Removal of ammonium and phosphorus ions from synthetic wastewater by the microalgae Chlorella vulgaris coimmobilized in alginate beads with the microalgae growth-promoting bacterium Azospirillum brasilense

Coimmobilization of the freshwater microalga Chlorella vulgaris in alginate beads with the microalgae growth-promoting bacterium Azospirillum brasilense under semi-continuous synthetic wastewater culture conditions significantly increased the removal of ammonium and soluble phosphorus ions compared to immobilization of the microalgae alone. In continuous or batch cultures removal of these ions followed a similar trend but was less efficient than in semi-continuous culture. It is proposed that coimmobilization of a microalgae with microalgae growth-promoting bacteria can serve as a tool in devising novel wastewater treatments.     

Recent advances in removing phosphorus from wastewater and its future use as fertilizer (1997-2003)

Large quantities of phosphate present in wastewater is one of the main causes of eutrophication that negatively affects many natural water bodies, both fresh water and marine. It is desirable that water treatment facilities remove phosphorus from the wastewater before they are returned to the environment. Total removal or at least a significant reduction of phosphorus is obligatory, if not always fulfilled, in most countries. This comprehensive review summarizes the current status in phosphorus-removal technologies from the most common approaches, like metal precipitation, constructed wetland systems, adsorption by various microorganisms either in a free state or immobilized in polysaccharide gels, to enhanced biological phosphorus removal using activated sludge systems, and several innovative engineering solutions. As chemical precipitation renders the precipitates difficult, if not impossible, to recycle in an economical industrial manner, biological removal opens opportunities for recovering most of the phosphorus and beneficial applications of the product. This review includes the options of struvite (ammonium-magnesium-phosphate) and hydroxyapatite formation and other feasible options using, the now largely regarded contaminant, phosphorus in wastewater, as a raw material for the fertilizer industry. Besides updating our knowledge, this review critically evaluates the advantage and difficulties behind each treatment and indicates some of the most relevant open questions for future research.     

A note on minimising total absolute deviation of job completion times on a two-machine no-wait proportionate flowshop

A popular measure used in service systems is that of total absolute deviation of job completion times (TADC). It is relevant to settings where the objective is to balance the level of service provided to different customers. During the last decade, TADC has been studied in various machine settings, and under various assumptions on the job processing times. In this note, we study TADC on a two-machine no-wait proportionate flow shop, i.e. a flow shop with machine-independent processing times, and with no buffer between the machines. A very surprising and unique result is introduced: a simple index policy (the well-known largest processing time (LPT) first sequence) is shown to be optimal for instances of no more than seven jobs. This property does not hold for larger instances. We show that for instances of eight and nine jobs, there are exactly two schedules which are candidates for optimality. For the 10-job instance, the number of candidates increases. This uncommon behaviour of the optimal solution and, consequently, the complexity of the problem studied here, remain open questions, and are challenging topics for future research.     

Mood and global–local focus: Priming a local focus reverses the link between mood and global–local processing.

Positive moods promote a focus on the forest (global focus) and negative moods, a focus on the trees (local focus). Is this well-established link fixed or variable? Does it reflect a direct influence of affect, as usually assumed, or is it frequently observed simply because a global perspective is often dominant? If affect serves as information about the value of currently accessible inclinations, and a global focus is generally the default perspective, then the global focus of positive affect and local focus of negative affect might be variable rather than fixed. Two experiments tested this hypothesis using different mood inductions, different tests of global–local focus, and different methods of inducing global and local perspectives. In each, we discovered that positive affect empowered whatever focus was momentarily dominant. Thus, whether individuals in happy moods saw the forest or the trees depended only on which of the two had been primed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On-line Prediction and Conversion Strategies

We study the problem of deterministically predicting boolean values by combining the boolean predictions of several experts. Previous on-line algorithms for this problem predict with the weighted majority of the experts' predictions. These algorithms give each expert an exponential weight ^m where is a constant in [0, 1) andm is the number of mistakes made by the expert in the past. We show that it is better to use sums of binomials as weights. In particular, we present a deterministic algorithm using binomial weights that has a better worst case mistake bound than the best deterministic algorithm using exponential weights. The binomial weights naturally arise from a version space argument. We also show how both exponential and binomial weighting schemes can be used to make prediction algorithms robust against noise.     

Efficient Detection of Vacuity in Temporal Model Checking

The ability to generate a counter-example is an important feature of model checking tools, because a counter-example provides information to the user in the case that the formula being checked is found to be non-valid. In this paper, we turn our attention to providing similar feedback to the user in the case that the formula is found to be valid, because valid formulas can hide real problems in the model. For instance, propositional logic formulas containing implications can suffer from antecedent failure, in which the formula is trivially valid because the pre-condition of the implication is not satisfiable. We call this vacuity, and extend the definition to cover other kinds of trivial validity. For non-vacuously valid formulas, we define an interesting witness as a non-trivial example of the validity of the formula. We formalize the notions of vacuity and interesting witness, and show how to detect vacuity and generate interesting witnesses in temporal model checking. Finally, we provide a practical solution for a useful subset of ACTL formulas.     

Multi-objective thermal design optimization and comparative analysis of electronics cooling technologies

A multi-objective thermal design optimization and comparative study of electronics cooling technologies is presented. The cooling technologies considered are: continuous parallel micro-channel heat sinks, in-line and staggered circular pin-fin heat sinks, offset strip fin heat sinks, and single and multiple submerged impinging jet(s). Using water and HFE-7000 as coolants, Matlab’s multi-objective genetic algorithm functions were utilized to determine the optimal thermal design of each technology based on the total thermal resistance and pumping power consumption under constant pressure drop and heat source base area of 100 mm². Plots of the Pareto front indicate a trade-off between the total thermal resistance and pumping power consumption. In general, the offset strip fin heat sink outperforms the other cooling technologies.     

A Recombinant Collagen–mRNA Platform for Controllable Protein Synthesis

We have developed a collagen–mRNA platform for controllable protein production that is intended to be less prone to the problems associated with commonly used mRNA therapy as well as with collagen skin‐healing procedures. A collagen mimic was constructed according to a recombinant method and was used as scaffold for translating mRNA chains into proteins. Cysteines were genetically inserted into the collagen chain at positions allowing efficient ribosome translation activity while minimizing mRNA misfolding and degradation. Enhanced green fluorescence protein (eGFP) mRNA bound to collagen was successfully translated by cell‐free Escherichia coli ribosomes. This system enabled an accurate control of specific protein synthesis by monitoring expression time and level. Luciferase–mRNA was also translated on collagen scaffold by eukaryotic cell extracts. Thus we have demonstrated the feasibility of controllable protein synthesis on collagen scaffolds by ribosomal machinery.