Modeling and Analysis of Seawater Intrusion in the Coastal Aquifer of Eastern Cap-Bon, Tunisia

A numerical model that treats density-dependent variably saturated flow and miscible salt transport is used to investigate the occurrence of seawater intrusion in the Korba aquifer of the eastern coast of Cap-Bon in northern Tunisia. We examine the interplay between pumping regimes and recharge scenarios and its effect on the saline water distribution. More localized simulations are used to examine, in vertical cross sections, the effects of well location and soil type and the role of the vadose zone in possible remediation actions. The exploratory simulations suggest interesting interactions between the unsaturated zone and the saltwater–freshwater interface with possible implications for groundwater exploitation from shallow unconfined coastal aquifers, involving in one case feedback between seawater intrusion and the high pressure head gradients around the pumping-induced drawdown cone and in another case threshold-like interface displacement for tight soils such as clays. The data processing steps undertaken in this GIS and modeling study are described in some detail, and a critical assessment is given of the data availability and of the requirements for successful monitoring and modeling of seawater intrusion risks in heavily exploited coastal aquifers such as those found in the semi-arid regions of the Mediterranean basin. It is shown how, with the aid of GIS, reasonably reliable information can be assembled from maps, surveys, and other sources of geospatial and hydrogeological data, an approach that is necessary in the many regions of the world with acute water resource problems but with limited means for undertaking systematic data acquisition and environmental monitoring actions. Nonetheless the need for more concerted monitoring of relevant parameters and processes and of closer coordination between monitoring and modeling is stressed. An idea of the extent of over-exploitation of the Korba aquifer is obtained by examining the pumping and rainfall/infiltration data, and the simulation results support groundwater pumping as the mechanism for and seawater intrusion as the origin of the salt contamination observed in the soils and subsurface waters of the Korba plain.     

Complete NMR assignments of bioactive rotameric (3 → 8) biflavonoids from the bark of Garcinia hombroniana

The genus Garcinia is reported to possess antimicrobial, anti‐inflammatory, anticancer, hepatoprotective and anti‐HIV activities. Garcinia hombroniana in Malaysia is used to treat itching and as a protective medicine after child birth. This study was aimed to isolate the chemical constituents from the bark of G. hombroniana and explore their possible pharmacological potential. Ethyl acetate extract afforded one new (1) and six (2–7) known 3 → 8 rotameric biflavonoids. Their structures were elucidated by UV, IR and NMR (1D and 2D) spectroscopy together with electron ionization/ESI mass spectrometric techniques and were identified as (2R, 3S) volkensiflavone‐7‐O‐rhamnopyranoside (1), volkensiflavone (2), 4″‐O‐methyl‐volkensiflavone (3), volkensiflavone‐7‐O‐glucopyranoside (4), morelloflavone (5), 3″‐O‐methyl‐morelloflavone (6) and morelloflavone‐7‐O‐glucopyranoside (7). The absolute configuration of compound 1 was assigned by circular dichroism spectroscopy as 2R, 3S. The coexistence of conformers of isolated biflavonoids in solution at 25 °C in different solvents was confirmed by variable temperature NMR studies. At room temperature (25 °C), compounds 1–7 exhibited duplicate NMR signals, while at elevated temperature (90 °C), a single set of signals was obtained. Compound 5 showed significant in vitro antioxidant activities against 1,1‐diphenyl‐2‐picrylhydrazyl and 2,2′‐azino‐bis‐3‐ethyl benzthiazoline‐6‐sulfonic acid radicals. The antibacterial studies showed that compounds 5 and 6 are the most active against Staphylococcus aureus, Bacillus subtilis and Escherichia coli. Compounds 3 and 6 also showed moderate antituberculosis activity against H₃₈Rv. Based on the research findings, G. hombroniana could be concluded as a rich source of flavanone–flavone (3 → 8) biflavonoids that exhibit rotameric behaviour at room temperature and display significant antioxidant and antibacterial activities. Copyright © 2014 John Wiley & Sons, Ltd.     

Elemental Analysis of Stone Fruits by Inductively Coupled Plasma Mass Spectrometry and Direct Mercury Analysis

This study reports the concentrations of eight trace essential (Zn, Mn, Cu, Ni, Cr, Co, V, and Se) and four toxic elements (Pb, As, Cd, and Hg) in commonly consumed stone fruits from South Korea. The samples were digested by microwave-induced combustion and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The concentrations of mercury were analyzed by direct mercury analysis (DMA). The analytical techniques were validated by linearity, limits of detection and quantification, precision, recovery, and for accuracy by analyzing a spinach leave-certified reference material; satisfactory results were obtained in all cases. The concentrations of essential trace elements varied considerably among the stone fruits. Generally stone fruits contained comparatively high concentrations of Zn (0.946 to 7.86?µg/g) and Mn (below the limit of detection to 1.66?µg/g), while lower contents of Cu (0.214 to 1.24?µg/g), Cr (0.032 to 0.114?µg/g), Ni (0.006 to 0.091?µg/g), Co (0.004 to 0.016?µg/g), V (below the limit of detection to 0.023?µg/g), and Se (0.0002 to 0.005?µg/g) were obtained. The concentrations (µg/g) of toxic metals were 0.007 (peach) to 0.016 (cherry) for Pb, 0.001 (plum) to 0.007 (cherry) for As, 0.002 (apricot and cherry) to 0.003 (peach) for Cd, and 0.0003 (peach) to 0.0016 (jujube) for Hg. The values for the estimated dietary intakes, target hazard quotients, and hazard indices were lower than the recommended safety limits by World Health Organization. Therefore, the analyzed stone fruits were deemed to be safe for human consumption.     

Spectroscopic study of BixEu1−xVO4 and BiyGd1−yVO4 mixed oxides

The mixed oxides Bi_xEu_1−xVO₄ and Bi_yGd_1−yVO₄ crystallize in a zircon-type structure, for 0 <x < 0.6 and 0 < y < 0.64, and in a fergusonite-type structure, for 0.94 < x < 1 and 0.93 < y < 1. A process of competition between the dominant and the constrained effects of the lone-pair 6s² of Bi³⁺ is discussed. The diffuse reflectance spectroscopic studies of these mixed oxides are presented. The observed broad bands are attributed to charge transfer processes and the sharp peaks in the Bi_xEu_1−xVO₄ spectra are ascribed to intra-configurational 4f – 4ftransitions of the Eu³⁺ ion. The broad absorption shift in BiLnVO₄ (Ln : Eu and Gd) compounds to the longer wavelengths range, when Bi is introduced in the LnVO₄ lattice, is ascribed to charge transfer processes in a Bi-VO₄ center and are interpreted assuming a Jahn-Teller effect in the excited state of Bi³⁺. The concept of an internal pressure of Bi³⁺ ions is also used to explain the broad A-band shifts.     

Deformed C λ-Extended Heisenberg Algebra in Noncommutative Phase-Space

We construct a deformed C _λ-extended Heisenberg algebra in two-dimensional space using noncommuting coordinates which close an algebra depends on statistical parameter characterizing exotic particles. The obtained symmetry is nothing but an exotic particles algebra interpolating between bosonic and deformed fermionic algebras. PACS numbers: 03.65.Fd, 02.40.Gh, 05.30.Pr     

Synthesis of hedychenone, yunnancoronarins and aframodial derivatives

Starting with larixol, syntheses of furan and 1,4-enedial labdane-type diterpenes are presented, which has enabled a preparation of hedychenone (20% yield).     

Quonic realization of the deformed Heisenberg-Weyl algebra

A consistent realization of an operatorial deformed Heisenberg-Weyl (HW) algebra is given. The explicit construction of the deformation matrix is discussed. The corresponding generalized Fock-like space is analyzed.     

A bioactive cycloartane triterpene from Garcinia hombroniana

The dichloromethane bark extract of Garcinia hombroniana yielded one new cycloartane triterpene; (22Z,24E)-3β-hydroxycycloart-14,22,24-trien-26-oic acid (1) together with five known compounds: garcihombronane G (2), garcihombronane J (3), 3β acetoxy-9α-hydroxy-17,14-friedolanostan-14,24-dien-26-oic acid (4), (22Z, 24E)-3β, 9α-dihydroxy-17,14-friedolanostan-14,22,24-trien-26-oic acid (5) and 3β, 23α-dihydroxy-17,14-friedolanostan-8,14,24-trien-26-oic acid (6). Their structures were established by the spectral techniques of NMR and ESI-MS. These compounds together with some previously isolated compounds; garcihombronane B (7), garcihombronane D (8) 2,3’,4,5’-tetrahydroxy-6-methoxybenzophenone (9), volkensiflavone (10), 4’’-O-methyll-volkensiflavone (11), volkensiflavone-7-O-glucopyranoside (12), volkensiflavone-7-O-rhamnopyranoside (13), Morelloflavone (14), 3’’-O-methyl-morelloflavone (15) and morelloflavone-7-O-glucopyranoside (16) were evaluated for cholinesterase enzymes inhibitory activities using acetylcholinesterase and butyrylcholinesterase. In these activities, compounds 1–9 showed good dual inhibition on both the enzymes while compounds 10–16 did not reasonably contribute to both the cholinesterases inhibitory effects.     

Discrimination of Chili Powder Origin Using Inductively Coupled Plasma–Mass Spectrometry (ICP-MS), Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP-OES), and Near Infrared (NIR) Spectroscopy

This study investigated the content of macronutrients (Ca, K, Mg, Na, P, and S), trace elements (Ba, Be, Co, Cr, Cu, Fe, Ga, Li, Mn, Ni, Rb, Se, Sr, V, and Zn), and trace toxic elements (As, Cd, In, Pb, and Tl) in chili powder from Korea, China, and Vietnam. For the analyses, inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectroscopy (ICP-OES) were used. In addition, near-infrared (NIR) spectroscopy was used to differentiate functional groups based on the chemical constituents. For the validation of the applied analytical methods, good linearity (coefficients of determination, 0.9443–0.99997), and relative standard deviations below 4% were obtained. The contents of the toxic elements were below the provisional tolerable weekly intake values. Linear discriminant analysis using elemental contents and NIR data was performed to establish and authenticate the geographical origin of chili powder, which confirmed the reliability of the obtained results.     

Estrogen fluoroimmunoassay with a fluorimeter designed for low-intensity light detection

A small, highly sensitive, inexpensive fluorimeter for the detection of very low fluorescence intensities for analytical and clinical purposes is described. High sensitivity is achieved by use of an inexpensive continuous wave laser with a power of a few milliwatts. The optical arrangement of the instrument has been thoroughly designed so that the effects of Rayleigh and Raman scattering are minimized. Fluorescence is dected through optical filters with a side-on photomultiplier. Concentrations of rhodamine B in ethanol as low as 10^?11 M can be measured. To use this instrument for a fluoroimmunoassay of urinary estrogens (10^?9?10^?7 M), a purified monoclonal IgG, raised against estradiol, was labelled with RITC (rhodamine isothiocyanate) in a 1:1 molar ratio. It was possible to measure IgG-RITC concentrations between 10^?9 and 10^?10 M with good accuracy and reproducibility.