Modeling the dispersion of drilling muds using the bblt model: the effects of settling velocity

The benthic boundary layer transport (bblt) model was widely used in the Atlantic Canadian offshore region to assess the potential impact zones from drilling wastes discharges from offshore oil and gas drilling. The current version of the bblt uses a single-class settling velocity scenario, which may affect its performance, as settling velocity is size, shape, and material dependent. In this study, the effects of settling velocity on bblt predictions were assessed by replacing this single-class settling velocity scenario with a multi-class size-dependent settling velocity scenario. The new scenario was used in a hypothetical study to simulate the dispersion of barite and fine-grained drilling cuttings. The study showed that the effects of settling velocity on bblt predictions are spatial, temporal, and material dependent.     

Integration of Wireless Sensor Networks into Cyberinfrastructure for Monitoring Hawaiian “Mountain-to-Sea” Environments

Monitoring the complex environmental relationships and feedbacks of ecosystems on catchment (or mountain)-to-sea scales is essential for social systems to effectively deal with the escalating impacts of expanding human populations globally on watersheds. However, synthesis of emerging technologies into a robust observing platform for the monitoring of coupled human-natural environments on extended spatial scales has been slow to develop. For this purpose, the authors produced a new cyberinfrastructure for environmental monitoring which successfully merged the use of wireless sensor technologies, grid computing with three-dimensional (3D) geospatial data visualization/exploration, and a secured internet portal user interface, into a working prototype for monitoring mountain-to-sea environments in the high Hawaiian Islands. A use-case example is described in which native Hawaiian residents of Waipa Valley (Kauai) utilized the technology to monitor the effects of regional weather variation on surface water quality/quantity response, to better understand their local hydrologic cycle, monitor agricultural water use, and mitigate the effects of lowland flooding.     

Determinants of Trust for Public Lands: Fire and Fuels Management on the Bitterroot National Forest

Management of public lands occurs today with high levels of scrutiny and controversy. To succeed, managers seek the support, involvement, and endorsement of the public. This study examines trust as an indicator of managerial success and attempts to identify and measure the components that most influence it. A review of trust literature yielded 14 attributes that were hypothesized to contribute to trust, grouped into the three dimensions of Shared Norms and Values, Willingness to Endorse, and Perceived Efficacy. Operationalizing these attributes and dimensions, a telephone survey was administered to a sample of Montana, USA, residents living adjacent to the Bitterroot National Forest (n = 1,152). Each of the attributes was measured in the context of federal lands fire and fuel management. Structural equation modeling showed that all 14 attributes were found to be influential contributors to levels of trust. Results suggest that if managers are to maintain or increase levels of public trust, they need to consider each of trust’s attributes as they make social, ecological, and economic resource decisions.     

Differences in Perceptions of Communication,Tourism Benefits,and Management Issues in a Protected Area of Rural Kenya

With record-breaking tourist visits in Kenya in 2005–2006, communities near the country’s renowned protected areas must undertake or revisit planning efforts to conserve and enhance the region’s natural, social, and economic resources. This article examines the differences between two stakeholder groups in the Samburu region of central Kenya: (1) protected area leadership and staff; and (2) members of the communities adjacent to the protected areas. Based on the results and analysis of 30 in-depth interviews, the authors identify differences between protected area staff and their community members regarding perceptions about communication between the two groups, and the economic benefits of tourism. The different stakeholders agreed, however, about challenges related to equitable distribution of tourism-based employment and revenue. The results indicate a need to reach consensus about what constitutes sufficient communication between national reserves and their community, and to what extent tourism-related revenue and employment should be distributed within the region. A discussion of the potential role of indicators and standards to make such decisions is presented.     

Falls from height during the floor slab formwork of buildings: Current situation in Spain

Problem

One of the phases with the highest risk of falls from a height in the construction of a building is during the floor slab formwork stage. This paper analyzes this particular risk, as well as the most frequently used fall-protection systems.

Method

A survey was carried out to define the current situation in Spain with regard to falls from a height during floor slab formwork and the fall-protection systems used to prevent such a risk.

Results

The results of the survey clarified the current situation in Spain with regard to this risk, and made it clear that there is considerable risk of falling from a height during the floor slab formwork stage.

Discussion

All the safety systems analyzed presented a series of weak points that should be studied in detail before they can be used on building sites.

Impact on industry

The risk of falling associated with floor slab formwork and the most frequently used protection systems are analyzed. As no research had been carried out to date on this type of risk, we consider the research presented in this article to be a pioneer in the field.     

Fuzzy logic for piping risk assessment (pfLOPA)

This paper explores the application of the fuzzy logic for risk assessment of major hazards connected with transportation of flammable substances in long pipelines. As a basis for risk assessment, the framework of the fuzzy Layer of Protection Analysis (fLOPA) was used. fLOPA presents a new approach to risk assessment based on two assumptions: 1. different effects of the layer of protection functions on particular elements of the risks (frequency and severity of consequence), and 2. the application of fuzzy logic system (FLS) composed of three elements: fuzzification, inference process and defuzzification. A further calculation follows LOPA methodology with the use of fuzzy logic system where fuzzy risk matrix is used for risk assessment. A typical case study comprising section of a long pipeline failure is performed and a comparison between the classical LOPA approach and fuzzy approach is made.     

Use of Stable Nitrogen Isotopes and Permeable Membrane Devices to Study what Factors Influence Freshwater Mollusk Survival in the Conasauaga River

Recent biological inventory data shows severe declines in freshwater mussel abundance and biodiversity in the Conasauga River Basin in Northwest Georgia, USA. Based on assessments of habitat conditions, mussel populations should be sustainable. We conducted a study of sediment and water quality to evaluate the impact of anthropogenic contamination on mussel populations. Permeable membrane devices (PMD), polar organic chemical integrative samplers (POCIS™), conventional water and sediment quality analyses, and stable nitrogen isotope ratio analyses (δ¹⁵N) of snails and sediments were used to assess sediment and water quality at target sites throughout the basin. Ambient concentrations of organic contaminants in water were well below any aquatic life criteria; concentrations of some nutrients were detected above aquatic life criteria levels. Most mussel species in the river are endangered or threatened; therefore, snails were collected for δ¹⁵N analyses. Mean δ¹⁵N values for snails collected at forested upper watershed sites (national forest areas) were significantly lower than δ¹⁵N values from snails in agricultural areas. δ¹⁵N values for raw cow manure and manure-treated soil were similar to δ¹⁵N values for snails collected in agricultural areas. Dissolved nitrate from water samples had elevated δ¹⁵N values similar to the upper range of δ¹⁵N values for snails in agricultural areas. Data, particularly stable nitrogen isotope data, indicates that a land use change from national forest land to agriculture alters nitrogen sources to the basin and snails. Implications of nutrient release on freshwater molluscan reproduction, growth, and survival are discussed.     

Receptor modeling of ambient particulate matter data using positive matrix factorization: review of existing methods

Methods for apportioning sources of ambient particulate matter (PM) using the positive matrix factorization (PMF) algorithm are reviewed. Numerous procedural decisions must be made and algorithmic parameters selected when analyzing PM data with PMF. However, few publications document enough of these details for readers to evaluate, reproduce, or compare results between different studies. For example, few studies document why some species were used and others not used in the modeling, how the number of factors was selected, or how much uncertainty exists in the solutions. More thorough documentation will aid the development of standard protocols for analyzing PM data with PMF and will reveal more clearly where research is needed to help future analysts select from the various possible procedures and parameters available in PMF. For example, research likely is needed to determine optimal approaches for handling data below detection limits, ways to apportion PM mass among sources identified by PMF, and ways to estimate uncertainties in the solution. The review closes with recommendations for documenting the methodological details of future PMF analyses.     

Catalytic destruction of 1,2-dichlorobenzene on V2O5-WO3/Al2O3-TiO2 catalyst

Studies on the catalytic destruction of 1,2-dichlorobenzene were carried out on a specially constructed semi-technical equipment whose most important element was a catalytic reactor with a monolithic catalyst in the form of 150 x 150 x 100 mm cubes. A catalyst made from cordierite with an active layer composed of Al2O3 - 64 wt%, TiO2 - 26 wt%, V2O5 - 6.6 wt% and WO3 - 3.4 wt% was used. The reactor made it possible to carry out the process in the temperature range 150-350 degrees C, at variable catalyst loading and different velocities of gas flow through the reactor. The content of 1,2-dichlorobenzene in the air was analysed by a chromatographic method. A significant effect of catalyst loading and temperature on 1,2-dichlorobenzene destruction efficiency was observed and no effect of the linear flow velocity through the catalyst on o-dichlorobenzene destruction efficiency was reported. The applied vanadium-tungsten catalyst on a monolithic carrier made from TiO2/gamma-Al2O3 revealed very good activity that resulted in an over 80% efficiency of 1,2-dichlorobenzene destruction at the temperature around 250 degrees C at a very high catalyst loading reaching ca. 8200 h(-1). Additionally, in this study the kinetics of 1,2-dichlorobenzene decomposition was determined, specifying the order of reaction and dependence of the decomposition rate constant on temperature, using a simple power-rate law model.