The construction of efficient conductive porous cathodes with prevention of polysulfides dissolution is essential for useful application of lithium-sulfur batteries. In this work, a micro-mesoporous ...carbon/magnesium oxide/sulfur composite is developed for lithium-sulfur batteries. The novel micro-mesoporous carbon powders grown on diatomite substrates by chemical vapor deposition provide efficient pathways for electron migration in the cathode and alleviate the structural failure caused by volume expansion. Our combined experimental and simulated results confirm that the synergistic magnesium oxides play an important role in anchoring lithium polysulfides. We find in this study that micro-mesoporous carbon/magnesium oxide/sulfur composite with 10 wt% magnesium oxide shows the best cycle and rate performance: a) the battery exhibits an initial specific capacity of 1143 mAh g−1 at 0.2 C and a reversible capacity of 592 mAh g−1 after 500 cycles with an average of 99% columbic efficiency. b) A reversible discharge capacity of 664 mAh g−1 is achieved after 400 cycles at 2 C which corresponds to a very small capacity decay per cycle ~ 0.065%. c) 90% reversible capacity remains after 200 cycles even under a current density as high as 5 C.
A micro-mesoporous carbon/magnesium oxide/sulfur composite is developed for lithium-sulfur batteries, in which the novel carbon is developed via chemical vapor deposition and etching processes on diatomite substrates. Display omitted
•A novel micro-mesoporou carbon (MC) is developed via chemical vapor deposition process using diatomite as the substrates.•The MC/MgO/S composite demonstrates a reversible discharge capacity of 664 mAh g-1 after 400 cycles at 2 C with a low capacity decay of 0.065% per cycle.•Even at a high current rate of 5 C, 90% reversible capacity remains after 200 cycles.
This study discusses an approach that gives the Natural Rubber (NR) vulcanizates an elevated hydrophobic character. The method used a chemically treated filler called diatomaceous earth (DE) to ...deliver the hydrophobic characteristics to NR. DE has a nanoscale roughness. It was chemically treated with hexadecyltrimethoxy silane to obtain low surface energy. The combination of nanoscale roughness and low surface energy gave superhydrophobic properties to DE. A series of treated-DE was made with varying silane percentages to find an optimum silane to DE ratio to get the maximum possible hydrophobicity. The optimum ratio was recorded as 38% w/w, and the treated DE displayed a superhydrophobic water contact angle (WCA) of 152
°
. The treated-DE was added to the rubber as a filler during the compounding process. The filler was added in varying amounts of 5 phr, 10 phr, 15 phr, and 20 phr to observe the changes in the hydrophobic property. The wettability and morphology of developed vulcanizates were measured using WCA measurements and scanning electron microscope (SEM) analysis, respectively. NR compounded with 20 phr filler exhibited an enhanced WCA of 136
°
, compared to the WCA of 92
°
of the NR vulcanizate with no treated-DE, and displayed improved tensile, and tear properties.
Using a simple method of impregnation and then calcination, diatomite supported binary transition metal sulfates (Fe and Zr, designated as Fe
2
(SO
4
)
3
&Zr(SO
4
)
2
@diatomite) were prepared and ...used as a catalyst in the preparation of renewable biofuels. The synthesised Fe
2
(SO
4
)
3
&Zr(SO
4
)
2
@diatomite catalyst (Fe
2
(SO
4
)
3
: Zr(SO
4
)
2
: diatomite = 1 : 2 : 6, mass ratio) was thoroughly characterised using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, microbeam X-ray fluorescence (μ-XRF) spectroscopy and thermogravimetric analysis (TG). The results demonstrated that the sulfate was successfully loaded onto the diatomite with a uniform distribution. The N
2
adsorption/desorption analysis indicated that the catalyst's specific surface area was 1.54 m
2
g
−1
. The catalyst exhibited outstanding performance in the preparation of renewable biofuel (biodiesel) from waste fatty acids and the optimal parameters were methanol-to-oil 1.25 : 1, reaction temperature 70 °C, catalyst concentration 10 wt%, reaction time 4 h. The conversion was found to reach 98.90% under optimal parameters, which is better than that of Fe
2
(SO
4
)
3
·
x
H
2
O, Zr(SO
4
)
2
·4H
2
O, Fe
2
(SO
4
)
3
@diatomite and Zr(SO
4
)
2
@diatomite. Moreover, the catalyst can be recycled by simple filtration and reused for three cycles after regeneration without noticeable reduction in catalytic activity.
A new catalyst: diatomite supported binary transition metal sulfates (Fe
2
(SO
4
)
3
and Zr(SO
4
)
2
) was prepared. It exhibited excellent catalytic activity in the synthesis of biodiesel from waste fatty acids (conversion close to 100%).
Display omitted
Lead (Pb) is one of the key heavy metals which have a significant influence on the individual components of the natural environment. A glasshouse pot experiment was designed to ...evaluate the potential use of different amendments as immobilizing agents in the aided phytostabilization of Pb-contaminated soil, using Lolium perenne L. The research aimed to determine the influence of Pb in doses of 0, 100, 200, 400 and 800mg/kg of soil, as well as diatomite, chalcedonite, dolomite, limestone, and activated carbon amendments on the content of trace elements in the above-ground parts and roots of L. perenne. The study utilised analysis of variance (ANOVA), principal component analysis (PCA) and Factor Analysis (FA). The content of trace elements in plants, pseudo-total and extracted by 0.01M CaCl2, were determined using the method of spectrophotometry. All of the investigated element contents in the tested parts of L. perenne were significantly different in the case of applying reactive amendments to the soil, as well as increasing concentrations of Pb. The greatest average above-ground biomass was observed when diatomite and chalcedonite were amended into the soil. Activated carbon, limestone and chalcedonite caused significant increases of Pb concentrations in the roots.
In this work the natural and the surfactant modified diatomite has been tested for ability to remove uranium ions from aqueous solutions. Such controlling factors of the adsorption process as initial ...uranium concentration, pH, contact time and ionic strength have been investigated. Effect of ionic strength of solution has been examined using the solutions of NaCl, Na
2CO
3 and K
2SO
4. The pseudo-first order and the pseudo-second order models have been used to analyze the adsorption kinetic results, whereas the Langmuir and the Freundlich isotherms have been used to the equilibrium adsorption data. The effects of the adsorbent modification as well as uranium adsorption on the diatomite surface have been studied using X-ray powder diffraction, scanning electron microscopy and FTIR spectroscopy. The maximum adsorption capacities of the natural and the modified diatomite towards uranium were 25.63
μmol/g and 667.40
μmol/g, respectively. The desorptive solutions of HCl, NaOH, Na
2CO
3, K
2SO
4, CaCO
3, humic acid, cool and hot water have been tested to recover uranium from the adsorbent. The highest values of uranium desorption (86%) have been reached using 0.1
M HCl.
Bu çalışmada Türkiye’nin 4 farklı bölgesinden alınan diatom topraklarının (DE) çeltik üzerinde, pirinç biti, Sitophilus oryzae L. erginlerine karşı insektisidal etkinliği araştırılmıştır. Bu amaçla 4 ...farklı Türk diatom toprağı (AGN-1, ACN-1, FB2N-1 ve CCN-1) ile ticari diatom toprağı (Silicosec)’nın 100, 300, 500, 900 ve 1500 ppm (mg DE/kg çeltik) dozları çeltikle karıştırılmıştır. Diatom toprakları ile karıştırılan çeltikler 100 ml şişelere konularak üzerine
In this study, the insecticidal effect of 4 different Turkish diatomoceus earth (DE) were tested against the rice weevil, Sitophilus oryzae L. on paddy rice. Paddy rice was treated at 100, 300, 500, 900 and 1500 ppm (mg DE/kg paddy rice) concentrations of four Turkish diatomaceous earths (AGN-1, ACN-1, FB2N-1 and CCN-1) and commercial diatom earth (Silicosec). Paddy rice samples were mixed with DE and then filled into 100 ml glass vials. Rice weevil adults (
Maize is one of the major staple foods in Sub-Saharan Africa and there is serious loss in maize storage due to insect damage. This study compared the bioactivity of Bamboo Leaf Ash (BLA) and Bularafa ...Diatomaceous Earth (BDE) against Maize Weevil (Sitophilus zeamais Motschulsky) under laboratory conditions. Insecto®, a commercialized DE was also tested as standard check. Adults of the insects were exposed on maize admixed with the BLA at dose rate of 5,000, 10,000 and 20,000ppm; BDE and insecto® at a dose rate of 1,000ppm, at 28.20C and 82.2% relative humidity. Mortality increased with increasing exposure duration and all treatments showed mortality of more than 80% after 14days post-treatment compared to negative control with 0%.The treatments suppressed F1 progeny. Treated grains have weight loss less than 4%, kennel damage less than 14% and grain germination showed no significant change. The decreasing efficacy of the dusts against this insect is Insecto®> BLA > BDE. BLA and BDE have potential for the management of insect pests of stored grain in Nigeria.
Objectives Millions of workers worldwide are employed in occupations involving potentiality hazardous exposure to crystalline silica. The diatomaceous earth industry can have particularly high ...exposures, but there is a lower likelihood of simultaneously occurring confounding exposures. We extended follow-up for diatomaceous earth industry workers previously studied for mortality. Methods The cohort included 2342 white men who were employed for at least 1 year at a diatomaceous earth plant in Lompoc, California beginning in 1942. Workers’ vital status was updated using the National Death Index through 2011, an extension of 19 years from earlier studies. Detailed work history and quantitative air monitoring measurements estimated exposure intensity. Cox proportional hazards modelling estimated HRs and 95% CIs. SMRs were calculated. Results Elevated mortality was observed by quartile of cumulative crystalline silica exposure for lung cancer (HR=2.03, 95% CI 1.07 to 3.85, highest quartile, unlagged) and non-malignant respiratory disease (NMRD) (HR=3.59, 95% CI 1.94 to 6.67, highest quartile, unlagged), although trends were not statistically significant. Associations were attenuated when adjusted for smoking and asbestos exposure. Mortality from NMRD was significantly increased over the entire follow-up compared to the general population (SMR=1.37, 95% CI 1.17 to 1.60). An increase for lung cancer was confined to the earlier follow-up (SMR=1.29, 95% CI 1.01 to 1.61). Conclusions The risk of lung cancer and NMRD mortality remained elevated, although generally non-significant, and exposure-response trends with cumulative crystalline silica persisted on extended follow-up of this cohort. The findings support a generally consistently observed aetiological relation between crystalline silica and lung cancer.
Background and Aims
Simple methods for determining Cu forms in wine do not currently exist. This study demonstrates the relevance of measuring a specific fraction of Cu in wine, and introduces ...simplified methods for its measurement utilising either colorimetry, or filtration in combination with routine measures of total Cu in wine.
Methods and Results
Electrochemically detectable Cu provided a threshold level of Cu that related directly to the accumulation of free hydrogen sulfide and free methanethiol in bottled wines. A simple colorimetric method using bicinchoninic acid was optimised to allow a rapid approximation of this fraction of Cu in white wine. By modification of the measurement conditions, an extra fraction of Cu associated with the partial release of Cu from thiols could also be quantified. The use of diatomaceous earth depth filters to isolate these fractions of Cu was also assessed. After passing red wine through the filters, the concentration of Cu in the filtrate correlated well with the electrochemically detectable Cu. Alternatively, for white wine the concentration of filtrate Cu overestimated this fraction of Cu and this was attributed to its inability to distinguish sulfhydryl‐free Cu from Cu loosely bound to thiols.
Conclusions
Multiple and simplified approaches have been devised to allow measurement of Cu fractions in wine.
Significance of the Study
These methodologies will allow an important fraction of Cu in wine to be measured with a spectrophotometer.
In this paper, the adsorption composite materials based on the incorporation of diatomite (DE) and graphene oxide (GO) were developed and characterized by different techniques (UV-vis, Raman, SEM and ...XRD). The adsorption behaviors for methylene blue (MB) as received GO-DE composite materials adsorbents have been investigated. The results indicate that GO-DE composite materials can significantly hoist the adsorption capacity of DE and improve the separation trouble of GO with outstanding adsorption ability. It is concluded that the GO-DE composite material retain the porous structure of DE, and GO nanosheets bind physically to the surface of DE. The adsorption experiments show that the kinetic data fit well with pseudo-second-order model. The adsorption isotherms follow the Freundlich isotherm model. The adsorption behavior of the GO-DE composites is an exothermic and spontaneous process. The GO-DE composite materials can be a promising candidate as an adsorbent for the removal of cationic dyes from wastewater.
