OPTIMISATION OF THE PREPARATION OF RANEY COPPER-ZINC CATALYSTS FOR METHANOL SYNTHESIS

The large number of variables involved in the preparation of Raney copper-zinc catalysts for methanol synthesis were screened by statistical methods using a Plackett-Burman screening design. Three important variables, leach reaction temperature, leach digestion temperature and leach digestion time were further investigated using a central composite design. It was found that active Raney copper-zinc catalysts were produced using high (348-358?K) extraction temperature, low (298-318?K.) digestion temperature and long (70-80 min) digestion time     

Obesity. The food research agenda

It is estimated that almost 287 million children will be obese by 2010, and the overall obese population could rise to 700 million by 2015. The metabolic syndrome is a condition characterized by central obesity, hypertension, and disturbed glucose and insulin metabolism, and has been linked to increased risk of both type 2 diabetes and cardiovascular diseases. Diet, socioeconomic, and lifestyle factors have a central role to play in the obesity epidemic. In this respect, the role of particular dietary components on satiety and regulation of food and energy intake, are discussed as are technological approaches to manufacture of foods with low obesigenicity.     

MULTIRESPONSE MODELING OF THE OXIDATION OF NAPHTHALENE OVER A VANADIA CATALYST

The oxidation of naphthalene was studied over an industrial vanadium pentoxide (V₂O₅) catalyst which was promoted by potassium sulphate. Multi-response data were obtained at 335, 350, 365 and 380°C for oxygen to naphthalene mole ratios from 47:1 to 3:1. The data were fitted to the two-step Redox and Steady State Adsorption (SSAM) Models using multiple-response non-linear regression techniques.

In this, the first reported study of the application of multi-response techniques to modeling of naphthalene oxidation, certain inadequacies in the two-step models have been found. In particular, negative activation energies were obtained for the oxidation of naphthalene and 1,4-naphthoquinone in the formation of phthalic anhydride. An activation energy of 146 kJ.mol^-1 was obtained for the rate of oxidation of the catalyst. The overall process of naphthalene oxidation was highly temperature-sensitive over the range of temperatures investigated as evidenced by an effective activation energy of 125 kJ.mol^-1.     

EFFECT OF SOLUBLE POLYLACTIC ACID DURING REFRIGERATED STORAGE OF GROUND MEATS INOCULATED WITH ESCHERICHIA COLI O157:H71

Ground beef, ground pork, and commercial breakfast sausage were inoculated (6.5 log₁₀ CFU/mL) with a five strain mixture of Escherichia coli 0157:H7 and treated either with sterile water, or 1% or 2% solutions of soluble polylactic acid (SPLA) in sterile water and stored at 4C for 1, 24, 72 and 168 h. After 168 h, 2% SPLA was significantly (p0.05) more effective than both 1% SPLA and sterile water in reducing E. coli 0157:H7 and resulted in overall reductions of 1.68, 1.70, and 1.32 log₁₀ CFU/mL for beef, pork, and pork sausage, respectively, when compared to control samples. The meat samples treated with 1% and 2% SPLA maintained significantly (p 0.05) lower pH values throughout refrigerated storage of 168 h with the higher concentration sustaining pH values from 3.83 to 3.92. Although the inhibitory effect of this acid increased with storage time, E. coli 0157:H7 survived these acidic conditions, with water activity levels ranging from 0.972 to 0.991.     

Inflorescence and bunch architecture development in Vitis vinifera L.

Inflorescence development from budburst to harvest was analysed in four cultivars of grapevine. Two cultivars with tight or compact bunches (Riesling, Chardonnay) and two with loose or open bunches (Exotic and Sultana) were selected to define differences in bunch development for future genetic analysis. A range of phenotypic characters for both inflorescence and shoot architecture were measured. Differences in the rate of rachis elongation rates were observed between tight and loose bunch cultivars commencing at the earliest stages of inflorescence development after budburst. At anthesis, five phenotypic characters showed significant differences between tight and loose cultivars: (1) total inflorescence length, (2) node number per inflorescence rachis, (3) combined length of two consecutive internodes of the rachis and (4) shoot node position at which the inflorescence was present and (5) mature tendril length. A quantitative estimate of bunch compactness was calculated at bunch maturity. Exotic and Sultana had significantly more open space than did compact bunch cultivars Riesling and Chardonnay. Comparison of flower number at anthesis and berry number at maturity indicated that the proportion of berries set was similar in all cultivars studied and, therefore, did not contribute to variability in bunch openness between cultivars. Internode length of the inflorescence rachis was the major trait responsible for inflorescence openness. Cellular studies using SEM, fluorescence microscopy and DNA content demonstrated that differences in rachis internode lengths were mostly associated with cell expansion.     

EXTENDING SET FUNCTIONS AND RELATIONS

Abstract

Zadeh's extension principle is applicable to functions defined upon elements of a set. A new extension principle is developed for functions defined upon power sets. Another extension is proposed for relations between sets, such as subsethood. A formal relation connects the two new extension principles. The new extension principles are not a consequences of Zadeh's original.     

A KNOWLEDGE-BASED NAVIGATION SCHEME FOR AUTONOMOUS LAND VEHICLES

A knowledge-based navigation system for autonomous land vehicles (ALVs) has been developed which can successfully negotiate an obstacle and threat-laden terrain, even if nothing is known beforehand about the terrain. The ALV stores new information in its memory as it travels, has the ability to backtrack out of unexpected dead ends, and performs spontaneous decision making in the field based on local sensor readings. The optimal global route of the ALV journey is obtained using dynamic programming, and decision making is accomplished via a production rule-based system. Execution examples demonstrate the power of the prototype system to solve navigation problems. This establishes the feasibility of constructing a valid ALV by combining search techniques with artificial intelligence tools such as production rule-based systems.     

FRP加强R/C梁防火性能调查研究

对纤维加强聚合物(FRP)材料加强钢筋混凝土梁在火灾中的防火性能进行了研究。试验结果显示,防火材料能够帮助构件达到标准防火性能,同时对不断增长的FRP应用也很重要。介绍了不同文献对FRP在高温下的性能所做的研究以及目前标准对建筑构件的耐火极限要求。对两个大型试验进行了介绍。试验材料为混凝土梁构件,外部用FRP板加强,并且三分之二用专利耐火隔热材料保护。给出了试验结果,并重点强调了曝火状态下所测得的构件温度。试验数据验证了热传导数值模型,该模型可用于预测加强并绝缘钢筋混凝土梁构件内的温度。试验结果和模型数据显示,正确设计和进行绝缘保护的FRP加强梁构件耐火极限能够达到4h或者以上。