Sökresultat

Filtyp

Din sökning på "*" gav 531332 sökträffar

Large Lakes Dominate CO2 Evasion From Lakes in an Arctic Catchment

CO2 evasion from freshwater lakes is an important component of the carbon cycle. However, the relative contribution from different lake sizes may vary, since several parameters underlying CO2 flux are size dependent. Here we estimated the annual lake CO2 evasion from a catchment in northern Sweden encompassing about 30,000 differently sized lakes. We show that areal CO2 fluxes decreased rapidly wi

Field experiment and numerical simulation of point source irrigation with multiple tracers

Dyes like Brilliant Blue have similar adsorptive behaviour as some organic contaminants, e.g., pesticides. Bromide ions, on the other hand, move much like NO3-N (fertilizer) in soil. Consequently, by using these two tracers, it is possible to in a general way mimic how organic contaminants and fertilizers may move through soils. Three plots with sandy soil in semiarid Tunisia were irrigated during

Compact 200 kHz HHG source driven by a few-cycle OPCPA

We present efficient high-order harmonic generation (HHG) based on a high-repetition rate, few-cycle, near infrared (NIR), carrier-envelope phase stable, optical parametric chirped pulse amplifier (OPCPA), emitting 6 fs pulses with 9 μJ pulse energy. In krypton, we reach conversion efficiencies from the NIR to the extreme ultraviolet (XUV) radiation pulse energy on the order of ∼10-6 with less tha

Vegetation demographics in Earth System Models : A review of progress and priorities

Numerous current efforts seek to improve the representation of ecosystem ecology and vegetation demographic processes within Earth System Models (ESMs). These developments are widely viewed as an important step in developing greater realism in predictions of future ecosystem states and fluxes. Increased realism, however, leads to increased model complexity, with new features raising a suite of eco

Challenges of using air conditioning in an increasingly hot climate

At present, air conditioning (AC) is the most effective means for the cooling of indoor space. However, its increased global use is problematic for various reasons. This paper explores the challenges linked to increased AC use and discusses more sustainable alternatives. A literature review was conducted applying a transdisciplinary approach. It was further complemented by examples from cities in

Ultrafast Charge Transfer Processes Accompanying KLL Auger Decay in Aqueous KCl Solution

X-ray photoelectron and KLL Auger spectra were measured for the K+ and Cl- ions in aqueous KCl solution. While the XPS spectra of these ions have similar structures, both exhibiting only weak satellites near the main line, the Auger spectra differ dramatically. Contrary to the chloride case, a very strong extra peak was found in the Auger spectrum of K+ at the low kinetic energy side of the D1 sta

Two new species of Phanerochaete (Basidiomycota) and redescription of P. robusta

In the current study, the new species Phanerochaete bambucicola and P. incarnata, from subtropical Taiwan are presented, while P. robusta is redescribed. We amplified the 5.8 s and LSU ribosomal genes along with RPB1. We generated an ITS dataset and a concatenated 5.8 s + nLSU + RPB1 dataset, which we analyzed using Maximum Parsimony and Bayesian methods. Our results suggest that the two new speci

HIMMELI v1.0 : HelsinkI Model of MEthane buiLd-up and emIssion for peatlands

Wetlands are one of the most significant natural sources of methane (CH4) to the atmosphere. They emit CH4 because decomposition of soil organic matter in waterlogged anoxic conditions produces CH4, in addition to carbon dioxide (CO2). Production of CH4 and how much of it escapes to the atmosphere depend on a multitude of environmental drivers. Models simulating the processes leading to CH4 emissi

Tracer particle diffusion in a system with hardcore interacting particles

In this study, inspired by the work of Nakazato and Kitahara (1980 Prog. Theor. Phys. 64 2261), we consider the theoretical problem of tracer particle diffusion in an environment of diffusing hardcore interacting crowder particles. The tracer particle has a different diffusion constant from the crowder particles. Based on a transformation of the generating function, we provide an exact formal expa

Dynamic Testing Characterization of a Synchronous Reluctance Machine

The dynamic testing method has been shown to accurately characterize the electromagnetic model of permanent magnet synchronous machines by describing the relationship between the phase currents and the linked magnetic flux with minimal amount of test equipment compared to traditional methods. Within this work, a performance evaluation of the dynamic testing method applied to the synchronous reluct

Time-space complexity and the opening hours of commerce : A study of four European cities

The aim of this article is to develop the concept of time-space complexity as a way of discussing how territorial time-space production affects urban life and use. The discussion is based on a comparative study of opening hours in four centrally located European retail areas: Angers, Lisbon, Malmö and Porto. Following a comparative study of these areas, we discuss tendencies of temporal and spatia

Spatial and temporal patterns of economic segregation in Sweden’s metropolitan areas : A mobility approach

The statistical resources at hand for segregation research are usually almost exclusively confined to annual or decennial records where the only available spatial information is the individual’s place of residence. This coarse temporal periodicity and spatial resolution provides a very limited account of people’s diurnal lives. Incorporating mobility and temporal dimensions in segregation analysis

Essays on Regional Economics

This thesis is, to its nature, somewhat wide in scope. The common denominator for theincluded essays is regional economics. Within this very wide area of research, the thesis isdivided rather sharply between one part regarding trading of emission permits in theinternational aviation sector and another part concerned with real estate markets. The basis ofthis thesis is five essays all written for t