Occurrence and distribution of novel botryococcene hydrocarbons in freshwater wetlands of the Florida Everglades

A high abundance of isoprenoid hydrocarbons, the botryococcenes, with carbon numbers from 32 to 34 were detected in the Florida Everglades freshwater wetlands. These compounds were present in varying amounts up to 106microg/gdw in periphyton, 278microg/gdw in floc, and 46microg/gdw in soils. Their structures were determined based on comparison to standards, interpretation of their mass spectra and those of their hydrogenation products, and comparison of Kovats indexes to those reported in the literature. A total of 26 cyclic and acyclic botryococcenes with 8 skeletons were identified, including those with fewer degrees of unsaturation, which are proposed as early diagenetic derivatives from the natural products. This is the first report that botryococcenes occur in the Everglades freshwater wetlands. Their potential biogenetic sources from green algae and cyanobacteria were examined, but neither contained botryococcenes. Thus, the source implication of botryococcenes in this ecosystem needs further study.     

Torque Production Using Handwheels of Different Size During a Simulated Valve Operation Task

Opening and closing valves in industrial facilities often requires operators to use bars and wrenches as levers (cheaters) in order to overcome initial actuation forces. In order to determine more appropriate operational specifications, the maximum torque production capability was measured when 12 male participants used 4 different valve handwheels at 3 different heights and 2 different angles (in relationship to the coronal plane). The results indicate that the participants produced significantly greater torque when the largest of the 4 wheels (40.6 cm diameter) was used than when the medium (22.9 cm), small (20.3 cm), and handled (17.8 cm) handwheels were used. Although the main effect of heights was found to be statistically significant, post-hoc analyses between the heights found them to be, essentially, equal. In addition, the vertical and horizontal wheel orientations were not found to be different. The results are applicable to all industries where handwheels are used and applicable to valve manufacturers for designing operational torque specifications below the values found in this study.     

Torque Production Using Hand Cranks in a Simulated Gear-Operated Valve Opening Task

Hand cranks are used in a variety of industries to actuate valves and in other gear-operated applications. In order to evaluate these types of operations and their compatibility with operator strength capabilities, a rotational dynamometer was used to measure torque production capability of operators using a hand crank at different heights and angles (with respect to the coronal plane). The tests were conducted for both clockwise and counterclockwise rotations using the dominant arm of each test participant. A total of 18 tests were completed by each of five male right-handed test participants. A 0° declination angle, counterclockwise operation, and both 40.65 cm and 60.96 cm heights were found to be associated with the greatest torque production capabilities.     

Framing environmental indicators: moving from causal chains to causal networks

In recent years, there has been a boom in environmental assessment reports utilizing environmental indicators. Most of these publications are based on the casual chain frameworks (e.g., Pressure–State–Response (PSR), Driving force–State–Response (DSR), and Driving force–Pressure–State–Impact–Response (DPSIR)). These frameworks have made an important contribution by emphasising the importance of causality. However, the reliance on simple uni-directional chains is at the same time not very conducive to a good understanding of the complexity of the processes behind environmental indicators. This limits the usefulness of these frameworks for environmental (impact) assessments. In this paper we propose an enhanced DPSIR (eDPSIR) framework for environmental indicators that takes inter-relations of indicators into account by relying on the use of causal networks rather than causal chains. It will be shown how the concept of causal networks can increase insight into the inter-relation of environmental issues and associated indicators, can facilitate the identification of key indicators for particular kinds of questions, and can provide a useful first step to the establishment of dose–response functions. Working with causal networks can contribute to more appropriate environmental policies and better management decisions.     

The Economics Of Environmental Quality Measurement

With the increasing public concern over the environment, corporate management is now faced with the problem of first, organizing its efforts to be responsive to the public and legislation, and second, obtaining maximum value for its expenditures. This paper discusses how a firm can approach the problem of deciding when to use environmental consultants and when to perform tasks using an in-house staff organization.     

The metabolization of lindane in a culture of mould and the degradation scheme of lindane

The metabolism of Lindane, gamma-Pentachlorcyclohexene and isomeric Tetrachlorobenzenes in a culture of Mould was investigated in this work. 1,2-, 1,4-Dichlorobenzene, 1,2,3-, 1,2,4-, 1,3,5-Trichlorobenzene, 1,2,3,4-, 1,2,4,5- and/or 1,2,3,5-Tetrachlorobenzene, Pentachlorobenzene, gamma-Pentachlorocyclohexene, Hexachlorobenzene, Tetrachlorocyclohexenol, 2,3,4-, 2,4,6-Trichlorophenol, 2,3,4,5-, 2,3,4,6- and/or 2,3,5,6-Tetrachlorophenol and Pentachlorophenol could be identified as metabolites of Lindane. A degradation scheme is proposed. It includes gamma-Pentachlorocyclohexene, Hexachlorocyclohexene, Pentachlorocyclohexenol, Tetrachlorocyclohexenol and Polychlorophenols as main metabolites. The pathway based on many earlier published experimental results of these and other authors so far as possible.In former papers we have already reported about the known literature concerning the metabolism of Lindane (1 – 4).Comprehensive studies about the metabolism of Lindane in cultures of mould (1, 5, 6), in rats (7 – 9), and in men (2, 3) are to contribute in explaining away any uncertainties about the degradation of Lindane. Many investigations contributed to work out degradation schemes of Lindane (10 – 21).