Classical chemical sciences
Concrete admixtures can be prepared in various water samples such as rain water, well water, and sea water. These waters contain various types of ions. So corrosion behaviour of mild steel immersed in simulated concrete pore solution prepared with the above water samples will vary. Corrosion resistance of mild steel in simulated concrete pore solution prepared with above water samples has been evaluated by polarization study. The corrosion resistance of mild steel in various samples of water is as follows: Rain water>Well water>Sea water. The corrosion resistance of mild steel in simulated concrete pore solution prepared in various water samples are in the decreasing order: Rain water>Well water> Sea water. This is revealed by the linear polarization resistance values and corrosion current values.
Keywords: simulated concrete pore solution, mild steel, rain water, well water, sea water, polarization study.
Thymol (Thy) is a widely known anti-microbial agent and can be found as one of the components of many essential oils. Intermolecular charge-transfer complexes between the Thy as a donor and picric acid (PA), chloranilic acid (CLA), 1,3-dinitrobenzene (DNB) or pchloranil (p-CHL) as a -acceptor have been structurally and thermally studied in methanol at room temperature. Based on elemental analyses (CHN) and photometric titrations, the stoichiometry of the complexes (Thy: acceptor molar ratios) was determined to be 1:1 for all four complexes. The formation constant (KCT), molar extinction coefficient (CT) and other spectroscopic data have been determined using the Benesi–Hildebrand method and its modifications. The newly synthesized CT complexes have been characterized via elemental analyses (CHN), IR, 1H-NMR, and electronic absorption spectroscopy. Thermogravimetric analyses (TG) were also used to investigate the thermal stability of the synthesized solid CT complexes.
Keywords: Thymol, Charge-transfer, Benesi–Hildebrand method, Thermal analysis
The aims of the review are the collection, concise description and evaluation of the multivariate mathematical-statistical methodologies used for the elucidation of the similarities and dissimilarities among retention parameters measured under various chromatographic conditions and the determination of the relationship between the physicochemical parameters and chromatographic retention behaviour of solutes.
Keywords: multivariate regression; retention behavior, retention-structure relationships
The extraction of Ni(II) ions in aqueous media was studied using chloroform solution of N,N’-ethylenebis(4-butanoyl-2,4-dihydro-5- methyl-2-phenyl-3H-pyrazol-3-oneimine) (H2BuEtP) Schiff base as the organic extractant. The synergistic effect of 4-butanoyl-2,4- dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one (HBuP) in these extractions were also investigated. The pH½ of extraction of Ni(II) was significantly lowered from a near neutral pH 7.14 ± 0.10 to an acidic region of 5.51 ± 0.10 when a mixture of the ligands was used. The partition coefficient (log KDNi1) 1.89 ± 0.05 (H2BuEtP) was same as (log KDNi2) 1.89 ± 0.02 (H2BuEtP-HBuP) while the extraction constant (log KexNi1) -12.39 ± 0.64 (H2BuEtP) was slightly less than (log KexNi2) -10.57 ± 0.10 (H2BuEtP-HBuP). Data analysis indicated that Ni(II) distributed slightly better into chloroform solution of H2BuEtP/HBuP as Ni(HBuEtP)(BuP)(o) than into a solution of H2BuEtP as Ni(HBuEtP)2(o) . Mineral acids show a masking effect in the extractions in both ligand alone and mixed ligands systems while mixed ligands system was shown to be a better extractant system for Ni(II) ions in the presence of anions and auxiliary complexing agents studied. Acetate, fluoride, and phosphate ions gave the best percentage extractions and the extraction of Ni(II) ions with the ligand is more efficient at near neutral to basic pH
Keywords: Extraction, Nickel(II), N,N’-Ethylenebis(4-butanoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one imine), Effect of pH and anions
Materials and environmental chemistry
Using participant observation and appraisal methods, the present study shows that with traditional knowledge, technologies and practices, a significant quantity of household waste was diverted away from the landfill and transformed into organic compost for use by farmers with the possibility of improving existing carbon sinks and reducing net CO2 emissions.
Keywords: composting; traditional technologies, practices and knowledge; climate change mitigation
The potential to remove Chromium (VI) from aqueous solutions through sorption using powder of calcined brick (PCB) was investigated using batch tests. The influence of physico-chemical key parameters such as the initial metal ion concentration, agitation time and the particle size of adsorbent have been considered in batch tests. The optimum results were determined at an initial metal ion concentration was10 mg L-1, agitation time – 60 min, and the particle size ( 0.6 mm). The % adsorption, Lagergren rate constant (Kad (min-1)=6.60 x 10-2 for Cr(VI)10 mg L-1) were determined for the adsorption system as a function of sorbate concentration . The kinetic data obtained were fitted to pseudo first order model.
Keywords: Adsorption, Cr (VI) ions, powder of calcined brick, Particle size, Adsorption Kinetics, Langmuir Lagergren rate constant.
Biochemistry, molecular biology and biotechnology
The essential oils from seeds and stem-bark of Monodora myristica (Annonaceae) growing wild in south western Nigeria and used as spice in many parts of Nigeria were extracted by hydrodistillation and analysed by GC- MS. The percentage yields of oils were 2.16%v/w and 0.25%v/w, respectively. The essential oil of seeds contained germacrene D-4-ol (25.48%), tricyclo[5.2.1(1,5)dec-2-ene (13.35%), δ- cadinene (11.09%) and linalool (15.10%) as major constituents while the dominant constituents of the stems-bark oil were γ-cadinene (31.31%), α-elemene (17.98%), α-cubebene (6.70%) and γ-muurolene (5.94%). The major constituents of the seeds oil of Monodora myristica from Nigeria were compared based on literature.
Keywords: Essential oil; Monodora myristica; Hydrodistillation; Nigeria
Plantain (Plantago lanceolata L.) is a popular medicinal plant for its beneficial effect for respiratory and other antiinflammatory diseases. As the metal ions have significant role in inflammatory processes and antiinflammatory effect, the element content of plantain drug and in extracts has been determined. Element content in drug and different extracts (decoctum and infusum) was measured by inductively plasma optical emission spectrometry (ICP-OES) after nitric acid digestion. Most of the elements in drug had average concentration, except Al, Ba, Ca, S, Sn, Sr and Ti concentration that crossed their average level. Significant difference was found in the concentration of Al, Ba, Ca, Co, Cu, Fe, K, Mg, Mn, Na, S, Sr and V between decoctum and infusum. In most cases concentration of elements was evidently higher in decoctum samples, than in infusum. In conclusion decoctum is a richer source of elements than that of other extracts and generally these teas are relevant sources for several elements (Ca, Co, Cu, K, Mn).
Keywords: plantain, decoctum, infusum, essential elements.
Industrial and engineering chemistry
The productivity and demand of wax in the world market has been reviewed. The production and consumption of wax, candle and ranking of manufactures in the world market have also been discussed. The production capacity and importance of quantity of Chinese wax have also been a matter of evaluation. The complete development of wax products has resulted in good economic and social benefits around the world.
Keywords: overview; wax production; requirement, world market
Radiochemistry and isotopes
This paper represents synthesis of a new family of a fluoride-free Fe-Biotite type compound having the general formula NaFe2.5(Al,Si)4O10 (OH)2. It was prepared carefully by using solid- state reaction technique with nominal compositions of individual oxides in the main formula for the potential remediation of heavy metals and some radioactive elements from applying solution. The structural and micro-structural properties were determined using both XRD, SEM and IR techniques. The particle size estimated was 56 nm. Further electron spin resonance (ESR) proved that Fe-biotite is paramagnetic in nature, electrical conductivity was measured as a function of absolute temperature, while the thermal stability of the samples were studied using thermogravimetry (TG). Analytical applications were done by using (AAS). Investigations proved that synthetic fluoride-free Fe-biotite has medium of strong efficiency as cation selective clay towards metals under test.
Keywords: biotite, heavy metals, uranium, thorium, removal, fluoride-free , wastewater