Magnetic Susceptibility Methods Research Articles

The Pleistocene ice-sheet dynamics in north-central Poland based on magnetic fabrics of tills and landform analysis

Abstract This research was carried out in north-central Poland, which was occupied by the ice sheet of the Saalian (Marine Isotope Stage [MIS] 6) and Upper Stadial of the Weichselian (MIS 2) glaciation. The application of the anisotropy of magnetic susceptibility (AMS) method supported by a digital elevation model (DEM) analysis of the orientation of glacial landforms allowed for the reconstruction of ice-sheet extent and ice movement directions of these two Pleistocene glaciations. The research used an innovative method of collecting AMS till samples from the glacial plateau areas. Based on the research, it was found that during the general recession of the ice sheet of the Saalian glaciation, a previously undescribed glacial transgression occurred, characterized by a different direction of ice-sheet movement. On the basis of detailed geomorphological studies of the area of terminal moraines, previously described in fragments, the maximum extent of the ice sheet during the Weichselian glaciation was clarified. The recession of the ice sheet of the Weichselian glaciation from the area of north-central Poland took place in four regressive or transgressive–regressive stages with variable directions of ice-sheet movement. The results obtained indicate the great potential of the AMS method in paleoenvironmental studies of glaciated areas.

Synergetic impact of dual substitution on anionic–Cationic activity of P2-type sodium manganese oxide

P2-type sodium-deficient cathodes with the local Na–O–A configuration (A=Li, Mg, Zn, and vacancy) have attracted great interest due to their high capacity, stemming from the additional contribution of the oxygen-redox chemistry. However, such materials suffer from irreversible oxygen redox, oxygen release, structural distortion, and capacity fading. Herein, we introduce a dual-doping Li/Cu strategy to improve the properties of P2-NaxMnO2 cathode material. The unique sodium-storage mechanism in P2-Na0.75[Li0.15Cu0.15Mn0.7]O2 is verified using operando X-ray diffraction (o-XRD), X-ray absorption, X-ray photoelectron spectroscopy, and magnetic susceptibility methods. O-XRD and 7Li solid-state nuclear magnetic resonance analysis reveal that the P2 phase is maintained within charge and discharge; however, at high voltage, a small portion of O-type stacking faults are emerged due to the migration of Li to octahedral Na sites. Furthermore, various spectroscopy and magnetometry techniques combined with density functional theory calculation demonstrate the stable activity of cationic Cu2+/Cu3+ and Mn3+/Mn4+ and anionic O2−/(O2)n− redox processes. This work highlights the efficacy of Li and Cu doping in P2-type layered materials and the contribution of oxygen redox to additional capacity at high voltages, suggesting the potential for future development of cathode materials for Na-ion batteries with oxygen redox.

Rheological context of emplacement of the Dori, Gorom-Gorom and Touka Bayèl granitic plutons (northeast Burkina Faso, West African Craton)

The reconstitution of the geodynamic processes of the Eburnean orogeny in the time span around 2.1 Ga in Dori area is here carried out through the examination of the internal structures and microstructures of the Dori, Gorom-Gorom and Touka Bayèl granitic plutons. The radiometric ages of these plutons vary between 2164 Ma and 2148 Ma. The internal structures have been evidenced using the Anisotropy of Magnetic Susceptibility (AMS) method and the examination of microstructures through thin sections under optical microscope.The organization of the internal fabrics strongly suggests a diapiric emplacement for the Dori and the Touka Bayèl plutons in a still soften crust. The pluton of Gorom-Gorom seems to be constituted of four small plutons. Three of them, coalescent in the southern part, are emplaced by the diapirism and the fourth in the northern part can be interpreted as emplaced in a tension gash.The overall disposition of the fabrics lets suggest a synchronous emplacement in accordance with the dextral sense of the Tiébélé-Dori-Markoye (TDM) shear zone in a regional E-W shortening context responsible of a crustal thickening.The two emplacement mechanisms (diapirism and tension gash) identified through the internal fabrics testify a rheological contrast of the crust during this early period of the Eburnean Orogeny.

Spatio-temporal variability of seawater mixing in the coastal aquifers based on hydrogeochemical fingerprinting and statistical modeling

This study discusses monitoring and characterization of spatial and temporal variability to comprehend groundwater salinization based on hydrogeochemical fingerprinting and statistical modeling in the coastal belt of Digha-Shankarpur-Tajpur-Mandarmani, West Bengal, India. An integrated study of hydrogeochemical, bulk magnetic susceptibility, multivariate statistical, and geochemical modeling methods is implemented. The major cationic and anionic concentrations in groundwater are in the order Na+ > Ca2+ > Mg2+ > K+ and Cl− > HCO3− > SO4− > NO3− > F− respectively. The major water types are dominated by (Ca2+ – HCO3−) followed (Ca2+ - Mg2+ - Cl−), (Ca2+ - Na+ - HCO3−), (Na+ - HCO3−), and (Na+ - Cl). The results showed that the groundwater quality continuously declined steadily from pre-monsoon 2020 to pre-monsoon 2022. The deterioration of groundwater is due to an interplay of multiple factors, i.e., water-rock interaction, including ion-exchange, seawater mixing, and anthropogenic actions. Furthermore, it is also found that the regions showing higher seawater mixing index and oversaturated with carbonate minerals are also areas where groundwater is unsuitable for irrigation. The findings are beneficial in assisting local communities and legislators in designing appropriate management and mitigation techniques to arrest seawater intrusion in coastal regions.

Magnetic Mineral Consistency Analysis the main ingredients of cement and Rowmix materials with Magnetic Susceptibility Method using Bartington Magnetic Susceptibility Type B (MS2B)

Cement has hydraulic properties (mixed with water) will form a bond and harden. Cement-making materials consist of the main ingredients (Limestone, Iron Sand, Silica, and Clay) which are the ingredients in the manufacture of Rowmix in the Rowmill. In the main ingredient there is a magnetic mineral content for the manufacture of Component Compoun. To see changes in magnetic minerals from the cement manufacturing process, it is necessary to analyze the consistency of the material until the initial manufacture. The purpose of this study was to determine the consistency of the magnetic mineral as the main ingredient of cement in the Rowmix manufacturing process. The research method used is rock magnetism using a Bartington Susceptibility Meter Type B (MS2B) which can measure based on mass and volume with 2 different frequencies, namely Low Frequency and High Frequency. This measurement uses 6 different samples, namely the main ingredients of cement (Limestone, Irond Sand, Silica, Clay) and Rowmix materials (Rowmix 1 (RX1) and Rowmix 2 (RX2). From these measurements, the susceptibility values obtained from the main ingredients including Limestone approx. 23.7 x 10−8 m3/kg - 46.6 x 10−8 m3/kg, Irond Sand ranged from 470 x 10−8 m3/kg - 1791.1 x 10−8 m3/kg, Clay ranged from 852.7 x 10−8 m3/kg - 986.4 x 10−8 m3/kg, Silica ranges from 148.2 x 10−8 m3/kg - 166.9 x 10−8 m3/kg, while in Rowmill I process (Rx1) around 133, 4 x 10−8 m3/kg - 180.3 x 10−8 m3/kg, Rowmill 2 (Rx2) 133.4 x 10−8 m3/kg - 244.2 x 10−8 m3/kg, Magnetic susceptibility values in the main material range from 1532 x 10−8 m3/kg up to 2838,6 x 10−8 m3/kg, while the value of Rowmix 1 (RX1) and Rowmill 2 (Rx2) is lower than the magnetic susceptibility value of the main ingredient.

Analysis of the geothermal formation mechanisms in the Gonghe Basin based on thermal parameter inversion

Gonghe Basin is the most critical distribution area of hot dry rock (HDR) geothermal resources in China. Geophysical results (resistivity, velocity, density, etc.) provide an indirect way to image the spatial distribution to understand its genesis, which has a multisolution problem. However, heat flow and thermal conductivity are the most direct and reliable evidence to reveal the distribution of geothermal resources. The conventional thermal conductivity and heat flow obtained based on geologic surveys and rock samples are highly accurate, but it is challenging to characterize the regional distribution characteristics. In this paper, we develop the heat transfer adaptive finite-element equation parameter inversion workflow to invert the thermal parameters and analyze the geothermal formation mechanisms in the Gonghe Basin. First, the synthetic model test verifies that our inversion process has reliable accuracy and strong antinoise ability. For the Gonghe Basin HDR geothermal example, we use high-precision aeromagnetic data to estimate the Curie depth using the improved Parker-Oldenburg method. Then, the regional conductivity thermal and temperature field can be established according to the empirical formula as the initial input model for the inversion procedure. In addition, we collect the temperature data of six HDR geothermal wells across the Gonghe-Guide Basin as a priori constraint information. Combined with the inverted thermal parameters (thermal conductivity, geothermal gradient, and heat flow), geologic structure, and geophysical result, we infer that the high thermal conductivity layer at a depth of 5–10 km provides the main deep heat source channel and the shallow low thermal conductivity fine sandstone layer of Neogene provides good caprock protection for forming a high-temperature geothermal reservoir.

Z-scan and degenerate four wave mixing studies on newly synthesized copper complexes of curcumin

Designing novel metal complexes with high nonlinear optical (NLO) susceptibilities is a special interest for coordination compounds. They include a wider selection of metals with a variety of ligands and oxidation states, which can result in tuneable electronic capabilities. Paramagnetic Copper (II) complexes of curcumin were synthesized using different metal precursors and keeping curcumin as the base ligand. All the complexes were characterized by elemental analysis, magnetic susceptibility, and spectroscopic methods (UV–vis, FT-IR, ESR, and mass spectrometry). Nonlinear optical transmission measurements were carried out using nanosecond laser pulses with 532 nm wavelength, via a Z-scan and Degenerate four-wave mixing (DFWM) techniques. CuAcCur, CuClCur, and CuThCur complexes provided with 1.34 × 1024, 3.61 × 1024, and 4.05 × 1024 m3/W2, proved that these complexes possess excellent NLO properties and CuThCur being best among them. The NT dropped from 100 % to 78 %, 65 %, and 75 % in CuAcCur, CuClCur, and CuThCur respectively, showing that all the complexes have great potential for optical limiting (OL) application. The Conceptual-Density-Functional-Theory (CDFT) were employed to perform the theoretical analyses of complexes. Calculations on the various CDFT-based parameters such as electronegativity, HOMO-LUMO energy gap, molecular hardness, softness, dipole moment, and electrophilicity index of both species are performed. This work introduces three copper complexes with curcumin that show an excellent NLO and OL behavior.

New mixed‐ligand thioether‐quinoline complexes of nickel(II), cobalt(II), and copper(II): Synthesis, structural elucidation, density functional theory, antimicrobial activity, and molecular docking exploration

The main purpose of the current work is the design and synthesis of new Co(II), Ni(II), and Cu(II) mixed‐ligand complexes derived from simple and easily synthesized azo‐ligand, [2‐(phenylthio)phenyl]diazenyl}‐2‐naphthol (HTe), with 8‐hydroxyquinoline (HQ) to improve and understanding their action as an antimicrobial candidate and their therapeutic efficiency with the aid of density functional theory (DFT) calculations and molecular docking studies, which considered a hot topic of research. To access this target, and to explore the effect of changing metal ion type, the new Co(II), Ni(II), and Cu(II) mixed‐ligand complexes were firstly synthesized and characterized via elemental analysis, Fourier transform infrared (FT‐IR), mass spectrometry, ultraviolet–visible spectroscopy, magnetic susceptibility, thermogravimetric analysis (TGA), and stoichiometry analysis molar ratio method. Upon further inspection, the octahedral structures of the isolated metal complexes were found. The compounds' molecular structures were optimized using the DFT technique, and the quantum chemical parameters were evaluated. To determine whether or not these compounds are effective in preventing the spread of harmful bacteria and fungi, two of the most common environmental pollutants in the Arab world, a disc diffusion test was conducted. The prepared complexes were much more efficient against bacteria than the pristine ligands. Molecular docking experiments helped researchers learn which medicines inhibited the 1fj4 protein. All other tested compounds were found to have lower binding affinities than CuTeQ. This suggests that these compounds have the potential as starting points for the production of new classes of antibiotics. Finally, a correlation of the in vitro activity with the DFT and molecular docking data has been done and discussed.

Ru(II) and Ru(III) complexes containing N‐acylthiourea ligands: Supramolecular structures and synthons, reduction, and reaction pathway of aromatic nitro compounds

Four ruthenium complexes {[RuCl(CO)(PPh3)2L1], [RuCl(CO)(PPh3)2L2], [RuCl2(PPh3)2L1] and [RuCl2(PPh3)2L2]} supported with N‐acylthiourea‐based ligands were synthesized. The compounds prepared were characterized by 1H NMR, 13C NMR, elemental analysis, UV–vis, and magnetic susceptibility methods. The characterization of the molecular structure of two ruthenium complexes {[RuCl(CO)(PPh3)2L1] and [RuCl2(PPh3)2L1]} was also performed using the single crystal X‐ray diffraction method. Single crystal X‐ray analyses indicates the existence of different non‐covalent interactions between different parts of the molecules, which led to the formation of three‐dimensional supramolecular architectures and synthons. The magnetic susceptibility and UV‐vis spectra of the prepared ruthenium complexes propose that they are of low‐spin states, where Ru(II) is d6 and Ru(III) is d5 low spin. These ruthenium compounds functioned as catalysts for the NaBH4‐mediated reduction of various nitro compounds. The catalytic results show that the [RuCl2(PPh3)2L] type complexes exhibit higher catalytic activity than the [RuCl(CO)(PPh3)2L] type complexes, and [RuCl2(PPh3)2L1] has high catalytic selectivity and efficiency in a short time (>99 yield with catalyst loading 0.01 mol in 0.5 h). Furthermore, the catalytic activity of [RuCl2(PPh3)2L1] was investigated using nitrobenzene as a model substrate to understand the reaction pathway, and this study proved that this nitro reduction proceeds via a direct pathway, with the formation of N‐hydroxylamine as the main intermediate followed by the occurrence of aniline.

Investigation of heavy metal contamination and ecological and health risks in farmland soils from southeastern phosphate plateaus of Khouribga (Morocco)

The present study was conducted in the SE area of phosphate plateaus (Khouribga) located in central Morocco. It attempted to assess the heavy metal (HM) (Cd, Cr, Cu, Pb, Zn) contamination in the farmland soils and their potential ecological hazard and non-non-carcinogenic risks using various pollution indices, magnetic susceptibility (MS), and Geographical Information System (GIS) methods. A total of 41 soil samples were collected and analyzed for pH, electrical conductivity (EC), grain-size, organic matter (OM), calcium carbonate (CaCO3), and MS and HM elements. The results showed a mean dominance order of Zn>Cr>Cu>Pb>Cd where mean concentrations of HMs, except Pb, exceeded their local background and Food and Agriculture Organization (FAO) and World Health Organization (WHO) permissible guidelines. The values of geo-accumulation index (Igeo), nemerow pollution index (PI), and pollution load index (PLI) revealed significant high level of HM contamination in soils. The MS values showed a spatial distribution pattern similar to those of HMs, attesting the ability of the MS method for mapping the contaminated soils. Agricultural and mining activities and geologic materials were the main sources of HM accumulation. According to the potential ecological risk index (RI) (195.93<RI<1092.53), the soil samples had moderate (65.85%) to high ecological (34.15%) risk. The hazard index (HI) showed that adults and children are not exposed to non-carcinogenic risk from the studied HMs, apart from two soil samples where Cd posed health risks to children compared to the other studied HMs. The statistical results revealed that soils are polluted by anthropogenic activities. Accordingly, effective agricultural practices that respect the environment, including the reduction of inputs as fertilizers, pesticides, herbicides, and fungicides should be required to guarantee the safety of cropland and the residents in the studied area. Hence, the findings from this study provided some useful information for soil pollution control and management in the study area.

High-Temperature Spin Crossover in Iron(II) Complexes with 2,6-Bis(1H-imidazol-2-yl)pyridine

Novel iron(II) coordination compounds containing a ligand 2,6-bis(1H-imidazol-2-yl)pyridine (L), having such a composition as [FeL2]SO4·0.5H2O, [FeL2]Br2·H2O, [FeL2](ReO4)2, [FeL2]B10H10∙H2O, [FeL2]B12H12∙1.5H2O had been synthesized and studied using UV-Vis (diffuse reflectance), infrared, extended X-ray absorption fine structure (EXAFS), and Mössbauer spectroscopy methods, as well as X-ray diffraction and static magnetic susceptibility methods. The analysis of the μeff(T) dependence in the temperature range of 80–600 K have shown that all the obtained complexes exhibit a high-temperature spin crossover 1A1 ↔ 5T2.

Novel Copper(II) Complexes with Dipinodiazafluorene Ligands: Synthesis, Structure, Magnetic and Catalytic Properties.

The reactions of CuX2 (X = Cl, Br) with dipinodiazafluorenes yielded four new complexes [CuX2L1]2 (X = Cl (1), Br (2), L1 = (1R,3R,8R,10R)-2,2,9,9-Tetramethyl-3,4,7,8,9,10-hexahydro-1H-1,3:8,10-dimethanocyclopenta [1,2-b:5,4-b’]diquinolin-12(2H)-one) and [(CuX2)2L2]n (X = Cl (3), Br (4), L2 = (1R,3R,8R,10R,1’R,3’R,8’R,10’R)-2,2,2’,2’,9,9,9’,9’-Octamethyl-1,1’,2,2’,3,3’,4,4’,7,7’,8,8’,9,9’,10,10’-hexadecahydro-1,3:1’,3’:8,10:8’,10’-tetramethano-12,12’-bi(cyclopenta [1,2-b:5,4-b’]diquinolinylidene). The complexes were characterized by IR and EPR spectroscopy, HR-ESI-MS and elemental analysis. The crystal structures of compounds 1, 2 and 4 were determined by X-ray diffraction (XRD) analysis. Complexes 1–2 have a monomeric structure, while complex 4 has a polymeric structure due to additional coordinating N,N sites in L2. All complexes contain a binuclear fragment {Cu2(μ-X)2×2} (X = Cl, Br) in their structures. Each copper atom has a distorted square-pyramidal coordination environment formed by two nitrogen atoms and three halogen atoms. The Cu-Nax distance is elongated compared to Cu-Neq. The EPR spectra of compounds 1–4 in CH3CN confirm their paramagnetic nature due to the d9 electronic configuration of the copper(II) ion. The magnetic properties of all compounds were studied by the method of static magnetic susceptibility. For complexes 1 and 2, the effective magnetic moments are µeff ≈ 1.87 and 1.83 µB (per each Cu2+ ion), respectively, in the temperature range 50–300 K, which are close to the theoretical spin value (1.73 µB). Ferromagnetic exchange interactions between Cu(II) ions inside {Cu2(μ-X)2X2} (X = Cl, Br) dimers (J/kB ≈ 25 and 31 K for 1 and 2, respectively) or between dimers (θ′ ≈ 0.30 and 0.47 K for 1 and 2, respectively) were found at low temperatures. For compounds 3 and 4, the magnetic susceptibility is well described by the Curie–Weiss law in the temperature range 1.77–300 K with µeff ≈ 1.72 and 1.70 µB for 3 and 4, respectively, and weak antiferromagnetic interactions (θ ≈ −0.4 K for 3 and −0.65 K for 4). Complexes 1–4 exhibit high catalytic activity in the oxidation of alkanes and alcohols with peroxides. The maximum yield of cyclohexane oxidation products reached 50% (complex 3). Based on the data on the study of regio- and bond-selectivity, it was concluded that hydroxyl radicals play a decisive role in the oxidation reaction. The initial products in reactions with alkanes are alkyl hydroperoxides.

Preliminary Investigation of Soil and Sediments Using Magnetic Susceptibility Method in Kogi State, Nigeria

Over the years, there has been significant increase in population and urbanization in Kogi State as a result of rural - urban migration. This has become a major threat to soil sustainability which is a natural non-renewable resource. The aim of this research is to carry out magnetic susceptibility mapping on the surface and subsurface soil of Kogi State using environmental magnetism techniques and geochemical analysis. The susceptibility test on rock samples and background soil samples within the study area shows an average of about 112.0 × 10^-5 SI. The magnetic susceptibility measurement on soil from Kogi State shows magnetic susceptibility enhancement of about (450.0 - 700.0) × 10^-5 SI. These values were dominant along the major towns, road pavements and commercial areas at the surface to a depth of about 50.0 cm in soil profiles. The 2D spatial distribution of magnetic susceptibility with depth reveals that these magnetic grains are distributed in the subsurface as a result of anthropogenic loading. The frequency-dependence of magnetic susceptibility (χfd%) values are very low (2 - 10.0 %) in most of the areas on the surface soil. These values indicate that the magnetic properties are predominantly contributed by the coarse multi-domain (MD) and stable single-domain (SSD) grains of anthropogenic origin. Atomic Absorbtion Spectrometer (AAS) analysis of these soil samples indicates the presence of Lead (300.0 - 900.0) mg/l and Cadmium (20.0 - 60.0) mg/l in large concentration at the surface soil in most part of the Kogi State. While Chromium show relatively low concentration on the surface soil. From the statistical correlation analysis, Lead and Cadmium show high positive correlation with magnetic susceptibility. These results suggests that the high enhancement of magnetic susceptibility on the surface and sub-surface soil in most part of Kogi State arise from anthropogenic activities rather than lithological and pedogenic processes and most likely cause by high concentration of Lead and Cadmium.

The Research on the Complexity of 1T-TaS2 at Ultra-low Temperatures

Graphene, as a successfully industrialized two-dimensional material, has greatly promoted the development of other two-dimensional materials, such as transition metal dichalcogenide (TMDs). 1T-TaS2 is a classical TMDs material, which presents metallicity at high temperature. It undergoes a variety of charge density wave (CDW) phase transitions during the temperature declining process, and presents insulating properties at low temperature. During the temperature rise period, 1T-TaS2 goes through a phase transition, from an energy band insulator to Mott insulator, followed by an insulation-metal phase transition. The complexity of 1T-TaS2 phase diagram encourages researchers to conduct extensive research on it. This paper, via means of resistance, magnetic susceptibility and other technical methods, finds out that the ultra-low temperature of 1T-TaS2 suggests additional complexity. In addition, with the angle resolved photoemission spectroscopy (ARPES) technique of in-situ alkali metal evaporation, this paper proposes that the 1T-TaS2 ultra-low temperature ground state may exist a combination of state and surface state. Our findings provide more experimental evidence for the physical mechanism of this system.

Spin crossover in iron(II) complexes with new ligand 2,6-bis(4,5-dimethyl-1H-imidazole-2-yl)pyridine

Iron(II) coordination compounds containing a new ligand, 2,6-bis(4,5-dimethyl-1H-imidazol-2-yl)pyridine (L), of composition [FeL2](NO3)2·H2O (1·H2O), [FeL2](ClO4)2·0.5H2O (2·0.5H2O), [FeL2]SO4·0.5H2O (3·0.5H2O), or [FeL2](ReO4)2·2H2O (4·2H2O) have been synthesized and studied by UV–vis (diffuse reflectance), infrared, extended X-ray absorption fine structure (EXAFS), and Mössbauer spectroscopies, as well as X-ray diffraction and static magnetic susceptibility methods. The structure of a copper(II) complex with L of composition [CuL2]SO4·3H2O has been successfully determined. The analysis of the μeff(T) dependence in the temperature range of 80–520 K showed that complexes [FeL2](NO3)2·H2O, [FeL2](ClO4)2·0.5H2O, and [FeL2](ReO4)2·2H2O and their dehydrated counterparts are subject to high-temperature spin crossover 1A1 ↔ 5T2.

Studies of Mixed Ligand Lanthanum Complexes: Synthesis, Spectral Interpretations and Antibacterial Study

The mixed ligand lanthanum complexes have been synthesized using polydentate ligands. The (2Z)-2-(N-hydroxyimino)-1,2-diphenylethan-1-ol (cupron) was used as a primary ligand and L-isolucine, L-threonine, L-lysine and L-glycine were used as secondary ligands for the synthesis. Conductometry, elemental analysis, magnetic susceptibility measurements, complexometric estimation, UV-Visible spectroscopy, FTIR spectroscopy, thermal analysis and XRD methods were used for structural interpretation of all synthesized complexes. All complexes were solid and white and slight yellow in colour. They are non-electrolytic and diamagnetic in nature, as confirmed by conductometric and magnetic susceptibility methods respectively. All the complexes were synthesized by combination of lanthanum metal ion, primary ligand and secondary ligands in 1:2:1 ratio which was confirmed by elemental analysis. During reaction between lanthanum ion, primary ligand and secondary ligands there was transition of electrons which was confirmed by UV-Visible spectroscopy. Identification of functional group in the complexes was carried out and confirmed by FTIR spectroscopy. The decomposition temperature and thermal behaviour of the complexes have been concluded by thermal and XRD techniques. Tube dilution and agar cup methods have been employed to study antibacterial activities of all synthesized lanthanum complexes. The inhibition potential was seen to some extent.

Potentially toxic elements in fen peatland soils located near lignite-fired power plants in Central Poland

The Grójec Valley (GV) peatland area in Central Poland is located close to lignite-fired power plants, which could be sources of potentially toxic elements (PTE). The aims of this study are: (1) to determine the effect of the lignite-fired power plants on soil pollution, (2) to evaluate pollution indices and magnetic susceptibility methods for determining the origin and distribution of PTE in soils, and (3) to demonstrate the importance of appropriate geochemical background (GB) selection for pollution studies in peatland soils. In order to comprehensively assess the soil pollution, four pollution indices (calculated using various types of GBs), and the mass-specific magnetic susceptibility method were used. The low content of analyzed PTE (Cd, Cr, Cu, Ni, Pb, Zn), the calculated pollution indices, and the magnetic susceptibility values (overall >20 × 10−8 m3 kg−1) indicated generally low pollution levels in the studied soils. This would suggest that power plants have had a minor impact on the fen soils, although exceptions were observed in the southernmost part of GV, the highest content of Cr (6.87–9.11 mg kg−1), Ni (7.11–10.3 mg kg−1) and Cu (14.1–19.5 mg kg−1). In addition, based on the Potential Ecological Risk (RI) and Contamination Security indexes (CSI), this area showed the highest potential ecological risk (81.9–102) and limit of toxicity (0.59–0.67) among the studied plots, respectively. The Enrichment factor (EF) and Contamination Security index (CSI) values were the most comparable, thus we consider that, in combination with magnetic susceptibility measurements, they comprise a useful set of tools for fen soil contamination studies. Furthermore, we suggest the application of an local organic GB (i.e. PTE content in the deeper organic layer) in such studies.

Silica-Supported Fe(II), Co(II) and Ni(II) Complexes as Efficient Catalysts to Esterification of Levulinic acid with Polyol

Biomass-derived feedstocks were used to synthesize a new polyol-based ester for biolubricant production to overcome the dependence on mineral oil. Although biomass-derived oil is a potential alternative to polyol ester, upgrading is inevitable before using it as a biolubricant. Levulinic acid (model acid), obtained from a bio oil, was used for the esterification of two polyols, for example, neopentyl glycol (NPG) and trimethylolpropane (TMP), in the presence of ligand metal Fe(II), Co(II), and Ni(II) complexes as catalyst. Silica-supported Fe(II), Co(II) and Ni(II) complexes viz. [Fe(Tyr)(Amp)]Cl·SiO2, [Co(Phe)(Bpy)]Cl·SiO2 and [Ni(Leu)(Phen)]Cl·SiO2 were synthesized by the reaction of ligands [L-phenylalanine (Phe), L-tyrosine (Tyr), L-leucine (Leu), 4,4′-bipyridine (Bpy), 2-aminopyridine (Amp) and 1,10-phenanthroline (Phen)] with respective metal(II) chloride salts. All the metal complexes were characterized by elemental analysis, magnetic susceptibility, TGA/DTA, FTIR, powder-XRD and SEM methods. The catalytic activities of the complexes were further investigated via esterification of two polyols (e.g. neopentyl glycol and trimethylolpropane) by biomass-derived levulinic acid (LA). Herein, iron(II) complex was found to be more active, demonstrating its better efficiency as a catalyst towards the esterification of levulinic acid for synthesizing ester-based oils.

Dielectric and magnetic properties, NEXAFS spectroscopy of Co-doped of multicomponent bismuth niobate pyrochlore

Two series of Bi2Mg1-xCoxNb2O9 and Bi2MgNb2-2xCo2xO9-δ preparations with pyrochlore structure were synthesized using solid phase method. It was found that solid solutions are formed in Bi2MgNb2-2xCo2xO9-δ series, foreign phases of MgNb2O6 and Bi5Nb3O15 are fixed in Bi2Mg1-xCoxNb2O9 samples, no impurity cobalt-containing phases were detected. The method of magnetic susceptibility and NEXAFS-spectroscopy investigated the electronic state and character of exchange interactions of cobalt atoms in solid solutions with the pyrochlore structure. According to X-ray spectroscopy and magnetic susceptibility of cobalt atoms in solid solutions in a dominant amount are in the charge state of Co(II) in the form of monomers and exchange-bound clusters mainly with antiferromagnetic type of exchange. Ceramics Co-doping of multicomponent bismuth niobate pyrochlore has at room temperature a high dielectric permeability of 84 and small dielectric losses of 0.001. The energy of activation of conductivity is equal to 0.75–1.03 eV. This type of ceramics with excellent dielectric properties can potentially be used as multilayer ceramic capacitors.

The use of magnetic susceptibility and chemical analysis data for characterizing heavy metal contamination of topsoil in Denizli city, Turkey

Denizli is one of the most rapidly growing cities in Turkey having experienced fast urban and industrial development in the last decades, engendering a serious threat to the environment and the population health. Therefore, this study used the magnetic susceptibility method to evaluate the contamination degree of most parts of Denizli city. X-ray fluorescence (XRF) analysis was performed on samples chosen from different parts of the study area to identify the quantity and origins of the heavy metals present in the study area corresponding to the magnetic susceptibility measurements. Multivariate statistical analysis such as Cluster analysis (CA) and the principal component analysis (PCA) was performed for the best understanding of the relationship between heavy metal contamination, magnetic susceptibility measurements and XRF analysis results. The environmental status of the study area was evaluated by the aid of elaboration and interpretation of the contamination factor (CF), geoaccumulation index (Igeo), Enrichment factor (EF) and the pollution load index (PLI) which allowed the comparison between the different polluted parts of the study area. The results obtained as maximum values from the calculation of the contamination factor were found as follows: Fe (30.98), Cr (25.86), Ni (14.71), Zn (9.24), Cu (7.96), Pb (5.86). The mean values obtained for the implemented geoaccumulation index were found for each element as follow; Fe (4.39), Cr (4.12), Ni (3.29), Cu (2.44), Pb (2.01) Zn (2.62) while the enrichment factor's results were found as follow Fe (11.80), Cr (11.07), Ni (5.90), Cu (3.87), Pb (2.71) Zn (4). The average value of the pollution load index reflects the heavy pollution of the study area by reaching a value of 7.7. The contour maps plotted for the distribution of heavy metals concentration and magnetic susceptibility measurement showed similar pollution degrees in the city industrial zone and near the main highway (Antalya Highway), which passes through the city. This high heavy metal load gradually decreases toward the city borders. Furthermore, the content of heavy metal and the PLI are notably positively correlated with the magnetic susceptibility measurements. Overall, results testify to the effectiveness of the magnetic susceptibility method for applications in determining environmental contamination caused by heavy metals.