Suche
Anzeige der Dokumente 891-900 von 1188
Aufsatz
![Open Access](/themes/Mirage2/images/Open_Access_logo_PLoS_transparent.svg)
Factors and Components Affecting Dairy Smallholder Farmers and the Local Value Chain— Kvemo Kartli as an Example
(2021-05-20)
Smallholder farmers are the cornerstone of the livestock sector and an essential element in building and developing the local dairy value chain, critical for developing its local economy. In Georgia, and despite the efforts made since independence from the Soviet Union until now, farmers still face many problems that prevent them from participating effectively in developing the dairy value chain, especially heavy metal pollution that afflicts the study region. This research study refers to smallholder farmers’ ...
Aufsatz
![Open Access](/themes/Mirage2/images/Open_Access_logo_PLoS_transparent.svg)
Molecular Basis for Ser/Thr Specificity in PKA Signaling
(2020-06-25)
cAMP-dependent protein kinase (PKA) is the major receptor of the second messenger cAMP and a prototype for Ser/Thr-specific protein kinases. Although PKA strongly prefers serine over threonine substrates, little is known about the molecular basis of this substrate specificity. We employ classical enzyme kinetics and a surface plasmon resonance (SPR)-based method to analyze each step of the kinase reaction. In the absence of divalent metal ions and nucleotides, PKA binds serine (PKS) and threonine (PKT) substrates, ...
Aufsatz
![Open Access](/themes/Mirage2/images/Open_Access_logo_PLoS_transparent.svg)
Characterization of Mechanical Properties, Macroscopic Deformation Behavior, and Microstructure of Functionally Graded 22MnB5 Steel
(2021-03-24)
The focus of this study is on the characterization of the local plastic deformation and failure of functionally graded 22MnB5 plates after hot stamping using an in situ approach. Various forming strategies at elevated temperatures are performed using differentially tempered forming tools to locally tailor the microstructure. By controlling the cooling rate, graded as well as martensitic and ferritic–pearlitic microstructures are obtained. Experimental analysis includes evaluation of the material- and geometry-dependent ...
Aufsatz
A simulation-based approach to evaluate objective material parameters from concrete rheometer measurements
(2019-12-31)
Modern concretes such as ultra-high performance concrete (UHPC) show excellent strength properties combined with favorable flow properties. However, the flow properties depend strongly on process parameters during production (temperature, humidity etc.), but also change sensitively even with slight variations in the mixture. In order to ensure desired processing of the fluidlike material and consistent process quality, the flow properties of the concrete must be evaluated quantitatively and objectively. The usual ...
Aufsatz
![Open Access](/themes/Mirage2/images/Open_Access_logo_PLoS_transparent.svg)
Sphaeropsis sapinea and fungal endophyte diversity in twigs of Scots pine (Pinus sylvestris) in Germany
(2020-09-03)
Sphaeropsis sapinea is the causal fungal agent of Diplodia tip blight disease of Scots pine (Pinus sylvestris) and other coniferous trees of relevance to forestry in Germany. In this study, the distribution and occurrence of S. sapinea and accompanying endophytic fungi in twigs of healthy and diseased Scots pine was investigated on a spatial and temporal scale. Sampling of 26,000 twig segments from trees in 105 temperate coniferous forest stands in Germany resulted in isolation of 33,000 endophytic fungi consisting ...
Aufsatz
Introducing the Logarithmic finite element method: a geometrically exact planar Bernoulli beam element
(2016-09-15)
We propose a novel finite element formulation that significantly reduces the number of degrees of freedom necessary to obtain reasonably accurate approximations of the low-frequency component of the deformation in boundary-value problems. In contrast to the standard Ritz–Galerkin approach, the shape functions are defined on a Lie algebra—the logarithmic space—of the deformation function. We construct a deformation function based on an interpolation of transformations at the nodes of the finite element. In the case ...
Aufsatz
![Open Access](/themes/Mirage2/images/Open_Access_logo_PLoS_transparent.svg)
Assessing spatial variability of barley whole crop biomass yield and leaf area index in silvoarable agroforestry systems using UAV-borne remote sensing
(2021-07-13)
Agroforestry systems (AFS) can provide positive ecosystem services while at the same time stabilizing yields under increasingly common drought conditions. The effect of distance to trees in alley cropping AFS on yield-related crop parameters has predominantly been studied using point data from transects. Unmanned aerial vehicles (UAVs) offer a novel possibility to map plant traits with high spatial resolution and coverage. In the present study, UAV-borne red, green, blue (RGB) and multispectral imagery was utilized ...
Aufsatz
Soil Gaseous Emissions and Partial C and N Balances of Small-Scale Farmer Fields in a River Oasis of Western Mongolia
(2019-06-18)
During the last decades, Mongolian river oases were subjected to an expansion of farmland. Such intensification triggers substantial gaseous carbon (C) and nitrogen (N) losses that may aggravate disequilibria in the soil surface balances of agricultural plots. This study aims to quantify such losses, and assess the implications of these emissions against the background of calculated partial C and N balances. To this end, CO2, NH3, and N2O soil emissions from carrot, hay, and rye plots were measured by a portable ...
Aufsatz
![Open Access](/themes/Mirage2/images/Open_Access_logo_PLoS_transparent.svg)
Impact of Process Parameters and Bulk Properties on Quality of Dried Hops
(2020-11-20)
Hops are critical to the brewing industry. In commercial hop drying, a large bulk of hops is dried in multistage kilns for several hours. This affects the drying behavior and alters the amount and chemical composition of the hop oils. To understand these changes, hops of the var. Hallertauer Tradition were dried in bulks of 15, 25 and 35 kg/m² at 60 °C and 0.35 m/s. Additionally, bulks of 25 kg/m² were also dried at 65 °C and 0.45 m/s to assess the effect of change in temperature and velocity, respectively. The results ...
Aufsatz
Solid Fuel Production from Semi-Natural Grassland Biomass - Results from a Commercial-Scale IFBB Plant
(2018-11-01)
Biomass-based energy accounts for a notable share of renewable heat and electricity generation in Germany. Due to limited alternative uses, biomass obtained from management of semi-natural grasslands is a potential feedstock. Technical and environmental limitations exist in using this biomass for combustion, due to the presence of harmful elements. Converting biomass using integrated generation of solid fuel and biogas from biomass system (IFBB) produces a solid fuel with lower concentrations of harmful elements and ...