Proceedings of SAT Competition 2014 : Solver and Benchmark Descriptions

Peer reviewe

Proceedings of SAT Competition 2013 : Solver and Benchmark Descriptions

Peer reviewe

Towards a Generic CNF Simplifier for Minimising Structured Problem Hardness

CNF simplifiers play a very important role in minimising structured problem hardness. Altough they can be used in an in-search process, most of them serve in a pre-search phase and rely on one form or another of resolution. Based on our understanding about problem structure, in the paper, we extend the single pre-search process to a multiple one in order to further simplify the hard structure in a problem. This extension boosts the performance of state-of-theart clause learning and lookahead based SAT solvers when solving both satisfiable and unsatisfiable instances of many real-world hard combinatorial problems

Automated Deduction – CADE 28

This open access book constitutes the proceeding of the 28th International Conference on Automated Deduction, CADE 28, held virtually in July 2021. The 29 full papers and 7 system descriptions presented together with 2 invited papers were carefully reviewed and selected from 76 submissions. CADE is the major forum for the presentation of research in all aspects of automated deduction, including foundations, applications, implementations, and practical experience. The papers are organized in the following topics: Logical foundations; theory and principles; implementation and application; ATP and AI; and system descriptions

Sewage sludge heavy metal analysis and agricultural prospects for Fiji

Insoluble residues produced in Waste Water Treatment Plants (WWTP) as by products are known as sewage sludge (SS). Land application of SS, particularly in agricultural lands, is becoming an alternative disposal method in Fiji. However, currently there is no legislative framework governing its use. SS together with its high nutrient and organic matter contents, constitutes some undesired pollutants such as heavy metals, which may limit its extensive use. The focus of this study therefore was to determine the total concentrations of Pb, Zn, Cd, Cu, Cr, Ni and Mn in the SS produced at the Kinoya WWTP (Fiji) and in the non-fertile soil amended with the SS at 20, 40, 60, 80% application rates and in the control (100% Soil). The bioavailable heavy metals were also determined as it depicts the true extent of metal contamination. The treatment mixtures were then used to cultivate cabbage plants in which the total heavy metal uptake was investigated. Total Zn (695.6 mg/kg) was present in the highest amounts in the 100% SS (control), followed by Pb (370.9 mg/kg), Mn (35.0 mg/kg), Cu (65.5 mg/kg), Cr (20.5 mg/kg) and finally Cd (13.5 mg/kg) and hence a similar trend was seen in all treatment mixtures. The potential mobility of sludgeborne heavy metals can be classified as Ni > Cu > Cd > Zn > Mn > Cr > Pb. Total metal uptake in plant leaves and stems showed only the bioavailable metals Cu, Cd, Zn and Mn, with maximum uptake occurring in the leaves. Ni, despite being highly mobile was not detected, due to minute concentrations in the SS treatments. Optimum growth occurred in the 20 and 40% SS treatments. However maximum Cu and Mn uptake occurred in the 40% SS treatment thereby making the 20% treatment the most feasible. Furthermore the total and bioavailable metal concentrations observed were within the safe and permitted limits of the EEC and USEPA legislations