Converting activities to processes for operational efficency improvement of a South African agricultural equipment manufacturer

Includes bibliographical references.South African agricultural equipment manufacturers face increasing pressures from global competition, in response they have resorted to manufacturing customised machinery in a bid to secure market share. This strategy, while successful, introduces a high degree of product variation and complexity - increasing strain on the manufacturing operation. In response to these strains, manufacturers are placing emphasis on finding new ways to improve manufacturing costs and accelerate product delivery. The objective of this dissertation is to assemble and sequence a practical framework, using commonly available (and established) tools and improvement methodologies, which will allow its user to effectively direct process oriented improvement through analysis and modification of the operations at the activity level. The framework seeks to achieve this by formalising the operating structures already present and subsequently modifying it, in a value driven manner, using lean principles and heuristic methods for the purposes of providing practical, easily integrate-able and affordable solutions aimed at promoting operational excellence while eliminating Lean wastages. Testing conducted showed that regardless of environment lean principles can be successfully adapted to produce significant reductions in lead time and gains in both product flow and overall quality

The performance of Shariah compliant investment funds in South Africa

Abstract : Please refer to full text to view abstract.M.Com. (Financial Management

The development of new methods for the assessment of oxygen radical-mediated oxidative damage to biomolecules with special reference to lipids

The involvement of chemically-reactive oxygen radical species (RORS) in the pathogenesis of inflammatory joint diseases has been well documented. Much of the toxicity produced by increased superoxide ion (O2.-) and hydrogen peroxide (H2O2) generation has been attributed to the production of the highly reactive hydroxyl radical (.OH) which is mediated by low-molecular-mass iron chelates such as iron-citrate complexes. The .OH radical is extremely reactive and proving its formation in vivo is very difficult. Hence, assays for the assessment of .OH radical activity in the inflamed rheumatoid joint have involved identification and/or quantification of ‘unnatural’ chemical species produced by the attack of OH radical on a range of endogenous or, alternatively, therapeutically-administered exogenous 'target' molecules. This study involves: (1) An investigation of the precise chemical nature of intermediates in and so called 'endproducts' of the process of lipid peroxidation. Second-derivative (2D) electronic absorption spectrophotometry has been applied to the analysis of isomeric conjugated hydroperoxydienes, hydroxydienes and ketodienes and also to thiobarbituric acidreactive material in synovial fluid (SF) obtained from patients with inflammatory joint diseases. (2) A method for determining the extent of RORS-dependent peroxidation of polyunsaturated fatty acids (PUFAs) has been further developed for application to biological samples. This technique involves the conversion of conjugated hydroperoxydienes and compounds derived therefrom, i.e. oxodiene and hydroxydienes, to strongly chromophoric conjugated triene and tetraene species. The chromophore(s) produced are measured by their absorbance in the ultra-violet or near ultra-violet regions of spectra using 2D spectrophotometry. (3) An evaluation of the chemical nature of non-transferrin-bound iron in inflammatory synovial fluid is investigated by high-resolution, high-field proton (1H) nuclear magnetic resonance (NMR) spectroscopy, combined with the use of powerful iron(III) chelators (desferrioxamine and nitrilotriacetate), and the iron(lII)-binding protein apotransferrin in order to 'speciate' catalytic, low-molecular-mass iron complexes present in inflammatory SF samples. (4) The application of high field proton NMR spectroscopy to evaluate the abilities of the antioxidant thiol drug N-acetylcysteine and exogenous cysteine to protect metabolites present in intact inflammatory SF samples against oxidative damage arising from reactive oxygen radical species generated via gamma-radiolysis (5.00 kGy) in the presence of atmospheric oxygen

Turbulence model augmented physics informed neural networks for mean flow reconstruction

Experimental measurements and numerical simulations of turbulent flows are characterised by a trade-off between accuracy and resolution. In this study, we bridge this gap using Physics Informed Neural Networks (PINNs) constrained by the Reynolds-Averaged Navier-Stokes (RANS) equations and accurate sparse pointwise mean velocity measurements for data assimilation (DA). Firstly, by constraining the PINN with sparse data and the under-determined RANS equations without closure, we show that the mean flow is reconstructed to a higher accuracy than a RANS solver using the Spalart-Allmaras (SA) turbulence model. Secondly, we propose the SA turbulence model augmented PINN (PINN-DA-SA), which outperforms the former approach - up to 73% reduction in mean velocity reconstruction error with coarse measurements. The additional SA physics constraints improve flow reconstructions in regions with high velocity and pressure gradients and separation. Thirdly, we compare the PINN-DA-SA approach to a variational data assimilation using the same sparse velocity measurements and physics constraints. The PINN-DA-SA achieves lower reconstruction error across a range of data resolutions. This is attributed to discretisation errors in the variational methodology that are avoided by PINNs. We demonstrate the method using high fidelity measurements from direct numerical simulation of the turbulent periodic hill at Re=5600

The role of Fas in human SLE

SLE - Systemic Lupus ErythematosusAvailable from British Library Document Supply Centre-DSC:DXN019853 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Equisingular Approximation of Analytic Germs

This thesis deals with the problem of approximating germs of real or complex analytic spaces by Nash or algebraic germs. In particular, we investigate the problem of approximating analytic germs in various ways while preserving the Hilbert-Samuel function, which is of importance in the resolution of singularities. We first show that analytic germs that are complete intersections can be arbitrarily closely approximated by algebraic germs which are complete intersections with the same Hilbert-Samuel function. We then show that analytic germs whose local rings are Cohen-Macaulay can be arbitrarily closely approximated by Nash germs whose local rings are Cohen- Macaulay and have the same Hilbert-Samuel function. Finally we prove that we may approximate arbitrary analytic germs by topologically equisingular Nash germs which have the same Hilbert-Samuel function

Long Term Impact of New Jersey National Summer Transportation Institute Hosted at Rowan University on Career Choices of Cohorts (Evaluation)

In the summer of 2017, 2018, and 2019, the Center for Research in Education in Advanced Transportation Engineering Systems (CREATEs) at Rowan University hosted the National Safety Transportation Institute. The goal of this program is to provide an exposure to high school students to transportation engineering. More than 50% from underrepresented minority groups, including women, African American, and Hispanics/Latinos attended the twoweek program. In the summer of 2017 and 2019, the program was non-residential lasting four and two weeks, respectively. In summer 2018, the program was two-week residential. In all programs, the students got a chance to explore different modes of transportation, such air, road, rail, water, with an overarching theme of safety and sustainability. The experience was provided through: a) hands-on experiments; b) field trips; and c) federal, state and industry speakers. The goal of this paper is to evaluate how this program impacted their career choices. A total of 36 students have graduated from high school out of the total enrollment of 58 students. The authors reached out to all parents whose students completed the program and have graduated from high school. Of the 36 students, at least 20 indicated that they are pursuing a degree in engineering in college. Although the remaining 16 were unresponsive, it is most likely that the majority of high school graduates who participated in NSTI went on to pursue further engineering education. The authors will continue to reach out to the remaining students. The overwhelming response was one of appreciation at the opportunity provided their students to attend college-level engineering lectures, hands-on demonstrations and field trips to industry partners to which they would not otherwise have access. More specifically, many parents expressed confirmation that participating in the program opened their students’ minds to opportunities in engineering which they had not otherwise considered. In some cases, it was determined that participation simply confirmed the engineering field already chosen when the student entered the program. Another promising response was that several students expressed interest to return as speakers at future NSTI sessions. These NSTI graduates will be amazing role models for future participants of the NSTI program. The paper presents the findings about the career choice of the students and what aspects of the NSTI program, if any, impacted them the most. This paper will provide a blueprint to other NSTI programs across the country as they design their own curriculum

Review on machining of additively manufactured nickel and titanium alloys

The machining of nickel and titanium-based superalloy components is very expensive and involves unusually high lead times compared with other engineering metals such as steels and aluminum. This has led to the development of most suitable additive manufacturing (AM) processes to fabricate these difficult-to-machine metals into near-net shape parts, thereby reducing the lead time and material waste, and significantly increasing productivity. Nonetheless, finish machining is still required on the AMed metal components to meet the dimensional and surface requirements of the application. Several research studies have investigated the machinability of AMed nickel and titanium alloy workpieces and have compared the results with the machining responses of wrought counterparts, which is detailed in this review. The categorization of the literature is based on the machining operations including turning, milling, drilling, and non-conventional machining, and the observations are discussed in accordance with various input parameters such as workpiece characteristics (hardness, microstructures) and anisotropy in mechanical properties due to build orientations during the AM process. Moreover, the influence of these parameters on cutting forces and temperatures, chip formation, and tool wear is analyzed and reported. From this review, it is found that the machinability of AMed nickel and titanium workpieces is quite different to the machining responses of their wrought counterparts. Further thorough experimentation is required to develop optimized machining parameters for AMed metal parts, while an exploration of different cutting tool geometries, coolant, and lubrication strategies for enhanced tool performance for machining AMed workpieces is essential. Finally, this study reviews the state of contemporary research, and offers suggestions for future research