Main Chemical Composition Research Articles

Introducing nitrogen-fixing tree species and mixing with Pinus massoniana alters and evenly distributes various chemical compositions of soil organic carbon in a planted forest in southern China

There are potential effects of converting a planted-forest type from conifer to broadleaf or mixed-species on soil organic carbon (SOC) chemical composition, and the quantity and distribution of various chemical compositions of SOC remain uncertain. An afforestation experiment with different tree species (Pinus massoniana, Erythrophleum fordii [N-fixing species], and mixed P. massoniana and E. fordii) was conducted in clear-cut sites of P. massoniana-planted forests in a subtropical region. Topsoil organic C quality and microbial diversity were assessed after eight years of afforestation. Referring to the species diversity index in the community, Pielou’s evenness index was used for estimating the evenness of distribution of various organic C compositions in the total organic C of soil, litter, and fine roots. The proportions of alkyl C and carbonyl C in SOC, as well as the alkyl C/O-alkyl C (A/O-A) ratios and the distributed evenness of the four main SOC chemical compositions were higher in the monospecific E. fordii and mixed-species-planted forests than in the monospecific P. massoniana-planted forest. Positive relationships of the A/O-A ratio and the evenness of distribution of various SOC chemical compositions in the litter as well as fine root C quality were observed. Microbial biomass C was positively correlated with the labile SOC (O-alkyl C). Multivariate analysis showed that the fine roots had a closer correlation with the chemical composition of SOC than the litter. These results highlight that introducing native N-fixing broadleaf tree species and mixing N-fixing species into conifer forests probably enhances the SOC chemical stability. It also minimizes the risk of C decomposition posed by any one soil organic matter (SOM) constituent having a huge impact during climate change through increasing the proportion of recalcitrant C components and even distribution of various SOM chemical compositions.

Characteristics of six criteria air pollutants before, during, and after a severe air pollution episode caused by biomass burning in the southern Sichuan Basin, China

Biomass burning (BB) seriously affect air pollution, human health and global climate. A severe pollution episode (PE) caused by BB was investigated in the southern Sichuan Basin (SSB), one of the most polluted areas in China. Hourly variations in criteria air pollutants (PM2.5, PM10, SO2, NO2, CO, and O3), chemical components, and sources of PM2.5 before, during, and after the severe regional air PE were characterized at three sites, namely Neijiang (NJ), Zigong (ZG), and Yibin (YB). The results showed that combination of intensive pollution from BB, stable meteorological conditions, and the basin topography caused this severe regional PE in the SSB. The average daily concentrations of PM2.5 during the PE were 1.8–6 times those measured during the periods before and after the PE, and 4.0–7.4 times that of World Health Organization air quality guidelines in the SSB. The highest PM levels occurred in ZG, where the peak values of PM2.5 and PM10 reached 536 μg m−3 and 578 μg m−3 at night, respectively. PM10, NO2, and CO also increased dramatically at night in the SSB. O3 formation was affected by BB, showing lower levels at night but higher levels in the day during the PE than before and after the PE, whereas SO2 levels were not affected. Sulfate–nitrate–ammonium in PM2.5 was the main chemical compositions before the PE, whereas organic matter (OM) and K+ became characteristics compositions during and after the PE. Higher OC/EC and Kexcess/EC ratios were observed during the PE and Kexcess/EC ratio was a better indicator of BB in the SSB than OC/EC ratio. The results of a positive matrix factorization model indicated that BB was the most significant contributor to PM2.5 during the PE, accounting for 58% in NJ, 65% in ZG, and 56% in YB. Backward trajectory analysis confirmed that the SSB is susceptible to pollutants from Chongqing and other surrounding cities, especially in ZG and NJ, due to the unique topography of the basin. Our findings suggest that BB in the basin topography can cause severe regional air pollution events at night, thus supporting the critical need for BB control in the basin to improve regional air quality.

Chemical Constituents and Chemotypes of Fresh Leaf Essential Oil of Wild Species Belonging to Sect. Camphor (Trew.) Meissn. in Southeastern China

The aim of the study was to analyze the chemical compositions and chemo types of the essential oil obtained from the fresh leaves of wild species belonging to Sect. Camphor (Trew.) Meissn. in the southeastern of China. Hydro-distillation of essential oils was carried out by the refined oil extraction equipment of Nanchang Institute of Technology (patent application number: 201710158988.8), quality and quantity analysis of the essential oil was carried out by gas chromatography/mass spectrometry (GC/MS). After 3 years of investigation more than 1000 individuals, 7 chemotypes were classified in southeast China, including citral- type, linalool-type, camphor-type, cineol-type, safrole-type, methyleugenol-type and nerolidol-type, the last three were the newly discovered of SCM in the area. Especially the individual plants sample number 108 and 107 obtained a high yield of fresh leaf essential oil of 1.35 % and 1.96 % in linalool-type and safrole-type, respectively. The sample number 108 contained twenty-eight compounds which accounting for 99.87 % of the whole essential oil and the content of α-linalool (95.18 %) was the main chemical composition. The sample number 107 contained twenty-six compounds which accounting for 99.90 % of the whole essential oil and the content of safrole (97.04 %) was the main chemical composition. The results indicated that highly economic value natural plant essential oil linalool and safrole superior individual of varieties were found in the study, which are available for the next study and further development of natural plant essential oils.

Optimization of ZnO-nanorods addition toward Li4Ti5O12 (LTO) performance using sol-gel solid state method as half-cell lithium-ion battery anode

Performance optimization for the anode of lithium-ion batteries (LIBs) can be conducted by adding ZnO through sol-gel solid-state reaction. In this research, the Li4Ti5O12 (LTO) used was synthesized through the sol-gel solid-state process and added with ZnOnanorods obtained ZnO synthesis after LTO synthesis done. LTO-ZnO obtained was characterized to determine the main phase and chemical composition by XRD and SEM-EDS respectively. Electrochemical performance of LTO-ZnO was tested by EIS, CV, and CD. ZnOnanorods characterization with SEM-EDS results shows that the ZnO inside the LTO dispersed homogeneously. Characterization using XRD revealed that the ZnO successfully enter the LTO with the variation of the amount of 4, 7, and 10 wt% of ZnO. Electric conductivity test shows improvement at an optimum addition amount of ZnO at 4 wt%, although BET result shows at the optimum amount of surface area with 75.545 m2/g. Electrochemical performance result shows optimum performance in ZnO at 4 wt% for its ability to withstand EIS test at 20C compared to 7 wt% and 10 wt%. Also, the capacity of 4 wt% added is 110.2 mAh/g compared to 7 wt% with 109.1 mAh/g and 10 wt% with 96.7 mAh/g.

Impact of Milk Fortification on the Microbiological and Physicochemical Properties of Set-Type Skimmed Yoghurt Using Three Commercial Soluble Prebiotics.

The impact of milk fortification on the microbiological and physicochemical properties of a set-type skimmed yoghurt using three commercial soluble prebiotics (inulin, iso-malto-oligosaccharides, and xylo-oligosaccharides) at either 3 or 5 g/kg was assessed. The three prebiotics had an insignificant impact on yoghurt fermentation because all yoghurt samples had similar titratable acidity and similar pH values after their lactic acid fermentation. Regarding the control yoghurt samples without prebiotics usage, the prebiotics-fortified yoghurt samples showed no difference in their main chemical compositions, hardness, syneresis extent, and apparent viscosity (p > 0.05), but had a slightly higher lactic acid content and a viable quantity of starter strains. All yoghurt samples had the same acetic acid content, while propionic and butyric acids were not produced. Yoghurt storage at 4 °C for 21 day gave these yoghurt samples decreased pH values and a viable quantity of starter strains (especially Lactobacillus delbrueckii subsp. bulgaricus) and unchanged acetic acid; however, it increased lactic acid contents. Overall, prebiotics fortification up to 5 g/kg had a completely insignificant impact on the fermentation and quality attributes of yoghurt samples but could possibly improve the health of consumers due to higher dietary fibers and starter strain populations.

High Performance Capillary Electrophoresis Characteristic Fingerprint of Schisandra chinensis

Background: The quality control indexes detected by the existing methods are less and lack specificity, and cannot truly reflect their intrinsic quality because of the similarity of Schisandra chinensis and Schisandra sphenanthera in both their appearance and their main chemical composition. Therefore, it is urgent to establish an effective method for the quality control of the both. High-performance capillary electrophoresis (HPCE) method was used to establish the fingerprints of Schisandra medicinal materials. Methods: The HPCE was performed, in which a 50µm × 50cm (the effective length was 41.5cm) uncoated fused silica capillary column was applied, the buffer solution was 10 mM phosphate buffer (pH 8)-37.5 mM SDS-35% acetonitrile (v/v), the working voltage was 28 kV, the temperature was 25°C, the samples were injected at 50mbar pressure for 3s, and the detection wavelength was 214nm. The chromatographic fingerprints of samples were analyzed using “traditional Chinese medicine chromatographic fingerprint similarity evaluation system 2004A version” software and cluster analysis. Results: 10 common peaks were confirmed and 8 components were identified in the HPCE fingerprints of 20 batches of Schisandra chinensis and Schisandra sphenanthera, and the results of clustering were consistent with those of similarity evaluation. Conclusion: This method should be accurate and reliable, and can provide a scientific basis for the quality evaluation of Schisandra medicinal materials.

Comparison of spectral properties of three hyperspectral imaging (HSI) sensors in evaluating main chemical compositions of cured pork

Hyperspectral imaging (HSI) is a promising technique to evaluate food quality in a rapid and non-destructive way. Several types of HSI sensors are now commercially available. The aim of the current study was to compare one single shot and two line-scanning based HSI sensors in different spectral regions by using two wavelength dispersive devices – a prism-grating-prism monochromator and a mosaic wavelength dispersion unit. The research sample was cured pork meat, which is a popular meat product due to its flavor and long shelf life. Three main chemical compositions of cured pork meat – moisture, protein and fat content – were evaluated. The spectral properties of the three sensors were employed to establish partial least squares regression (PLSR) predictive models by applying different optimal wavelengths selection strategies. The results showed that optimal wavelength selection was more important than the selection of the wavelength dispersion device.

Plant origin authentication of Sonoran Desert propolis: an antiproliferative propolis from a semi-arid region.

The main chemical composition of Sonoran propolis (SP), as well as its antiproliferative activity on cancer cells through apoptosis induction, has been reported. The chemical constitution of SP remained qualitatively similar throughout the year, whereas the antiproliferative effect on cancer cells exhibited significant differences amongst seasonal samples. The main goal of this study was to provide phytochemical and pharmacological evidence for the botanical source of SP and its antiproliferative constituents. A chemical comparative analysis of SP and plant resins of species found in the surrounding areas of the beehives was carried out by HPLC-UV-DAD, as well as by 1H NMR experiments. The antiproliferative activity on cancerous (M12.C3.F6, HeLa, A549, PC-3) and normal cell lines (L-929; ARPE-19) was assessed through MTT assays. Here, the main polyphenolic profile of SP resulted to be qualitatively similar to Populus fremontii resins (PFR). However, the antiproliferative activity of PFR on cancer cells did not consistently match that exhibited by SP throughout the year. Additionally, SP induced morphological modifications on treated cells characterised by elongation, similar to those induced by colchicine, and different to those observed with PFR treatment. These results suggest that P. fremontii is the main botanical source of SP along the year. Nevertheless, the antiproliferative constituents of SP that induce that characteristic morphological elongation on treated cells are not obtained from PFR. Moreover, the presence of kaempferol-3-methyl-ether in SP could point Ambrosia ambrosioides as a secondary plant source. In conclusion, SP is a bioactive poplar-type propolis from semi-arid zones, in which chemical compounds derived from other semi-arid plant sources than poplar contribute to its antiproliferative activity.

UPLC-MS~n analysis and certification evaluation of main chemical composition in naphthopyrone reference extract of Cassiae Semen

The main chemical constituents of naphthopyrone reference extract( NRE) with definite content and relatively fixed chemical composition were analyzed and determined. Ultra-high performance liquid chromatography-LTQ-Orbitrap XL mass spectrometry and high performance liquid chromatography were used to systematically study NRE from the aspects of main chemical components and determination. The results showed that the chemical composition of naphthopyrone reference extract of Cassiae Semen was relatively fixed,and seven naphthalopyranones were identified. Cassiaside B_2,cassiaside C_2,rubrofusarin-6-O-β-D-gentiobioside and cassiaside C were the main chemical constituents of NRE,of which the determination and uncertainty results were( 11. 40+ 0. 26) %,( 11. 68+0. 24) %,( 16. 60+0. 22) %,( 28. 8+0. 48) %,respectively. This study contributed to the accurate evaluation of NRE and the foundation for the application of NRE in the quality control of Cassiae Semen,and provided a new idea for the replacement of single chemical reference substance by the reference extract of traditional Chinese medicine.

Influence by chemical constitution of aggregates on demulsification speed of emulsified asphalt based on UV-spectral analysis

Emulsified asphalt as an indispensable raw material for pavement engineering construction is subjected to various combinations of aggregates and varying environmental conditions leading to uncontrollable demulsification speed. In this respect, this research examined the influence of chemical composition of aggregate on emulsified asphalt demulsification speed. Three representative types of domestic road limestone aggregates with various appearances were studied by chemical analysis method. Experimental results indicate that the Magnesium oxide, alumina, calcium oxide, ferric oxide and silicon oxide were the main chemical compositions of limestone aggregate and their contents varied significantly among different types of aggregate. Ultraviolet spectrophotometry was used to evaluate effects of each chemical component on the demulsification speed of emulsified asphalt. Results indicate that mixing ratio of chemical components has a significant effect on demulsification speed of asphalt emulsion. Magnesium oxide accelerated the demulsification speed of emulsified asphalt, while calcium oxide showed an opposite trend. Iron oxide, alumina and silica had little effect on the speed of demulsification. Finally, grey correlation analysis was performed, and a clear relationship was established. The results which are expressed as the magnesium oxide, alumina, iron oxide and silicon dioxide content with differing ratio in the aggregate affected significantly on the demulsification speed of emulsified asphalt. However, there is no clear relationship between the demulsification speed and emulsified asphalt when the ratio of the calcium oxide content is changed.

The mechanism behind lack-of-effect of lanthanum on seed germination of switchgrass.

Switchgrass (Panicum virgatum L.) is a perennial warm-season C4 grass identified as a model species for bioenergy feedstock production. Lanthanum (La) as a rare earth element can stimulate the physiological processes of plant growth. The purpose of this study was to investigate the effect of lanthanum on seed germination of switchgrass. However, no significant differences in seed germination were found. The energy dispersive X-ray analysis showed that abundant lanthanum deposits resided on the pericarp and testa of the seed while few lanthanum deposits were present on the aleurone and endosperm. This phenomenon demonstrates that a semi-permeable layer, which could restrict or impede solute exchange, while allowing the permeability of internal and external water and gas, may be located between the testa and aleurone. Light microscopy and histochemical analysis revealed that the main chemical composition of the semi-permeable layer would be expected to be suberin because the layer was stained yellow with aniline blue. The quantum chemical calculations predict that the intervals between adjacent carbon chains in suberin molecule are so small that lanthanum ([La(H2O)8]3+) cannot pass through the suberin molecule. In conclusion, the seed germination of switchgrass is not affected by lanthanum because the semi-permeable layer restricts the penetration of lanthanum into the embryo.

Laboratornye issledovaniya osnovnogo komponentnogo sostava gipergalinnykh ozer

Introduction. Composition of water is an important hydrochemical characteristic of a salt water body. It is very important in shaping the conditions for the ecosystem functioning. This factor should be taken into account in determining water salinity since salinity measurements carried out by the standard oceanologic equipment using electrical conductivity in the water where the ion ratio is different from that in the oceanic water results in significant errors. Data and methods. Described are the analytical methods for laboratory determining the chlorides, sulfates, calcium, magnesium and total dissolved inorganic carbon concentrations using potentiometric titration, the potassium content – by the gravimetric method. These methods are adapted for hyperhalin waters the ion-salt composition of which is different from that of the oceanic one. The method’s error (relative deviation) did not exceed 1.7% for halogens, 4% for sulfates, 1.5% for carbonate ions, 0.7% for bicarbonate ions, 4% for calcium ions, 3,2% for magnesium and 1.3% for potassium. Results. The components of main chemical composition of the hypergaline reservoirs, namely the Aral and Dead seas, and the Lake Urmia are obtained. Salinity of these water bodies represented by total amount of the basic ions is defined. Discussion and conclusion. The natural basins under study represent the terminal lakes characterized by high water salinity, which is many times higher than that of the ocean water. The ratios of the main ions in the studied sources differ from each other significantly as well as from the similar ratios in the world ocean.

Chemical Characteristics of Size-Resolved Aerosols in Coastal Areas during KORUS-AQ Campaign; Comparison of Ion Neutralization Model

Measurements for size-resolved chemical composition were made at the Anmyeon Island station on the western coast of the Republic of Korea between May 28 and June 20, 2016. This study determined the main chemical compositions of size-resolved particulate matter (i.e., organic carbon, elemental carbon, water-soluble organic carbon, water-soluble ions, and benzene carboxylic acids) from a total of eight chemically size-resolved sets using micro-orifice uniform deposit impactors. The sum of the species presents a prominent accumulation mode peak at a diameter of 0.56 μm without the coarse mode peak. In the accumulation mode, SO42− (49.3%) was the dominant particle component in the size range of 0.1–1.8 μm. Organic carbon and elemental carbon accounted for 13.5% and 0.4%, respectively. Benzene carboxylic acids indicate the accumulation mode peak at the diameter of 0.56 μm. The size-resolved equivalent ion concentration ratios between all measured cations and anions and the ion neutralization model, which uses four major ions, were compared. As a result, the concentration of Na+ is of importance in the accumulation mode for the equivalent ion concentration.

Bioinspired Hairy Crab Claw Polymer Surface with Excellent Self-Cleaning Wettability in Muddy or Oil-Contaminated Water.

The hairy crab Eriocheir sinensis lives in muddy freshwaters such as ponds and paddy fields. The crab's claw features dense patches of setae and exhibits an excellent self-cleaning surface in muddy waters. This study examined the micronano structure and wettability properties of the crab claw. The results showed that the claw consists of 3D cross-linked fibers with a hierarchical micronano structure, and the main chemical composition of these fibers was determined chitosan molecules. The claw also has special superoleophobic and self-cleaning properties in muddy water. Inspired by the structure of the crab claw, 3D-layered micro/nanostructures with poly(vinyl alcohol)/chitosan/poly(N-isopropylacrylamide) were prepared by electrospinning and in situ polymerization. This novel bioinspired polymer surface exhibits superhydrophilicity in the air, superoleophobicity underwater (with an oil contact angle of 163°), and excellent self-cleaning potential in muddy water.

Radiological evaluation of industrial residues for construction purposes correlated with their chemical properties

This study characterises the naturally occurring radionuclide (NOR) contents of a suite of secondary raw materials or industrial residues that are normally disposed of in landfills or lagoons but now are increasingly used in green concretes. This includes ashes from a variety of industrial processes and red mud from aluminium production, as well as air pollution control residue and cement kiln dust. The chemical composition of the samples was determined with X-ray fluorescence spectroscopy (XRF). The Ra-226, Th-232 and K-40 activity concentrations were obtained by gamma spectrometry, and the results were compared with recently published NOR databases. The correlation between the NOR contents and the main chemical composition was investigated. The radioactive equilibrium in the U-238 chain was studied based on the determination of progeny isotopes. The most commonly used calculation methods (activity concentration index and radium equivalent concentration) were applied to classify the samples. The radon exhalation rate of the samples was measured, and the radon emanation coefficient was calculated. Significant correlation was found between the NORs and certain chemical components. The massic exhalation demonstrated a broad range, and it was found that the emanation coefficients were significantly lower in the case of the residues generated as a result of high-temperature combustion processes. The results showed a weak correlation between the Ra-226 concentration and the radon exhalation. This emphasises that managing the Ra-226 content of recycled material by itself is not sufficient to control the radon exhalation of recycled materials used in building products. The investigated parameters and their correlation behaviour could be used to source apportion materials found during the process of landfill mining and recovery of material for recycling.

An Experimental Investigation on the Properties of Concrete Using Copper Slag as a Partial Replacement of Fine Aggregate

Now a days, infrastructure development holds the key for the development of every nation. Concrete is one of the most utilized material by the construction industry which is a homogeneous material prepared of heterogeneous materials like Cement, sand and aggregates. However rapid urbanization has created a huge demand for natural sand hence made it even more expensive. This led the researchers to find other materials which could be used as a replacement of sand whose main chemical composition is Silica (SiO2). After a great extent of research, researchers found that materials like Stone dust, Copper Slag, Coal Fly Ash, Carbonate Sand etc. having silica composition could be used as a replacement of sand. The Present experimental investigation is carried out for M20 grade of concrete mixes with partial replacement of Fine Aggregate (Sand) with Copper Slag. Compressive Strength and Split Tensile Strength at the ages of 7, 28 days for various combinations of Copper Slag and Sand were investigated. Sand was replaced with Copper Slag by 0%,10%, 30%, and 50%.

Investigation of the Inhibitory Effects of Mangrove Leaves and Analysis of Their Active Components on Phaeocystis globosa during Different Stages of Leaf Age.

The presence of harmful algal blooms (HABs) can cause significant problems to the quality of the water, the marine ecosystems, and the human health, and economy worldwide. Biological remediation can inhibit harmful algal growth efficiently in an environmental-friendly manner. Therefore, the research conducted on biological remediation with regard to the inhibition of HABs is becoming a major focus in marine ecology. To date, no study has been reported with regard to the red tides occurring in mangrove wetlands. Therefore, the present study used two mangrove species, namely Bruguiera gymnorrhiza and Kandelia candel and one harmful algae species Phaeocystis globosa as experimental organisms. The present study determined the inhibitory effects and algae physiology of specific aqueous extracts from mangrove leaves on the viability of harmful algae, and analyzed the main chemical composition of the aqueous extracts by ultra-performance liquid chromatography coupled to high resolution mass spectrometry (UPLC-QTOF-MS). The results indicated that the aqueous extracts from different leaf ages of B. gymnorrhiza and K. candel leaves exhibited apparent inhibitory effects on the growth of P. globosa. The inhibitory effects of B. gymnorrhiza and K. candel leaves aqueous extracts on the growth of P. globosa were in the following order: senescent > mature > young leaves. The levels of the parameters superoxide dismutase (SOD) activity, glutathione (GSH), and malondialdehyde (MDA)content in P. globosa following treatment with B. gymnorrhiza and K. candel leaves aqueous extracts were increased as follows: senescent > mature > young leaves. Simultaneously, the intensity of the ion peaks of the specific secondary metabolites assigned 4 (No.: 4 Rt: 2.83 min), 7 (No.: 7 Rt: 3.14 min), 8 (No.: 8 Rt: 3.24 min), 9 (No.: 9 Rt: 3.82min) and 10 (No.: 10 Rt: 4.10 min) were increased. These metabolites were found in the aqueous extracts from B. gymnorrhiza leaves. The intensities of the ion peaks of the secondary metabolites 7, 8 in the aqueous extracts from the K. candel leaves were also increased. The majority of the substances that inhibited the algae found in the mangrove plants were secondary metabolites. Therefore, we considered that the norsesquiterpenes compounds 4, 8, 9, and 10 and a phenolic glycoside compound 7 were the active constituents in the aqueous extracts of the mangrove leaves responsible for the inhibition of algae growth. This evidence provided theoretical guidance for the development of biological methods to control red tides and for the further use of substances with antiproliferative activity against algae.

Assessment of nutrient and heavy metal content and speciation in sewage sludge from different locations in Iran

More than 80% of sewage sludge (SS) produced in Iran is landfilled with high environmental impact. The chemical properties of SS produced from wastewater plants of cites of Arak, Isfahan, Kermanshah, Rasht, Saveh, Shiraz, Sanandaj, Tehran, Takestan, and Toyserkan were studied to assess the potential beneficial effects of their application to agricultural soil as sustainable SS management. The pH and EC values, total content and water-soluble concentration of nutrients and heavy metals, their water-extractable pools were determined, and their speciation was done through the NICA–Donnan model using the Visual MINTEQ software. Relatively high contents of N, P, and physiologically active cations indicated potential beneficial effects of SS for land application in the agro-ecosystems, whereas the heavy metal content depended on the SS production site, with higher levels found in the SS of the Arak and Saveh wastewater treatment plants. The pH value was the main factor controlling the metal speciation, with Cu and Pb having the highest affinity for the organic matter, and Zn and Mn being mainly present as free ions or inorganic species. Results showed that SS from different locations in Iran differed in their main chemical properties and elemental composition and that speciation analysis could be used to predict potential beneficial and harmful effects of SS, particularly upon the modeling of metal–organic complexes by the NICA–Donnan approach. Globally, our results confirmed that while the SS produced in Iran has potential suitable chemical properties for use in agriculture, their heavy metals load should not be ignored.

Risk Factors and Chemical Composition of Urinary Stones in the Azorean Population (São Miguel Island - Portugal): A Preliminary Study

Introduction: Urinary stone disease is one of the most common disorders of the urinary tract. However, the main risk factors and chemical composition of urinary stones in the population of the Azores are unknown. The objective of this study was to define the most important factors associated with the formation of urinary calculi, investigating eating habits, family history and chemical composition of the calculi in the population of the Azores.
 Methods: The data were collected from 46 patients of the Hospital do Divino Espirito Santo and 48 healthy volunteers. A questionnaire was recorded on the medical and family history of the participants and on their life habits. The chemical composition of the calculi was evaluated by ICP-MS.
 Results: It was observed that the study group has a higher prevalence of diabetes and cases of urinary calculi in the family compared to the reference group. A positive correlation was found between calcium in the stones and the contents of sodium, magnesium, zinc, molybdenum and strontium.
 Conclusion: This study reveals that family history, diabetes and water consumption play an important role in the development of urinary calculi in the population of the Azores. The chemical content of the stones should also be considered since these data could help the medical community to understand the causes of urinary stone formation and adapt the medication and preventive measures to the patient and to the type of kidney stone produced.

Study on the sodium oxidation properties of low-iron vanadium-titanium magnetite with high vanadium and titanium

ABSTRACTIn this work, the oxidation properties of low-iron vanadium-titanium magnetite with high vanadium and titanium in a laboratory muffle furnace was investigated. XRD, SEM, and TG-DSC method are employed to identify the main phases and chemical composition of the samples. The roasting time of 4h and Na2CO3/vanadium titanium magnetite mass ratio of 7.5:100 were determined. The results showed that the blank oxidation roasting temperature ranged from 593°C to 1035°C, the mixed oxidation roasting temperature of vanadium-titanium magnetite and Na2CO3 at the range of 204°C to 825°C, and the forming temperature of soluble vanadate at the range of 700°C to 825°C. When roasting temperature reached 1000°C, consolidation was started. When roasting temperature was 850°C, the roasting conversion efficiency, acid leaching efficiency and water leaching efficiency were 92.4%, 87%, and 85%, respectively.