Applied Chemistry

A high molecular weight linear unbranched polymers free of macrocycles has been synthesized by long polycondensation time under high-intensity mixing conditions at about 80°C between cheaper chloro-monomers (instead of fluorinated monomers)1 and 5,5’,6,6’-tetrahydroxy-3,3,3’,3’-tetramethylspirobisindane (TTSBI). From the porosity analysis, it is clear that the prepared polymers are analogous to polymers of intrinsic microporosity (PIMs) with high surface area (500-700 m2/g). The hydrogen storage capacity of the prepared PIM-Cl(1-7) and were promising (up to 1.19 wt%, 77 K, at 1.13 bar). The results of this study demonstrate that controlling polymerization condition can provide a uniform microporous morphology in the target polymers.

The novel ligand, 2-(6-(2-hydroxy phenyl)-[1,2,4] triazolo [3,4-b][1,3,4] thiadiazol-3-yl)-N-phenyl benzamide (TTS) (2) was prepared from 2-(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)-N-phenylbenzamide (1) with salicyldehyde. The transition metal ions were used to synthesize various metal chelates of ligand (2).The synthesized ligand and its metal chelates were analyzed by elemental analysis, spectral study, ratio of M:L and magnetic characterization. Antifungal activities of the entire novel synthesized ligand and its metal chelates were screened.

The date palm (Phoenix dactylifera L.) is known to be one of the oldest cultivated trees in the world, claimed to have anti-diarrhoea activity traditionally. Phytochemical components of the plant material are dependable sources for the treatment of health problems. Extract from fruit were screened for bioactivity against Salmonella spp and Shigella spp. The results significantly show activity at various concentrations for the distilled water, methanol and petroleum ether extracts. The crude and chloroform extracts revealed insignificant activities. Phytochemical analysis on the plant extracts reveals the presence of tannins, steroids, flavonoids and alkaloids. However, physiochemical analysis was also carried for the various solvent extract.

 The proximate, mineral and antimicrobial activity pawpaw (Carica papaya) was carried out; this sample seed was obtained from discardsof plants and prepared for use by decocting, sun drying and grinding into powder.Using petroleum ether; of boiling range 40-60oC, their fats were extracted, theprotein content, ash content, crude fibre, moisture, carbohydrate as well as themineral contents were determined using standard methods. The fats yield of 26.01±0.00%, crude protein 8.75±0.01%, crude fibre 14.01±020%, carbohydrate content 36.25±0.01% and calories 414.09±0.02kcal/100gwas obtained for the sample.The mineral compositions determination of the sample showed that 13.70±0.12, 5.46±0.003, 26.58±0.02 and9.06±0.30 mg/100g for potassium, calcium, iron and copper respectively. The antimicrobial activity of the methanol extract of C. papaya seed was determined. The MIC value for the methanol extract was between 0.875 and 1.75 mg/ml, while that of MBC was between 1.75 and 2.5 mg/ml.

The effect of grinding MgTiO3 on the particle size and electrical properties was studied. Initially, good dispersion conditions were optimized via rheological characterizations of the aqueous slurry in variant dispersant amounts. Then, 50% MgTiO3 slurry was grinded using balls of different diameter sizes (0.8 and 0.4 mm) for two consecutive cycles. The milled powder was characterized using laser granulometry, BET method, X-ray diffraction and scanning electron microscopy techniques. The crystallite size was calculated using Halder-Wagner methods. The electrical and dielectrical properties were also monitored for different particle size. These results revealed impurities from the zirconium balls, however, without affecting the particle size even if prepared with different grinding operations.

Cobalt(II) complexes with 2,4-pentanedione, salicylaldehyde and 4,4,4-trifluoro-1-(2-Naphthyl)-1,3-butanedione(tfnb) as primary ligand, ethylenediamine, 2,2'-bipyridine and 1,10-phenanthroline as secondary ligand have been synthesized and characterized by metal analysis, infrared, electronic spectral studies, conductance, magnetic susceptibility measurements and antimicrobial studies. The conductivity measurement in nitromethane indicates that the complexes and adducts are non-electrolytes while the different shifts of the carbonyl frequencies were revealed by the infrared spectral measurements. The electronic measurements are indicative of a probable six-coordinate octahedral geometry for all the cobalt(II) compounds except [Co(tfnb)2] with a probable four-coordinate square planar geometry. The ligands and the cobalt(II) compounds were screened for in vitro antimicrobial activity against ten microorganisms. [Co(tfnb)2Bipy] and [Co(tfnb)2en] showed more promising antimicrobial than antifungal activity.

Azanza garckeana is a wild edible indigenous fruit tree species in western Sudan locally named (Jakhjakh). The physiochemical and analytical study of Azanza garckeana fruit, physical parameters of fruits determined length ranges 2.52 – 3.52 cm, Width 2.07 – 2.68 cm, Thickness 2.00 – 2.72 cm, Weight 4.05 – 7.98 g, Edible part + peels 2.89 – 5.92 g, Seeds 1.15 – 2.06 g. The chemical contents Crude Protein 9.21%, Moisture 3.82%, Fat 1.19%, Crude Fiber 45.23%, Ash 22.2%, Carbohydrates 42.17%, Energy Value 219.28%, Total Sugar 31.36%, Reducing Sugars 17.72%, Total treatable acidity 0.13%, Vitamin C 41.92%, B-carotene(IU/100g) Vitamin A 18.50% and Pectin 0.26%. The elements determined using ICP-OES the metal levels are decreasing in order Sr > Mn > Ti > Ba > As > Zn > Cu > Cr > V > Co. And essential elements found in higher level order degrease as Ca > K > Mg > P > Na > Si > Fe > Al > Li = Be.

A methodology based on flame atomic absorption spectrometry (FAAS) was developed and validated to quantify lithium in spodumene mineral sample. Validation parameters, including linearity and range, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ), were evaluated. The method is linear over 1.0 – 9.0 µg mL-1, with a coefficient of correlation (r) > 0.999. The LOD and LOQ were 0.2 ?g mL-1 and 0.7 ?g mL-1. This method is very precise; intraday precision measurements had a relative standard deviation (RSD) value of 4.00 %. This RSD value was lower than that required by Horwitz. The mean recovery percentage was 99.06 %, indicating that this method could accurately quantify the lithium in the studied mineral. The percentage of lithium oxide in the spodumene mineral sample was 0.33 –0.39%.

Thisstudy compares the heat transfer coefficients for film and dropwise condensation of steam.Copper tube was coated with oleic acid to promote dropwise condensation of steam rather than a continuous film. Excellent dropwise condensation was observed when the cooling surface was coated with oleic acid, and this helps to enhance droplet formation without wetting the surface.The experimental results shows that the value of overall heat transfer coefficient is 50000 W/m2K in dropwise and 12500W/m2K in filmwise condensation.Thus, theoverall heat transfer coefficients during dropwise condensation are approximately four times greater than those during filmwise condensation at the same surface subcooling degrees.

Early studies on the adsorption and ion exchange potential of coconut coir dust (Cocos nucifera L.) shows that it has great proficiency for removal of trace metal ions from waste water and industrial effluents. Several factors influence the process of waste water detoxification by agricultural biomass. In this paper the effect of Particle sizes of coconut coir dust on the removal of metal ions by ion exchange has been studied by batch adsorption process for Pb(II), Zn(II), Cu(II), and Cd(II). Percentage sorption of Pb(II), Cu(II), Cd(II), Zn(II) increase with decrease in particle sizes of coir dust: 50 µm > 63 µm > 150 µm > 212 µm > 300 µm > 425 µm > 600 µm. The adsorptivities of the metal ions on the unmodified coir dust decreased in the descending order: Pb(II) > Cd(II) > Zn(II) > Cu(II).