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1 year ago

Differences of heavy metal concentrations in sediment

4. Discussion
4.1. Heavy metal burden in environmental compartments
4.1.1. Sediment
Many aquatic pollutants are strongly allied with the fine deposits that NMS-P715 are rich in organic matter, and the way of interaction with these deposits determines the bioavailability and toxicity of these metals (Chen and White, 2004). Besides the natural input of organic matter, sewage and urban discharges are released directly in the estuarine system especially in the Passagem canal. This area is at higher risk from human discharge (industrial and urban) leading to higher concentrations of heavy metal in the sediment, which could be increased by dredging and port activities. The sea side in Espírito Santo Bay is characterized by more course oceanic sediment with diverse physio-chemical characteristics because of the tidal perturbation and higher circulation.
4.1.2. Water and suspended matter
In the present study, we found higher concentrations of dissolved metals in water and suspended matter in the sites with low salinity such as river mouths, the upper Vitória Bay estuarine area, and sewage canals. Direct discharge from house hold, sewage disposal and effluents from the nearby industries into the riverine system or the enclosed bay might have contributed to a higher level of heavy metal load among freshwater and estuarine stations.

1 year ago

Calcium nitrate tetrahydrate Ca NO

Calcium nitrate tetrahydrate (Ca(NO3)2⋅4H2O, AR), aluminum nitrate nonahydrate (Al(NO3)3⋅9H2O, AR) and holmium chloride hexahydrate (HoCl3⋅6H2O, AR) were used as starting materials with sodium hydroxide (NaOH, AR) as precipitant. All starting materials were weighed according to Wnt-C59 ratios of C12A7–x mol.% Ho3+ (Ca:Al = 12:14 with x = 0, 1, 2 and 5).

1 year ago

Conclusions Silver nanoparticles were synthesized successfully

2. Experimental procedure
2.1. Materials
All reagents were used as received. Hafnium chloride (HfCl4), cerium nitrate (Ce(NO3)3⋅6H2O), citric AC 45594 (C6H8O7) and ethylene glycol (C2H6O2) were obtained from Aldrich.
2.2. Preparation of Ce-doped HfO2 nanoparticles
Pure and Ce-doped HfO2 nanoparticles with different Ce content (2.5–10% in weight) were prepared using the solgel technique. The preparation of the nanoparticles was as follows: appropriate amount of citric acid was dissolved in distilled water to prepare a clear solution. To this solution, proper amounts of hafnium chloride and cerium nitrate were added with constant stirring and ensuring a total dissolution of salts. Then, ethylene glycol was added into the mixed solution with citric acid:ethylene glycol molar ratio of 1:4. The mixture was stirred continuously at room temperature until a sol formed. The sol was evaporated 80 °C and then dried at 130 °C for 24 h in an oven to form a precursor resin. The precursor resin was transferred into a porcelain crucible and calcined at 500 and 700 °C for 2 h to decompose the organic matter completely and form the pure and Ce-doped HfO2 nanoparticles.

1 year ago

The yield of pyrolysis oil was determined by measuring the

In this UM 191 study, microwave pyrolysis using a reactor bed of particulate-carbon was performed on waste oil in the additional presence of different amounts of metallic-char produced previously from the pyrolysis process as the catalyst in order to understand the influence of the chemical nature and amount of the metallic-char on the yield of pyrolysis products and with an emphasis on the chemical composition of the oil and gaseous products. The metallic-char catalyst was pre-treated by calcination and characterized by different analytical methods before and after being subjected to pyrolysis. In addition, a study was performed to examine the heating characteristics of the mixture of waste oil and metallic-char in the presence of a microwave-heated bed of particulate-carbon through monitoring its temperature profile during the pyrolysis. These evaluations are important to examine if the metallic-char could act as a microwave-absorbent and heat up by microwave radiation, and if the metallic-char could be used as a catalyst in the pyrolysis of waste oil. Most existing waste oil pyrolysis studies focus on conventional electric-resistance-heated and electric-arc-heated pyrolysis [26], [27] and [28], and there are very few studies about the pyrolysis products generated from microwave pyrolysis of waste oil, and in particular no similar studies have been reported on the application of metallic-char as a catalyst in microwave pyrolysis of waste oil; plasmodesmata study aims to rectify these deficiencies.

1 year ago

Carbon as a support is reportedly preferable to

HRTEM images of the catalysts were obtained on a Tecnai G2 20 Icotinib microscope with a 0.14 nm lattice-fringe resolution and an accelerating voltage of 200 kV. The high-resolution images of the periodic structures were analysed using the Fourier method. Local energy-dispersive X-ray analysis (EDXA) was carried out on an EDXA spectrometer fitted with a Si (Li) detector with a 130 eV resolution. The samples used for HRTEM were prepared on a perforated carbon film mounted on a copper grid, and 10–15 representative micrographs were obtained for each catalyst in high-resolution mode. Typically, the lengths of at least 400 slabs were measured for each catalyst. To measure the extent of WS2 dispersion, the average fraction of W atoms at the WS2 edge surface (D) was calculated, assuming cell body the WS2 slabs were perfect hexagons [10]. WS2 dispersion (D) was statistically evaluated by dividing the total number of W atoms at the edge surface (We), including corner sites (Wc), by the total number of W atoms (WT) using the slab sizes measured in the TEM micrographs:equation(1)D=We+WcWT=∑i=1..t6ni−6∑i=1..t3ni2−3ni+1,where ni is the number of W atoms along one side of the WS2 slab, as determined by its length, and t is the total number of slabs in the TEM micrograph.

1 year ago

Subsequently photo generated electrons and

The photo-generated electrons also have a weak ability to reduce nitrate and nitrite [Eqs. (8)– (12)]. Doudrick et al. [18] have demonstrated that electrons could be used for photocatalytic reduction of nitrate. Because no treatment was taken to deal with the dissolved oxygen during the reaction, the reduction of nitrate and nitrite might compete by the oxidation of nitrite by oxygen (E?(O2/H2O) = 1.23 V; E?(NO3−/NO2−) = 0.94 V).

1 year ago

XRD patterns of the as synthesized BPA c BPA

The surface area and the pore-size distribution were examined by adopting nitrogen-sorption analysis (Fig. 3). In order to see the effect of the agglomerate structure on the photocatalytic activities, two distinct types of agglomerates were prepared: (i) pristine BPA and (ii) crushed BPA (c-BPA) that Calhex 231 was processed by ball milling. Their properties are summarized in Table 1. The specific surface area was calculated by employing the Brunauer–Emmett–Teller (BET) adsorption model. For both types of samples, H1-type hysteresis [38] and type IV isotherms with a sharp capillary-condensation step were observed at high relative pressures. This suggests the presence of mesopores in both types of samples (Fig. 3a). The estimated pore size and the total pore volume are 6.53 nm and 0.1676 cm3 g−1 for BPA, and 6.92 nm and 0.1937 cm3 g−1 for c-BPA according to the Barrett–Joyner–Halenda (BJH) model (Table 1). After the ball-milling process, the volume of smaller mesopores (3–10 nm) decreases while stomata of larger mesopores (10–80 nm) increases, with a broadening in the size distribution (Fig. 3b). The specific surface area is 42.0 ± 0.5 m2 g−1 for BPA and 42.2 ± 0.3 m2 g−1 for c-BPA, respectively, which remains unchanged. The significant increase in the volume of large mesopores and the pore size after the ball-milling treatment indicates that the ordered arrangement of BP nanoparticles in the BPA structure is disrupted (at least, partly) by the ball-milling process. The fact that the ball milling did not induce any change in the XRD spectrum of BPA (See Fig. 2a) implies that the ball milling process was mild enough not to change the crystalline structure of BPA but disrupted only the aggregate structure.

1 year ago

Strong hydrogen bonds for K INT

3.3. Covalent graft
3.4. Intercalation energy
Table 3.
Formation energies (ΔEform, in kJ mol−1) BIBO 3304 different kinds of intercalation models of DEOA and water in kaolinite with d(0 0 1) value of 11.2 Å. aReactionΔEformPhysical intercalation(1) K-112 + DEOA → K-INT-DEOA−31.1(2) K-112 + DEOA + H2O → K-INT-W-DEOA−49.2Covalent graft(5) K-112 + DEOA-H2O → K-GRA-A-DEOA−44.3(6) K-112 + DEOA → K-GRA-A-W-DEOA−65.7Double covalent graft(7) K-112 + DEOA-2H2O → K-GRA-B-DEOA13.5(8) K-112 + DEOA → K-GRA-B-2W-DEOA25.5aThe labels “A” and “B” indicate fossil grafted kaolinite complexes have one covalently grafted organic arm and two organic arms covalently bridging two vicinal structure units of the mineral, respectively.Full-size tableTable optionsView in workspaceDownload as CSV

1 year ago

The numeric values of certain

Boundary and structure adequacy tests were conducted throughout the modeling process to assure that Donitriptan the model is appropriate for the given purpose. Finally, dimensional consistency test was conducted (provided by the software) and demonstrated that all units and dimensions are adequate. Thus, the testing results allowed us to gain confidence that the essential factors and parameters determining the dynamic behavior of the real system are included in the model and that the boundaries and level of detail describe the real system with sufficient granularity.
To perform the behavior validation, the key variables of the model were compared to the historical data. In our case, the aim of the model was to calculate GHG emissions from various sectors of agriculture. Fig. 3 shows the comparison of simulated and historical data of the total GHG emissions in the agricultural sector in Latvia. The historical data were taken from the Latvia\'s National Inventory Report (LNIR, 2014) acetylcholine was submitted under the United Nations Framework Convention on Climate Change and the Kyoto Protocol. It can be seen that the simulated amount of GHG emissions reasonably match the historical GHG emissions\' data.

1 year ago

The peak shift and line broadening in PXRD profiles

5 shows the excitation spectra of CeO2 NPs by monitoring the emission at 425 nm. The excitation spectra consists of a sharp peak at 388 nm corresponding to intra-configuration (f–f) transitions of Ce4+ ions.
Fig. 5. PL emission spectra of CeO2 NPs obtained with different LA leaf extract concentration excited at 388 nm (inset: variation of PL intensity of CeO2 NPs versus LA concentration in ml and excitation spectra of CeO2 sample S4).Figure optionsDownload full-size imageDownload as PowerPoint slide