthetic, and Modified Zeolites

Initially, of the rate of metal removal from the solution is higher. This higher rate corresponds to the external surface adsorption or boundary layer effect [59], [70]. In the second portion which may be called the intra particle diffusion or pore diffusion step, the adsorption gradually increases since equilibrium had almost been reached. The slope of the second linear part of this plot was used to determine the rate parameter of pore diffusion stage which is the rate limiting step of the process. The calculated parameters for intra particle diffusion are presented in Table 2-5. All these results suggest that the sample with lower concentration of 10 g/L demonstrated immediate uptake of Hg(II) at a much higher capacity than the CFA-ZA samples with higher concentration. For various concentrations of CFA-ZA, the adsorption process is controlled by external mass transfer followed by intra-particle diffusion mass transfer.
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On the Hydrogen Evolution Reaction at Nickel-Coated Carbon Fibre in 30 wt. % KOH Solution

On the Hydrogen Evolution Reaction at Nickel-Coated Carbon Fibre in 30 wt. % KOH Solution

were clearly observed. The stability of the Pd reference electrode was occasionally checked by recording its potential shift in time, in 30 wt.% KOH solution. No significant potential shift was observed for such prepared Pd reversible hydrogen electrode, up to 120 hours (at room temperature) from its initial H charging. Thus, all the potentials throughout this work are given on the RHE scale. A counter electrode was made of a coiled Pt wire (1.0 mm diameter, 99.9998% purity, Johnson Matthey, Inc.). Prior to its use, the counter electrode was cleaned in hot sulphuric acid.
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Removal of manganese by using activated carbon as biosorbent

Removal of manganese by using activated carbon as biosorbent

pH influences the surface charge of the adsorbent, the degree of ionization and the species of adsorbate. So pH is an important factor controlling the process of adsorption. In the present investigation, adsorption data are obtained in the pH range of 3 to 12 for manganese initial concentration of 1 gm/lit and 1 gm of 150 µ m size adsorbent. The effect of pH of the aqueous solution on % removal of manganese is drawn in fig.6. The % removal of manganese dye is increased from 4.5% to 37.2% as pH is increased from 1 to 7.28. The graph reveals that % removal increased significantly from 3 to 12 . With an increase in P H of the solution the % removal decreases. Here for manganese at a P H of 3 the % removal is around 38%, where as with the further increase in the P H of the solution let it be 12 the % removal decreases to 4.5%.In the present investigation, the maximum % removal of manganese is obtained for 1 gm of 150 µm size adsorbent at optimum agitation time. The principal driving force for dye ion adsorption is the electrostatic interaction (i.e) attraction between adsorbent and adsorbate. The greater the interaction, adsorption of dye will be more. With an increase in interaction, the dye ions replace H+ ions bond to the adsorbent for forming part of the surface functional groups such as –OH, -COOH etc. As the electro-negativity of Activated carbon powder is greater, more manganese ions are adsorbed.
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Effect of Various Alkaline Activator Solutions on Compressive Strength of Fly Ash-Based Geopolymer Concrete

Effect of Various Alkaline Activator Solutions on Compressive Strength of Fly Ash-Based Geopolymer Concrete

oligomers. Hence, by using KOH, more geopolymers are produced, leading to a stronger and more compact microstructure [38], which will result in low 3- and 7-day compressive strengths, slow hardening rate, and high 28- day compressive strength in comparison with NaOH. On the other hand, at the same concentration, NaOH is capable of dissolving more inorganic components than KOH, which leads to faster reaction rate for Na+ ions over K+ [25,26]. Due to the higher reaction rate of Na+, higher initial compressive strength and more rapid hardening would be observed by using NaOH. However, simultaneous inclusion of NaOH and KOH (N50K50) would reduce the compressive strength of GPC noticeably. This could be attributed to the different performances of NaOH and KOH during the geopolymerization process. The high reactivity of Na+ in the dissolution of Si and Al presented in the aluminosilicate source is very strong and could not be balanced with the tendency of K+ ions towards condensation reaction [26]. This interference phenomenon reduces with the decrease in the percentage of NaOH and KOH combination from 50-50 to 25-75 and thus the N25K75 and N75K25 specimens provided greater compressive strength than the N50K50 specimen.
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STABILITY AND ANALYSIS OF MEROPENEM AND β LACTAMASE INHIBITORS IN INJECTABLE PREPARATIONS

STABILITY AND ANALYSIS OF MEROPENEM AND β LACTAMASE INHIBITORS IN INJECTABLE PREPARATIONS

a) Dilution of reconstituted injection into normal saline solution.-Required quantity of powder injectable powder preparation equivalent to 250 mg Meropenem and 125 mg Sulbactam (1/4 average weight) was transferred to 250 mL volumetric flask. This dissolved and diluted with normal saline to make 250 mL to give 1.0+0.5 mg/mL concentration. This was diluted at time interval of 0, 1, 2, 3, 5 and 7 h with water to give 0.120+0.06 mg/mL concentration of Meropenem and Sulbactam.

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ELECTROSPUN TIO 2NANOFIBERS AS A MATRIX TO ENHANCE THE DRUG LOADING

ELECTROSPUN TIO 2NANOFIBERS AS A MATRIX TO ENHANCE THE DRUG LOADING

The prepared polymer solution is taken in a syringe tube of diameter 15.6mm and placed in the electro spinning apparatus. Cleaned FTO glass plate which is masked by using scotch tape is fixed on the aluminum foil in the apparatus. The distance between the needle tip and the glass plate is set as 14.5 cm. Set the values of duration as 1h and feed rate as 0.5 mL/h, 0.9 mL/h and 1.1 mL/h. By applying proper voltage 12 kV, TiO 2 Nanofiber will

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A Study on Synthesis and Characterization of Biobased Carbon Nanoparticles from Lignin

A Study on Synthesis and Characterization of Biobased Carbon Nanoparticles from Lignin

0˚C in nitrogen atmosphere for 2 hours. It was ob- served that the carbonized lignin without KOH results in the formation of solid mass where as the lignin samples modified with KOH yielded ultrafine particles. The chal- lenging issue in fabricating carbon nanoparticles is the yield, which indicates the efficiency of the conversion process. The thermal stabilization yield fraction (Y TS ) is

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WELCOME TO KOH SAMUI

WELCOME TO KOH SAMUI

Featuring full length glass windows and a grass lawn breakout area overlooking the Gulf of Thailand, the Aow Thai Function Room offers a unique destination for discerning group travelle[r]

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Synthesis of Quercetin Loaded Nanoparticles Based on Alginate for Pb(II) Adsorption in Aqueous Solution

Synthesis of Quercetin Loaded Nanoparticles Based on Alginate for Pb(II) Adsorption in Aqueous Solution

1 mL 6 min −1 . Keep stirring for another 60 min. Then, the alginate nano-emulsions was transferred into Eppendorf tubes, centrifuged at 3800 r min −1 for 10 min, and then left for equilibration at 25 °C. The upper phase (oil of surfactant or reverse micelles) of the phase- separated samples was discarded, whereas the lower phase containing alginate nanoparticles was collected [18]. (4) An equal volume of ethyl ether was added into alginate nanoparticles and vibrated gently. And the upper phase (solution of ethyl ether and residual liquid paraffin) was removed. Purge lower phase with nitrogen gas to replace ethyl ether. The obtained algin- ate nanoparticles were filtrated with a 0.22-μm mem- brane filter and lyophilized or kept in a refrigerator until further investigation.
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Synthesis, characterization of a multi component metal oxide (Al0 88Fe0 67Zn0 28O3) and elimination of As (III) from aqueous solution

Synthesis, characterization of a multi component metal oxide (Al0 88Fe0 67Zn0 28O3) and elimination of As (III) from aqueous solution

Batch experiments were performed to remove As (III) from aqueous solution considering various parameters such as effect of pH, contact time, initial arsenic con- centration, temperature and sorbent dosage. The maximum sorption capacity of the surface was almost steady from pH 4 to pH 9. Kinetic study shows that As (III) sorption is following second order rate equation with the rate constant of 80 × 10 –2 g·mg –1 ·min –1 at room

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Thermally promoted addition of undecylenic acid on thermally hydrocarbonized porous silicon optical reflectors

Thermally promoted addition of undecylenic acid on thermally hydrocarbonized porous silicon optical reflectors

[15,16]. These un-reacted Si-H bonds on PSi surface are susceptible to oxidation, and furthermore, oxidized sur- face slowly dissolves in aqueous basic solutions [2,17]. This phenomenon has been linked with baseline drift of PSi-based biosensors, leading to non-reproducible results [17]. More complete surface passivation may be obtained with the thermal hydrocarbonization (THC) treatment [18]. Moreover, the utilization of THC-treated PSi opti- cal filters, in gas sensing applications, has already been demonstrated [19]. Lately, it has also been shown that the THCPSi surface may also be further functionalized by attaching molecules with a functional group to the hydrocarbonized surface [20,21].
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