The Swedish monitoring of surface waters: 50 years of adaptive monitoring

For more than 50 years, scientific insights from surface water monitoring have supported Swedish evidence-based environmental management. Efforts to understand and control eutrophication in the 1960s led to construction of wastewater treatment plants with phosphorus retention, while acid rain research in the 1970s contributed to international legislation curbing emissions. By the 1990s, long-time series were being used to infer climate effects on surface water chemistry and biology. Monitoring data play a key role in implementing the EU Water Framework Directive and other legislation and have been used to show beneficial effects of agricultural management on Baltic Sea eutrophication. The Swedish experience demonstrates that well-designed and financially supported surface water monitoring can be used to understand and manage a range of stressors and societal concerns. Using scientifically sound adaptive monitoring principles to balance continuity and change has ensured long-time series and the capability to address new questions over time.     

Spatial Distribution of Particulates from Sugar Cane Fires in Hawaii: Measurements and Calculations

Since cotton today is machine picked, the mere process of ginning creates a significant amount of trash and dust. A large cotton gin in Fresno operating at 23 bales per hour uses two rotating filters to control this material. Total emissions from the facility are in the order of 50 pounds per hour, or about one-half the emissions from a typical gin using cyclones as control equipment.     

Improvement of Baltic proper water quality using large-scale ecological engineering

Eutrophication of the Baltic proper has led to impaired water quality, demonstrated by, e.g., extensive blooming of cyanobacteria during the premium summer holiday season and severe oxygen deficit in the deepwater. Sustainable improvements in water quality by the reduction of phosphorus (P) supplies will take several decades before giving full effects because of large P storages both in soils in the watershed and in the water column and bottom sediments of the Baltic proper. In this article it is shown that drastically improved water quality may be obtained within a few years using large-scale ecological engineering methods. Natural variations in the Baltic proper during the last decades have demonstrated how rapid improvements may be achieved. The present article describes the basic dynamics of P, organic matter, and oxygen in the Baltic proper. It also briefly discusses the advantages and disadvantages of different classes of methods of ecological engineering aimed at restoring the Baltic proper from eutrophication effects. Preliminary computations show that the P content might be halved within a few years if about 100 kg O2 s(-1) are supplied to the upper deepwater. This would require 100 pump stations, each transporting about 100 m3 s(-1) of oxygen-rich so-called winter water from about 50 to 125 m depth where the water is released as a buoyant jet. Each pump station needs a power supply of 0.6 MW. Offshore wind power technology seems mature enough to provide the power needed by the pump stations. The cost to install 100 wind-powered pump stations, each with 0.6 MW power, at about 125-m depth is about 200 million Euros.     

Release of fluorocarbons from insulation foam in home appliances during shredding

It is a current practice that refrigerators and freezers in many countries are shredded after the end of useful lives. The shredder residue is deposited in landfills. During the shredding process a significant fraction of blowing agent (BA) in the insulation foam may be released into the atmosphere. The objective of this study is to determine the fraction of BA released from foam during shredding, by comparing the BA content in insulation foam of refrigerator units before shredding with the BA content of shredded foam. All foam samples analyzed were manufactured with trichlorofluoromethane [CFC-11 (CCl3F)] as BA. The average content of BA in the insulation foam from eight U.S. refrigerator units manufactured before 1993 was found to be 14.9% +/- 3.3% w/w. Several refrigerator units also identified as being manufactured before 1993 were stockpiled and shredded at three shredder facilities, of which one was operated in both wet and dry modes. The selected shredder facilities represent typical American facilities for shredding automobiles, refrigerators, freezers, and other iron containing waste products. Shredded material was collected and separated on location into four particle size categories: more than 32 mm, 16-32 mm, 8-16 mm, and 0-8 mm. Adjusting for sample purity, it was found that the majority (>81%) of the foam mass was shredded into particles larger than 16 mm. The smallest size fraction of foam (0-8 mm) was found to contain significantly less BA than the larger size categories, showing that up to 68% +/- 4% of the BA is released from these fine particles during the shredding process. Because only a minor fraction of the foam is shredded into particles smaller than 8 mm, this has a minor impact on the end result when calculating the total BA release from the shredding process. Comparing BA content in shredded samples from the three shredder facilities with the measured average BA content of the eight refrigerator units, it was found that on average 24.2% +/- 7.5% of the initial BA content is released during the shredding process.     

Stabilization of As, Cr, Cu, Pb and Zn in soil using amendments--a review

The spread of contaminants in soil can be hindered by the soil stabilization technique. Contaminant immobilizing amendments decrease trace element leaching and their bioavailability by inducing various sorption processes: adsorption to mineral surfaces, formation of stable complexes with organic ligands, surface precipitation and ion exchange. Precipitation as salts and co-precipitation can also contribute to reducing contaminant mobility. The technique can be used in in situ and ex situ applications to reclaim and re-vegetate industrially devastated areas and mine-spoils, improve soil quality and reduce contaminant mobility by stabilizing agents and a beneficial use of industrial by-products. This study is an overview of data published during the last five years on the immobilization of one metalloid, As, and four heavy metals, Cr, Cu, Pb and Zn, in soils. The most extensively studied amendments for As immobilization are Fe containing materials. The immobilization of As occurs through adsorption on Fe oxides by replacing the surface hydroxyl groups with the As ions, as well as by the formation of amorphous Fe(III) arsenates and/or insoluble secondary oxidation minerals. Cr stabilization mainly deals with Cr reduction from its toxic and mobile hexavalent form Cr(VI) to stable in natural environments Cr(III). The reduction is accelerated in soil by the presence of organic matter and divalent iron. Clays, carbonates, phosphates and Fe oxides were the common amendments tested for Cu immobilization. The suggested mechanisms of Cu retention were precipitation of Cu carbonates and oxy-hydroxides, ion exchange and formation of ternary cation-anion complexes on the surface of Fe and Al oxy-hydroxides. Most of the studies on Pb stabilization were performed using various phosphorus-containing amendments, which reduce the Pb mobility by ionic exchange and precipitation of pyromorphite-type minerals. Zn can be successfully immobilized in soil by phosphorus amendments and clays.     

The use of petroleum coke as fuel in a 10 kWth chemical-looping combustor

Tests were made in a 10 kW_th chemical-looping combustor with a petroleum coke as the solid fuel and the oxygen carrier ilmenite, an iron titanium oxide. The fuel reactor is fluidized by steam and the oxygen carrier reacts with the volatiles released as well as the gasification intermediates CO and H₂. A constant fuel flow corresponding to a thermal power of 5.8 kW was introduced into the fuel reactor and a total of 11 h of operation was reached. The effects of particle circulation and carbon stripper operation on solid fuel conversion, conversion of gas from the fuel reactor and CO₂ capture were investigated. The actual CO₂ capture ranged between 60% and 75% while the solid fuel conversion was in the range of 66–78%. The low values of solid fuel conversion reflect loss of char due to low efficiency of the fuel reactor cyclone. The incomplete conversion of the gas from the fuel reactor is expressed as oxygen demand. The oxygen demand corresponds to the fraction of oxygen lacking to achieve full gas conversion and was typically 25%, due to presence of CH₄, CO and H₂ from the fuel reactor. Typical ratios of CH₄, CO and H₂ over the total gaseous carbon from the fuel reactor are respectively 5, 10 and 25%. Low loss of non-combustible fines from the system indicates very low attrition of the oxygen carrier.     

Understanding knowledge hiding in organizations

In our introduction to this special issue on understanding knowledge hiding in organizations, we provide some context to how and why this phenomenon should be studied. We then describe the five articles that comprise the special issue, and we note some common themes and divergences in this collection. Our introduction concludes with some suggestions for future research on knowledge hiding in organizations.     

Linking patch-use behavior, resource density, and growth expectations in fish

Optimality theory rests on the assumptions that short-term foraging decisions are driven by variation in environmental quality, and that these decisions have important implications for long-term fitness. These assumptions, however, are rarely tested in a field setting. We linked behavioral foraging decisions in food patches with measures of environmental quality covering larger spatial (resource density) or temporal (growth parameters) scales. In 10 lakes, we measured the food density at which benthic fish give up foraging in experimental food patches (giving-up density, GUD), quantified the biomass of benthic invertebrates, and calculated the maximum individual size (L(infinity)) of bream (Abramis brama L.), a typical benthivore in these lakes. We found positive relationships between resource density and both GUD and L(infinity), and a positive relationship between L(infinity) and GUD. Prey characterized as vulnerable to predation contributed most to the relationships between resource density and either GUD or L(infinity). A path analysis showed that resource density and L(infinity) directly explained 54% and 28%, respectively, of the variation in GUD, whereas 86% of the variation in L(infinity) was explained by resource density, with mostly indirect contribution from GUD. We conclude that the short-term foraging behavior of benthivores matched our expectations based on optimality theory by being positively linked to variables on environmental quality operating at both a larger spatial scale and a longer temporal scale.     

The effectiveness of electronic stability control (ESC) in reducing real life crashes and injuries

Electronic Stability Control (ESC) was introduced on the mass market in 1998. Since then, several studies showing the positive effects of ESC have been presented. OBJECTIVE: In this study, data from crashes occurring in Sweden during 1998 to 2004 were used to evaluate the effectiveness of ESC on real life crashes. The effectiveness was analyzed for different road conditions, and some accident types and injury levels. METHODS: The study used statistical analysis. To control for exposure, induced exposure methods were used, where ESC-sensitive to ESC-insensitive crashes and road conditions were matched in relation to cars equipped with and without ESC. Cars of similar or, in some cases, identical make and model were used to isolate the role of ESC. RESULTS: The study shows a positive and consistent effect of ESC overall and in circumstances where the road has low friction. The overall effectiveness on all injury crash types, except rear end crashes, was 16.7 +/- 9.3%, while for serious and fatal crashes; the effectiveness was 21.6 +/- 12.8%. The corresponding estimates for crashes with injured car occupants were 23.0 +/- 9.2% and 26.9 +/- 13.9%.For serious and fatal loss-of-control type crashes on wet roads the effectiveness was 56.2 +/- 23.5% and for roads covered with ice or snow the effectiveness was 49.2 +/- 30.2%. It was estimated that for Sweden, with a total of 500 vehicle related deaths annually, that 80-100 fatalities could be saved annually if all cars had ESC.CONCLUSIONS: ESC was found to reduce crashes with personal injuries, especially serious and fatal injuries. The effectiveness ranged from at least 13% for car occupants in all types of crashes with serious or fatal outcome to a minimum of 35% effectiveness for single/oncoming/overtaking serious and fatal crashes on wet or icy road surface. No difference in deformation pattern was found for cars with or without ESC.