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MSCAGR (Animal Science) / Department of Animal Science / Soya bean (Glycine max) is a legume that is mostly cultivated for food grain which can be used as high-protein forage for grazing, haying or ensiling. The use of forage soya bean by small holder farmers is currently very limited. The objective of the current study was to evaluate the nutritive value of three trifoliate forage Soya bean cultivars (Locally denoted as 4-LF, PAN, and TGX). The study was carried out at the University of Venda where the soya beans were planted in 63 25L pots (21 pots for each cultivar) which were randomly placed on the floor of an open, wire-net protected house. Forage harvested at three growth stages (pre-anthesis, anthesis and postanthesis). Samples of the forage were analyzed for dry matter (DM), ash, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) micro and macro minerals. Ruminal DM and CP degradability were evaluated in situ by incubation of samples within nylon bags (external dimension: 6 × 12 cm, pore size of 46 μm) in the rumen of three Bonsmara steers for 0, 6, 12, 16, 24, 48, 72, and 96 hours. Estimates of rapidly degradable fraction “a”, slowly degradable fraction “b”, constant outflow rate ‘c’ and the DM or CP degradability (p) at time (t) were estimated by fitting the degradability data into the exponential equation P = a + b (1 - e-ct) using the NEWAY computer programme. Parameters were subjected to ANOVA for a 3 X 3 factorial treatment arrangement using the General Linear Model procedures of MINITAB software (version 17 of 2014). Effective degradability ED) was estimated asED = a + bc at fractional outflow rates of k= (k +c) 2%, 5% and 8%. In vitro enzymatic DM and CP digestibility of rumen undegradable residues collected after 24 and 48-hour incubation was determined by simulating sequential gastro-small intestinal digestion. Cultivar PAN harvested post anthesis had significantly higher (p< 0.05) CP than other cultivars. The CP content increased with growth stage. Cultivar 4LF harvested preanthesis had significantly highest (p< 0.05) NDF. The cultivar had no significant effect (p> 0.05) on DM, ash, CP, NDF, ADF and minerals. Cultivar PAN harvested pre-anthesis had significantly highest (p< 0.05) Mg. The harvest stage significantly affected (p< 0.05) mineral content other than (p> 0.05) Zn and Cu. Cultivar TGX harvested pre-anthesis had significantly highest (p< 0.05) effective degradability of dry matter at k=0.08. Fraction ‘c’ and ED at k= 0.08 were lower (p> 0.05) in cultivar * growth stage interaction in dry matter degradability. Fraction ‘a’ for CP was highest (p< 0.05) for cultivar TGX harvested post-anthesis. Fraction ‘c’ was lower (p> 0.05) for cultivar 4LF harvested at anthesis stage. There was a significant effect (p< 0.05) on crude protein soluble fraction ‘c’ and effective degradability k=0.08 in cultivar and growth stage interaction. There was no significant interaction (p> 0.05) of the cultivar X growth stage on crude protein degradability at 48 hours, IVCPD at 24 and 48 hours with significant effect on crude protein degradation at 24 hours caused by cultivar TGX at pre-anthesis growth stage. In conclusion, growth stage increases the chemical composition of soya bean but does not affect digestibility. / NRF

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“Building processes seem best evoked in terms of various forms of endemic uncertainty which, in turn, define an essentially turbulent industrial environment. The pursuit of stability is re-interpreted as ‘unstable equilibrium’ in building processes, requiring constant feedback to maintain control.” (Groak, 1992) The process of addressing a troubled spatial legacy within the context of South Africa has presented a challenging atmosphere regarding the preservation or reprogramming of urban and architectural space. This becomes a prevalent issue when considering critical urban regions such as Westbury in Johannesburg, where the social and built environment remain in a constant struggle for identity and defensibility. The need to address this reformation of urban space as well as urban programme has lead this dissertation to question the manifestation of social processes in spatial form. This dissertation hopes to propose a system of architecture and supporting infrastructure that will address existing spatial legacy, through responding to social and contextual issues; leading to a new platform for the sustainable progression of social activity and identity in the form of urban densification. / Mini Dissertation (MArch(Prof)) --University of Pretoria, 2018. / Architecture / MArch(Prof) / Unrestricted

Advanced combustion concepts are required to meet the increasing global energy demand and stringent emission regulations imposed by the governments on automobile manufacturers. Improvement in efficiency and reduction in emissions can be achieved by downsizing the Spark Ignition (SI) engines. The operating range of SI engine is limited by occurrence of knock, pre-ignition and the following super-knock due to boosting of intake pressure, to account for the reduction of power, as a result of downsizing the engine. Super-knock, which represents high momentary pressure accompanied with pressure oscillations, is known to permanently damage the moving component of the engines. Therefore fundamental comprehensive understanding of the mechanism involved in pre-ignition and super-knock are required to design highly efficient spark ignition engines with lower emissions that can meet the increasing government regulations. \nThe thesis focuses on auto-ignition characteristics of endgas and the bulk mixture properties that favor transition of pre-ignition to super-knock. Direct numerical studies indicate that super-knock occurs to due to initiation of premature flame front that transition into detonation. In literature, many sources are reported to trigger pre-ignition. Due to the uncertainty of the information on the sources that trigger pre-ignition, it is extremely difficult to predict and control pre-ignition event in SI engines. Since the information on the source of pre-ignition is not available, the main focus of this work is to understand the physical and chemical mechanisms involved in super-knock, factors that influence super-knock and methods to predict super-knock. \n
Pre-ignition was initiated at known locations and crank angle using a hotspot of known size and strength. Different parametric cases were studied and the location and timing of pre-ignition initiation is found to be extremely important in determining the transition of pre-ignition event to super-knock. Pre-ignition increases the temperature of the endgas and the overall bulk mixture, that transitions the pre-ignition flame front to a detonation. The transition of the flame propagation mode from deflagration to detonation was investigated with different type of analysis methods and all results confirmed the transition of pre-ignition flame front to detonation that results in super- knock.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / In the mining industry of Peru, as a consequence of large scale mineral extraction and a dynamic process of ore dressing, the different activities of the operation are neglected. This neglect, in some cases, generates collateral damages that affect the structures, generate extra costs, and result in constant accidents due to rock-fall and delays in the activities of the mining cycle and the ones following it, which seriously harms the Mining Unit and directly affects the workers. In addition, this is directly related to the progress of the daily work and, in turn, it is related to the design of the mine mesh that is prepared to extract the largest possible mineral amounts per shift. This means that, by modifying the design of the mine mesh, the blasting method, and the type of explosive used, the current scenario and the results could be modified. In this respect, a research was conducted, exclusively based on simulations using the JK Simblast software, applying the pre-splitting blast method in the underground mine of the Minera Aurífera Retamas SA company, resulting in a reduction of over break in more than 60% as compared to the mesh used initially. This has an impact on the level of support to be used, and therefore, on the maintenance costs, which were reduced by 18%. Therefore, this article presents the possibility of reducing maintenance costs in underground mining using pre-splitting blasting. Copyright 2019.

Sandra Cardenas (Perú)- Expositora / Gerente de RR.HH de Alicorp nos compartirá una hoja de ruta para iniciar las prácticas pre profesionales y los tips en cada una de las etapas.

Bambara groundnut (Vigna subterranean L.) is considered a good source of protein in some parts of sub Saharan African countries. Long cooking time of about three hours contributed to its limited consumption and utilisation. Micronisation is an infrared heating process. It can reduce the cooking time of pre-moisture conditioned legume small seeds size such as cowpea and lentil, but mostly tempering of seeds has been used as the pre-conditioning techniques. The resulting flour from the pre-conditioned micronised cowpea can reduce pasting viscosity and has potentials in food systems as an instant product. This study aimed at (1) determining the effects of micronisation of pre-soaked whole and dehulled bambara groundnut seeds on their cooking characteristics, (2) determining the effects of micronisation and dehulling treatment of pre-soaked bambara groundnut on physicochemical, microstructure and functional properties of the resulting flours and (3) determining the effects of micronisation of pre-soaked whole and dehulled bambara groundnut seeds on the viscosity, nutritional and health benefits of the cooked samples in order to produce a quick cooked bambara groundnut with functional, nutritional and health benefits. Micronisation (130 ºC) at a different time (0, 5, 10 and 15 min) was used to optimise the process for pre-soaked (53% moisture) bambara groundnuts. Micronisation (130 ºC) reduced cooking time of pre-soaked (53% moisture) bambara groundnut (whole and dehulled) following cooking. Micronisation reduced the 162 min cooking of raw bambara groundnut to 109, 83, 75 and 62 min when micronized for 0, 5, 10 and 15 min. Micronisation (53% moisture, 130 ºC) caused molecular changes such as solubilisation of pectin which was responsible for the disruption of the middle lamella and separation of parenchyma cell observed by light microscopy and scanning electron microscopy (SEM). It also caused disruption in the structure of starch granule, protein matrix in the cotyledon. These changes in seeds structure and molecular properties of starch, protein and pectin, facilitate water hydration rate and cell separation during cooking, leading to the shorter cooking time of the bambara groundnuts. Micronisation of pre-soaked (53% moisture) bambara groundnuts caused molecular changes such as partial starch gelatinisation and reduced protein solubility in the resulting flours. The changes in the starch and proteins modified the resulting flours functional properties such asincrease swelling of the resulting flours, while reducing the water solubility. The pasting viscosities of resulting flours of pre-soaked bambara groundnut reduced following micronisation due to the denatured protein matrix preventing embedded starch hydration, dispersibility and molecular entanglement during pasting.This was evident by light and confocal laser scanning microscopy (CLSM) that showed the aggregates of denatured protein matrix surrounding embedded pre-gelatinised starch granules increase with micronisation in the resulting flours and cooked soft porridge of bambara groundnut. Micronisation has an effect on the apparent viscosity, nutritional, bioactive compound such as phenolics and hence the antioxidant properties of cooked soft porridge of bambara groundnut. All cooked soft porridge of bambara groundnut exhibited a shear thinning behavior and micronised bambara groundnut had lower viscosity increased in the starch and protein digestibility of cooked soft porridge of bambara groundnut. It also increased the phenolic content and antioxidant properties of cooked soft porridge of whole bambara groundnut, but these were reduced in cooked soft porridge of dehulled bambara groundnut due to seed coat absence. Thus, micronisation of pre-soaked bambara groundnut (whole and dehulled) would contribute towards increased utilisation of bambara groundnut as well as improving house hold nutrition and health promoting properties.Micronisation of bambara groundnut has potential to produce a quick paste with low viscosity which depend on the pre-soaking and micronisation time of the bambara groundnut. Flours from micronised bambara groundnut can therefore be used as instant flour ingredient in food products. / Thesis (PhD)--University of Pretoria, 2016. / National Research Foundation (NRF) of South Africa / Food Science / PhD (Food Science) / Unrestricted

The vertical force generated from terrain-tire interaction has long been of interest for vehicle dynamic simulations and chassis development. As the terrain serves as the main excitation to the suspension system through pneumatic tire, proper terrain and tire models are required to produce reliable vehicle response. Due to the high complexity of the tire structure and the immense size of a high fidelity terrain profile, it is not efficient to calculate the terrain-tire interaction at every location. The use of a simpler tire model (e.g. point follower tire model) and a pre-filtered terrain profile as equivalent input will considerably reduce the simulation time. The desired produced responses would be nearly identical to the ones using a complex tire model and unfiltered terrain, with a significant computational efficiency improvement. In this work, a terrain pre-filtering technique is developed to improve simulation efficiency while still providing reliable load prediction. The work is divided into three parts. First a stochastic gridding method is developed to include the measurement uncertainties in the gridded terrain profile used as input to the vehicle simulation. The obtained uniformly spaced terrain is considered probabilistic, with a series of gridding nodes with heights represented by random variables. Next, a constraint mode tire model is proposed to emulate the tire radial displacement and the corresponding force given the terrain excitation. Finally, based on the constraint mode tire model, the pre-filtering technique is developed. At each location along the tire's path, the tire center height is adjusted until the spindle load reaches a pre-designated constant load. The resultant tire center trajectory is the pre-filtered terrain profile and serves as an equivalent input to the simple tire model. The vehicle response produced by using the pre-filtered terrain profile and the simple tire model is analyzed for accuracy assessment. The computational efficiency improvement is also examined. The effectiveness of the pre-filtering technique is validated on probabilistic terrain by using different realizations of terrain profiles. It is shown through multiple profiles that the computational efficiency can be improved by three orders of magnitude with no statistically significant change in resulting loading. / Ph. D.

Hatching eggs storage has also a negative impact on hatching in Japanese quails. Hatchability is significantly reduced when the eggs are stored longer than 10 days. The pre-incubation used in broiler chickens is a method that could reduce the negative impact of long-term storage in the Japanese quail too. In the experiments, a total of one thousand two hundred and ninety pieces of Japanese quail eggs were used. This eggs were divided into pre-incubated eggs and eggs without pre-incubation. The pre-incubation was 8 hours, 3x 1 hour (including pre-incubation on the day of egg collection and subsequently every 5th day), 2x 1 hour (every 5th day of storage) and 3x 1 hour (every 5th day during the 21 day storage). The pre-incubation time was measured, when 35 °C was reached on the surface of the shell (37.5 °C inside the incubator). The eggs were stored at 12.0 °C for 14 and 21 days. Embryonal mortality was determined after hatching. Pre-incubation 8 hours had statistically significant negative effect (P<0.05) on hatchability at storage of 14 days; the hatchability was 76.2% in the non-heated eggs and 56.5% in the pre-incubated eggs. The pre-incubation for 3x 1 hour and 2x 1 hour during the 14 day storage period had positive effect on hatchability, which was improved by 7.1% (pre-incubation for 3x 1 hour) and by 4.8 % (pre-incubation 2x 1 hour), but these positive effects were not statistically significant (P > 0.05). At the last experiment, pre-incubation was applied 3 times for 1 hour during the 21 days of storage, and the positive effect of the pre-incubation, which increased the hatching by 0.9%, was observed. This positive effect was also not statistically significant (P>0.05).