Earth Metal Research Articles

蛍光色素diOC<sub>2</sub>(3)が吸着した油水界面へのアルカリ金属・アルカリ土類金属イオンの促進移動

蛍光色素diOC<sub>2</sub>(3)が吸着した油水界面へのアルカリ金属・アルカリ土類金属イオンの促進移動

Theoretical Study on Inverse Sandwich Complexes [E-C5−nH5−nNn-E]+ and [E-C5−nH5−nPn-E]+ (n=1, 2, 3; E=Al, Ga, In, Tl)

The inverse sandwiches [E-C5−nH5−nNn-E]+ and [E-C5−nH5−nPn-E]+ (n=1, 2, 3; E=Al, Ga, In, Tl) with low-valent boron group elements are studied. The (η5, η5) coordinated inverse sandwich [E-C5−nH5−nNn-E]+ is unstable in energy or nonexistent. However, the (η5, η5) coordinated [E-C5−nH5−nPn-E]+ is not only stable in energy, but also stable against dissociation. The dissoction stability [E-C5−nH5−nPn-E]+ with the same E element decreases as the number n increases, while for the certain n number, the dissociation energies with different E elements are close to each other. [E-C4H4P-E]+ has similar dissocition stability to the well-known [E-C5H5-E]+. The inteaction between C5−nH5−nPn and low-valent E element is mainly ionic. Since lone pairs of electrons locate on both E and P atoms, the (η5, η5) coordinated inverse sandwich [E-C5−nH5−nPn-E]+ would act as multi electron-donors.

Aromaticity of benzenoid hydrocarbons with inserted –B=B– and –BH–BH– groups: a comparison

Structures of selected polycyclic conjugated hydrocarbons with –B=B– and –BH–BH– moieties inserted in different places were calculated at the B3LYP/6-311++G** level and their aromatic properties evaluated. HOMA, NICS(0), NICS(1)zz, Λ and PDI indices were used for studying their aromatic properties. Both optimized planar (as in parent hydrocarbons) and non-planar structures were taken into account. It is shown that insertion of both types of boron groups disturbs and decreases the aromaticity of the corresponding hydrocarbons. The decreasing effect of the –BH–BH– group is much stronger. What is quite intriguing is that it appears that non-planar structures of the studied compounds have a little higher aromaticity than the strictly planar ones. Mutual correlations between results obtained by different aromaticity indices are calculated and thoroughly discussed.

A Short Review on Effect of Heat Treatment on Microstructure and Mechanical Properties of ADC12/SiC Metal Matrix Composite

Aluminium, being the second most abundant metal in earth’s crust, has emerged as an important metal in human civilization’s development. It has served as an excellent substitute for many conventional materials like wood, copper, iron and steel. Now a days, more Aluminium is consumed (on a volumetric basis) than all other non-ferrous metals/alloys including copper.Aluminium and aluminium alloy are gaining huge industrial significance because of their good combination of mechanical, physical properties over the base alloy. In some few recent years the use of metal matrix composite material increases very rapidly due to their high weight to strength ratio, low density, low thermal expansion coefficient, low maintenance and high temperature resistance. Metal matrix composites are widely used in aerospace and automotive engine components. The aluminum alloys are reinforced with Al2O3, B4C and TiC and fabricated by stir casting, centrifugal casting, and powder metallurgy process. In the fabricated metal matrix composites some different tests were conducted to show mechanical properties, micro-structural characterizations of materials were also done. When composite subjected to heat treatments then it significantly affects the micro-structural developments of composite causing to relieving of stress.

Effect of Moringa oleifera on hematological parameters of calves reared in industrial fluorotic area.

Aim:The present study was undertaken to evaluate the ameliorative potential of dried Moringa oleifera fruit powder in fluorosis affected calves reared around the vicinity of aluminium smelter plant.Materials and Methods:Total 107 calves were screened on the basis of clinical signs and higher plasma fluoride (more than 0.2 ppm) level for evidence of fluorosis. Out of that, 90 samples found positive and from them 18 calves of 6-12 months age group were selected and divided equally into three groups named as Group II, III, and IV. Group II remained as disease control group whereas Group III calves were supplemented with dried M. oleifera fruit powder of 25 g/calve for 60 days. Group IV calves were supplemented with calcium carbonate at 100 mg/kg body weight and boric acid at 10 mg/kg for the same experimental period. Group I consisted of six numbers of healthy calves taken from the non-fluorotic zone, i.e. Bhubaneswar. Plasma fluoride level, hemoglobin (Hb), packed cell volume (PCV), total leukocyte count (TLC), differential count (DC), total erythrocyte count, mean corpuscular volume (MCV), mean corpuscular Hb (MCH), and MCH concentration (MCHC) were estimated on day 0, 30, and 60 of the experiment.Results:Supplementation of dried M. oleifera fruit powder to fluorosis affected calves resulted in significant reduction in plasma fluoride level and increase in Hb%, PCV, TLC and altered DC. Similar results were also recorded in calcium+boron group, except PCV and Hb. No significant changes were observed in MCV, MCH, and MCHC values.Conclusion:The present study concluded that supplementation of dried M. oleifera fruit powder daily for 60 days has shown protection against chronic fluoride toxicity in calves.

Highly selective potentiometric determination of Fe(III) ions using Tris-(1,2-diiminocyclohexylmethyl-5-Cl-2-hydroxyl benzaldehyde) based membrane electrode

A novel ion-selective poly(vinyl chloride) membrane sensor for Fe(III) ions based on Tris-(1,2-diiminocyclohexylmethyl-5-Cl-2-hydroxyl benzaldehyde) are reported in this paper. The electrode exhibits a good potentiometric response for Fe(III), response time ≤ 20 s, over a wide concentration range 1.0 × 10-5 to 1.0 × 10-1 M with a slope 19.4 ± 0.5 mV/decade. The potentiometric response is independent on the pH of solution in the range of 1.5-5.0. The proposed electrode can be used for at least two months without any considerable divergence in potentials.It exhibits very good selectivity relative to a wide variety of alkali, alkaline earth, transition and heavy metal ions. The electrode assembly was also used as indicator electrode in the potentiometric titration of Fe(III) with EDTA.

ВЛИЯНИЕ ДЕЯТЕЛЬНОСТИ ГОРНО-МЕТАЛЛУРГИЧЕСКИХ ПРЕДПРИЯТИЙ НА ХИМИЧЕСКИЙ СОСТАВ ДОННЫХ ОТЛОЖЕНИЙ ОЗЕРА ИМАНДРА, МУРМАНСКАЯ ОБЛАСТЬ

Крупнейший водоем Мурманской области – озеро Имандра – более 80 лет испытывает загрязнение промышленными сточными водами горнодобывающих и металлургических предприятий и коммунально-бытовыми стоками населенных пунктов, что сказалось в значительных преобразованиях химического состава воды и донных отложений озера, ухудшении экологического состояния озера и изменении структуры гидробионтов. Для оценки современного экологического состояния оз. Имандра и изучения истории развития и загрязнения озера был исследован химический состав донных отложений, для чего отбирались их колонки, и проводился послойный анализ накопления элементов. Определялись содержания тяжелых металлов (Ni, Cu, Co, Zn, Cd, Pb, As, Hg, Mn, Fe, Cr), щелочных и щелочноземельных металлов (Na, K, Ca, Mg, Sr), а также Al и P. Установлено, что геохимический состав донных отложений оз.Имандра претерпел значительные изменения по всей акватории вследствие как прямого поступления сточных вод предприятий горно-металлургического комплекса и коммунально-бытовых стоков, так и аэротехногенного загрязнения водосбора озера и ветровых нагонных течений. Наибольший вклад в эти преобразования оказывают горнометаллургические, горнодобывающие и горноперерабатывающие предприятия – комбинат «Североникель», ОАО «Апатит» и «Олкон». Самые значительные преобразования химического состава произошли на акватории поступления стоков металлургического комбината «Североникель», где в поверхностных слоях донных отложений происходит лавинное увеличение концентраций всех исследуемых тяжелых металлов. Концентрации Ni и Cu увеличились на три и два порядка соответственно по сравнению с глубокими фоновыми слоями – до 3 и 0,6%. Увеличение содержания более чем на порядок зафиксировано и для остальных тяжелых металлов – Co, Zn, Cd, Pb, As, Hg, Cr, которые являются сопутствующими металлами в медно-никелевой руде. Влияние стоков предприятий ОАО «Апатит» сказалось в увеличении концентраций элементов, содержащихсяв апатитонефелиновых рудах и в скрышных породах (Ca, P, Na, K, Al, Sr). Обнаружилось также аномальное увеличение содержания Hg, связанное с проведением взрывных работ на рудниках.

Removal of toxic and alkali/alkaline earth metals during co-thermal treatment of two types of MSWI fly ashes in China

This study aims to vaporize heavy metals and alkali/alkaline earth metals from two different types of fly ashes by thermal treatment method. Fly ash from a fluidized bed incinerator (HK fly ash) was mixed with one from a grate incinerator (HS fly ash) in various proportions and thermally treated under different temperatures. The melting of HS fly ash was avoided when treated with HK fly ash. Alkali/alkaline earth metals in HS fly ash served as Cl-donors to promote the vaporization of heavy metals during thermal treatment. With temperature increasing from 800 to 900°C, significant amounts of Cl, Na and K were vaporized. Up to 1000°C in air, less than 3% of Cl and Na and less than 5% of K were retained in ash. Under all conditions, Cd can be vaporized effectively. The vaporization of Pb was mildly improved when treated with HS fly ash, while the effect became less pronounced above 900°C. Alkali/alkaline earth metals can promote Cu vaporization by forming copper chlorides. Comparatively, Zn vaporization was low and only slightly improved by HS fly ash. The low vaporization of Zn could be caused by the formation of Zn2SiO4, ZnFe2O4 and ZnAl2O4. Under all conditions, less than 20% of Cr was vaporized. In a reductive atmosphere, the vaporization of Cd and Pb were as high as that in oxidative atmosphere. However, the vaporization of Zn was accelerated and that of Cu was hindered because the formation of Zn2SiO4, ZnFe2O4 and ZnAl2O4 and copper chloride was depressed in reductive atmosphere.

Роль и перспективы редкоземельных металлов в развитии физико-механических характеристик и областей применения деформируемых алюминиевых сплавов

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Aluminum Activation in Ionic Liquids

Aluminum (Al) is the third most abundant element (after oxygen and silicon) and the most abundant metal in Earth's crust. Al is quite remarkable as it holds a low density and it has the ability to resist corrosion due to surface passivation. This passivation layer protects Al from corrosion in a relatively wide range of pH and potentials. Nevertheless, in aqueous media, the layer is vulnerable in both highly acidic and basic environments, leading to rapid corrosion reactions. As an anodic material, Al has a theoretical gravimetric capacity of 2.98 Ah/gr and its volumetric capacity is as high as 8.1 Ah/cm3. For the sake of comparison, Li metal holds capacities of 3.86 Ah/g and 2.06 Ah/cm3, respectively. In non-aqueous media electrochemical dissolution of Al is partly hampered due to inefficient and thus insufficient passivation layer removal prior to any current application. Similar issues pertain when the non- aqueous solutions employed are Room Temperature Ionic Liquids (RTIL). In the present work an activation of Al was studied in EMIm(HF)2.3F RTIL. For this specific electrolyte it was already established that electrochemical dissolution of Al occurs, in considerable rates, sufficient for application in Al-Air batteries [1]. The alteration of the surface, as detected by FTIR, XPS and STEM, suggests on the formation of passivating Al-O-F compounds on the surface, instead of native oxide passivation. The source of this specific activation is established in this work, and the surface of Al prior to and following activation was identified. The applied methodology was also used for identification and study of Al activation in other family of RTILs. The preliminary results of this specific electrochemical system will be also presented. [1] D. Gelman, B. Shvartsev, Y. Ein-Eli, J. Mater. Chem. A. 2.47 (2014) 20237-20242.

A Prototype Rechargeable Aluminum Battery

Although Lithium-ion battery technologies have made significant positive impact on portable electronics and electric vehicle industries, the feasibility of wide deployment of lithium-based batteries for land-based renewable energy storage and grid applications may be questionable due to the limited lithium resource, the resource geographic distribution, and the cost of lithium mining and recycling. Therefore, alternative rechargeable battery technologies based on abundant elements need to be developed for sustainable energy storage. Among the potential candidates, aluminum (Al) may be the ultimate choice as the anode material: Al is not only the most abundant metal in earth’s crust, but also has attractive capacity due to its trivalency. Al has the second highest specific capacity of 2980 mA h g-1 (Li has 4634 mA h g-1) and the highest capacity density of 8046 mA h cm-3 (Li has 2456 mA h cm-3) among all metal anodes. To date, there were only scarce investigations on rechargeable Al batteries with little success. For the first time, we demonstrate a new prototype rechargeable Al battery comprised of Chevrel phase molybdenum sulfide (Mo6S8) as the intercalation-type cathode, Al metal as the anode, and a mixture of AlCl3 and 1-butyl-3-methyimidazolium chloride (AlCl3-[BMIm]Cl) as the electrolyte. The Mo6S8 cathode shows unambiguous electrochemical activity for reversible Al intercalation and extraction and good cycle stability. The chronopotentiometric plateaus in Al-Mo6S8 charge-discharge curves indicate phase-transition type of electrochemical reactions. In addition to the electrochemical analysis, XRD studies provide the crystallographic information of the Al intercalated Mo6S8. We conclude that the theoretical chemical formula of fully Al intercalated Mo6S8 is Al2Mo6S8 with Al occupying two different sites in the Mo6S8 crystal lattice. The theoretical material-level specific energy of the Al-Mo6S8 battery is approximately 90 Wh kg-1 (assuming 0.5 V nominal voltage), which makes this new rechargeable battery technology an attractive alternative for large-scale sustainable energy storage.

Optimization of Reaction and Substrate Activation in the Stereoselective Cross-Coupling of Chiral 3,3-Diboronyl Amides.

A method has been developed for the chemo- and stereoselective Suzuki-Miyaura cross-coupling of optically enriched gem-diboronyl compounds with various aryl bromides. Experimental evidence suggests that the Lewis acidity of the second boron group in these substrates plays a significant role in facilitating these otherwise challenging cross-coupling processes. β-Diboronyl esters may be successfully cross-coupled in excellent yield and enantiomeric excess with prior conversion of the pinacol boronate to the corresponding trifluoroborate salt. In contrast, a substrate bearing a Weinreb amide can undergo direct coupling of the Bpin moiety, likely due to the stronger coordination of the more basic amide carbonyl group. The resulting optically enriched secondary boronate may be used in a second enantioselective cross-coupling to afford pharmaceutically relevant diarylmethane products. The use of a Weinreb amide substrate allows for facile postcoupling modification, as demonstrated by a transformation to the corresponding ketone.

Human mining activity across the ages determines the genetic structure of modern brown trout (Salmo trutta L.) populations.

Humans have exploited the earth's metal resources for thousands of years leaving behind a legacy of toxic metal contamination and poor water quality. The southwest of England provides a well-defined example, with a rich history of metal mining dating to the Bronze Age. Mine water washout continues to negatively impact water quality across the region where brown trout (Salmo trutta L.) populations exist in both metal-impacted and relatively clean rivers. We used microsatellites to assess the genetic impact of mining practices on trout populations in this region. Our analyses demonstrated that metal-impacted trout populations have low genetic diversity and have experienced severe population declines. Metal-river trout populations are genetically distinct from clean-river populations, and also from one another, despite being geographically proximate. Using approximate Bayesian computation (ABC), we dated the origins of these genetic patterns to periods of intensive mining activity. The historical split of contemporary metal-impacted populations from clean-river fish dated to the Medieval period. Moreover, we observed two distinct genetic populations of trout within a single catchment and dated their divergence to the Industrial Revolution. Our investigation thus provides an evaluation of contemporary population genetics in showing how human-altered landscapes can change the genetic makeup of a species.

Cation Diffusivity and the Mixed Network Former Effect in Borosilicate Glasses

Understanding the structural origins of cationic diffusion processes in silicate glasses is important for high-tech applications of silicate glasses. For glasses with more than one network former, transport properties such as diffusivity are often nonlinear functions of the particular distribution of these network formers, a phenomenon known as the mixed network former effect. Here, we investigate the sodium-potassium interdiffusion (D̅Na-K) and the calcium inward diffusion (DCa) in soda lime borosilicate glasses with varying silica/borate ratio but constant modifier content. Indeed, the structural organization of borosilicate glasses results in a pronounced nonlinear composition dependence of D̅Na-K and DCa (i.e., the mixed network former effect). Initial addition of B2O3 to the glass system results in a significant decrease in both diffusivities, whereas the change in diffusivity per mole of added B2O3 decreases with increasing B2O3 concentration. Besides the influences of water content and atomic packing degree, we find that 99% of the composition dependence of log D̅Na-K can be ascribed to the change in concentration of tetrahedral boron groups. This indicates that the formation of BO4/2 groups slows down diffusion processes of alkali and alkaline earth ions. Therefore, the mixed network former effect of the studied glass series is linked with the change of the concentration of tetrahedral boron groups, which is caused by the interactions between the different types of network formers.

Ligand-controlled regiodivergent Cu-catalyzed aminoboration of unactivated terminal alkenes.

A ligand-controlled regiodivergent Cu-catalyzed aminoboration of unactivated terminal alkenes with diboron reagents and hydroxylamines has been developed. The xantphos-ligated CuCl complex guides the boron and amino groups to the terminal and internal positions, respectively. On the other hand, the opposite regioisomers are selectively obtained under the N-heterocyclic carbene-based IPrCuBr catalysis. The two Cu catalysts can readily transform simple and abundant terminal alkenes into highly valuable β-borylalkylamines regiodivergently.

Tuning into blue and red luminescence in dual-phase nano-glass–ceramics

A series of γ-Ga2O3 and β-YF3 nanocrystals embedded dual-phase glass ceramics co-doped with rare earth (Eu3+ or Tm3+) and transition metal (Cr3+) activators were successfully prepared by high-temperature melt-quenching to explore blue/red luminescent materials for potential application in photosynthesis of green plants. It is experimentally verified that Eu3+ (or Tm3+) ions partitioned into the crystallized orthorhombic YF3 nanophases, while Cr3+ ones entered into the precipitated cubic Ga2O3 nanocrystals after glass crystallization. Such spatial separation of the different active ions in the dual-phase glass ceramics can effectively suppress adverse energy transfers between rare earth and transition metal ions, resulting in their independent and efficient luminescence. As an example, it is experimentally demonstrated that both intense Tm3+ blue and Cr3+ deep-red emissions are easily achieved in the Tm3+/Cr3+ co-doped dual-phase glass ceramics.

The effects of borax on milk yield and selected metabolic parameters in Austrian Simmental (Fleckvieh) cows

This study was conducted to determine the effects of orally administered borax on milk yield and on several blood variables related to metabolism in early lactation in Austrian Simmental cows (Fleckvieh). Twenty primiparous cows were selected at parturition and then assigned to one of two groups, the control group or the borax group. The study lasted for four weeks. Borax was administered orally at 0.2 mg/kg/day (Boron group) to all treatment cows shortly after the noon milking, whereas cows in the control group were not treated. All cows consumed the same diet. All feeds in the diet were analysed for crude cellulose, protein, ether extract, ash, and dry matter according to the Weende Analysis Systems, in addition to ADF and NDF, according to Van Soest. Blood samples were collected from all cows via the vena jugularis on lactation Days 0, 7, 15, 21 and 28 and ana - lysed for the following: serum boron (B), non-esterified fatty acids (NEFA), beta-hydroxybutyric acid (BHBA), total cholesterol (TChol), high density lipids (HDL), total protein (TP), blood urea nitrogen (BUN), albumin (ALB), creatine (CRE), uric acid (UA), glucose (GLU), aspartate aminotransferase (AST), alanine aminotrans - ferase (ALT) and gamma-glutamyl transpeptidase (GGT) concentrations. Serum B concentration was higher in the borax group than in the control group at Weeks 1, 2, 3, and 4 of the experiment. Serum B concentration did not change in the control group during these weeks, but it gradually increased in the borax group week by week (P < 0.05). Borax administration increased serum TP and decreased the serum UA concentration at Week 4, and decreased serum HDL concentration at Week 3 of the experiment. Serum TChol, BHBA, and BUN concentrations increased ( < 0.05), while NEFA decreased ( P < 0.05) after parturition in both groups. The BHBA concentration gradually increased in the control group, but it began to decrease in the borax group during the final week of the experiment. Moreover, milk yield did not differ between the groups for 14 weeks. The results indicate that borax administration did not have any negative effects on the health of Austrian Simmental (Fleckvieh) cows during early lactation. However, studies of longer duration are needed to reveal the effectiveness of borax administration with respect to early lactation in cows.

Synthesis of Boron‐ and Silicon‐Containing Amino Acids through Copper‐Catalysed Conjugate Additions to Dehydroalanine Derivatives

AbstractA copper‐based catalytic technique for the regioselective hydroboration and hydrosilylation of dehydroalanine derivatives has been developed. This method introduces synthetically versatile boron and silicon groups, while simultaneously performing a catalytic anti‐Markovnikov hydrofunctionalization of dehydroalanines and dehydropeptides for the synthesis of amino acids and peptides bearing unnatural side‐chains. The products obtained were expediently converted into valuable nonproteinogenic amino acid building blocks for polypeptide synthesis.

Analysis and Prediction of Stacking Sequences in Intercalated Lamellar Vanadium Phosphates

AbstractAn approach is presented that enables the analysis and prediction of stacking sequences in intercalated lamellar vanadium phosphates. A comparison of previously reported vanadium phosphates reveals two modes of intercalation: (i) 3d transition metal ions intercalated between VOPO4 layers and (ii) alkali/alkaline earth metal ions between VOPO4·H2O layers. Both intercalations were investigated using DFT calculations in order to understand the relative shifts of the vanadium phosphate layers. These calculations in addition to an analysis of the stacking sequences in previously reported materials enable the prediction of the crystal structures of Mx(VOPO4)·yH2O (M = Cs+, Cd2+ and Sn2+). Experimental realization and structural determination of Cd(VOPO4)2·4H2O by single‐crystal X‐ray diffraction confirmed the predicted stacking sequences.

Facile and Effective Functionalization of Graphene Oxide by Boron–Oxygen Covalent or Bingel Cyclopropanation Reaction

Functionalized graphene oxide (GO-BPh2), was obtained via one step reaction between triphenyl boron and oxygen-containing groups on graphene sheets. In addition, functionalized graphene oxide (GO-Carbene) was obtained via bingel cyclopropanation reaction of active double bands on graphene sheets. Both functionalized materials can be homogeneously distributed into ortho-dichlorobenene. They were characterized by FTIR spectroscopy, UV Vis NIR spectroscopy, thermal gravimetric analysis, raman spectra, and X-ray photoelectron spectroscopy (XPS). FTIR, TGA and XPS results prove that phenyl boron has been successfully attached to the graphene sheets by covalent bonds. And the Raman spectra and XPS confirm that many carbon double bands changed into carbon single bands on graphene sheets after cyclopropanation reaction.