The Flotation Concentration of a Complex Low-Grade Lead Zinc Ore

This report is concerned primarily with the beneficiation of a low-grade complex lead-zinc ore. The depletion of high grade veins has caused the mineral engineer to seek deposits deeper in the earth\u27s crust or to find lower grade deposits. The other alternative has placed more research problems on Mineral Dressing Engineers in particularly the iron, copper, lead and zinc fields

A combinatorial characterization of tight fusion frames

In this paper we give a combinatorial characterization of tight fusion frame (TFF) sequences using Littlewood-Richardson skew tableaux. The equal rank case has been solved recently by Casazza, Fickus, Mixon, Wang, and Zhou. Our characterization does not have this limitation. We also develop some methods for generating TFF sequences. The basic technique is a majorization principle for TFF sequences combined with spatial and Naimark dualities. We use these methods and our characterization to give necessary and sufficient conditions which are satisfied by the first three highest ranks. We also give a combinatorial interpretation of spatial and Naimark dualities in terms of Littlewood-Richardson coefficients. We exhibit four classes of TFF sequences which have unique maximal elements with respect to majorization partial order. Finally, we give several examples illustrating our techniques including an example of tight fusion frame which can not be constructed by the existing spectral tetris techniques. We end the paper by giving a complete list of maximal TFF sequences in dimensions less than ten.Comment: 31 page

P1_1 Everybody knows the moon is made of cheese...

This report investigates the possible implications of our moon being made of cheese as suggested in the Wallace and Gromit film 'A Grand Day out'. If it were the same size as the current moon, and made of Wensleydale, then it would exert 13.1 x1019N less force on Earth. If it were to exert the same force then its radius would increase by 0.78 x 106m, appearing 144% larger in the night sky

A Regression Analysis on the Macroeconomic Variables Affecting Taiwan’s Export Value to the US before and after 2008 Financial Crisis

The booming of international trade since 1980 has resulted in the sharp economic growth of Taiwan. It is therefore important to understand the influential factors and their impacts on Taiwan’s international trade and export. This research adopts multiple regression method to identify the respective influential macroeconomic variables affecting the export values of Taiwan to the U.S. before and after 2008 financial crisis. It also analyzes the correlations among these macroeconomic variables. The results of this research indicate that, the first lag period of: (1) Taiwan industrial production index, (2) exchange rate of U.S. dollar to New Taiwan dollar, (3) US Interbank real call loan rate, and (4) U.S. industrial production index are influential macroeconomic variables affecting export values of Taiwan to the U.S. before 2008 financial crisis. After 2008 financial crisis, the influential macroeconomic factors are the first lag period of (1) exchange rate of U.S. dollar to New Taiwan dollar, (2) Taiwan’s industrial production index, (3) Mainland China’s consumer price index yearly increment, and (4) Taiwan’s wholesale price index yearly increment (excluding service)

Academics’ understandings of the authorial academic writer: a qualitative analysis of authorial identity

Research on authorial identity has focused almost exclusively on the attitudes and beliefs of students. This paper explores how academics understand authorial identity in higher education. Semi-structured interviews were conducted with 27 professional academics and analysed using thematic analysis, identifying themes at two levels. At the semantic level was a main theme called ‘the authorial writer’, with five subthemes: ‘authorial confidence’, ‘valuing writing’, ‘ownership and attachment’, ‘authorial thinking’, and ‘authorial goals’. At the latent level were two integrative themes: ‘tacit learning’ and ‘negotiating identities’. The semantic subthemes represent attributes that could be targets for pedagogic interventions. The integrative themes suggest processes in the development of authorial identity, which can inform more effective teaching. By identifying attributes and processes associated with authorial identity, these findings help towards a psychological understanding of authorial identity, informing development of more effective pedagogy to help students improve their academic writing and avoid plagiarism.Postgraduate studentship awarded to Kevin Yet Fong Cheung by the Teaching Informed by Research fund at the University of Derb

Maritime intent estimation and the detection of unknown obstacles

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.Includes bibliographical references (p. 195-196).The benefits of using Unmanned Undersea Vehicles (UUVs) in maritime operations are numerous. However, before these benefits can be realized, UUV capabilities must be expanded. This thesis focuses on improving certain aspects of the Maritime Reconnaissance and Undersea Search and Survey capabilities of a UUV. An algorithm is first presented which provides the UUV with the ability to estimate the intent of the contacts it is observing (intent estimation). This was accomplished by developing a probabilistic model of the contact's possible intents and then using those models to estimate the contact's actual intent. The results from that algorithm are used to analyze the contact's observed path to determine a probabilistic belief of the potential location of obstacles in the environment (obstacle detection) that the contact is avoiding. These values are recorded in an obstacle inference map, which is capable of incorporating the results from the analysis of any number of observed paths from multiple contacts. The laws of probability were used to develop the algorithms in this thesis-with an emphasis on Bayes' rule. Various scenarios are presented to demonstrate the capabilities and limitations of the intent estimation and obstacle detection algorithms.by Edward Hsiang Lung Fong.S.M

Computational fluid dynamics modeling of symptomatic intracranial atherosclerosis may predict risk of stroke recurrence.

BackgroundPatients with symptomatic intracranial atherosclerosis (ICAS) of ≥ 70% luminal stenosis are at high risk of stroke recurrence. We aimed to evaluate the relationships between hemodynamics of ICAS revealed by computational fluid dynamics (CFD) models and risk of stroke recurrence in this patient subset.MethodsPatients with a symptomatic ICAS lesion of 70-99% luminal stenosis were screened and enrolled in this study. CFD models were reconstructed based on baseline computed tomographic angiography (CTA) source images, to reveal hemodynamics of the qualifying symptomatic ICAS lesions. Change of pressures across a lesion was represented by the ratio of post- and pre-stenotic pressures. Change of shear strain rates (SSR) across a lesion was represented by the ratio of SSRs at the stenotic throat and proximal normal vessel segment, similar for the change of flow velocities. Patients were followed up for 1 year.ResultsOverall, 32 patients (median age 65; 59.4% males) were recruited. The median pressure, SSR and velocity ratios for the ICAS lesions were 0.40 (-2.46-0.79), 4.5 (2.2-20.6), and 7.4 (5.2-12.5), respectively. SSR ratio (hazard ratio [HR] 1.027; 95% confidence interval [CI], 1.004-1.051; P = 0.023) and velocity ratio (HR 1.029; 95% CI, 1.002-1.056; P = 0.035) were significantly related to recurrent territorial ischemic stroke within 1 year by univariate Cox regression, respectively with the c-statistics of 0.776 (95% CI, 0.594-0.903; P = 0.014) and 0.776 (95% CI, 0.594-0.903; P = 0.002) in receiver operating characteristic analysis.ConclusionsHemodynamics of ICAS on CFD models reconstructed from routinely obtained CTA images may predict subsequent stroke recurrence in patients with a symptomatic ICAS lesion of 70-99% luminal stenosis