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Aufsatz
Typology of smallholder’s pig production systems in South Kivu, Democratic Republic of Congo: Challenges and opportunities
(2020-06-30)
Pig farming plays an important role in farmers’ livelihoods in many tropical countries. It contributes to food security of the poorest as well as the development of rural economy through multiplier effects. In the South Kivu province, pig farms are almost exclusively owned by smallholders. A few studies have attempted to describe thoroughly pig farming systems in this province. This study was undertaken to characterise pig production systems, in order to better understand their current situation, namely constraints ...
Dissertation
Das New Public Management als Grundlage für eine effiziente und effektive Verwaltung, untersucht am Beispiel der Verwaltung von Hoima, Uganda
(kassel university press, 2010-08-09)
In der Dissertation wird die Möglichkeit untersucht, die deutschen Erfahrungen mit dem New Public Management (NPM) für die Entwicklung der Verwaltung in Uganda nutzbar zu machen. Inhaltlich betrifft die Arbeit 3 Hauptkomponenten: Das NPM als Konzept für die öffentliche Verwaltung, die Erfahrungen mit dem NPM in Deutschland, die Transfermöglichkeit des NPM und insbesondere der deutschen Erfahrungen mit dem NPM nach Uganda, wobei auch die deutschen Erfahrungen mit der Verwaltungshilfe nach dem 1990 erfolgten Beitritt ...
Buch
Modellierung und Simulation viskoelastischer Polymerschmelzen
(kassel university press, 2012)
Die vorliegende Dissertation behandelt Kunststoffschmelzen als viskoelastische Fluide, bzw. im allgemeinen als Nicht-Newtonsche Fluide. Schmelzen dieser Art zeigen in der Tat viskoelastisches Verhalten, aber auch u.a. Strukturviskosität bzw. Scherentzähung und
Normalspannungsdifferenzen.
Diese Fülle an verschiedenen, beobachtbaren Phänomene werden mit linearen Ansätzen nicht mehr ausreichend beschrieben. In dieser Arbeit werden Modelle eingesetzt, die auf makroskopischen und mikroskopischen Konzepten basieren. Dazu ...
Aufsatz
On the structural integrity of Fe-36Ni Invar alloy processed by selective laser melting
(2020)
Specimens made from pre-alloyed Invar (Fe-36Ni) powder were fabricated by selective laser melting and stress-relief heat treated afterwards. A relative density of the fabricated parts of 99.6 % was determined by computed tomography. The microstructure and mechanical behavior under monotonic and particularly cyclic loading at ambient temperature were investigated. Results reveal a bimodal microstructure containing columnar and equiaxed grains with an average grain size of 75 μm and pronounced texture 〈001〉 || BD. The ...
Aufsatz
Cyclic degradation of Co49Ni21Ga30 high-temperature shape memory alloy - On the roles of dislocation activity and chemical order
(2015)
Conventional shape memory alloys (SMAs), such as binary Ni-Ti, are typically limited to service temperatures below 100 °C. Recent studies on Co-Ni-Ga high temperature (HT) SMAs revealed the potential that these alloys can be used up to temperatures of about 400 °C. Analysis of the cyclic functional properties showed that degradation in these alloys is mainly triggered by intensive dislocation motion. However, data on the cyclic stress-strain response and the mechanisms leading to functional degradation of Co-Ni-Ga ...
Aufsatz
Dynamic Tensile Deformation of High Strength Aluminum Alloys Processed Following Novel Thermomechanical Treatment Strategies
(2020-05-14)
Herein, the effects of a very recently introduced novel thermomechanical process route on the microstructural evolution and dynamic tensile deformation behavior of two different precipitation hardenable aluminum alloys, i.e., AA6082 and AA7075, are studied. The investigated materials are hot formed and quenched in differently tempered tools to reveal the influence of cooling rate. Microstructure analysis is conducted to study the influences of different cooling strategies on the microstructure evolution and prevailing ...
Aufsatz
Effect of Compositional Variation Induced by EBM Processing on Deformation Behavior and Phase Stability of Austenitic Cr-Mn-Ni TRIP Steel
(2020-01-24)
Electron beam melting (EBM) is an established powder bed-based additive manufacturing process for the fabrication of complex-shaped metallic components. For metastable austenitic Cr-Mn-Ni TRIP steel, the formation of a homogeneous fine-grained microstructure and outstanding damage tolerance have been reported. However, depending on the process parameters, a certain fraction of Mn evaporates. This can have a significant impact on deformation mechanisms as well as kinetics, as was previously shown for as-cast material. ...
Aufsatz
On the Impact of Texture and Grain Size on the Pseudoelastic Properties of Polycrystalline Fe–Ni–Co–Al–Ti Alloy
(2020-05-08)
The effects of thermomechanical treatments on crystallographic texture and grain size evolution and their impact on the pseudoelastic properties in Fe41–Ni28–Co17–Al11.5–Ti2.5 (at.%) were studied in the present paper. The results show that cold rolling leads to brass-type texture in this alloy, which is typical for low stacking fault energy materials. Thermal treatments up to 1300 °C were conducted and it is shown that the presence of β-phase helps to control grain growth. After the dissolution of the secondary phase ...
Masterarbeit
The Sundarbans in Bangladesh
(2019)
Bangladesh is an agricultural-based country. Agriculture contributes 42.70% (BER) in the labor market through 4 categories namely crops, fisheries, livestock, and forestry. Forestry has the most significant role in renovation of infrastructures and balancing the natural environment. Due to human and natural induced threats, the forest resources are in danger and currently, the percentage of forest in Bangladesh is 13.22 % (BER). The sector is still mistreated on the basis of compared to the other three parts of ...
Konferenzveröffentlichung
Multicomponent Injection Molding Of Thermoplastics And Liquid Silicone Rubber (LSR) – Either Cured By Heat Or UV Light
(Society of Plastics Engineers, 2016)
For processing thermally curing liquid silicone rubber (LSR) as well as UV light curing LSR for multicompo-nent injection molding with thermoplastics in an compa-rable way a processing center was designed and set into operation.
For the production of the multicomponent specimens a modular tool was designed. In there a thermoplastic plate gets molded on the one side, then gets transferred auto-matically by a robot system and gets overmolded by the silicone on the other side. The complete silicone side of the tool is ...