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Transportation is a major sector of energy consumption in most, if not in all, European countries. Besides the energy used for traction, energy is also consumed for ventilation, heating, and cooling inside the vehicles to assure traveler comfort. This issue gains increasing importance as the demand for public transport increases in the future. There is a need for retrofit to improve the thermal resistance of the envelope of existing vehicles to reduce the heat loss to the environment during the cold period of the year, especially in the Alpine region. A major concern in adding insulation material to the envelope is the possibility of convective moisture transfer due to air circulation in the vehicle, which would cause condensation accumulation on the cold surfaces. The present investigation addresses this topic by measuring surface and air temperature, air moisture, air flow, and heat flow at several critical locations of a vehicle during its travel in the Swiss Alpine region over several months during the cold period of the year. Temperature measurements showed the potential of reducing the heat losses in some parts of the vehicle. The level and duration of the moisture exposure did not suggest a relevant formation of condensation in the cross-section of the vehicle wall. The observed increase in relative humidity when driving through tunnels is too short to cause relevant condensation in the vehicle shell. The measured low air flow justifies the assumption that no forced convection occurs in the envelope cavities.

Periphyton metabolism was studied at five sites along a 70km unshaded stretch of the Truckee River below the City of Reno, Nevada (USA). Sites differed with respect to concentrations of soluble reactive phosphorus and total dissolved inorganic nitrogen because a water pollution control facility discharged its treated wastewater through a small tributary into the river downstream of site 1 (most upstream located site). Unglazed tiles were incubated at each site from late June to August (summer) and from September to November (autumn) 1986. At the end of each incubation period, oxygen metabolism of the periphyton communities growing on tiles was measured in transparent flow-through respiration chambers for 24h under near natural light and temperature conditions. In August, when biomass and metabolism were positively correlated with nitrogen and phosphorus, mean chlorophyll a ranged from 53 (site 1) to 290mgchl a m−2 (site 2, 3km downstream of the wastewater input). Periphyton gross primary production varied between 3.3 ± 0.8 (site 1) and 9.1 ± 1.4 g O2 m−2d−1 (site 2), and respiration between 2.1 ± 0.4 and 10.1 ± 1.3 g O2 m−2d−1. P/R ratios ranged from 0.9at site 2 to 1.8 about 65km downstream from the wastewater input. In November, chlorophyll a was significantly higher (99 ± 29 to 509 ± 155mg chl a m−2 and gross primary production and respiration on average 50 and 65% lower, respectively, than in August. Hence, colder temperatures appeared to reduce respiration more than primary production and significantly increased P/R. Neither gross primary production nor respiration were correlated with autumn nutrient concentrations

We examined the response of stream macroinvertebrates to a multiple-year experimental flood regime downstream of a large reservoir. Benthic samples were collected from the River Spöl prior to the initial flood (1999) and at periodic intervals before and after eight floods from 2000 through 2002. Three artificial floods occurred each in 2000 and 2001, and two floods were implemented in 2002. We also sampled macroinvertebrates in an adjacent tributary (Val da l'Aqua) on the same dates as in the Spöl to assess the natural temporal variability in assemblage structure. The regulated baseflow discharge in the Spöl was 40 m3/s for a short period. Repeated measures ANOVA indicated that the floods significantly reduced macroinvertebrate densities in the Spöl, although recovery to pre-flood densities occurred within a matter of weeks to densities found in 1999. A principal components analysis revealed that assemblage composition shifted in response to the recurring floods, first from 1999 to 2000 and then from 2000 to 2001/2. Taxa that decreased in abundance due to the floods included the Gammaridae (Gammarus fossarum) and Turbellaria (Crenobia alpina). Taxa that increased in abundance included Baetidae, Chironomidae, and Simuliidae. Some Plecoptera, Trichoptera, and Heptageniidae that were negatively impacted by the floods in 2000, subsequently increased in abundance. Our data suggest that the response of macroinvertebrates to experimental floods occurs over a period of years rather than months, as species composition adjusts to the new and more variable habitat template. Future changes are expected as additional species begin to colonize the river from adjacent sources. The results clearly show that the experimental flood regime should be maintained if resource managers wish to sustain the development of a more natural macroinvertebrate assemblage

Ecosystems, 13 (5), ISSN:1432-9840, ISSN:1435-0629

Vor rund 20 Jahren begann die Entwicklung des geklebten Glasrahmenverbundes. Massgeblich daran beteiligt waren Experten der Berner Fachhochschule. Im Interview erzählen sie, wie das damals vor sich ging, welche Schwierigkeiten es gab und wo man heute steht.

Methodological problems with in vivo, fluorescence (IVF) measurement using an in situ pulse light fluorometer were investigated in order to validate this method for monitoring the vertical and horizontal chlorophyll a (chl. a) distribution in lakes. The correlation between chl. a and IVF was poor in the upper epilimnion (0-5 m) of a mesotrophic lake. The IVF of algal cultures and natural phytoplankton is very sensitive to changes in the light environment. The response of the IVF to rapid light fluctuations depends on the amplitude of the light intensity and the light conditions to which the algae were exposed before the onset of light fluctuations. The variability of the ratio IVF:chl. a concentration makes a permanent calibration of the IVF against chl. a necessary

Nowadays, building skins, including doors and windows, are highly energy efficient constructions designed to minimize energy consumption. With the improvement of the thermal insulation properties of modern building skins, access systems (e.g., locks) have gained attention as a place where energy is lost and condensation occurs. Moisture from condensation is of particular concern for access systems relying on electronics. However, no standards as to the thermal efficiency and air and water tightness of such access systems exist as of today. Researchers at Bern University of Applied Sciences, while investigating the performance of existing access systems, had to develop a set of standards to be able to compare the performance of different products and settings. For this purpose, the researchers combined knowledge from existing standards for similar products and used new ideas to test access system performance.

We examined for a glacial fingerprint on the ecology of two postglacial streams within the Swiss National Park over a 14 yr period (1999-2013). One stream (Aqua) emerges from a small rock glacier (0.2% of the catchment area), whereas the other stream (Fuorn) flows from a remnant ice field (0.02% of the catchment area). In general, abiotic and biotic properties of each stream showed a typical glacial-nival seasonality and strong between-year synchrony. Benthic organic matter and periphyton biomass peaked during so-called “windows of opportunity” in early spring and late autumn as in other glacial streams. Importantly, the streams contrasted regarding the glacial signature in which Fuorn had highest average turbidity, total inorganic carbon (TIC), particulate organic carbon and phosphorus levels, whereas Aqua had highest average nitrogen levels and lowest temperature and electrical conductivity. The difference in glacial signature also was evident in macroinvertebrate density (fourfold higher in Aqua) and diversity (lower in Aqua) differences between streams. In contrast to most proglacial streams, macroinvertebrate assemblages were relatively diverse and dominated by typical alpine stream species, stoneflies in particular. Both streams experienced increases in phosphorus and TIC following 2006 in response to external climate drivers with concomitant increases in simuliids and Leuctra stoneflies and decreases in heptageniid mayflies in Fuorn and Protonemura stoneflies in Aqua. Our results suggest that a glacial legacy is an inherent feature of most postglacial alpine streams, this being especially important as glacial streams transform to postglacial status in response to ongoing transformation of alpine glacial landscapes globally.