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Effect of Surfactants on the Flow Patterns of Horizontal Tube Bundles with a Falling Film
(2020-03-24)
The influence of two alcoholic surfactants on the flow patterns of falling film tube bundles is investigated. The flow patterns are measured in a single‐stage absorption chiller in the absence of surfactants. The surface tension of H2O/aqueous LiBr solution with different concentrations of 1‐octanol and 2‐ethylhexanol is measured at low pressure in a saturated atmosphere. Small quantities of surfactants in the aqueous solution do not have an influence on the flow patterns of the condenser and evaporator, while a shift ...
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Spatio-temporal patterns of herbage availability and livestock movements: A cross-border analysis in the Chinese-Mongolian Altay
(Springer, 2016-07-04)
Due to increasing population and the recent implementation of policies to intensify the use of land and water resources, the transhumant pastoral systems in the Chinese-Mongolian Altay-Dzungarian region are rapidly changing, leading to modifications of herd size, herd composition and spatial distribution of livestock grazing. This may have major consequences for the supply and quality of rangeland biomass. Despite similar topographic settings, the socio-political framework for Chinese and Mongolian pastoralists differs ...
Aufsatz
A structural topic model approach to scientific reorientation of economics and chemistry after German reunification
(2020-08-05)
The detection of differences or similarities in large numbers of scientific publications is an open problem in scientometric research. In this paper we therefore develop and apply a machine learning approach based on structural topic modelling in combination with cosine similarity and a linear regression framework in order to identify differences in dissertation titles written at East and West German universities before and after German reunification. German reunification and its surrounding time period is used because ...
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Exploration of production conditions: a step towards the development of a community-based breeding program for Butana cattle
(2020-11-17)
In Sudan, many Butana cattle farmers practice indiscriminate crossbreeding to improve the milk yield performance of cows, as organized breeding programs are lacking. Objectives of this study were to identify the current production conditions of Butana cattle and to determine farmers’ production objectives and trait preferences using a field survey. The overall aim was to explore the possibility of establishing a community-based breeding program for the genetic improvement of the breed. A semi-structured questionnaire ...
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Dissolution of Portlandite in Pure Water: Part 1 Molecular Dynamics (MD) Approach
(2022-02-14)
The current contribution proposes a multi-scale bridging modeling approach for the dissolution of crystals to connect the atomistic scale to the (sub-) micro-scale. This is demonstrated in the example of dissolution of portlandite, as a relatively simple benchmarking example for cementitious materials. Moreover, dissolution kinetics is also important for other industrial processes, e.g., acid gas absorption and pH control. In this work, the biased molecular dynamics (metadynamics) coupled with reactive force field ...
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Runs of Homozygosity and NetView analyses provide new insight into the genome-wide diversity and admixture of three German cattle breeds
(2019-12-04)
Angler (RVA) and Red-and-White dual-purpose (RDN) cattle were in the past decades crossed with influential Red Holstein (RH) sires. However, genome-wide diversity studies in these breeds are lacking. The objective of the present study was to elucidate the genome-wide diversity and population structure of the three German cattle breeds. Using 40,851 single nucleotide polymorphism markers scored in 337 individuals, runs of homozygosity (ROH) were analysed in each breed. Clustering and a high-resolution network visualisation ...
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Combined leaching and plant uptake simulations of PFOA and PFOS under field conditions
(2020-08-31)
Per- and polyfluoroalkyl substances (PFASs) are used in industrial production and manufacturing but were repeatedly detected in agricultural soils and therefore in cash crops in recent years. Dissipation of perfluoroalkyl acids (PFAAs), a sub-group of PFASs, in the environment was rather attributed to the formation of non-extractable residues (NER) than to degradation or transformation. Currently, there are no models describing the fate of PFAAs in the soil-plant continuum under field conditions, which hampers an ...
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Bis‐[3]Ferrocenophanes with Central >E−E’< Bonds (E, E’=P, SiH): Preparation, Properties, and Thermal Activation
(2019-06-26)
A series of bis‐[3]ferrocenophanes of the general type Fe(C5H4E’)2E−E(E'C5H4)2Fe (E=P, SiH and E’=PtBu, NneoPentyl, NSi(CH3)3) with an isolobal molecular framework have been prepared and characterized by heteronuclear NMR spectroscopy and X‐ray crystallography. The thermal dissociation behavior with respect to homolytic fission of the central bond generating phosphorus centered radicals was investigated using EPR spectroscopy and quantum chemical calculations.
Aufsatz
Socio-Economic Viability of Urban Agriculture - A Comparative Analysis of Success Factors in Germany
(2019-04-04)
Socio-economic viability of urban agriculture (UA) is, especially regarding non-commercially oriented initiatives, at most a generically treated issue in scientific literature. Given a lack of data on yields, labor input, or saved expenditures, only a few studies have described it either from a cost-avoidance or a specific benefit generation perspective. Our hypothesis is that hybrid roles of consumers and producers in urban agriculture challenge the appraisal of socio-economic viability. This paper presents an ...
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Distributed Learning in the Classroom: Effects of Rereading Schedules Depend on Time of Test
(2019-01-09)
Research with adults in laboratory settings has shown that distributed rereading is a beneficial learning strategy but its effects depend on time of test. When learning outcomes are measured immediately after rereading, distributed rereading yields no benefits or even detrimental effects on learning, but the beneficial effects emerge two days later. In a preregistered experiment, the effects of distributed rereading were investigated in a classroom setting with school students. Seventh-graders (N = 191) reread a text ...