The intriguing twist-bend nematic phase (NTB) is formed, primarily, by liquid crystal dimers having odd spacers. Typically the phase is preceded by a nematic phase (N) via a weak first-order transition.Our aim is to obtain dimers where the NTB phase is formed directly from the isotropic phase via a strong first-order phase transition. The analogy between such behaviour and that of the smectic A (SmA)-N-I sequence suggests that this new dimer will require a short spacer. This expectation is consistent with the prediction of a molecular field theory since the decrease in the spacer length results in an increase in the molecular curvature. A vector of odd dimers based on benzoyloxybenzylidene mesogenic groups with terminal ethoxy groups has been synthesised with spacers composed of odd numbers of methylene groups. Spacers having 5, 7, 9, and 11 methylene groups are found to possess the conventional phase sequence NTB-N-I; surprisingly for the propane spacer the NTB phase is formed directly from the isotropic phase. The properties of these dimers have been studied with care to ensure that the identification of the NTB phase is reliable.

In this study, pine fruit was used as solid adsorbent for removal of ferrous and copper ions from aqueous solutions through batch equilibrium technique. The influence of contact time, pH of the solution and initial concentration of metal ions on adsorbed amount of metal ions were investigated. 90 minutes of adsorption time was found sufficient to reach equilibrium for ferrous ion and 120 minutes for copper ion. Adsorption of metal ions were pH dependent and the results indicate the optimum pH for the removal of Fe+2was found to be 5.0 and that of Cu+2was 7.0, the highest adsorption capacity was found to be 4.8 and 14.1 mg of metal ion per gram of adsorbent at initial concentration of 22.22 mg/L and 57.6 mg/L of ferrous and copper ions respectively and would be higher with higher initial concentration. Ferrous ion was removed by 96.3 - 97.3% and copper ion by 94.1-96% along the whole range of initial concentrations. Isotherm studies showed that the data were best fitted to the Freundlich isotherm model. The kinetic data corresponded well with the pseudo-second order equation, suggesting that the adsorption process is presumably a chemisorption.

Series of new Schiff bases and their derivatives (Oxazepine) have been synthesized during two steps. The first step synthesis of imines derivatives (1-10) by the condensation reaction of 1, 7-diaminohepatane and 1,8-diaminooctane with different substituted aromatic aldehydes by using glacial acetic acid as catalyst. The second step includes reaction of the prepared Schiff bases derivatives with phathalic anhydride in dry benzene to obtain   seven-membered heterocyclic ring derivatives (11-15).  The biological activities of some prepared compounds were also studied against different kinds of bacteria. The new derivatives were confirmed by suing a range of experimental techniques including 1HNMR, 13C NMR, IR and Mass spectra.