Adsorption of cadmium and lead from palm oil mill effluent using bone-composite: optimisation and isotherm studies

The adsorption of Cd and Pb ions from palm oil mill effluent on a mesoporous-activated cow bone composite powder has been investigated. Adsorbent was developed from cow bones, coconut shells and zeolite. The composite examined in the present work has a BET surface area of 248.398 m²/g. The optimisation of the removal efficiency of the heavy metals was investigated using central composite design and analysed using response surface methodology. The analysis of variance of the quadratic model signified that the model suitably predicted the uptake of the heavy metal ions at a 95% confidence level. The optimal operating condition was recorded at pH 4, 50 rpm, within 24 h and 1 mm of particle size and 12.5 gL^?1 of adsorbent dosage. The characteristics of the composite were investigated using the Fourier transform irradiation. The morphology and chemical composition of composite was examined using the scanning electron microscopy equipped with energy dispersive x-ray. Characterisation study was conducted before and after the adsorption process. The results obtained illustrated that the removal of cadmium and lead from POME was influenced by the functional groups available on the surface of the composite. The carboxyl and hydroxyl groups are mainly responsible for the removal of cadmium and lead through chelating process. The point of zero charge (pH_pzc) revealed that the adsorbent contained acidic sites with negatively charge surface which influenced the adsorption process. The experimental data of the heavy metals of Cd and Pb investigated were fitted to the Langmuir and Freundlich models. The result revealed that the adsorption equilibrium data fitted better to the Langmuir model for the adsorption Cd and to the Freundlich model for the adsorption of Pb.     

Unusual coupling constants n J(195Pt—1H) and Pt↼H—C interactions in new Schiff base complexes of N-alkyl-1-(ferrocen-1-yl)methanimine

A series of novel ferrocenylimine complexes of platinum(II) ethene of general formula trans-[PtCl₂( ²-C₂H₄) (imine)], imine = N-alkyl-1-(ferrocen-1-yl)methanimine, (alkyl = Me; i-Pr, i-Bu, s-Bu, t-Bu, ±CH(Me)Ph, CH₂Ph and Ph) have been prepared and characterized by elemental analysis, i.r, ¹H-, ¹³C-n.m.r. spectra (¹⁵N- and ¹⁹⁵Pt-n.m.r. in part). Unusual coupling constants ³ J(¹⁹⁵Pt—¹H), 92–98 Hz were observed between the imino proton H₆ and platinum(II) which are too large for three bond coupling constants, thereby suggesting a PtH—C interaction.     

Synthesis,characterization, inequivalency of methylene proton and proton lability in the amino ligand of trans-[dichloro[(N-ferrocenyl methyl)amine](eta2-ethene)platinum] complexes

A series of complexes of the type trans-[PtCl(2)(eta(2)-ethene)(N-ferrocenyl methyl)amine)] complexes, N-ferrocenylmethylamine=[(eta(5)-C(5)-H(5))Fe(eta(5)-C(5)-H(4)CH(2)NHR], R=(Me, Pr(i), Bu(s), Bu(t), CH(2)Ph, (p-OCH(3))Ph, (o-(OCH(3))Ph, (p-CH(3))Ph, (o-CH(3))Ph, (m-CH(3))Ph, (p-Cl)Ph) have been synthesized and characterized on the basis of elemental analysis, IR, 1H and 13C NMR spectroscopic methods. The CpCH(2)NHR (Cp=(eta(5)-C(5)H(5))Fe(eta(5)-C(5)H(4)), region of the 1H NMR spectrum of the complexes has been investigated and shown to contain inequivalent methylene protons, NH-CH and 195Pt-N-CH coupling take place.     

Chemiluminescence determination of iron(II) and titanium(III) by flow injection analysis based on reactions with and without luminol

Titanium(III) and iron(II) are shown to stimulate luminol chemiluminescence in the absence of added oxidant. Down to 10^?9 M titanium can be determined. Both metal ions also produce chemiluminescence when injected into 0.1 M carbonate buffer (pH 10.4), allowing >10^?6 M of each to be determined. The intensities are greater when the solutions have been deoxygenated by a stream of nitrogen, and when rhodamine B is used as a sensitizer.     

HPLC-DAD Based Polyphenolic Profiling and Evaluation of Pharmacological Attributes of Putranjiva roxburghii Wall.

The current study was intended to explore the phytochemical profiling and therapeutic activities of Putranjiva roxburghii Wall. Crude extracts of different plant parts were subjected to the determination of antioxidant, antimicrobial, antidiabetic, cytotoxic, and protein kinase inhibitory potential by using solvents of varying polarity ranges. Maximum phenolic content was notified in distilled water extracts of the stem (DW-S) and leaf (DW-L) while the highest flavonoid content was obtained in ethyl acetate leaf (EA-L) extract. HPLC-DAD analysis confirmed the presence of various polyphenols, quantified in the range of 0.02 ± 0.36 to 2.05 ± 0.18 μg/mg extract. Maximum DPPH scavenging activity was expressed by methanolic extract of the stem (MeOH-S). The highest antioxidant capacity and reducing power was shown by MeOH-S and leaf methanolic extract (MeOH-L), respectively. Proficient antibacterial activity was shown by EA-L extract against Bacillus subtilis and Escherichia coli. Remarkable α-amylase and α-glucosidase inhibition potential was expressed by ethyl acetate fruit (EA-F) and n-Hexane leaf (nH-L) extracts, respectively. In case of brine shrimp lethality assay, 41.67% of the extracts (LC₅₀ < 50 µg/mL) were considered as extremely cytotoxic. The test extracts also showed mild antifungal and protein kinase inhibition activities. The present study explores the therapeutic potential of P. roxburghii and calls for subsequent studies to isolate new bioactive leads through bioactivity-guided isolation.     

Proof of Positive Definiteness of FI and Extended Finite Element Tearing and Interconnecting XFETI

We propose a mathematical theorem to prove the positive definiteness of the term FI used in Finite Element Tearing and Interconnecting introduced by Farhat [1]. Furthermore, we introduce a new idea to extend FETI to include non-self adjoint operators emerging from, for example, elastoplastic large deformation, non-associative plasticity or when coupling BEM and FEM [2]. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

DFT,ADMET and Molecular Docking Investigations for the Antimicrobial Activity of 6,6′-Diamino-1,1′,3,3′-tetramethyl-5,5′-(4-chlorobenzylidene)bis[pyrimidine-2,4(1H,3H)-dione]

Heterocyclic compounds, including pyrimidine derivatives, exhibit a broad variety of biological and pharmacological activities. In this paper, a previously synthesized novel pyrimidine molecule is proposed, and its pharmaceutical properties are investigated. Computational techniques such as the density functional theory, ADMET evaluation, and molecular docking were applied to elucidate the chemical nature, drug likeness and antibacterial function of molecule. The viewpoint of quantum chemical computations revealed that the molecule was relatively stable and has a high electrophilic nature. The contour maps of HOMO-LUMO and molecular electrostatic potential were analyzed to illustrate the charge density distributions that could be associated with the biological activity. Natural bond orbital (NBO) analysis revealed details about the interaction between donor and acceptor within the bond. Drug likeness and ADMET analysis showed that the molecule possesses the agents of safety and the effective combination therapy as pharmaceutical drug. The antimicrobial activity was investigated using molecular docking. The investigated molecule demonstrated a high affinity for binding within the active sites of antibacterial and antimalarial proteins. The high affinity of the antibacterial protein was proved by its low binding energy (−7.97 kcal/mol) and a low inhibition constant value (1.43 µM). The formation of four conventional hydrogen bonds in ligand–protein interactions confirmed the high stability of the resulting complexes. When compared to known standard drugs, the studied molecule displayed a remarkable antimalarial activity, as indicated by higher binding affinity (B.E. −5.86 kcal/mol & Ki = 50.23 M). The pre-selected molecule could be presented as a promising drug candidate for the development of novel antimicrobial agents.     

Development and experimental investigation of a Quadrotor’s robust generalized dynamic inversion control system

Nonlinear Dynamics - The development of a two-loops Quadrotor’s robust generalized dynamic inversion (RGDI)-based control system is presented. The outer (position) loop utilizes PD position...     

Dipolar cycloaddition based multi-component reaction: Synthesis of spiro tethered acenaphthylene–indolizine–pyridinone hybrids

The stereoselective syntheses of novel dispiro acenaphthylene–indolizine–pyridinone hybrid heterocycles have been achieved through one-pot four-component domino 1,3-dipolar cycloaddition–Michael addition–air oxidation sequence of reactions.     

Determination of urinary methylhippuric acids using MIL-53-NH2 (Al) metal–organic framework in microextraction by packed sorbent followed by HPLC–UV analysis

For the analysis of methylhippuric acids (MHAs) in human urine samples, in this study, a new method based on the metal–organic framework (MOF) of MIL-53-NH₂ (Al) in microextraction by packed sorbent (MEPS) was developed. The synthesis of MIL-53-NH₂ (Al) was characterized by Fourier transform infrared spectra, field emission-scanning electron microscopy and X-ray diffraction. Response surface methodology was used to investigate the influences of several parameters including type and volume of elution, type of conditional solvent, sample volume and extraction cycle on MEPS efficiency. The results showed good recoveries (>94%) and excellent extraction efficiencies (>96%) at three different concentrations of 50, 500 and 1500 μg ml⁻¹ (as low, mid and high concentrations, respectively) of MHA isomers. Calibration curves of MHAs were linear over the concentration range of 1–1500 μg ml⁻¹, with high correlation coefficients (r ≥ 0.998). The reproducibility of the proposed MIL-53-MEPS for determination of three isomers of MHA was found to be in the range of 3.5–11.1%. After optimization of the proposed technique, it was used to analyze MHAs in urine samples of workers exposed to xylenes in a petrochemical plant in Asalouyah, Iran. The results indicated that the MOF–MEPS method was selective, sensitive, rapid and efficient for the extraction of urinary MHAs. The technique is also environmentally friendly and inexpensive, and the MOF sorbent is reusable.