In recent years, new and powerful research into "condition numbers" for convex optimization has been developed, aimed at capturing the intuitive notion of problem behavior. This research has been shown to be important in studying the efficiency of algorithms, including interior-point algorithms, for convex optimization as well as other behavioral characteristics of these problems such as problem geometry, deformation under data perturbation, etc. This paper studies measures of conditioning for a conic linear system of the form (FPd): Ax = b, x E Cx, whose data is d = (A, b). We present a new measure of conditioning, denoted pd, and we show implications of lid for problem geometry and algorithm complexity, and demonstrate that the value of = id is independent of the specific data representation of (FPd). We then prove certain relations among a variety of condition measures for (FPd), including ld, pad, Xd, and C(d). We discuss some drawbacks of using the condition number C(d) as the sole measure of conditioning of a conic linear system, and we then introduce the notion of a "pre-conditioner" for (FPd) which results in an equivalent formulation (FPj) of (FPd) with a better condition number C(d). We characterize the best such pre-conditioner and provide an algorithm for constructing an equivalent data instance d whose condition number C(d) is within a known factor of the best possible.

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Copies of author's previously published articles inserted. / Bibliography: p. 110-123. / xiii, 123 p. : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Two types of polymer, latex, a hydrophobic natural uncharged polymer, and, poly-diallyl dimethil ammonium chloride (poly-DADMAC), a hydrophilic synthetic positively charged polymer, were used as soil conditioners. Their effects on the stability of soil structure, hydrophobicity and on the growth of ryegrass were investigated. The study also monitored the rate of decomposition of latex in soil. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil Science, 1997

A project report submitted to the Faculty of Engineering, University of the Witwatersrand in partial fulfilment of the requirements for the degree of Master of Science in Engineering. / Until recently use of ionic chemical soil stabilisers seemed hit or miss. The paper by paige-Green and Bennett explains that the stabilisers work only on soils containing reactive clays. The author's findings confirm this conclusion. It was shown that a CBR test, which can be done in any road soils laboratory, can be used to measure the chanqe in strength caused by the treatment of the soil with a chosen ionic stabiliser. South Africa is faced with a serious unemployment problem. The World Bank and the International Labour Organisation have shown that employment in construction can be significantly increased by the use of labour instead of machinery. Field trials showed that ionic stabilisers can readily be applied labour intensively. These stabilisers could improve marginal materials to road-building standard and this could further reduce the dependence on machinery by reducing the need to transport quantities of high quality gravel. / Andrew Chakane 2019

Reclamation of four salt-affected soils collected from southern Arizona was studied in the greenhouse and laboratory. Two rates of four amendments (sulphuric acid, gypsum, ammonium polysulphide, and ammonium thiosulphate) were applied in triplicate. Results were evaluated in terms of changes in nutrient availability, ions removed by leaching, plant growth, and infiltration rates. In most cases the high rates of sulphuric acid and gypsum increased the solubility of the major cations (Na, K, Ca, and Mg) in the soil. If the required amount of leaching water were applied to the soil, a significant amount of these cations, especially Na, was leached from the soil. For the Gothard soil (saline-sodic) two pore volumes were sufficient to accomplish leaching, but were insuffcient for the Guest (nonsaline-slightly sodic) and Gilman (highly saline-sodic) soils. High rates of sulphuric acid and gypsum decreased the pH and increased the EC for all soils, although the EC was not significant at the 5% level for the Mohall (nonsaline-nonsodic, calcareous) soil. All treatments decreased the pH of the Gothard soil significantly; however, the greatest increase in EC and least pH were obtained from acid application. Regarding changes in phosphorus (P), all treatments increased the amount of soluble P in the leachates from the Gothard and Guest soils; whereas available soil P increased significantly only with the acid treatments. None of the treatments affected the amount of P in the Gilman soil leachates, but acid and gypsum increased the available soil P. Ammonium polysulphide and ammonium thiosulphate tended to increase available P but the increase was not significant at the 5% level. None of the treatments affected the P parameters for the Mohall soil. Sulphuric acid increased growth and P uptake of alfalfa plants on all soils except the Mohall. Gypsum and ammonium polysulphide increased P uptake on the Gothard and Guest soils whereas ammonium thiosulphate increased P uptake only for the Guest soil. Sulphuric acid and gypsum increased the infiltration rates for all four soils. Thiosulphate produced intermediate infiltration rates while the lowest rates were found with ammonium polysulphide and the untreated soils. Although amendment rates were based on equivalent amounts of sulphur and their effectiveness in supplying soluble calcium, and the exchangeable sodium status of each soil, results varied according to such factors as rate of oxidation of the amendment, lime content of the soil, soluble salts present in the soil, and soil texture.

A traffic conditioner is an element of the Differentiated Services architecture. This architecture is used to regulate quality of service in computer networks. Five traffic conditioners were selected for the study. These include the token bucket marker and four conditioners described in RFCs. The contribution of this dissertation is two-fold. Firstly, it presents process algebra models of the five identified traffic conditioners. These models provide succinct descriptions of the conditioners thereby highlighting essential features. The models are, however, not intended for model checking purposes, but rather serve as a convenient pedagogical device. The second and main contribution of the dissertation is a simulation study to investigate the relative performance of the five traffic conditioners across a range of simulated scenarios in which traffic patterns and subscription levels are varied in a fixed network topology. Two performance measures—TargetRatio and GreenRatio—are defined, justified, and used to compare the traffic conditioners. The GreenRatio measure was found to be more discriminating than the TargetRatio measure. A variant of the GreenRatio measure was used to further illuminate the differences between conditioners. The simulation results suggest that the performance of the conditioners are sensitive to parameter values such as token bucket size and that bursty traffic patterns are particularly sensitive to these parameters. Under such bursty conditions, these parameters should be chosen with care. / Dissertation (MSc (Computer Science))--University of Pretoria, 2007. / Computer Science / unrestricted

A long-term project was initiated in order to stuq the et!ecta of sawdust Jlltll.ch and two .forms of a synthetic soil conditioner on the yield of vegetable crops. Data is in this thesis concerning experimental results of two years, 1953 and 1954. In addition, a report is given on a preliminary study which was conducted in 1952. In general, not enough research has been done on this project to formulate definite conclusions. However, certain tr.nds are apparent: 1. The soil treatments have caused no significant changes in the pH values of the soil. 2. The treatments have caused no wide fluctuations in the amounts of calcium, magnesium, phosphoric acid, or potash in the soil. 3. The potassium dichromate and sulphuric acid tests, used by the Soils Laboratory of this institution, did not indicate that the soil treatments increased the organic matter content of the soil. 4. In general, synthetic soil conditioners as used in this test have produced no significant effects. 5. Incorporation of sawdust into the soil mq result in nitrate deficiency. However, this deficiency can be readily corrected by the addition or fertilizers containing nitrogen. 6. Sawdust mulch has, in general, benefitted the production of vegetable crops. The beneficial effects are probably caused by conservation of soil moisture (including an increase in the percentage of moisture available to plants), and by reduction of soil temperature fluctuations. / Master of Science

International Telemetering Conference Proceedings / October 13-16, 1986 / Riviera Hotel, Las Vegas, Nevada / In Aerospace missions it is often required to have a flexible telemetry system for carrying out flight test on aircraft, in which the bit rate, sampling rate and the number of channels can be programmed. This enables the pilot of the aircraft to reconfigure the telemetry system to suit any particular test missions. An L-Band PCM/FM Telemetry System containing a Stored Programme Multiplexer, 12 bit ADC and other digital interfaces for carrying out the measurements on Speed, Events, etc has been developed as a flight instrumentation telemetry for HAL, India. This paper not only presents complete details of the system, which was qualified to meet MIL-5422 levels but also the performance of the system during actual aircraft missions.

Among all thermal energy storage (TES) systems, latent heat thermal energy storage (LHTES) attracts high interest due to its high energy density and high exergetic efficiency. Due to the high enthalpy of fusion and low cost, inorganic salts are becoming popular as phase change materials and are used as the storage media in LHTES systems. The main drawbacks for the inorganic salts are their low thermal conductivity and high reactivity above 500°C. Therefore, designing a cost-effective containment at these conditions with longevity is a challenge. Macro-encapsulation of the PCM is one way to solve both the PCM containment issue as well as the low thermal conductivity problem. However, finding a practically viable encapsulation technique is a challenge especially for temperatures above 500°C. In the present study, encapsulation techniques were investigated for two temperature ranges; 500°C – 600°C and 600°C above. Metallic encapsulation was adopted for the 500°C – 600°C temperature. Commercially available, low-cost carbon-steel tubes were used, and the encapsulation shape was cylindrical. A 200µm coating of Ni was applied to strengthen the corrosion resistance. For temperatures above 600°C, a novel approach involving the use of ceramic materials was investigated for encapsulating chloride based PCMs. Low-cost ceramics with excellent thermal and chemical stability under molten-salt conditions were identified as the encapsulants. The influence of sintering temperature on the reactivity of feldspar, ball clay, kaolin and the mixture thereof with molten sodium chloride was investigated. The results were used to develop an optimum ceramic capsule fabrication procedure, using a green ceramic body followed by sintering at 1190°C. An innovative sealing process of in-situ layered eutectic formation was introduced. Sealing was performed at a temperature above the eutectic melting point of the salt mixture but below the individual melting points of each salt. The fabricated capsule survived more than 500 thermal cycles without showing degradation in its thermo-physical properties. Alumina (99%) based capsule containing NaCl-KCl was tested successfully for 1000 thermal cycles with a PCM weight loss of less than 5%. A lab-scale setup was designed and constructed to test an industry scalable LHTES system suitable for supplementing heat to a steam-powered cycle. Metallic cylindrical capsules were used with a eutectic of sodium sulfate (Na2SO4) and potassium chloride (KCl), which melts at 515°C, as the PCM for energy storage. This system was modeled and validated with experimental measurements. The calculated ratio of exergy to energy efficiency was around 89% (for 380-535°C). Flow irregularities were found due to a bend in the flow channel. Therefore, flow conditioners were investigated. A modified system with the flow conditioners and radiation shields showed 98% exergy to energy efficiency ratio (for 495-535°C). The overall efficiency of the system, however, was found to be low due to the heat losses from the storage tank. Finally, a novel design of a TES system using spherical capsules is proposed with additional enhancement gained from the experimental work on the lab-scale LHTES system. The innovation of this design lies in the manufacturing process to forms multiple spherical capsules using sheet metals. The adoptability of this technique for higher or lower temperature LHTES applications depends on the properties of the selected sheet metal. Any formable sheet metal can be used depending on the compatibility with PCM and HTF.