The Category 'D' Reconsidered

This study deals with the categorial status of a set of words known as 'determiners' and the features encoded in them. We argue, following a suggestion in Chomsky, 1975, that 'Optimality' conditions on grammar require grammatical categories to be 'primitive' in the sense that they must be unanalysable into further entities. The status of many words classified as determiners does not conform with this suggestion. The category 'D' is therefore a non-standard grammatical category. We have provided mathematical, morphological and syntactic arguments and facts drawn from a number of languages including Arabic, English, French, German, Hebrew, Italian, ...etc. showing that the category 'D' is not a 'primitive' category and therefore should be suspended and replaced by its 'primitive5 components. We have shown that 'genuine' determiners are morphologically complex where each element encodes a functional feature, such as 'person9, 'number9, 'gender9, 'proximate', 'definite', ...etc. These features, we claim, are functional categories. Many words classified as belonging to the category 'd' are in fact nouns or adjectives. Adopting an articulated theory of 'D' in which functional features are taken as functional categories is not only theoretically motivated but also has implications for language learn ability

Experimental and quantum chemical calculations on corrosion inhibition of mild steel by two furan derivatives

Two furan derivatives namely 5-methylfurfurylamine (MFA) and furfurylamine (FAM) were investigated as corrosion inhibitors for mild steel in 1 M HCl. The corrosion inhibition efficiencies (IE) were measured at 0.005M of the inhibitors using electrochemical potentiodynamic polarization measurements. The studied furan derivatives inhibit mild steel corrosion in acidic medium. The MFA shows higher inhibition efficiency of 84.77% compared to FAM of 41.75%. Quantum chemical calculations were performed at the B3LYP/6-311++G(d,p) level of density functional theory (DFT). Several quantum parameters were calculated to study the correlation between the molecular structures and the corrosion inhibition performance of the inhibitors. The MFA inhibitor shows higher HOMO energy, softness (S), fraction of electrons transferred (ΔN), and lower energy gap (ΔE) compared to the FAM. This result indicates a better corrosion inhibition performance of the MFA inhibitor. The results show that the calculated values of the quantum parameters using DFT calculations are consistent with the experimental findings

A multi-cycled sequential memetic computing approach for constrained optimisation

In this paper, we propose a multi-cycled sequential memetic computing structure for constrained optimisation. The structure is composed of multiple evolutionary cycles. At each cycle, an evolutionary algorithm is considered as an operator, and connects with a local optimiser. This structure enables the learning of useful knowledge from previous cycles and the transfer of the knowledge to facilitate search in latter cycles. Specifically, we propose to apply an estimation of distribution algorithm (EDA) to explore the search space until convergence at each cycle. A local optimiser, called DONLP2, is then applied to improve the best solution found by the EDA. New cycle starts after the local improvement if the computation budget has not been exceeded. In the developed EDA, an adaptive fully-factorized multivariate probability model is proposed. A learning mechanism, implemented as the guided mutation operator, is adopted to learn useful knowledge from previous cycles. The developed algorithm was experimentally studied on the benchmark problems in the CEC 2006 and 2010 competition. Experimental studies have shown that the developed probability model exhibits excellent exploration capability and the learning mechanism can significantly improve the search efficiency under certain conditions. The comparison against some well-known algorithms showed the superiority of the developed algorithm in terms of the consumed fitness evaluations and the solution quality

Antimicrobial, antioxidant and phytochemical investigation of Balanites aegyptiaca (L.) Del. edible fruit from Sudan

The methanol extract of the fruit (edible mesocarp) of Balanites aegyptiaca (L.) Del., a popular plant from Sudan, widely employed in Sudanese folk medicine was screened for antimicrobial, antioxidant and some active phytochemical compounds. The extract showed the presence of saponin, terpenoids, phenolic compounds and alkaloids. The methanolic extract of the fruits extracted from B. aegyptiaca exhibited a strong antioxidant activity in the DPPH assay and a potent capacity in preventing linoleic acid oxidation. Methanol extracts (50 and 100 mg/ml) were tested on several microbial strains using agar-well diffusion, minimum inhibitory concentration (MIC), minimum bacterial concentration (MBC) and minimum fungal concentration (MFC) methods. These experiments were performed on ten bacterial strains (five Gram-positives and five Gram-negatives) and four fungal strains. Methanol extracts, particularly at concentration of 100 mg/ml was found to be active against all bacterial and fungal strains and it was comparable to standard antibiotics Gentamicin and Amphotericin B. These findings support some of the traditional applications of the fruit of B. aegyptiaca against microbial aliments. It is therefore recommended that further studies regarding fractionation, separation and purification of these active antimicrobial compounds are required, in addition to toxicological evaluation in vivo.Key words: Balaneties aegyptiaca, antibacterial, antifungal, phytochemical, antioxidant, methanol extract

Studies of fat and surfactant systems in bread-making

Call number: LD2668 .T4 1978 A44Master of Scienc