Geomorphological process development under the impact of man-made reservoir operation,a case study: Bratsk reservoir,Baikal-Angara hydroengineering system,Russia

Bulletin of Engineering Geology and the Environment - The Bratsk reservoir is one of the constituents of the Baikal-Angara hydroengineering system. Large hydropower reservoirs created worldwide...     

Structural characterization of flavonoid glycosides by multi‐stage mass spectrometry

Flavonoids are secondary plant metabolites of great structural variety and high medicinal significance. The search for new chemical entities and the quality control of flavonoid containing natural products require easy‐to‐use but reliable and robust analytical methodologies. For structural elucidation of flavonoids and their glycosides, nuclear magnetic resonance (NMR) and mass spectroscopy (MS) are the generally used techniques. In phytochemical analyses, however, high amounts of flavonoids are difficult to isolate for NMR, thus low sample volume requiring MS based methods are emerging. This review summarizes and compares currently available methods for structural elucidation of flavonoids by LC–MS and LC–MSⁿ, and focuses on the identification options of unknown flavonoid glycosides in complex samples (e.g., plant extracts) with the emphasis on the differentiation of isomeric compounds. © 2008 Wiley Periodicals, Inc., Mass Spec Rev 29:1–16, 2010     

Remote sensing of in-use heavy-duty diesel trucks

On-road measurements in 2005 of carbon monoxide (CO), hydrocarbons, nitric oxide, nitrogen dioxide, and sulfur dioxide from 1641 individually identified heavy-duty diesel trucks at two locations in Colorado are reported. Carbon monoxide and nitric oxide show increasing emissions with increased altitude. Oxides of nitrogen (NOx) emissions have decreased with more recent model years over the last 10 years but are the same as vehicles that are 20 years old. At the Golden, CO site, there was a statistically significant decrease in fleet emissions of CO and NOx since a similar study in 1999. There was no emission trend for CO or NOx with gross vehicle weight or odometer in units of grams of pollutant per kilogram of fuel consumed. Data from this study suggest that on-road remote sensing can detect illegal, high sulfur fuel use from individual heavy-duty diesel trucks. Ammonia emissions from this study were below the detection limit of the instrument but will be useful as a baseline value for future comparison.     

Field testing of a long-span arch steel culvert during backfilling and in service

The paper presents the first part of the in-situ measurements and data analyses for the tests conducted during backfilling and during service of a long-span corrugated steel culvert railway bridge over Skivarpsån, Rydsgård, Sweden. Static and dynamic tests were carried out measuring strains and displacements. Temperature readings were taken along with the measurements. Comparisons of moments during compaction showed that there is good agreement between test results and theoretical values. The theoretical calculation of the rise of the crown during compaction and the crown moments due to live load seem to be conservative, while the theoretical axial forces agree reasonably with the measured axial forces.     

Effects of Arbuscular Mycorrhiza on Plant Chemistry and the Development and Behavior of a Generalist Herbivore

Arbuscular mycorrhiza (AM) formed between plants and AM fungi (AMF) can alter host plant quality and thus influence plant-herbivore interactions. While AM is known to affect the development of generalist chewing-biting herbivores, AM-mediated impacts on insect behavior have been neglected until now. In this study, the effects of Rhizophagus irregularis, a generalist AMF, on phenotypic and leaf metabolic traits of Plantago major plants were investigated. Further, the influence of AM-mediated host plant modifications on the development and on seven behavioral traits of larvae of the generalist Mamestra brassicae were recorded. Tests were carried out in the third (L3) and fourth (L4) larval instar, respectively. While shoot water content, specific leaf area, and foliar concentrations of the secondary metabolite aucubin were higher in AM-treated compared to non-mycorrhized (NM) plants, lower concentrations of the primary metabolites citric acid and isocitric acid were found in leaves of AM plants. Larvae reared on AM plants gained a higher body mass and tended to develop faster than individuals reared on NM plants. However, plant treatment had no significant effect on any of the behavioral traits. Instead, differences between larvae of different ages were detected in several behavioral features, with L4 being less active and less bold than L3 larvae. The results demonstrate that AM-induced modifications of host plant quality influence larval development, whereas the behavioral phenotype seems to be more fixed at least under the tested conditions.     

Delay Asymptotics and Scalability for Peer-to-Peer Live Streaming

A large number of peer-to-peer streaming systems have been proposed and deployed in recent years. Yet, there is no clear understanding of how these systems scale and how multipath and multihop transmission, properties of all recent systems, affect the quality experienced by the peers. In this paper, we present an analytical study that considers the relationship between delay and loss for general overlays: we study the trade-off between the playback delay and the probability of missing a packet and we derive bounds on the scalability of the systems. We present an exact model of push-based overlays and show that the bounds hold under diverse conditions: in the presence of errors, under node churn, and when using forward error correction and various retransmission schemes.     

Differences in meat quality between organically and conventionally produced pigs

This study compared organic pig meat production with conventional production with regard to carcass- and meat quality traits. 80 crossbred female and castrated male pigs were used [(Swedish Landrace × Swedish Yorkshire) × Hampshire] of which 40 were raised under organic conditions and the other 40 were raised in a conventional production system. The organic pigs were raised outdoors in one large group following the regulations for organic standards. The conventionally raised animals were kept indoors in groups of eight and were given a conventional feed mixture. It was found that meat of organically raised non-carriers of the RN(-) allele was of poorer quality (higher drip loss and increased shear force values) compared with meat from the other animals. The RN genotype had a relatively small effect on carcass and technological traits in this study. The sex of the animals affected carcass traits.     

Wave energy potential in the Baltic Sea and the Danish part of the North Sea, with reflections on the Skagerrak

Wave power, along with renewable energy-generating sources like tides and streams, is underestimated considering its advantageous physical properties and predictability. This paper examines possible examples of wave power installations in the Baltic Sea and the Danish part of the North Sea. Hindcasting data is used allowing estimations of wave energy generated and results show promising areas in the North Sea, but also several parts of the Baltic Sea are of interest. The study is based upon linear generator technique, placed on the seabed using point-absorbers arranged in arrays of up to several thousand units. The study aims at showing the physical possibilities of wave energy, including economical feasibility and environmental advantages of wave energy even in moderate wave climates. With discussion from two examples in the Baltic Sea, one in the Danish North Sea and a new pilot study site in the Swedish part of Skagerrak, this study show feasible illustrations of wave energy takeouts. Project examples vary in size due to distance to grid, grid voltage, and may thus be economically feasible. Examples also show considerations in societal and nature conservation matters, including aspects such as industrial and military interests, archaeological or marine reserves and local geology. The authors conclude that wave energy electric conversion is an option that needs more attention and which has several advantages compared to conventional renewable sources. Sound engineering, in combination with producer, consumer and broad societal perspective is advised for a sustainable development of wave energy conversion.     

Rheology and adhesive properties of filled PIB-based pressure-sensitive adhesives. II. Probe tack and 90° peel testing

Two nanosized fillers (fumed silica Rosil-175 and halloysite nanotubes) were used to eliminate the problem of the cold flow and to increase the adhesion strength for polyisobutylene-based formulations. Well-dispersed silica, having high specific area, allowed to obtain up to 2 orders of magnitude increase in PIB’s shear resistance at 20 wt% Rosil content. PIB–20 wt% Rosil formulations mostly demonstrated slightly increased tack characteristics – up to 20–50%. Adhesive peel of the PIB-Rosil systems was observed with the peel strength of the systems staying at the level of the pristine PIB matrices or slightly changing (depending on the film thickness and peeling rate). Transition to the mixed failure mode was observed for thin PIB-20 wt% Rosil films tested under increased peeling rate accompanied by up to 300% peel strength increase. Formation of the three-dimensional filler networks in PIB-halloysite formulations allowed notably lower increase in the shear resistance of the systems – only 4–5 times in the case of much higher filler content (40 wt%), which was connected with the low strength of the network. Incorporation of 40 wt% halloysite into the PIB matrix did not lead to notable changes in tack properties, except for the tack of 150-μm films – in this case, 30–60% decrease in the tack characteristics was obtained. Peel strength of PIB-halloysite systems stays at the level of the pristine PIB matrices or increases up to 300% when the failure mode shifts from adhesive for the thin films to cohesive for the thick films.