Developing a process equipment failure knowledge base using ontology approach for process equipment related incident investigations

Process equipment failures (PEFs) are one of the most important causes of process incidents occurrences. To investigate and prevent the PEFs, in addition to having the previous data, it is necessary to have some resources of the PEFs domain knowledge. Nowadays, PEFs data are usually retrieved from existent databases. Customary databases present only previously stored data of equipment failures but, for carrying out a comprehensive PEFs management it is necessary to have access to the PEFs desired knowledge and not only stored data. This paper aims to offer a knowledge base for the PEFs through adopting an ontological approach and then to use the proposed knowledge base for further applications particularly, process incident investigation activities. Through adding semantic search capability, the proposed knowledge base could upgrade the data presenting feature of the common databases into a knowledge presenting feature. Using this approach, the user would be able to extract the desired knowledge of the PEFs along the virtual stored data of occurred cases. The knowledge extraction process and the data mining of occurred incidents are both necessary for the PEFs investigation.     

On–off control of aeration time in the simultaneous removal of ammonia and manganese using a biological aerated filter system

The biological aerated filter (BAF) system, a new alternative in drinking water treatment, was designed to remove NH₄⁺–N and Mn²⁺ simultaneously. This study aimed to control the aeration time in the BAF system for simultaneous NH₄⁺–N and Mn²⁺ removal to achieve the Malaysian effluent quality regulation for drinking water. The experiment was conducted under four strategies of S1, S2, S3 and S4. The results demonstrated that acceptable levels of NH₄⁺–N and Mn²⁺ were achieved over a 6 h aeration period (S1), producing effluent concentrations of 0.7 mg/L (93.2% removal) and 0.08 mg/L (79.6% removal), respectively. At the initial treatment of S1 and S2, the dissolved oxygen (DO) level rapidly increased until it reached a saturated concentration (6.8 mg/L DO) after 2 h period. Automatic on–off aeration time to maintain 3 mg/L DO set point (S4) resulted with a good effluent quality of NH₄⁺–N and Mn²⁺ compared with the 2 mg/L DO set point (S3) which did not meet the regulated standard limits. Through the automatic on–off aeration time, the saturated and excessive DO levels in the BAF system can be avoided consequently reduce the wastage of energy and electrical consumption for simultaneous NH₄⁺–N and Mn²⁺ removal from drinking water treatment.     

Online sorting of recovered wood waste by automated XRF-technology. Part I: detection of preservative-treated wood waste

Waste wood is frequently contaminated with wood treatment preservatives including chromated copper arsenate (CCA) and alkaline copper quat (ACQ), both of which contain metals which contaminate recycled wood products. The objective of this research was to propose a design for online automated identification of As-based and Cu-based treated wood within the recovered wood waste stream utilizing an X-ray fluorescence (XRF) system, and to evaluate the detection parameters of such system. A full-scale detection unit was used for experimentation. Two main parameters (operational threshold (OT) and measurement time) were evaluated to optimize detection efficiencies. OTs of targeted metals, As and Cu, in wood were reduced to 0.02 and 0.05, respectively. The optimum minimum measurement time of 500 ms resulted in 98%, 91%, and 97% diversion of the As, Cu and Cr mass originally contained in wood, respectively. Comparisons with other detection methods show that XRF technology can potentially fulfill the need for cost-effective processing at large facilities (>30 tons per day) which require the removal of As-based preservatives from their wood waste stream.     

Potential neoplastic effects of parathion-methyl on rat liver

The mutagenic and carcinogenic effects of parathion-methyl were examined by bacterial reverse assay and a long term experiment with Wistar rats. The potential mutagenic effect of parathion-methyl in Salmonella typhimurium TA100 bacterial cells was observed without rat liver S9 metabolic activation. Parathion-methyl was further investigated for pathological changes in rat pancreas and liver. The long-term rat experiments showed that parathion-methyl exposure for 3 months can cause pathological changes in rat pancreases acinar cells and pancreatic hepatocytes. Atypical acinar cell focuses (AACF) were determined in the liver and pancreas of the rats. The results from short-term Ames test and long-term rat experiments suggest that parathion-methyl would be potential carcinogenic.     

Techno-environmental risks and ecological modernisation in “double-risk” societies: reconceptualising Ulrich Beck’s risk society thesis

By utilising a relatively underused framework developed by Maurie J. Cohen (1997. Risk society and ecological modernisation alternative visions for post-industrial nations. Futures, 29 (2), 105–119), this theoretical paper joins two of the most debated theories of environmental politics – ecological modernisation (EM) and Ulrich Beck’s risk society thesis – into a unified framework and problematises some of their implicit assumptions to theoretically introduce the notion of a “double-risk” society. In addition, it explains the differences between the traditional “Risk Society” theorised by the German sociologist Ulrich Beck and the newly introduced concept of a “double-risk” society. The arguments put forward in this paper provide some fresh perspectives facilitating the study of the techno-environmental risks and other ecological problems faced by “double-risk” societies. Theoretically, this paper adds to both EM theory and the risk society thesis as the generalisability of their existing versions is limited precisely because they fail to address some important social changes at the global structural level.     

Negative carbon via Ocean Afforestation

Ocean Afforestation, more precisely Ocean Macroalgal Afforestation (OMA), has the potential to reduce atmospheric carbon dioxide concentrations through expanding natural populations of macroalgae, which absorb carbon dioxide, then are harvested to produce biomethane and biocarbon dioxide via anaerobic digestion. The plant nutrients remaining after digestion are recycled to expand the algal forest and increase fish populations. A mass balance has been calculated from known data and applied to produce a life cycle assessment and economic analysis. This analysis shows the potential of Ocean Afforestation to produce 12 billion tons per year of biomethane while storing 19 billion tons of CO₂ per year directly from biogas production, plus up to 34 billion tons per year from carbon capture of the biomethane combustion exhaust. These rates are based on macro-algae forests covering 9% of the world's ocean surface, which could produce sufficient biomethane to replace all of today's needs in fossil fuel energy, while removing 53 billion tons of CO₂ per year from the atmosphere, restoring pre-industrial levels. This amount of biomass could also increase sustainable fish production to potentially provide 200 kg/yr/person for 10 billion people. Additional benefits are reduction in ocean acidification and increased ocean primary productivity and biodiversity.     

Impacts of sublethal lead exposure on the hemato-immunological parameters in tilapia (Oreochromis mossambicus)

The effects of exposure of tilapia (Oreochromis mossambicus) to sublethal concentrations of lead on hematological and immunological parameters were investigated. The fish were semistatically exposed to low (L) (0.5 mg L^?1), medium (M) (2.5 mg L^?1), and high (H) (5 mg L^?1) lead concentrations for 14 days. At the end of the trial, red blood cell (RBC) count, hematocrit (Hct) ratio and hemoglobin levels showed significant decreases in M and H groups, while RBC was significantly increased in L group compared to control group. Lysozyme activity showed a decrease in all groups on day 14 compared to control. A decrease in myeloperoxidase activity was seen in M and H groups on day 7, and in all treatment groups on day 14. In conclusion, it was found that exposure of O. mossambicus to lead concentrations affected hematological and immunogical parameters adversely.     

Honey bee waggle dance communication: signal meaning and signal noise affect dance follower behaviour

Returning honey bee foragers perform waggle dances to inform nestmate foragers about the presence, location and odour of profitable food sources and new nest sites. The aim of this study is to investigate how the characteristics of waggle dances for natural food sources and environmental factors affect dance follower behaviour. Because food source profitability tends to decrease with increasing foraging distance, we hypothesised that the attractiveness of a dance, measured as the number of dance followers and their attendance, decreases with increasing distance to the advertised food location. Additionally, we determined whether time of year and dance signal noise, quantified as the variation in waggle run direction and duration, affect dance follower behaviour. Our results suggest that bees follow fewer waggle runs as the food source distance increases, but that they invest more time in following each dance. This is because waggle run duration increases with increasing foraging distance. Followers responded to increased angular noise in dances indicating more distant food sources by following more waggle runs per dance than when angular noise was low. The number of dance followers per dancing bee was also affected by the time of year and varied among colonies. Our results provide evidence that both noise in the message, that is variation in the direction component, and the message itself, that is the distance of the advertised food location, affect dance following. These results indicate that dance followers may pay attention to the costs and benefits associated with using dance information.     

Effect of zinc oxide nanoparticles on the trace element contents of soils

In the last few decades, metal oxide nanoparticles have shown impact in various areas, and such an impact causes an increased release in a different environment like soil, water, or air. A limited number of studies on soils showed that the biochemical parameters were affected by the metal oxide nanoparticles. However, the influence of metal oxide nanoparticles on soil elements has not been investigated. For this aim, zinc oxide nanoparticles were applied to two different soils; also, the effect of planting on soil elements was investigated via the cultivation of various plants roots (taproots, fibrous, bulb). Soils were treated with zinc oxide nanoparticles at 0, 1.0 and 20.0?mg during 4 weeks. Then, surface soil samples were collected and digested using an acid digestion procedure. Some biochemically important elements (Ca, Zn, Mg, Fe, Al, Cu, Co, Ni) were determined using a microwave plasma atomic emission spectrometer. The effect of time and dose-dependent zinc oxide nanoparticles on the element contents of different soils was investigated during planting, and the results were statistically evaluated.     

The perception of Malaysian pedestrians toward the use of footbridges

Objective: The footbridge is a vital structure in the road network and a cornerstone among crossing facilities. Yet, it suffers from low usage by pedestrians as they try to cross the street on the level. This study aims to analyze the perceptions of Malaysian pedestrians toward the use of footbridges with the consideration of different factors.

Method: The study was carried out by collecting data from field observation and questionnaire distribution on the street among the public. The data were statistically analyzed by applying multiple linear regression models and a series of chi-square tests.

Results: The study found that the most influential factor cited by pedestrians in decision making regarding using a footbridge is the existence of an escalator. Being in a hurry and the fear of heights were significantly associated with choosing not to use a footbridge. Zebra crossing was chosen as the most favorable type of crossing facility by the majority of respondents. In addition, installation of a fence and barriers was proposed as an effective procedure to prevent jaywalking. To construct new and efficient footbridges in the future, the study suggests consideration of traffic volume, posted speed limit, and the number of lanes, because these are the most influential factors to predict the usage rate.

Conclusions: The study encourages decision makers and stakeholders to consider providing escalators for new footbridges to enhance the safety of pedestrians.