A program for calculating diatomic molecule absorption coefficients using ’’exact’’ numerically computed radial wavefunctions was developed and used to examine critically a number of approximations which are frequently used in absorption coefficient calculations. These tests showed that both use of the delta function approximation, and fixing the rotational quantum number in the radial overlap integrals at J=0, introduce errors of ?4%–6% of the absorption coefficient maximum εmax. Similarly, errors of ?1%–2% of εmax are introduced by either fixing the initial state J at the average value for the given temperature, or by using Gislason’s Airy-function approximation for the unbound state wavefunction. A simple procedure for shrinking the sum over initial state J’s without significant loss of accuracy was therefore devised. These techniques were then applied to the analysis of the visible absorption continuum of Br2, and a nonlinear least-squares fitting procedure used to determine optimized final state potential curves and transition moment functions for the two overlapping electronic transitions. In the region to which the data are sensitive, 2.10≲R≲2.55 Å, the transition moments so obtained (in debyes, lengths in angstroms) are M0(R) =0.3905+0.265(R−2.3) for the B (3Π+Ou) ←X (1Σ+g) transitions and M1(R) =0.5060–0.154(R−2.3) for the 1Π1u←X (1Σ+g) spectrum. The concomitant repulsive potential curves for the B (3Π+Ou) and 1Π1u states are, respectively (in cm−1, expressed relative to the ground state dissociation limit; lengths in angstroms): V0(R) =−1174+5494 exp[−5.807(R−2.3)] and V1(R) =7654 exp[−4.637(R−2.3)−0.879(R−2.3)2], where the former expression applies only to the region inside the B-state inner turning point for v=8, R1(8) =2.4485 Å. Comparisons with experimental relative intensities in the discrete portion of the B–X spectrum, and with molecular beam photofragment spectroscopy measurements of the relative strengths of the two electronic transitions, are also reported.

This article reports the findings of data drawn from doctoral research on the extent to which recent changes in vocational training have addressed a perceived skills gap between the needs of private sector employers and potential workers in Saudi Arabia. While the Saudi government has made efforts to enhance the quality of vocational education, and has an ongoing policy of Saudisation to try to encourage employment of Saudi workers rather than expatriates, this study presents evidence that suggests a skills gap still exists. The findings highlight a perception among private sector employers that technical education fails to offer Saudi students sufficient vocational training to teach them the level of skills and attitudes to work that the employers require. The perceived skills gap centres on three factors: work ethics, specialised knowledge and generic skills.

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The recombination rate constant of Br atoms in argon has been measured up to 1273°K using a flash photolysis technique. At room temperature and up to 480"K, results agree with the literature, but at 1150°K the recombination rate constant is (2.7k0.3) x lo8 1.2/mo1e2 sec, which is about one third of the rate constant predicted from shock-wave studies of Br2 dissociation. The discrepancy can be explained by considering a model for coupling of vibrational relaxation and dissociation. The main assumptions of the model are that the vibrational relaxation in dissociating gas at reasonably low temperatures can be described by a single relaxation time and that diatomic molecules dissociate from the uppermost vibrational levels. The model reconciles the shock wave and flash photolysis data. In this model, the reduced vibrational relaxation time for Brz in argon at 1200°K was taken to be equal to 0-95 psec atm.An alternate model, which considers a coupling of electronic excitation and dissociation processes, is also discussed. This model suggests that the discrepancy observed may be explained if it is assumed that the activation energy of the transition between the ground and excited electronic states of Br2 is between 25 and 35 kcal/mole. There are no known electronic states in this energy region. The temperature dependence of the recombination rate constant between 300 and 2300°K can be expressed by the equation log kr = 13-35-1.6 log T, where kr is expressed in 1.2/mole2 sec.