Direct measurement technique for determining ventilation rate in the deposit feeding clam Macoma nasuta (Bivalvia,Tellinaceae)

An exposure chamber, the clambox, was developed to measure ventilation rate, sediment processing rate, and efficiency of pollutant uptake by Macoma nasuta conrad, a surface deposit-feeding clam. Clams, collected from Yaquina Bay, Oregon, USA, were cemented into a hole in a piece of rubber dental dam so that the inhalant and exhalant siphons were separated by a membrane. The dental dam was then clamped between two glass chambers. The inhalant and exhalant siphons were thus directed into separate chambers of the device so that the amounts of water or feces discharged into the exhalant chamber provided direct measures of ventilation rate and sediment processing rate, respectively. Clams exhibited no stress from the procedure. Ventilation rate was not affected by the imposition of a 5 mm hydraulic head in the exhalant chamber, by having sediment only in the inhalant chamber, or by exposure to organic-free sediment. The mean weight-specific ventilation rate for M. nasuta was 7.3 ml g^-1 h^-1 on a wet-flesh basis. This low rate, compared to rates for filter-feeding bivalves, supports the contention that deposit-feeding is the dominant feeding mode for M. nasuta. The short-term pattern was for ventilation to be intermittenly interrupted, essentially ceasing for 12 to 120 min, followed by a short period of active ventilation and then a resumption of the normal rate. Less than 3% of the total water flux could be attributed to water which entered the body cavity across the mantle margin. Water exhaled from the inhalant siphon during the ejection of pseudofeces was <10% of the ventilation rate. The clambox technique should be adaptable to studies on other tellinid bivalves.     

Anwendung energetischer und nicht-energetischer Ressourcen in Energiesystemen: Vergleichende Bewertung

Goal and Scope

Which impact does the use of non-energetic abiotic resources (ores, minerals, etc.) have in life cycles of energy systems based on biogenic and fossil fuels? Is this kind of resource use less or more environmentally harmful than the utilisation of energetic abiotic resources (mineral oil, natural gas, etc.) in the same life cycles? This paper aims at answering these questions. In Part 1, a methodology is presented and applied to the life cycles of selected energy systems. Part 2 presents and discusses the results.

Method

This study looks at the complete life cycles of selected energy systems. The methodology used bases on the state-of-the-art of life cycle assessment (LCA) methodology. For the assessment of energetic abiotic resource use, a widely recognised method can be used. For the assessment of non-energetic abiotic resource use, no overall recognised methodological approach exists. That is why for this aspect two different methods are exemplarily applied and compared with each other.

Results and Conclusion

Results will be presented and discussed in Part 2.

Recommendation and Perspective

Recommendation and conclusions will be derived from study results in Part 2.     

Influence of some additives to aluminium species distribution in aluminium coagulants

Aluminium ions hydrolyse and polymerise into different species in water. Main aluminium species in aluminium coagulant solutions are monomeric Al species (Al1) and polymeric Al species Al13O4(OH)24(7+) (Al13). The aluminium species distribution in coagulant solutions can be influenced by many parameters. This paper studies influences of concentrations of total aluminium species (Al(t)) and other species--OH-, polysilicic acid and ferric species, which were added in aluminium coagulant solutions, on the aluminium species distribution through 27Al nuclear magnetic resonance (NMR) analysis. Results show that only Al1 and no Al13 exist in coagulant solutions at higher Al(t) concentrations (over 1 mol l(-1)), while both species exist at lower Al(t) concentrations (0.1 mol l(-1)). The increase of OH/Al value (molar ratio) increases the concentration of Al13 in coagulant solutions, while the addition of polysilicic acid and ferric species decreases the concentration of Al13.     

Discrimination of factors influencing biota of a stream receiving multiple-source perturbations

Blaine Creek is a fifth-order stream located in eastern Kentucky that has been subject to contamination by oil brines, surface mining, and a coal fly ash settling pond discharge. Toxicity tests, effluent and receiving water chemical monitoring, and Blaine Creek benthic sampling were used to evaluate the effect of the ash pond effluent on the creek. Reproductive impairment of Ceriodaphnia was demonstrated at effluent concentrations ranging from 30 to 100%, but no instream impact on benthic invertebrates could be found at effluent flows that provided up to 65% of the creek's discharge. Correlation and regression analysis of physicochemical versus benthic monitoring data indicated that upstream oil brine contamination and scouring of the creek's predominately shifting sand substrate during rainfall events were the primary factors affecting the benthic fauna, and appeared to override potential effects from other sources. These results demonstrated the value of integrated field/laboratory investigations for effluent impact assessments.     

Naturwissenschaftliche Methoden zur Beurteilung von Gemälden und Graphik

Stylistic criteria are sometimes not sufficient in order to differentiate with certainty between copies or fakes and originals. Analyses of paints, supports and artistic technique may give an indication for the earliest possible date of a painting or a work of graphic arts. For example, supports made from oak, fir, spruce and beech can be dated by yearring analysis (dendrochronology). Exclusively methods on micro and ultramicro scale are suitable for the identification of various materials, i.e. microchemistry, emission spectrographic analysis, X-ray powder diffraction because only very tiny samples can be taken from the object.     

Assessing environmental performance by combining life cycle assessment, multi-criteria analysis and environmental performance indicators

We present a new analytical tool, called COMPLIMENT, which can be used to provide detailed information on the overall environmental impact of a business. COMPLIMENT integrates parts of tools such as life cycle assessment, multi-criteria analysis and environmental performance indicators. It avoids disadvantages and combines complementary aspects of these three tools. The methodology is based on environmental performance indicators, expanding the scope of data collection towards a life cycle approach and including a weighting and aggregation step. A case study on the Thai pulp industry illustrates the usefulness of COMPLIMENT.