This paper presents computational predictions of adiabatic film cooling effectiveness for effusion cooling systems with 90o and 30o holes. Predictions are performed for a range of coolant injection mass flow rates per unit surface area, G, of 0.1kg/sm2 - 1.6 kg/sm2 for 90o holes with constant pitch-todiameter ratio of X/D = 11 and 10 rows of holes and for 30o inclined holes with X/D = 11 and 15 rows of holes over a 152mm surface length. The computational works performed are steady-state and the turbulent governing equations are solved by a control-volume-based finite difference method with second-order upwind scheme and the k-epsilon turbulence model. The velocity and pressure terms of momentum equations are solved by the SIMPLE method. The CFD prediction were validated by comparing the predictions with literature data for single rows of inclined holes and then applied to effusion cooling. The predictions included the use of a tracer gas in the coolant, which was used to predict the mixing of the coolant with the hot mainstream gases. Also the surface distribution of the tracer gas was a direct prediction of the cooling effectiveness. The mixing of coolant with the mainstream was studied and boundary layer temperature and coolant mixing profiles were predicted. These were compared with temperature measurement in a hot effusion cooling test rig. 

1. This study investigated the impact of textual cohesive conjunctives on the reading comprehension of Libyan university students studying English as a foreign language. Conjunctions as defined by Halliday and Hasan (1976) in their theory of textual cohesion provide the theoretical background to this work. The literature reviewed revealed contradictory findings in relation to the effect of conjunctions on reading comprehension. Many linguists and psycholinguists found that all conjunctive types (i. e. additives, adversatives, causals, and temporals) can facilitate reading comprehension. However, other studies came to the conclusion that conjunctives affected reading comprehension in different ways, or that they had no effect or a negative effect on the reading comprehension of native and foreign language readers. In order to explore the effects of conjunctions on the reading comprehension of university students for whom English was a foreign language (i. e. 4 `h year English department students in two Libyan universities) an intervention programme was designed. This programme involved the application of pre-post tests and only post-test of reading comprehension. The first experiment was organised in the Gharian English Department and the second took place in the Sabrata English Department. The participants were divided into comparative/control and treatment/intervention groups. The treatment group was explicitly taught conjunctions for three months. The comparative groups were taught their current traditional syllabus. The rationale behind having two different types of experiments in two English departmentsis the recommendatioonf Bryman( 1989)a nd otherm ethodologisttso be cautious of the possible negative effect of pre-testing. There is a possibility that the participants who attend the pre-test could benefit from this experience when they answer the same questions in the post-test, especially if the interval between the tests is short. By organising two experiments enough data were available for the study even if a negative effect from the pre- and the post-test experiment was discovered. That was followed by interviewing the participants of the treatment groups and asking them about the strategies they had used in answering the reading comprehension test. By organising semi-structured interviews, the researcher was able to explore the extent to which the participants had used their understanding of conjunctions to facilitate reading comprehension. Descriptive and inferential statistics were used to analyse the collected data. T-tests were conducted to find out if there were any significant differences between the means of the treatment group, and the comparative groups' pre and post-tests results. The results revealed that all of the conjunctive types investigated facilitated the reading comprehension of the fourth year English students in the two Libyan university English departments. However, it was found that some conjunctive types were more facilitative of reading comprehension than others. The pedagogical implications of the findings for the teaching of reading in Libyan universities and beyond are discussed.

تمت إضافة ثلاثة أنواع نباتية للفلورا الليبية هي Ruta montana + Pimpinella cretica + plantago bellardii

تمت إضافة ثلاثة أنواع نباتية للفلورا الليبية هي Lactuca saligna + Sanguisorba minor

The use of computers for handling image data in the healthcare is growing The amount of data produced by modem image generating techniques, such as Computed Tomography (CT) and Magnetic Resonance (MR), is vast. The amount of data might be a problem from a storage point of view or when the data is sent over a network. To overcome these problems data compression techniques adapted to these applications are needed Many classes of images contain some spatial regions which are more important than other regions. Compression methods which are capable of achieving higher reconstruction quality of important parts of the image have been implemented For medical images, only a small portion of the image might be diagnostically useful but the cost of wrong interpretation is high. Algorithms which deliver lossless compression within the regions of interest (ROJ), and lossy compression elsewhere in the image, might be the key to providing efficient and accurate image coding to the medical community. In this thesis both of compression techniques (lossy and lossless) of medical images using the JPEG algorithm (DCT), will be discussed.

We have studied the effects of the fine structure of energy levels on the dynamics of the atom and light field. A significant influence is exhibited in the collapse-revival behavior of atomic inversion, the light squeezing, the phase of the field, and the antibunching of a light beam. When the energy difference between the doublet is large (Δ≥20g, where g is the coupling constant), the dynamics of the atomic inversion becomes identical to that of the usual Jaynes-Cummings model, as expected. However, the fine-structure effects on the phase and the antibunching of the light field exist in a much larger range. In particular, for a strong field, the normally ordered variance of the photon-number operator exhibits complicated collapse and revival patterns and the light displays strong antibunching in each revival envelope. Numerical calculations also show that this model does not produce significant squeezing due to the influence of the fine structure. 

We report on the first clear observation of a collisionally induced diffuse band of lithium dimer around 452.0 nm in direct single photon excitation using 337.1 nm (N2) laser radiation from an excimer laser. The band, which is being tentatively assigned to the 2 1Σ+u → X 1Σ+g transition and could only be observed at buffer gas pressures of ⩾ 75 mbar, had been theoretically pre dicted. We also report on the other violet band of Li2 around 458.0 nm, already assigned to the 2 3Πg → a 3Σ+u transition. Parametr ic dependences for the two bands are presented. Together with these continuum emissions, a number of strong atomic lithium lines are also observed. A possible correlation between the atomic and continuum emissions is presented which may help in a better understanding of the kinetics of the system.