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The power requirement for the soldier's equipment is largely supplied by batteries. Situational awareness is critical for a soldier to perform his tasks. Therefore the radio used by the soldier is a key element in situational awareness and also consumes the most power. The South African National Defence Force (SANDF) uses the A43 tactical radio specifically designed for them. The radios are regarded as old technology but will be in use for about another five years. The radios still use non-rechargeable alkaline batteries which do not last very long and are not cost effective. The purpose of this study is to research the new generation secondary batteries as a possible replacement for the alkaline battery packs. The new generation batteries investigated in this study are the latest rechargeable batteries, also called secondary batteries. They include nickel cadmium, nickel metal hydride, lithium ion, rechargeable alkaline manganese and zinc air. The main features of rechargeable cells are covered and the cell characteristics are defined to allow the technology to be matched to the user requirement. Li-ion technology was found to be the best choice. This research also showed that international trends in battery usage are towards Li-ion. A new Li-ion battery was designed based on commercial cells. Tests showed that commercial Li-ion cells can be used in the radio and that they outperform the current battery by far. The study also examined the design of a New Generation Battery System consisting of an intelligent battery, a charger which uses a Systems Management Bus and a battery 'state of health" analyser to assist the user to maintain the batteries. Tests were done to demonstrate that the battery can withstand typical military environmental conditions. Expected military missions for a battery system were defined and used to compare the cost between the existing batteries and the new batteries system. Important usage factors which will influence the client when using a New Generation Battery System were addressed. To summarise, this study showed that by using a New Generation Battery System, the SANDF could relieve the operational cost of the A43 radio while saving on weight and enabling the soldier to carry out longer missions. / Thesis (M.Ing. (Electronical Engineering))--North-West University, Potchefstroom Campus, 2008.

Replacing a diseased disc with a tissue engineered disc has the potential to restore normal spinal biomechanics. However, recreating the interface between annulus fibrosus (AF) and vertebral bone (VB) will be necessary to facilitate proper function of the implant in vivo. This study characterizes the native bovine AF-VB interface and assesses adult human discs. The AF insertion site in humans and cows is uniquely differentiated from other soft tissue-bone interfaces, as AF collagen fibers anchor into the calcified region of vertebral endplate through a zone of hyaline cartilage and have a different organization in inner and outer AF. Mineralization-associated proteins are present in this region and the chondroid tissue undergoes calcification over time. Based on these observations an in vitro AF culture system was developed and demonstrated that AF cells can induce mineralization. Understanding mechanism(s) regulating AF mineralization will help develop conditions to ensure proper integration of bioengineered AF.

Replacing a diseased disc with a tissue engineered disc has the potential to restore normal spinal biomechanics. However, recreating the interface between annulus fibrosus (AF) and vertebral bone (VB) will be necessary to facilitate proper function of the implant in vivo. This study characterizes the native bovine AF-VB interface and assesses adult human discs. The AF insertion site in humans and cows is uniquely differentiated from other soft tissue-bone interfaces, as AF collagen fibers anchor into the calcified region of vertebral endplate through a zone of hyaline cartilage and have a different organization in inner and outer AF. Mineralization-associated proteins are present in this region and the chondroid tissue undergoes calcification over time. Based on these observations an in vitro AF culture system was developed and demonstrated that AF cells can induce mineralization. Understanding mechanism(s) regulating AF mineralization will help develop conditions to ensure proper integration of bioengineered AF.

This thesis examined effects of dietary supplementations (0.75%) of the prebiotics of retrograded resistant cornstarch, fibersol-2 and inulin, and oat β-glucan in replacing feed antibiotics on growth performance, plasma urea concentrations, total tract dry matter (DM) and lactose digestibility, fecal scores, proximal jejunal and serum alkaline phosphatase (AP) kinetics and large intestinal fermentation in weanling pigs fed corn and soybean meal-based diets. There were no differences (P > 0.05) in the growth performance, plasma urea concentrations, DM and lactose digestibility and the volatile short-chain fatty acid concentrations in the cecal and fecal samples among the treatment diets. Dietary lactose was completely digested in the weanling pigs. Supplementations of fibersol-2, inulin and β-glucan significantly affected some of the jejunal and serum AP kinetics. In conclusion, lactose was a highly digestible carbohydrate and dietary supplementations of the three prebiotic and β-glucan at 0.75% had little effects on growth performance and plasma urea concentration but might affect gut and the whole body health status via influencing the AP detoxification kinetics in the weanling pigs. / Ontario Pork, Ontario Ministry of Agriculture, Agriculture Adaptation Council

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The extraction yields of insoluble dietary fibre (IDF) and soluble dietary fibre (SDF) from seven whole-grain cereals (WG) ranged from 11.73% to 23.71% and 2.28% to 5.15%, respectively. Eight monomeric phenolic acids and four diferulic acids were identified and quantified in cereal alkaline extracts by reversed phase high performance liquid chromatography coupled with quadrupole - time of flight mass spectrometry. IDF alkaline extracts had significantly (p < 0.05) higher levels of total phenolic content (TPC) and DPPH radical scavenging activity than WG and SDF extracts. Corn IDF (C-IDF) extracts exhibited the highest TPC and DPPH, followed by red rice. MTT cell viability assay indicated that 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) or xanthine-xanthine oxidase (X-XO) induced cell loss can be effectively reduced by pre-incubating Caco-2BBe or FHs 74 Int cells with certain levels of C-IDF extracts. This effect was speculated to be associated with the antioxidant activity of C-IDF linked phenolic compounds.

The treatment of Mn and SO42- contaminated mine drainage via a sulfate reducing bioreactor is expected to result in near-permanent immobilization of significant amounts of Mn and a portion of the sulfates within the matrix. This study tested several different combinations of organic amendments and inorganic substrates in an attempt to optimize sulfate reducing conditions and Mn removal capacity. Five different organic carbon sources, including corn mash, wood mulch, biosolids, soybean oil, and sorghum syrup in combination with five different inorganic substrates, including creek sediment, marble and limestone chips, polished gravel, and sand were tested in batch experiments. Results indicate a widely Mn variant removal potential among the treatments, ranging from 35% for soybean oil to 97% for the mulch mixture, with respective Eh ranges of +60 mV and -320 mV. Sulfate removal ranged from less than 10% to 85%. The most favorable combinations were tested in small scale bioreactors under dynamic conditions. Greater than 90% of Mn and 70% of sulfate was removed over a 65 day test period. Results indicate Mn removal mechanisms include sulfide, oxide, and carbonate formation and simple sorption and SO42- removal mechanisms of sulfide gas evolution, gypsum and MnS precipitation, and anion sorption/cation bridging.

This study revealed that ammonium ion exchange of natural zeolite could be a feasible method of nitrogen removal and recovery from permeate from anaerobic membrane bioreactors (AnMBRs). NaCl concentrations optimized for chemical regeneration in batch experiments did not match those in continuous column tests. Instead, the mass ratio of Na+ to Zeolite-NH4+-N was significant for improving regeneration efficiency in column experiments; this mass ratio was 750 g Na+/g Zeolite-NH4+-N required for regeneration efficiency over 90% in 2 hours at pH 9. ???To decrease the NaCl dose in regeneration of exhausted zeolite, a high pH regeneration method was developed using an NaCl concentration of 10 g/L at pH 12 (the mass of Na+ to Zeolite-NH4+-N of 4.2 ) which achieved a regeneration efficiency about 85%. The recovery of ammonium nitrogen from the exhausted zeolite was assessed with air stripping followed by ammonia collection in an acid scrubber. The effects of shaking and air stripping were investigated in batch tests and the results showed the superiority of air stripping over shaking. Liquid circulation and air flow rates were varied for optimization of ammonia recovery in a continuous zeolite-packed column combined with a regeneration chamber and a stripping column. The liquid circulation rate had no significant effect on either the regeneration efficiency or the ammonia transfer efficiency from ammonium nitrogen to ammonia gas, while the ammonia transfer efficiency significantly increased with the air flow rate.??? Furthermore, the effect of pH on ammonia recovery was tested. Both the regeneration efficiency and the ammonia transfer efficiency were significantly improved with increasing pH. When the pH was increased from 9.5 to 12, the regeneration efficiency increased from 9.2% to 84% and the ammonia transfer efficiency increased from 54% to 92%. The nitrogen recovery process that combines zeolite ammonium exchange and air stripping can decrease chemical costs for regeneration of exhausted zeolite and efficiently collect ammonium nitrogen to be reused as fertilizers. Hence, the integrated nitrogen process can resolve the challenge of nitrogen removal in anaerobic membrane bioreactors treating organic wastewater in sustainable manners.

The power requirement for the soldier's equipment is largely supplied by batteries. Situational awareness is critical for a soldier to perform his tasks. Therefore the radio used by the soldier is a key element in situational awareness and also consumes the most power. The South African National Defence Force (SANDF) uses the A43 tactical radio specifically designed for them. The radios are regarded as old technology but will be in use for about another five years. The radios still use non-rechargeable alkaline batteries which do not last very long and are not cost effective. The purpose of this study is to research the new generation secondary batteries as a possible replacement for the alkaline battery packs. The new generation batteries investigated in this study are the latest rechargeable batteries, also called secondary batteries. They include nickel cadmium, nickel metal hydride, lithium ion, rechargeable alkaline manganese and zinc air. The main features of rechargeable cells are covered and the cell characteristics are defined to allow the technology to be matched to the user requirement. Li-ion technology was found to be the best choice. This research also showed that international trends in battery usage are towards Li-ion. A new Li-ion battery was designed based on commercial cells. Tests showed that commercial Li-ion cells can be used in the radio and that they outperform the current battery by far. The study also examined the design of a New Generation Battery System consisting of an intelligent battery, a charger which uses a Systems Management Bus and a battery 'state of health" analyser to assist the user to maintain the batteries. Tests were done to demonstrate that the battery can withstand typical military environmental conditions. Expected military missions for a battery system were defined and used to compare the cost between the existing batteries and the new batteries system. Important usage factors which will influence the client when using a New Generation Battery System were addressed. To summarise, this study showed that by using a New Generation Battery System, the SANDF could relieve the operational cost of the A43 radio while saving on weight and enabling the soldier to carry out longer missions. / Thesis (M.Ing. (Electronical Engineering))--North-West University, Potchefstroom Campus, 2008.