Mix proportioning of underground cemented tailings backfill

The usage of cemented tailings backfill (cemented paste backfill) in the underground by mining industry is becoming increasingly important. However, until now, the mix proportioning of CTB has been mainly based on the realization of extensive laboratory tests on a large number of CTB mixes. Therefore, this paper presents a design method for mix proportioning of CTB to minimize the number of trial mixes and provide an appropriate mix proportion. This method is based on the pairing of the response surface method (RSM) and the desirability approach. First, the RSM was used to develop predictive models for the performance properties of CTB. The predicted properties in question are the uniaxial compression strength (UCS), the slump, the solid concentration (solid percent, %Solid) and the cost (based on cement cost) of the CTB. The predictive models that were developed were able to accurately represent the relationships between the physical and chemical characteristics of the CTB components (tailings, binder, water) and the above properties. The results of the modeling phase were then used as input data in the optimization phase (based on desirability approach) to develop optimal recipes for the studied CTBs. This study has demonstrated that the combination of the RSM and desirability approach represents an effective tool for CTB mix proportioning. It has also shown that the mix parameters (cement content, water-to-cement ratio, tailings fineness and density) affect the performance properties of CTB. The results of this research provide a more comprehensive engineering approach to CTB mix proportioning. The developed design method can be useful in reducing the laboratory test protocol needed for the determination of the optimal mix composition.     

Novel nanostructured pHEMA-TiO2 hybrid materials with efficient light-induced charge separation

We report on a new approach to the fabrication of an electronic material: organic-inorganic pHEMA-oxo-TiO(2) hybrid with efficient light-induced separation of charges. Particular attention is paid to the material nanoscale morphology. The size-selected 5.0 nm titanium oxo-alkoxy nanoparticles are prepared in a sol-gel reactor with rapid (turbulent) fluid micromixing and the ligand exchange results in a stable nanoparticulate precursor in HEMA solution, in which polymerization can be induced thermally or by photons. The obtained hybrid materials demonstrate the highest quantum yield of photoinduced charge separation of 50% and can store photoinduced electrons at a number density above 10% Ti atoms.     

Optimization of the side-chain density to improve the charge transport and photovoltaic performances of a low band gap copolymer

Poor processability and low molecular weights are often hindering the efficient utilization of novel conjugated polymers in optoelectronic devices. Increasing the alkyl side-chain density generally enhances the polymer solubility but may affect as well its optoelectronic properties. In this work, we use density functional theory to identify ways to increase the side-chain density of donor-acceptor alternate copolymers based on 2,1,3-benzothiadiazole, thiophene and thieno[3,2-b]thiophene units, without modifying there otherwise promising frontier orbital energy levels. Following the theoretical results, a new polymer could be synthesized, exhibiting good processability and improved charge transport. As a consequence, the photovoltaic device performances of this polymer family could be enhanced, reaching a 3.7% power conversion efficiency in a standard device configuration and without any post-deposition treatment.     

Influence of temperature, pH and NaCl concentration on the maximal growth rate of Brochothrix thermosphacta and a bioprotective bacteria Lactococcus piscium CNCM I-4031

The maximum specific growth rate (μ_max) of Brochothrix thermosphacta, a spoilage bacteria of cooked peeled shrimp, and Lactococcus piscium CNCM I-4031, a bioprotective strain, was investigated under different conditions of temperature, NaCl concentrations and pH. The basic modelling approach used was the Gamma concept (γ-concept) and the model developed was then adapted to shrimp. Cardinal growth parameters were quite similar for the two strains, except for NaCl. No NaCl was required for growth and the NaCl_max was three-times higher for B. thermosphacta than for L. piscium (62 and 23 g l⁻¹ respectively). However, tolerance to NaCl was higher in seafood than in liquid broth, possibly due to presence of osmoltically active molecules. L. piscium and B. thermosphacta were psychrotolerant, with T_min = −4.8 and −3.4 °C, T_opt = 23.4 and 27.0 °C and T_max = 27.2 and 30.8 °C respectively. The optimal pH was neutral and growth possible till pH = 4.8 for the two strains, assuming possible applications of the bioprotective strain in lightly marinated seafood. The μ_max of B. thermosphacta in shrimp was a little higher than in L. piscium whatever the environmental conditions. Validation of the model showed that the γ-concept was suitable for predicting μ_max of B. thermosphacta in shrimp. Data generated in this study can be used to adapt the model to other foods with few additional experiments and the effect of different parameters may be added in the future. The model was less accurate for the bioprotective strain and the effect of NaCl must be studied in more detail directly in the matrix.     

Adsorption kinetic of arsenates as water pollutant on iron, manganese and iron-manganese-modified clinoptilolite-rich tuffs

Arsenate adsorption from aqueous solutions onto clinoptilolite-heulandite rich tuffs modified with iron or manganese or a mixture of both iron and manganese in this work was investigated. A kinetic model was considered to describe the arsenates adsorption on each zeolitic material. The modified clinoptilolite-heulandite rich tuffs were characterized by scanning electron microscopy and X-ray diffraction analysis. The elemental composition and the specific surface area of the zeolitic material were also determined. The arsenate adsorption by the modified zeolites was carried on in a batch system considering a contact time from 5 min to 24h for the kinetic experimentation. The arsenic was detected by atomic absorption spectrometer using a hydride generator. The kinetics of the arsenate adsorption processes were described by the pseudo-second-order model and the obtained parameter k varies from 0.15 to 5.66 microg/gh. In general, the results suggested that the kinetic adsorption of arsenates on the modified clinoptilolite-rich tuffs depend of the metallic specie that modified the surface characteristics of the zeolitic material, the chemical nature of the metal as well as the association between different metallic chemical species in the zeolitic surface.     

The treatment of interstitial cystitis with supratrigonal cystectomy and ileocystoplasty: difference in outcome between classic and nonulcer disease

PURPOSE: Interstitial cystitis is a chronic debilitating condition that mainly affects women. Accumulated evidence indicates that interstitial cystitis is a heterogeneous syndrome. The nonulcer type seems to respond less favorably to various conservative treatments than the classic type. Supratrigonal cystectomy with ileocystoplasty is established treatment for interstitial cystitis refractory to conservative treatment. We evaluate whether classic interstitial cystitis responds differently than nonulcer disease to subtotal bladder resection and ileocystoplasty. MATERIALS AND METHODS: We evaluated 13 patients 27 to 79 years old with interstitial cystitis who underwent supratrigonal cystectomy and ileocystoplasty due to failure to respond to conservative treatment. RESULTS: In all 10 patients with classic interstitial cystitis symptoms were relieved after ileocystoplasty. In the 3 patients with nonulcer interstitial cystitis pain remained, while the frequency of voiding somewhat decreased. In these patients trigonal resection and urinary diversion with a Kock pouch resolved the symptoms. CONCLUSIONS: Our study confirms that supratrigonal cystectomy with ileocystoplasty results in a good outcome in classic interstitial cystitis. However, this method seems to be unsuitable for nonulcer disease. Identification of the relevant subtype of interstitial cystitis is of crucial importance for selecting the appropriate method of lower urinary tract reconstruction.     

Self-efficacy: An additional dimension in play therapy.

Describes the theoretical integration of play therapy theory and self-efficacy theory. A. Bandura (1986) theorized that 4 factors strengthened or weakened individuals' beliefs about personal efficacy: mastery experiences of performance, vicarious experiences that provide for social comparison, verbal persuasion and social influences, and physiological responses. Examples from a case study of a 6-yr-old girl were used to illustrate the principles involved. Implications for teaching the self-efficacy theory along with the play therapy theory are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

I4EU (Industry 4.0 for European Union) ——An European Initiative to Develop Training Activity

This paper presents an on-going European ERASMUS project to develop training programs and tools for Industry 4.0. After an introduction on the background and objective of the project, the paper will give an overview on the structure, partners and organization of the project. Based on the State-of-the-art, the targeted intellectual outputs (IOs) will be presented in detail and the set of planned activities to achieve IOs are outlined. The project progress and preliminary results are shown and the concluding summary will be given at the end of the paper.     

The State of the Art in Agent Communication Languages

Like societies of humans, there is a need for agents in a multi-agent system to rely on one another, enlist the support of peers in order to solve complex tasks. Agents will be able to cooperate only through a meaningful communication language that can bear correctly their mental states and convey precisely the content of their messages. In search for the ideal agent communication language (ACL), several initiatives like the pioneering work of the Knowledge Sharing Effort and the Foundation for Intelligent Physical Agents (FIPA) are paving the way for a platform where all agents would be able to interact regardless of their implementation environment. ACL is a new field of study that could gain from a survey in expanding its application areas. For this purpose, we examine in this paper the state of the art in ACL design and suggest some principles for building a generalized ACL framework. We then evaluate some existing ACL models, and present the current issues in ACL research, and new perspectives. Received 22 July 1999 / Revised 23 March 2000 / Accepted 2 May 2000