Applied Chemistry

A new semi organic nonlinear optical crystal, L-Alanine potassium nitrate has been synthesized and good optical quality single crystals were grown by slow evaporation technique. The growth conditions of the crystals are studied and the grown crystals are confirmed by powder X-ray diffraction studies. The grown crystal was characterized by using powderedXRD, FT-IR, UV–Vis–NIR, EDAX, and TG–DTA. The sharp peaks from powdered XRD spectrum shows high crystalinity of the grown crystal. The presence of various functional groups was confirmed by FT-IR spectroscopic technique. The UV–Vis–NIR spectrum indicates that the crystal has very good absorption in the entire visible and near IR region spectrum suggesting the suitability of the material for NLO applications. The decomposition temperatures and mass loss have been estimated from the thermo gravimetric analysis. The presence of potassium in the compound and composition of grown crystals was confirmed on the basis of energy dispersive analysis of X-ray (EDX).

The resin SHMF has been synthesized by the condensation of salicylicacid and hexamethylenediamine with formaldehyde and hydrochloric acid as catalyst. Thermal degradation curve has been discussed which shows four decomposition steps and detailed thermal degradation studies of the resin have been carried out to ascertain its thermal stability. Sharp–Wentworth and Freeman–Carroll methods have been used to calculate activation energies and thermal stability. The activation energy (Ea) calculated by using the Sharp–Wentworth (17.86 kJ/mol) has been found to be in good agreement with that calculated by Freeman–Carroll (18.96 kJ/mol) method. Thermodynamic parameters such as free energy change (?F), entropy change (?S), apparent entropy change (S*) and frequency factor (Z) have also been evaluated on the basis of the data of Freeman–Carroll method. The order of reaction (n) is found out to be 0.99. Electrical conductivity measurements have been also conceded to ascertain the semiconducting nature of the resin.

Proximate and polycyclic aromatic hydrocarbon (PAH) compositions were analyzed in raw and smoked samples of two exotic fish species; mackerel (Scomber scombrus) and horse mackerel (Trachurus trachurus) obtained from a local market in Umuahia, Nigeria. The fish were procured in triplicate and split into two equal parts. One part was analyzed raw while the other was smoked with firewood before analysis. Moisture content was higher in the raw samples compared to their corresponding smoked samples. Crude protein was higher in horse mackerel samples for both raw and smoked categories while other parameters were generally higher in mackerel. Horse mackerel had the higher value of 44.784 mg/kg for total mean PAH (?mPAH) but PAH4 (sum of the four indicators of PAH contamination; benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene and chrysene) was similar in raw mackerel and horse mackerel. Mean BaP concentrations were higher than the EU limits (2 µg/kg) while PAH4 values were within the EU limit (12 µg/kg) in raw samples of both species. For the smoked samples, Mean BaP concentrations and mean PAH4 exceeded the EU maximum limits in the muscle of smoked fish and public health authorities are urged to take appropriate action.

Metal- ligand complexation in solutions was studied in water-methanol media by pH-metric titration with the standard glass electrode at ionic strength of 0.1M KNO_3. The titrations were carried out at various temperatures 35^oC, 45^oC, and 55^oC and the pKa values (stability constants) were determined. Copper (II) with benzimidazole gave pKa’s of 2.86, 2.52, and 2.46; Stability constant (logK) 338.80, 331.13 and 288.40 while Nickel (II) benzimidazole gave pKa’s 2.51, 2.60 and 2.38 and Stability constant (logK) 323.59, 398.11 and 239.85 respectively.  It was revealed that the stability constants of the metal complexes decreased as the temperature increases. Formation constants obtained for these complexes showed that metal- ligand ratio were in the range of 1:1 and 1:2. The thermodynamic parameters were also determined at the working temperatures and the results obtained showed negative ?H and Gibb’s free energy (?G) indicating exothermic and spontaneous reactions.

In arid and semi arid area, irrigation is very essential for successful agriculture. Quality of irrigation water is an important factor of crop production .Whatever may be the source of irrigation water, some soluble salts are always dissolved there in these are mostly sodium, calcium, magnesium and some time potassium as cations and chloride , carbonate, and bi-carbonate as anions. Salinity hazard which is associated with high soluble salts in water and measured in terms of electrical conductivity (EC), water having an EC value of more than 2.25m.mhos/cm² is always unsafe for irrigation use. The alkali hazard is related to the development of alkalinity in the soil and is expressed as SAR Residual Sodium Carbonate is an indirect expression of CO3^-2 and HCO3^-1 of Na⁺in ground water. Based on the RSC value the irrigation water are classified in conclusion.

The proximate, mineral, vitamins and phytochemical compositions of a sample of pili fruit kernel have been investigated. The result revealed low values of ether extract (12.77±0.3%), crude fibre (4.72 ±0.2 %) and a very low crude protein value of 3.94 ±0.002.. It has a high value of carbohydrate (65.91±0.7%). The calculated metabolizable energy value (1659.94KJ/100g) shows that pili fruit kernel flour is a good source of energy. The pili fruit kernel has high values of the essential mineral elements: sodium (158 mg/100g), potassium (513 mg/100g), calcium (230 mg/100g), magnesium (365 mg/100g) and phosphorus (131 mg/100g) as well as the trace elements: iron (229.75 mg/kg), zinc (72.01 mg/kg), copper (121.75 mg/kg) and manganese (156.25 mg/kg).These values indicate that pili fruit kernel is a very rich (good) source of dietary minerals. The Ca/P (1.75) and Na/K (0.308) ratios have favorable health implications. The pili fruit kernel sample has high values of vitamin A (455.1mg/kg), niacin (8.50mg/kg), riboflavin (5.50 mg/kg) but low values of thiamin (1.25 mg/kg), vitamin C (8.60 mg/100g) and vitamin E (8.98mg/100g). The pili fruit kernel sample has high values of alkaloid (3.94±0.008%), flavonoid (4.82±0.003%) but low values of saponin (0.62±0.05%) , tannin (0.28 ±0.001 mg/100g), cyanogenic glycoside as HCN (0.52±0.002mg/kg) , phytate (0.02±0.0007%) and trace amount of trypsin inhibitor.

Functional properties and anti-nutritional factors of five wild seeds (Borassus aethiopum, Bombacopsis glabra, Entada africana, Entada gigas and Myrianthus arboreus) were carried out using standard methods. Functional properties of` the flour showed that the least gelation concentration for B. aethiopum, B. glabra, E. africana and M. arboreus were 10%, 6% 6% and 18% respectively. E. gigas flour however did not gel at 20%. B. aethiopum had the least foaming capacity 1.85% while B. glabra had the highest 27.27 %. Water absorption capacity ranged between 3.00% in M. arboreus and 30.0% in E. africana. Oil absorption capacity was between 13.00 % in M. arboreus and 22.00% in E. africana. Protein solubility increased with increase in pH in acidic medium and reached the peak at pH 7 (E africana exempted) before solubility began to decrease with further increase in pH at alkaline medium. Antinutrient content showed that saponin ranged between 0.29% in E .africana and 0.42% in B. glabra. Phytate was between 0.14mg/g in E. africana and 6.56mg/g in E. gigas. E. gigas had tannin content of 0.45mg/g, while M. arboreus had 4.87mg/g , B. aethiopum had the lowest oxalate 2.25mg/g while M. arboreus had the highest of 7.19mg/g.

Organotin compounds have attracted global attention due to their extensive use for agricultural, industrial, medicinal, and domestic applications. These applications have made them enter the environment. This has caused environmental concerns due to the proven toxicological relevance of the compounds. Their toxic effects result in extensive damage to non-target organisms at ultratrace concentration levels (ppt) and accumulation in sediments and biota. This leads to the legislative restriction place on the uses of some of these compounds. Despite the legislative restriction, their environmental pollutions continue. Hence, this review which is aimed at providing an overview of the application of organotin compounds and their environmental toxicities.

A copper complex of the type [Cu(Phen)(L-Tyr)(TSC)](ClO4), where Phen = 1,10 Phenanthroline, Tyr = Tyrosine and TSC = Thiosemicarbazide, was synthesised and characterised by elemental analysis, IR, conductivity measurement and EPR studies. DNA-binding properties have been studied by electronic absorption, emission, viscosity and cyclic voltametric methods. The results suggest that the copper(II) complex bind to DNA via different modes. Gel electrophoresis study reveals the fact that the copper complex cleaves super coiled pBR 322 DNA to nicked and linear forms in the presence and absence of ascorbic acid. The in vitro antimicrobial study indicates that the complex has good activity against gram positive, gram negative bacteria and fungus.

The effects of stress ratio on the fatigue crack propagation of the 6061 T6 alloy aluminum with a thickness of 5 mm were investigated at room temperature. The fatigue crack growth rates were studied at stress ratios of 0.1with stress range, Ds=80 MPa using centre cracked-tension specimen M (T). The results are expressed in term of crack tip stress intensity factor range that was derived from linear elastic theory. From the collected data, the fatigue crack growth versus stress intensity factor range was plotted. It was obtained that the overall stress intensity factor range is within 6 to 19.5 MPaÖ m, and the value of fatigue crack growth rate is within 10^-7 to 10^-3 mm/cycle. For R=0.1 the stress intensity factor range is within 8 to 19.5 MPaÖ m, and the value of fatigue crack growth rate is within 10^-6 to 10^-4 mm/cycle. Finally, the value of (m) and (C) were determined from the graph using the Paris Law equation. The results showed that the increase in continuous crack length and load cycle will result to the acceleration of fatigue crack growth. Scanning Electron Microscope (SEM) was used to check the microscopic of fractured surface. From the fractography analysis, the material fails in ductile fracture. Hopefully this collection data’s will used as reference to the next researcher.