Angular distribution, kinetic energy distributions, and excitation functions of fast metastable oxygen fragments following electron impact of CO2

Dissociative excitation of CO2 by electron impact was studied using the methods of translational spectroscopy and angular distribution analysis. Earlier time of flight studies revealed two overlapping spectra, the slower of which was attributed to metastable CO(a3 pi) fragments. The fast peak is the focus of this study. Threshold energy, angular distribution, and improve time of flight measurements indicate that the fast peak actually consists of five overlapping features. The slowest of the five features is found to consist of metastable 0(5S) produced by predissociation of a sigma u + state of CO2 into 0(5S) + CO(a3 pi). Oxygen Rydberg fragments originating directly from a different sigma u + state are believed to make up the next fastest feature. Mechanisms for producing the three remaining features are discussed

Perceptual assimilation, discrimination, and acquisition of non-native and second-language vowels assimilated as uncategorised

Non-native and second-language (L2) phones are perceived in terms of their similarities and differences to the listener’s native (L1) phonemes. A non-native phone that is reliably identified as similar to a single L1 phoneme is described as being categorised according to PAM/PAM-L2 (Best, 1995; Best & Tyler, 2007), and such categorised assimilations have been the focus of much of the research on non-native and L2 speech perception. It is also possible that non-native/L2 phones are perceived as being speech-like, but are not identified with any one particular L1 phoneme. In such instances, they are said to be assimilated as uncategorised. This thesis presents experiments designed to address how these uncategorised phones are perceived, discriminated, and acquired by adult L2 learners. The findings have theoretical implications for models of cross-language and L2 speech perception, and contribute to our understanding of the perception and acquisition of uncategorised phones. The first question addressed in this thesis was whether there were any systematic differences in the way in which uncategorised non-native phones are assimilated within the L1 phonological system. In the first experiment, native Egyptian Arabic speakers residing in Egypt perceptually assimilated and rated all of the Australian English vowels in relation to their L1 vowels. Results revealed new assimilation types for uncategorised phones. They may be perceived as being moderately similar to just a single L1 phoneme (focalised), to two or more L1 phonemes (clustered), or unlike any of the L1 phonemes (dispersed). This suggests that not all uncategorised phones are perceived in the same way, but rather, they vary in the extent to which they are perceptually identified with L1 phonemes. The second set of experiments addressed the issue of how well pairs of non-native phones might be discriminated when one or both phones are assimilated as uncategorised (i.e., Uncategorised-Uncategorised and Uncategorised-Categorised assimilations, respectively). Native Australian English speakers discriminated Danish monophthongal and diphthongal vowel contrasts varying in assimilation type, including Uncategorised-Uncategorised and Uncategorised-Categorised. Discrimination accuracy was modulated by the presence of perceived phonological overlap in the categorisations to L1 phonemes, with partially overlapping contrasts discriminated less accurately than non-overlapping contrasts. By considering the different uncategorised assimilations and the presence of perceived phonological overlap to L1 categories, it was possible to fine-tune predictions for Uncategorised- Uncategorised and Uncategorised-Categorised assimilations much better than if overlap were not considered. The final aim of this thesis was to examine the acquisition of uncategorised L2 phones in adults. It was predicted that new category formation would be more likely to occur for uncategorised, than for categorised, L2 phones. Egyptian Arabic speakers acquiring Australian English in an immersion setting were recruited for a 1-year longitudinal study. They were assessed on their perceptual assimilation of the English vowels, and also on their discrimination accuracy of English vowels that formed Uncategorised-Uncategorised and Uncategorised-Categorised assimilations, as it is these assimilations that should be easily acquired according to the PAM (Best, 1995) and SLM (Flege, 1995) theoretical models. The learners were not absolute beginners, but they differed on six factors related to L2 experience (i.e., length of residence, age of foreign language acquisition, age of immersion, proportion of L2 use, L2 vocabulary size, and duration of English as a foreign language training). There was no evidence of new category acquisition, perhaps because they had already reached a plateau in L2 learning at the start of the study, or possibly because a longer period of immersion may be needed to determine whether they show improvements over time. However, by considering variability among individual learners, the six factors were shown to predict discrimination accuracy to a certain extent, predominantly for Uncategorised-Uncategorised and Uncategorised-Categorised assimilations. Overall, the experiments reported in this thesis provided a much-needed systematic and thorough investigation into the perceptual assimilation, discrimination, and acquisition of uncategorised non-native/L2 phones. The experiments demonstrated that uncategorised phones vary in their perceptual assimilation to the L1, and that discrimination accuracy is dependent upon the presence of perceived phonological overlap for contrasts involving uncategorised phones. This has important theoretical implications for both cross-language and L2 speech perception models. A number of interesting questions are also raised for L2 phonological category formation, answers to which have the potential to provide a step forward in our understanding of L2 acquisition

Direct Negotiation and the Impact on Supplier Performance

This study explored the public procurement on the Direct Negotiation issues. There are various types of public procurements implemented in the Malaysian government procurement system, however, Direct Negotiation has become the contractors’ opportunities in abusing the system where many projects have failed to be completed as scheduled and others were completed with below standard which has not achieved the expectations. As stated in Ministry of Finance Circular 2013, the Direct Negotiation can only be awarded when there is urgent requirement, only for expert and credible contractor. This study has collected data from the Auditors General annual report from year 2015 until 2017, focuses mainly on auditor’s observation on Direct Negotiation issues. Despite many comments from the public on the corrupt practice in the public procurement, this study has identified that there might be non-compliance on the decision in appointing the contractor for the Direct Negotiation which many issues arise in Auditor General report were on inefficiency of the contractor which has defeated the purposes on awarding the project through Direct Negotiation to credible contractor. Therefore, this research has agreed and supported that in order to be transparent and open, the Malaysian Government should eliminate Direct Negotiation and apply open tender on all public procurement

Aspects of fiscal structure & policy in Iraq, 1953-1963 –with reference to their effects on economic development

The present study is basically a study of the main aspects of fiscal structure and policy in Iraq during 1953-1963, and with reference to their effects on economic growth in Iraq. The study is divided into five chapter s and three appendices. Chapter one deals mainly with the exposition of the national accounts of the Iraqi economy, with some emphasis on the role of the government’s sector. This chapter forms the factual background against which problems of fiscal structure and policy in Iraq are examined. Since the exposition in chapter one has been based mainly on one single source of statistical material on the national accounts of Iraq, other alternative estimates are shown in Appendix 1. Appendix 2 includes a brief survey of the major conceptual problems involved in the measurement of national income. Chapter two includes a detailed analysis of the role of fiscal policy in accelerating the growth rate of an underdeveloped economy. While it has been attempted to analyse a wide range of problems involved in fiscal policy the problem of the effect of fiscal policy on the rate of capital formation was stressed in particular, since the rate of capital formation is viewed as the primary parameter of growth. Hence, chapter two forms the analytical background against which problems of fiscal structure and policy in Iraq are examined. Chapter three examines the revenue system and tax policy in Iraq. The first three sections examine the revenue system in general, while the forth section includes a detailed analysis of tax policy in Iraq. This is done mainly against the factual and analytical backgrounds already developed in the previous two chapters. Chapter four includes a detailed examination of the pattern of government expenditure in Iraq, mainly with reference to its possible effect on the rate of capital formation in the economy. Chapter five includes the summary and conclusions of the study. Finally, all tables are included in the statistical appendix

Holographic optical trapping Raman micro-spectroscopy for non-invasive measurement and manipulation of live cells

We present a new approach for combining holographic optical tweezers with confocal Raman spectroscopy. Multiple laser foci, generated using a liquid-crystal spatial light modulator, are individually used for both optical trapping and excitation of spontaneous Raman spectroscopy from trapped objects. Raman scattering from each laser focus is spatially filtered using reflective apertures on a digital micro-mirror device, which can be reconfigured with flexible patterns at video rate. We discuss operation of the instrument, and performance and viability considerations for biological measurements. We then demonstrate the capability of the instrument for fast, flexible, and interactive manipulation with molecular measurement of interacting live cell systems

Evolving Genetic Programming Tree Models for Predicting the Mechanical Properties of Green Fibers

Advanced modern technology and the industrial sustainability theme have contributed to the implementation of composite materials for various industrial applications. Bio-composites are among the desired alternatives for green products. However, to properly control the performance of bio-composites, predicting their constituent properties is of paramount importance. This work introduces an innovative, evolving genetic programming tree model for predicting the mechanical properties of natural fibers for the first time based upon several inherent chemical and physical properties. Cellulose, hemicellulose, lignin, and moisture contents, as well as the Microfibrillar angle of various natural fibers, were considered to establish the prediction models. A one-hold-out methodology was applied for the training/testing phases. Robust models were developed utilizing evolving genetic programming tree models to predict the tensile strength, Young’s modulus, and the elongation at break properties of the natural fibers. It was revealed that the Microfibrillar angle was dominant and capable of determining the ultimate tensile strength of the natural fibers by 44.7%, comparable to other considered properties, while the impact of cellulose content in the model was only 35.6%. This would facilitate utilizing artificial intelligence to predict the overall mechanical properties of natural fibers without exhausting experimental efforts and cost to enhance the development of better green composite materials for various industrial applications. Doi: 10.28991/ESJ-2023-07-06-02 Full Text: PD