Experimental study on weathering of basalt in the present atmospheric and the early Proterozoic low oxygen environments under surface conditions

<p>In order to compare the mineral chemical effects of acid rain on surface materials in the present oxygen level and the Proterozoic low oxygen environments, artificial chemical weathering experiments using an improved Soxhlet extraction apparatus were conducted for basalt, which had been covered even on the early earth surface. Some dozens of polished basalt plates put in the extraction chamber were reacted to HCI. H<sub>2</sub>S0<sub>4 </sub>and HN0<sub>3 </sub>solutions at pH 4, and CO<sub>2 </sub>saturated water, and distilled water at 50 degrees Celsius for a different period of time up to 950 days in an open system. In the experiment under the low oxygen environment (5×10<sup>-4</sup> PAL), the whole extraction apparatus was placed in the acrylic glove box, and oxygen was removed by the deoxidizer, and it was carried out in the nitrogen gas flow. The basalt was composed mainly of olivine as a phenocryst, and plagioclase, CPX, ilmenite and glass as a groundmass. The leached sample solutions were collected, and analyzed using ICP-MS. Morphological, chemistry and altered product of each mineral surface were studied by SEM, EPMA, XRD and microscopy techniques. </p><p>   Under both the Proterozoic low oxygen and the present environments, SEM images showed that the dissolution of olivine surface by the H<sub>2</sub>SO<sub>4</sub>, HNO<sub>3 </sub>and HCl solutions is remarkable. The (Mg + Fe)/Si on the olivine surface and (Na + Ca + K)/(Al + Si) on the plagioclase surface decreased significantly with increasing experimental period. In chemistry of the leached solutions, molar ratios of Mg, Mn, Fe and so on were high by three kinds of acidic solutionsat pH 4, and low by CO<sub>2 </sub>saturated water and distilled water. The molar ratio is calculated from the cumulative total mole of released elements divided by the mole of individual elements in the unaltered basaltic rock. The ratio of Fe, Mg, Ni, Zn and Co near 70 pm in ionic radius is high, and reflect the dissolution from the octahedral coordination of olivine. The ratios of Ca, Na, Sm, Ce, La and Sr near 110 pm is high, and reflect the dissolution from the cavities within the framework of plagioclase. Under the low oxygen environment, major elements such as Fe, Mg, Mn, Ca, Na, and minor ones such as Ni, Co, Zn tend to dissolve easily. REE is soluble in pH 4 HCl, CO<sub>2 </sub>saturated water and distilled water under the low oxygen environment except for HNO<sub>3 </sub>solution, and does not change in H<sub>2</sub>SO<sub>4 </sub>under both environments. The leaching ion concentrations of Mn, Cu, Zn, Ni, Co and REE associated with marine resources such as manganese nodules and BIF under the low oxygen are higher than those in the present average seawater.</p>

Mathematical model of movement of a single spherical lupine particle in the extractor using low-frequency mechanical vibrations

In our case, the solid body is the raw material of plant origin-lupine, crushed into grits, and the extractant is the cheese whey. The turbulent situation in the apparatus was created by the imposition of low-frequency mechanical vibrations, which have a significant impact on the characteristics of hydro-mechanical, mass transfer and thermal processes. This feature must be taken into account in the calculation of the extraction apparatus. The basic assumptions for the solution of the problem are formulated. The equation of motion of a single particle, which is contained in a number of works (Sow, an introduction, Chen, Protodyakonov, etc.). It is true in the instant values of the parameters. A simpler equation describing the motion of the dispersed particle and time correlation tensors with their subsequent decomposition into the Fourier integral are written. Further, taking into account the definition of tensors, the dependences for the calculation of the intensity of the chaotic motion of continuous and dispersed phases are shown, and the final expression is obtained, showing the ratio of the intensities of the phases. The coefficient of turbulent diffusion of each phase is proportional to the intensity of the chaotic motion of the corresponding phase. Therefore, the written finite equation for the phase ratio allows to estimate the ratio of the turbulent diffusion coefficients of the liquid and dispersed phases in the extraction apparatus. In our case, the ratio of the density of Hg / Hg is 1.1. Since the density of lupine and cheese whey differ quantitatively, we should expect some increase in the relative velocity of the phases, which will increase the rate of mass transfer. The intensities of the phases chaotic motion will not be the same, as well as the coefficients of turbulent diffusion. Thus, the case of motion of a single particle in a turbulent flow is complex and can be solved only under sufficiently serious assumptions formulated below.

Effect of pretreatment on the proximate composition, physicochemical characteristics and stability of Moringa peregrina oil

The present research work was intended to study the influence of roasting and germination of the kernel seeds of Sudanese Moringa peregrina on the physicochemical characteristics and the oxidative stability of the extracted oil. Roasting was carried out at 180 ˚C for 25 minutes, whereas germination was done at ambient conditions in a wet jute bag for 5–7 days. The oil was extracted using n-hexane in a Soxhlet extraction apparatus. The results show that the oil contains α-tocopherols (152mg/kg) and oleic acid (above 70%) as the major tocols and fatty acids, respectively. Germination reduced the peroxide value and increased the acid value in a significant way (p < 0.05) whereas the opposite trend was noticed in the case of roasting. It is crucial to note that, with the exception of the acid value of the germinated sample, peroxide and acid values remained below one meq O2/Kg of oil and one mg KOH/g of oil, respectively. The oxidative stability of the oil from the roasted sample was increased almost by 80% compared to the raw one. Roasting of the kernels prior to oil extraction is imperative for improving its oxidation resistance and the physicochemical characteristics.

Effects of thermal processing on physicochemical properties and oxidative stability of Balanities aegyptiaca kernels and extracted oil

In the present study, the effects of roasting and boiling on the proximate composition of the kernels as well as the physicochemical properties and oxidative stabilities of the extracted oils of Balanites aegyptiaca were investigated. Roasting was performed at 180 ˚C for 15 minutes, whereas boiling of the kernels was carried out in tap water for one hour. The oils from raw and thermally processed samples were extracted using n-hexane in a Soxhlet extraction apparatus and characterized. The roasting significantly (p < 0.05) influenced the peroxide value and the oxidative stability of the extracted oil in a positive way; whereas boiling had the opposite effect. The oils were composed of linoleic, oleic, stearic, and palmitic acids as the major fatty acids (96%) and contained predominantly α- and γ-tocopherols (ca. 400mg/kg). The study suggests that the oil from roasted kernels could be used as a natural antioxidant for enhancing the characteristics of other edible oils via blending.

Statistical modeling of pressurized hot-water batch extraction (PHWE) to produce hemicelluloses with desired properties

The pressurized hot-water extraction (PHWE) process of Norway spruce sawdust has been optimized aiming at the production of a hemicellulose-rich fraction consisting mainly of galactoglucomannans (GGM). The independent process parameters temperature, reaction time, and liquid-to-wood (L/W) ratio were in focus of the statistical modeling. The main target product properties were the average molecular mass (Mw) and the GGM content of the dissolved solids in the extracts and the yield of polymeric hemicelluloses with Mw larger than 4 kDa in the ethanol-water precipitate. According to the model, the highest Mw (>30 kDa) of the total dissolved solids in the extract can be obtained at a low extraction temperature (ET), a short extraction time (Et), and a low L/W ratio. The best result was 37 kDa, corresponding to a degree of polymerization (DP) about 230. The highest GGM content of the extract (>11% of the sawdust, which is about 70% of the GGM in sawdust) can be obtained with a high ET, a long Et and a high L/W ratio. According to the model, the PHWE process gives rise to the largest possible amount of polymeric hemicelluloses at 170°C, 11 min reaction time, and at L/W 5. Provided that a large-scale extraction apparatus works under these conditions with the same efficiency, it should be possible to produce around 60 g polymeric hemicelluloses (mainly GGM) with a Mw around 15 kDa from 1 kg spruce sawdust, which is roughly 25% of the original hemicelluloses in the sawdust.

POTENTIAL OF TURMERIC EXTRACT AND ITS FRACTIONS TO CONTROL PEACH FRUIT FLY (DIPTERA: TEPHRITIDAE)

ABSTRACT Potential of turmeric extract and its chemical fractions were evaluated to control the infestation of Bactrocera zonata peach fruit fly in a mortality-based bioassay. The turmeric extract (TE) was taken on Soxhelt's extraction apparatus and chemically fractioned by thin layer followed by column chromatography into 6 fractions (F1 ...F6). Fifty pairs of the flies were fed in cages with 250 and 500 ppm TE and its fractions separately for 20 days along with flies fed on untreated diet to serve as control. The toxicity of TE and each of its fractions was evaluated by calculating percent mortality of fly population after every 5th day in 4 consecutive intervals. Mortality of fly population was observed to be positively correlated with increasing concentrations of TE and its fractions in diet. The mortality of flies fed at 250 and 500 ppm TE was significantly higher at 44.17 and 66.33% compared to 28.88% in control. Percent mortality was much higher in case of flies fed with fractions F1, F3 and F6 i.e. 72.22, 50.00 and 48.76 respectively. Maximum rise of mortality was observed at the end of 3rd interval; in case of flies fed at 500 ppm TE, 52.45 percent mortality was observed at the end of 3rd interval; highest mortality was caused by fraction F1, 51.39% in case of flies fed at 250 ppm and 70.37% in case of those fed at 500 ppm.