Effects of mineral admixtures and lime on disintegration of alkali-activated slag exposed to 50 °c

Alkali-activated slag can totally disintegrate when exposed to 50 C. This paper presents a study of possible solutions to avoid this disintegration by using silica fume (SF) and fly ash (FA) to partially replaceslag. It was found that partial replacement of slag with SF significantly reduces strength loss. A mixture of 50% slag 50% SF (cured at 25 and 60 C) showed no strength loss after the exposure. In comparison, a55% drop of strength was observed in a mixture of 50% slag 50% FA (cured at 25 C) after the same exposure.However, the strength loss of this mixture was reduced by 50% when cured at 60 C. The presence oflime in AAS pastes increases the degree of strength loss after the exposure. The mechanisms for the abovestrength results are discussed in terms of hydration products and microcracking.

Life events and cognitive processing in sexually dysfunctional individuals

The aim of this study was to make an assessment of the role of the cognitive component in the development of sexual dysfunction. Past studies have largely focused on the impact of particular events on sexual dysfunction and have not assessed the role of the perception of these events. A number of theories on sexual dysfunction have been developed to explain the influence of cognitions, but these have not been empirically tested. This study investigated the role of the cognitive evaluation of sexual experiences among 30 sexually dysfunctional participants and 30 control participants who were matched on age, marital status and biological sex. The Cognitive Aspects of Sexual Dysfunction Measure (CASDM) was constructed to evaluate sexual dysfunction. This measure was designed to tap into the major events in participants’ lives and, more importantly, the participants’ perceptions of these events. The components assessed were the intergenerational (family of origin), individual, current life and relationship aspects of the person’s life. These factors were measured from the responses to questions regarding the participant's cognitions about past experiences, the effect of the past experience on the participant at the lime it occurred and the influence this experience had on the participant's sense of self now, their relationship now and sexual functioning now. The main findings in the intergenerational area were that past experiences were perceived by the sexually dysfunctional group to be having an impact on the self, relationships and their sexual functioning although there were no actual differences between the sexually functional and the sexual dysfunctional participants in the occurrence of the event. For the individual factors, there were differences between the sexually functional and sexually dysfunctional participants in both values and lifestyle, although these were not perceived to be having an impact on the self, relationship and sexual functioning. In the relationship area, anger was the major factor separating the sexually functional and sexually dysfunctional groups. Anger was high among the sexually dysfunctional participants and was perceived to be having an impact on self, the couple’s relationship and their sexual functioning. The importance of all these variables in providing a better understanding of the cognitive factors in sexual dysfunction was discussed. The findings demonstrate the importance of cognitions in influencing sexual functioning. Clinicians should not simply deal with the life experiences of sexually dysfunctional people when attempting to change their behaviour, but should focus on changing cognitions about the behaviours in relation to sexual functioning.

Ranking of pre-treatment technologies for reverse osmosis for water recovery

Agro-industries are a life-line for sustainable future of human kind. However, the wastewater generated by agro-industries poses direct threat to the same sustainable future by polluting the freshwater sources when discharged into those freshwater sources. Thus, we need both advanced treatment technologies to treat those wastewater streams generated and better reuse practices for the treated effluents. Reverse osmosis (RO) is one of the advanced treatments to treat dissolved solids that are present in agricultural wastewater streams. But, RO is very sensitive to suspended solids (SS) present in the wastewater streams. Those SS can foul the RO membrane and make it ineffective in producing treated effluent at desired rates. Therefore, suitable pre-treatment scheme is necessary to treat the agro-wastewater streams before passing through RO. This study focuses on the qualitative and quantitative ranking of the available conventional and modern pre-treatment technologies as pre-treatment for RO. This study considers wastewater that has been treated through a secondary treatment system for example activated sludge process as the target water that needs pre-treatment. Based on qualitative ranking of conventional pre-treatment options, the Lime clarification/Granular Media filtration (GMF) option is ranked as the best; whereas finescreens/ micro-screens option ranked as the least preferred option based on the scores they attained in treating the water quality parameters that are considered essential. Based on the quantitative ranking, the low pressure membrane technology such as ultra-filtration (UF) stood first and microfiltration (MF) stood last.

A corrosion inhibition study of steel grinding balls in an oxygen and alkaline environment

The corrosion of steel grinding balls is a major recurrent cost for mill operators concerned with the production gold. Subsequently, the use of corrosion inhibitors in production fluids, which is typically at pH >9, is an attractive and economical option. This study reports on the corrosion wear of steel grinding balls under alkaline/oxygen conditions and in presence of cyanide. A fundamental study on the influence of several inorganic-based inhibitors (i.e., nitrite, chromate, silicate, hexametaphosphate) on the corrosion rate of carbon steel was undertaken. Subsequently, the corrosion performances of various inhibitors were evaluated in stirred vessels. Corrosion rates were determined via mass loss and electrochemical methods (i.e., linear polarisation, Tafel). It was observed that inhibitors based upon chromate provide superior protection under the conditions investigated in this study. In lime treated, high chloride waters, chromate gave over 80% protection at levels of 10 100 ppm with no evidence of pitting.

Large iterative multitier ensemble classifiers for security of big data

This paper introduces and investigates large iterative multitier ensemble (LIME) classifiers specifically tailored for big data. These classifiers are very large, but are quite easy to generate and use. They can be so large that it makes sense to use them only for big data. They are generated automatically as a result of several iterations in applying ensemble meta classifiers. They incorporate diverse ensemble meta classifiers into several tiers simultaneously and combine them into one automatically generated iterative system so that many ensemble meta classifiers function as integral parts of other ensemble meta classifiers at higher tiers. In this paper, we carry out a comprehensive investigation of the performance of LIME classifiers for a problem concerning security of big data. Our experiments compare LIME classifiers with various base classifiers and standard ordinary ensemble meta classifiers. The results obtained demonstrate that LIME classifiers can significantly increase the accuracy of classifications. LIME classifiers performed better than the base classifiers and standard ensemble meta classifiers.

Cement-Wood composites: effects of wood species, particle treatments and mix proportion

The aim of this research was to investigate the effects of wood species, particle treatments and mix proportion on the physical (density) and mechanical (compressive strength and dynamicmodulus of elasticity) properties of cement-wood composites. Different mix proportions were investigated, based on the cement: wood ratio of 0.3:0.7, in volume, with Pinus elliottii and Eucalyptus grandis sawdust percentages of 0-100, 25-75, 50-50, 75-25 or 100-0. Sawdust particles were pre-treated with either lime or cement coating to improve cement and wood compatibility. Results show that wood species, particle treatments and mix proportions may influence the physical and mechanical properties of cement-wood composites. In general, results confirm that Eucalyptus sawdust and cement are naturally compatible and do not require any previous particle treatment to avoid compatibility problems.