Suche
Anzeige der Dokumente 321-330 von 1091
Aufsatz
Revisiting climate change effects on winter chill in mountain oases of northern Oman
(2020-10-07)
For centuries, traditional high-altitude oases in Oman have depended on the cultivation of deciduous fruit trees. This study explores the effects of climate change on winter chill (estimated as Chilling Hours—CH and Chill Portions—CP), a prerequisite to overcoming dormancy and initiating flowering, in three Omani oases. The results are compared with findings from an earlier study which reported a decrease in the numbers of CH in high-elevation oases by an average of 1.2–9.5 CH year−1 between 1983 and 2008. Location-specific ...
Aufsatz
Exploring external factors affecting the intention-behavior gap when trying to adopt a sustainable diet: a think aloud study
(2021-02-19)
Not least from an ecological and health perspective, it can be posited that a broader part of consumers should practice sustainable diets. People who are already willing to do so are often confronted with the intention-behavior gap, caused by a range of internal and external factors. To eliminate these barriers requires a deeper and more comprehensive understanding of these factors and their interplay. Therefore, a think aloud study with 20 adult German participants was conducted to explore the four chosen external ...
Aufsatz
Fluorescence Microscopy of Superplasticizers in Cementitious Systems: Applications and Challenges
(2020-08-24)
In addition to the desired plasticizing effect, superplasticizers used in high and ultra-high performance concretes (UHPC) influence the chemical system of the pastes and for example retardation of the cement hydration occurs. Thus, superplasticizers have to be chosen wisely for every material composition and application. To investigate the essential adsorption of these polymers to particle surfaces in-situ to overcome several practical challenges of superplasticizer research, fluorescence microscopy is useful. In ...
Aufsatz
A Rentier State under Blockade: Qatar’s Water-Energy-Food Predicament from Energy Abundance and Food Insecurity to a Silent Water Crisis
(2020-04-08)
This article investigates Qatar’s sustainability crisis of the high levels of water, electricity and food use. The high levels of consumption have been enabled by Qatar’s significant hydrocarbons wealth, a generous rentier state’s redistributive water governance, and structural dependence on imported food and food production subsidies. The water crisis is silent because it does not generate supply disruptions nor any public discontentment. The geopolitical blockade Qatar is experiencing sparked discussions in policy ...
Aufsatz
Nitrogen turnover in a repeatedly manured arid subtropical soil: Incubation studies with 15N isotopes
(2019-07-23)
Under the hot and moist conditions of irrigated agriculture in the arid subtropics, turnover of organic matter is high, which can lead to considerable carbon (C) and nitrogen (N) losses. Therefore, sustainable use of these soils requires regular manure application at high rates. To investigate the contribution of consecutive manure applications to an arid sandy soil to various soil N pools, goat manure was isotopically labeled by feeding 15N‐enriched Rhodes grass hay and applied to the soil during a two‐year field ...
Aufsatz
Automatic Assessment of Keel Bone Damage in Laying Hens at the Slaughter Line
(2021-01-12)
Simple Summary
Keel bone damage (KBD) is very prevalent in commercial laying hen flocks with a wide range of affected hens/flock. It can cause pain, and affected hens have been found to be less mobile. The assessment of this animal welfare indicator provides important feedback for the farmer about flock health and consequently on the need for interventions. However, the assessment of keel bone damage is time-consuming, and prior training is needed in order to gain reliable results. Optical detection methods can be ...
Aufsatz
Exploring land-use histories of tree-crop landscapes: a cross-site comparison in the Mediterranean Basin
(2020-05-02)
Agroforestry landscapes in the Mediterranean Basin have emerged in a co-evolution between humans and nature and provide numerous ecosystem services to society. Tree crops are iconic elements of these landscapes and have frequently been managed in a sustainable way over centuries, shaping multifunctional landscapes and local people’s cultural identities. However, many Mediterranean tree-crop landscapes are undergoing substantial land-use changes, threatening important ecosystem services as a result. The overarching ...
Aufsatz
Predicting Forage Quality of Grasslands Using UAV-Borne Imaging Spectroscopy
(2020-01-01)
The timely knowledge of forage quality of grasslands is vital for matching the demands in animal feeding. Remote sensing (RS) is a promising tool for estimating field-scale forage quality compared with traditional methods, which usually do not provide equally detailed information. However, the applicability of RS prediction models depends on the variability of the underlying calibration data, which can be brought about by the inclusion of a multitude of grassland types and management practices in the model development. ...
Aufsatz
Cellular morphology of leg musculature in the water bear Hypsibius exemplaris (Tardigrada) unravels serial homologies
(2019-10-16)
Tardigrades (water bears) are microscopic, segmented ecdysozoans with four pairs of legs. Lobopodous limbs that are similar to those seen in tardigrades are hypothesized to represent the ancestral state of Panarthropoda (Tardigrada + Onychophora + Arthropoda), and their evolutionary history is important to our understanding of ecdysozoan evolution. Equally important is our understanding of the functional morphology of these legs, which requires knowledge of their musculature. Tardigrade musculature is well documented ...
Aufsatz
Review of Steady-State Electric Power Distribution System Datasets
(2020-09-15)
Publicly available grid datasets with electric steady-state equivalent circuit models are crucial for the development and comparison of a variety of power system simulation tools and algorithms. Such algorithms are essential to analyze and improve the integration of distributed energy resources (DERs) in electrical power systems. Increased penetration of DERs, new technologies, and changing regulatory frameworks require the continuous development of the grid infrastructure. As a result, the number and versatility of ...