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Influence of flow maldistribution on the pressure drop and water condensation in a 100 kw PEM fuel cell stack

The Proton Exchange Membrane (PEM) fuel cell has been investigated for a long time because it has a high power density, low emission, wide choice of fuel sources, etc. However, the performance of a stack of PEM cells degrades with respect to that of a single cell. This is mainly due to the introduction of the manifold in which supplies the reactants to individual cells. The manifold can induce an

Time-resolved and steady-state fluorescence studies of hydrophobically modified water-soluble polymers

A comprehensive study of the photophysical behavior of poly(acrylic acids) randomly labeled with pyrene using steady-state and time-resolved fluorescence spectroscopy is presented. The influence of external factors, such as different solvents and pH in the aqueous solution, on the polymer photophysics has been investigated. These factors induce major changes in the polymer conformation, which are

Estimation of gross primary productivity of an ombrotrophic bog in Southern Sweden

Eddy flux tower measurements, ground-based reflectance measurements, regionally modeled data, and data from the Moderate Resolution Imaging Spectroradiometer (MODIS) were used in this study of an ombrotrophic bog in southern Sweden. Linear regression analysis was used to investigate how the fraction of absorbed photosynthetically active radiation (FAPAR), light-use efficiency (epsiv), and gross pr

Emigrants’ Remittances and Dutch Disease in Cape Verde

Emigrants remittances have increased rapidly over the past two decades. While earlier studies have focused on their microeconomic effect on incomes and poverty in recipient countries, the present study concentrates on the macroeconomic impact of remittances on the real exchange rate in Cape Verde. A main conclusion is that remittances give rise to a sort of Dutch Disease effect and thereby have an

Channel Measurements and Analysis for Very Large Array Systems At 2.6 GHz

Abstract in UndeterminedVery large MIMO is a technique that potentially can offer large network capacities in multi-user scenarios where the users are equipped only with single antennas. In this paper we are investigating channel properties for a realistic, though somewhat extreme, outdoor base station scenario using a large array. We present measurement results using a 128 element linear array ba

Generating Real Business Value: Transcending the Socio-Technical Dimension.

Changes in technologies which have put computing power on the desktop over the past 25 years give an impression of increased empowerment for the end-user when compared to previous generations of hardware and software. However, in practice, latest developments in desktop computing and related technologies have led to more and more centralized control of ‘end-users’ workspaces. This phenomenon leads

Biodiversity and ecosystem functioning in soil

We review the current knowledge on biodiversity in soils, its role in ecosystem processes, its importance for human purposes, and its resilience against stress and disturbance. The number of existing species is vastly higher than the number described, even in the macroscopically visible taxa, and biogeographical syntheses are largely lacking. A major effort in taxonomy and the training of a new ge