Suche
Anzeige der Dokumente 301-310 von 940
Aufsatz
Modeling of fiber-coupled confocal and interferometric confocal distance sensors
(2022-04-06)
Laser distance sensors are a widespread, fast and contactless approach for distance and surface topography measurements. Main characteristics of those sensors are given by resolution, measurement speed and sensor geometry. With decreasing sensor size, the alignment of the optical components in sensor setup becomes more challenging. The depth response of optical profilers is analyzed to obtain characteristic parameters and, thus, to value the alignment and the transfer behavior of those sensors. We present a novel ...
Aufsatz
Food Flows and the Roles of Cities in West African Food Distribution Networks
(2022-05-31)
In West Africa, rampant urbanization is changing food systems, including the magnitude and composition of food flows and the length of supply chains. An increasing body of literature discusses pathways to sustainable transformation of urban food systems taking into account links between urban and rural spaces. Research and policy have focused on the role of cities as consumption centers receiving food from local, regional, and global hinterlands. This study aims at widening the perspective on the role of cities in ...
Aufsatz
Energy and Exergy Based Thermal Analysis of a Solar Assisted Yogurt Processing Unit
(2022-06-01)
Energy and exergy based thermal analysis was conducted for a solar assisted yogurt processing unit capable of performing required heating and cooling processes in a single container. The system consisted of a round-shaped fermentation chamber connected with a hot water storage tank coupled with an evacuated tube collector and a pillow plate at the bottom of the chamber for cooling through a PV-operated refrigeration unit. Experiments were conducted using three different volumes of cow’s raw milk (30, 40, and 50 L). ...
Aufsatz
Pathologies of a Different Kind: Dysfunctional Interactions between International Organizations
(2022-01-17)
This article develops the concept of “interorganizational pathologies” as an extension of Michael N. Barnett and Martha Finnemore's work on bureaucratic pathologies. Adopting an open system perspective, I argue that dysfunctional interactions may arise between international organizations (IOs) even when their cooperation is fairly institutionalized. To advance this line of reasoning, I examine interactions between the International Monetary Fund (IMF or Fund) and the World Bank (or Bank). Evidence from more than ...
Aufsatz
Using New Spare Parts for Repair of Waste Electrical and Electronic Equipment? The Material Footprint of Individual Components
(2022-02-21)
The growing production of waste electrical and electronic equipment (WEEE) requires close loop management to protect the environment and save resources. Repair and reuse can extend the product’s life span. However, debates on the differences seen in resource consumption linked to the different ways of repairing devices have received a limited amount of attention. This article demonstrates quantification of the resource consumption (cradle-to-gate) of five types of appliances on a component level based on life-cycle ...
Aufsatz
Static Grid Equivalent Models Based on Artificial Neural Networks
(2021-12-30)
Power systems are rapidly and significantly changing due to the increasing penetration of distributed energy resources (DERs) and the rapid growth of widespread grid interconnections. An increasing number of grid operators is thus interested in the reduced equivalent representation of a large, interconnected power system to reduce the amount of required computational resources and data exchange, e.g., between grid operators. However, state-of-the-art grid equivalents become more and more inapplicable since they are ...
Aufsatz
Development and Experiments on a Batch-Type Solar Roaster—An Innovative Decentralized System for Coffee Roasting
(2022-02-15)
About 70% of the harvested coffee is exported to the industrialized nations for value addition due to lack of processing and logistic facilities in developing coffee producer countries, thus leaving behind a marginal economic return for the growers. This research was conducted to investigate the roasting capacity of an innovatively developed batch-type directly solar radiated roasting system for the decentralized processing of coffee using solar energy. Central composite rotatable design (CCRD) was employed to design ...
Aufsatz
Inter- and Intra-Individual Variation in the Behavior of Feed Intake on Nutrient Availability in Early Lactating Dairy Cows
(2021-12-24)
Since energetic deficits in dairy cows can only be reduced at an animal level, the objective of the present study was to determine the extent of variation in intake behavior within and between animals during early lactation, to explore the magnitude of interactions between feed intake, intake behavior and nutrient digestibility, and to identify levers for maximizing feed intake at the individual animal level. Feeding behavior, intake and nutrient digestibility of 28 German Holstein dairy cows, fed TMR with 7.0 MJ ...
Aufsatz
Translatory and rotatory motion of exchange-bias capped Janus particles controlled by dynamic magnetic field landscapes
(2021-11-08)
Magnetic Janus particles (MJPs), fabricated by covering a non-magnetic spherical particle with a hemispherical magnetic in-plane exchange-bias layer system cap, display an onion magnetization state for comparably large diameters of a few microns. In this work, the motion characteristics of these MJPs will be investigated when they are steered by a magnetic field landscape over prototypical parallel-stripe domains, dynamically varied by superposed external magnetic field pulse sequences, in an aqueous medium. We ...
Aufsatz
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 ...