Use of chemometrics methods and multicriteria decision-making for site selection for sustainable on-site sewage effluent disposal

This paper presents a study undertaken to evaluate site suitability for sewage effluent renovation based on physico-chemical characteristics of the soil. The results obtained showed that as the soil becomes acidic, the phosphorus concentration in the soil reduces accordingly. The chloride ion concentration was found to be a reliable indicator for evaluating the soil capacity to remove nitrogen. A high cation exchange capacity (CEC) can enhance the renovation of sewage effluent. Soils with high quartz content had a low CEC with high organic matter content (OM) being able to compensate. Therefore, an understanding of the micro-nutrients in the soil, organic matter content and chloride ion concentration are important.To facilitate a multi-variate approach for site selection, multicriteria decision-making (MCDM) methods, PROMETHEE and GAIA, were applied for analysis of a sequence of three matrices consisting of 8, 16, and 48 soil site objects, respectively, and seven soil property parameters. Matrix models and the interpretation of results are discussed in detail. From these analyses, PROMETHEE II net outranking flows, ?, found that two sites were always among the top three ranks of the three matrix models, which suggested that they were the most suitable for sewage effluent renovation. The criteria CEC and OM, were particularly important for the selection of these better sites, but pH and Cl⁻ attributes discriminated the weaker performing sites from the better ones; as well the PO₄³⁻ and the NH₃-N criteria were in general opposition to CEC, OM, pH and Cl⁻ but were much less effective as discriminators. Consideration of net outranking flows suggested an approach method for the selection of other possibly suitable sites for sewage effluent renovation.     

New tetraaza macrocyclic complexes of palladium(II) and platinum(II) formed by the self-condensation of 5-amino-3-methyl-1-phenylpyrazole-4-carbaldehyde in the presence of metal ions. α-Amino ether and carbinolamine derivatives of the macrocyclic Schiff base metal complex

The self-condensation of 5-amino-3-methyl-1-phenylpyrazole-4-carbaldehyde (AMPC) in the presence of Pd^II and Pt^II ions yields the Pd^II and Pt^II complexes, [M(TAAP)]Cl₂, of the fully cyclized tetradentate macrocyclic ligand tetrapyrazolo[1,5,9,13]tetraazacyclohexadecine, (TAAP). Metathetical displacement of the chloride has led to isolation a series of complexes of the type [M(TAAP)]X₂, (X=I, ClO₄ and BF₄), the formulation of which is supported by elemental analysis, molar conductance and magnetic susceptibility measurements, and i.r. and u.v.–vis. spectra. Spectroscopic and other analytical results reveal that the complexes have square-planar stereochemistry with four donor nitrogen atoms coordinated to the metal ion in a planar array. The reaction which produces this new cyclic ligand is assumed to include the metal ion acting as a template for the condensation. Thus the probable mechanistic implications for the coordination template hypothesis are discussed to explain the formation of these new macrocyclic chelate compounds. Both Pd^II and Pt^II complexes appear to be sensitive to nucleophilic attack at the methine carbon, which is reversible upon acidification. The reaction of [Pt(TAAP)]²⁺ or [Pd(TAAP)]²⁺ with MeO^- or EtO^- ions results in the formation of partially solvolysed inner complexes containing two ionized -amino ether functions, stabilized by the macrocyclic chelate ring. Attempts to prepare discrete -carbinolamine derivatives were unsuccessful.     

Synthesis and characterization of new polyhydrazides based on 2,5-bis(mercapto-acetichydrazide)-1,3,4-thiadiazole moiety

New interesting class of novel polyhydrazides containing 1,3,4-thiadiazole moieties in the main chain was synthesized. A solution polycondensation technique was used in the synthesis of these polymers. The new monomer namely: 2,5-bis(mercapto-acetichydrazide)-1,3,4-thiadiazole III was synthesized from the nucleophilic replacement of 2,5-dimercapto-1,3,5-thiadiazole I with ethylchloroacetate, followed by hydrazinolysis. The model compound VII was synthesized from the monomer 2,5-bis(mercapto-acetichydrazide)-1,3,4-thiadiazole III with benzoyl chloride and characterized by ¹H- NMR, IR, and elemental analyses. The polyhydrazides were synthesized from the polymerization of monomer III with 4,4^′-biphenic, 3,3^′-azodibenzoyl, 4,4^′-azodibenzoyl dichlorides. These polymers were characterized by elemental and spectral analyses, viscometry and solubility. The thermal properties of these polymers were determined by thermal gravimetric analyses, and differential thermal analysis, and correlated with their structure. The crystallinity of some polymers was tested by X-ray analyses.     

Thermolysis of 3-phenyl-5-arylamino-1,2,4-oxadiazole and thiadiazole derivatives

Thermal reactions of 3-phenyl-5-arylamino-1,2,4-oxadiazoles I and II were investigated. Neat heating at ca. 250°C for 6 hours afforded H₂O, benzonitrile, arylcyanamides, arylamines, azobenzene, benzimidazole derivatives, and 3,3′-diphenyl-5,5′-bis[1,2,4-oxadiazolyl]. Analogous results were obtained by the thermolysis of 3-phenyl-5-anilino-1,2,4-thiadiazole III at ca. 200°C for 2 hours. In addition to H₂S, NH₃, and HNCS, phenyl isothiocyanate and thiocarbanilide were obtained. Thermolysis of III in quinoline as a radical trap gave analogous resuLts but also 2-anilinoquinoline. A free-radical mechanism has been suggested to account for the identified products. © 1997 John Wiley & Sons, Inc.     

Synthesis and antiviral activity of new substituted pyrimidine glycosides

A number of N‐substituted pyrimidine glycosides were synthesized by coupling reaction of the pyrimidine base with acetobromosugars followed by deprotection. The synthesized compounds were tested for their antiviral activity against Hepatitis B Virus (HBV). Plaque reduction infectivity assay was used to determine virus count reduction as a result of treatment with tested compounds which showed moderate to high anti viral activities. J. Heterocyclic Chem., (2011).     

Ternary Inclusion System of Chair Conformation of 4,6,10,12,16,18,22,24-Octahydroxy-2,8,14,20-tetraphenyl-resorcin[4]arene: Selective Green Synthesis,Supramolecular Behavior,and Biological Activity

Calix[4]resorcinarenes form different types of structural conformations. When their methylene carbons are substituted by four phenyl groups, the molecule can adopt both chair and cone conformations depending on the reaction temperature. The solvent-free synthesis of 4,6,10,12,16,18,22,24-octahydroxy-2,8,14,20-tetraphenyl-resorcin[4]arene led to the formation of chair conformer (C_2h) rather than the cone conformer forming a ternary inclusion complex upon crystallization from wet DMSO. The solid state structure of the ternary inclusion system was determined by single-crystal X-ray diffraction and proved that the host has adopted the chair conformation. The supramolecular interactions in the crystal structure of the solvated compound were carefully investigated. Studies on antimicrobial activities showed that the compound inhibited the growth of Gram-positive bacteria.     

Flow and heat transfer characteristics of drag reducing surfactant solution in a helically coiled pipe

The reduction characteristic of turbulent drag and heat transfer of drag reduction surfactant solution flowing in a helically coiled pipe were experimentally investigated. The drag reduction surfactant used in the present study was the amine oxide type nonionic surfactant of oleyldihydroxyethylamineoxide (ODEAO, C₂₂H₄₅NO₃=371). The zwitterion surfactant of cetyldimethylaminoaciticacidbetaine (CDMB, C₂₀H₄₁NO₂=327) was added by 10% to the ODEAO solution in order to avoid the chemical degradation of ODEAO by ionic impurities in a test tape water. The experiments of flow drag and heat transfer reduction were carried out in the helically coiled pipe of coil to pipe diameter ratio of 37.5 and the helically coiled pipe length to pipe diameter of 1180.5 (pipe diameter of 14.4 mm) at various concentrations, temperatures and flow velocities of the ODEAO surfactant solution. The ODEAO solution showed a non-Newtonian behavior at high concentration of the ODEAO. From the experimental results, it was observed that the friction factor of the ODEAO surfactant solution flowing through the coiled pipe was decreased to a great extent in comparison with water as a Newtonian fluid in the turbulent flow region. Heat transfer measurements for water and the ODEAO solution were performed in both laminar and turbulent flow regions under the uniform heat flux boundary condition. The heat transfer coefficients for the ODEAO solution flow were the same as water flow in the laminar region. On the other hand, heat transfer reduction of the ODEAO solution flow was remarkedly reduced as compared with that of the water flow in the turbulent flow region.     

Dielectric properties and microstructural characterization of cubic pyrochlored bismuth magnesium niobates

Cubic bismuth pyrochlores in the $\mathrm{Bi}_{2}\mathrm{O}_{3}$ –MgO– $\mathrm{Nb}_{2}\mathrm{O}_{5}$ system have been investigated as promising dielectric materials due to their high dielectric constant and low dielectric loss. Here, we report on the dielectric properties and microstructures of cubic pyrochlored $\mathrm{Bi}_{1.5}\mathrm{MgNb}_{1.5}\mathrm{O}_{7}$ (BMN) ceramic samples synthesized via solid-state reactions. The dielectric constant (measured at 1 MHz) was measured to be ${\sim}120$ at room temperature, and the dielectric loss was as low as 0.001. X-ray diffraction patterns demonstrated that the BMN samples had a cubic pyrochlored structure, which was also confirmed by selected area electron diffraction (SAED) patterns. Raman spectrum revealed more than six vibrational models predicted for the ideal pyrochlore structure, indicating additional atomic displacements of the A and $\mathrm{O}'$ sites from the ideal atomic positions in the BMN samples. Structural modulations of the pyrochlore structure along the [110] and [121] directions were observed in SAED patterns and high-resolution transmission electron microscopy (HR-TEM) images. In addition, HR-TEM images also revealed that the grain boundaries (GBs) in the BMN samples were much clean, and no segregation or impure phase was observed forming at GBs. The high dielectric constants in the BMN samples were ascribed to the long-range ordered pyrochlore structures since the electric dipoles formed at the superstructural direction could be enhanced. The low dielectric loss was attributed to the existence of noncontaminated GBs in the BMN ceramics.     

Giant magnetoimpedance in thin amorphous and nanocrystalline microwires

We present the results on Giant magneto-impedance effect (GMI) in amorphous and nanocrystalline microwires at frequencies until 4 GHz, paying special attention to tailoring the frequency and magnetic field dependence of the GMI effect. Correlation between magnetoelastic anisotropy and magnetic field dependences of diagonal and off-diagonal impedance components are observed.     

Fullerene‐β‐Cyclodextrin Conjugate Based Electrochemical Sensing Device for Ultrasensitive Detection of p‐Nitrophenol

The article describes the use of a fullerene (C₆₀)‐β‐cyclodextrin conjugate, synthesized via 1,3‐dipolar cycloaddition, for the ultrasensitive electrochemical detection of p‐nitrophenol. This conjugate was successfully immobilized on the surface of a glassy carbon electrode and the developed device showed high activity towards p‐nitrophenol due to the synergetic effect of C₆₀, the latter becoming highly conductive upon reduction. The determination of p‐nitrophenol was performed by using square wave voltammetry over a concentration range from 2.8×10^?9 mol L^?1 to 4.2×10^?7 mol L^?1 and the detection limit was calculated to be 1.2×10^?9 mol L^?1.