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Now showing items 1901-1910 of 1973
Aufsatz
On the Influence of Microstructure on the Corrosion Behavior of Fe–Mn–Al–Ni Shape Memory Alloy in 5.0 wt% NaCl Solution
(2020-10-03)
Herein the corrosion behavior of Fe–Mn–Al–Ni shape memory alloys characterized by different microstructures in a 5.0 wt% NaCl solution is investigated. Open circuit potential and potentiodynamic polarisation tests are conducted. Generally, Fe–Mn–Al–Ni shows corrosion properties being similar to pure iron. However, the polarization curves of single crystals indicate the presence of an unstable passive system. The corrosion damage is analyzed by means of optical microscopy and electron microscopy. It is revealed that ...
Aufsatz
Thermal Stability of Residual Stresses in Differently Deep Rolled Surface Layers of Steel SAE 1045
(2021-05-07)
The stability of compressive residual stresses generated by deep rolling plays a decisive role on the fatigue behavior of specimens and components, respectively. In this regard, deep rolling at elevated temperature has proven to be very effective in stabilizing residual stresses when fatigue analysis is conducted at ambient temperature. However, since residual stresses can be affected not only by plastic deformation but also when thermal energy is provided, it is necessary to analyze the influence of temperature and ...
Aufsatz
Cooling rate as a process parameter in advanced roll forming to tailor microstructure,mechanical and corrosion properties of EN AW 7075 tubes
(2022-12-14)
The effects of solution heat treatment parameters and quench media as a processing tool for tailoring microstructure, mechanical and corrosion properties in roll forming of EN AW 7075 alloy were studied. The highest yield stress and ultimate tensile strength were obtained for the specimens quenched in water, while the air-cooled specimens exhibited inferior mechanical properties. Microstructural analysis of specimens showed that except water-quenched specimens, the parts cooled/quenched in oil, in direct contact with ...
Aufsatz
In-situ full-field deformation analysis of injection-molded microcellular polycarbonate according to foam morphology patterns
(2023-06-02)
Deformation behavior of microcellular foam materials are sensitive to microstructural details. Therefore, the distinctive foam morphology patterns of foam injection-molded Polycarbonate are identified. These morphology patterns are investigated regarding their cell size, distance between cells, cell density, density reduction, homogeneity of cell size distribution, sphericity of cells and cell volume. Consequently, the predefined foam morphologies, the resulting modulus of elasticity and the elongation at break are ...
Aufsatz
Effect of storage conditions on soybean seed quality produced by smallholder farmers within two districts of Gauteng, South Africa
(2024-05-22)
Seed quality comprises of physical, physiological, and health attributes. Moreover, significant aspects of seed quality include seed viability and vigour. Maintaining good seed quality under sub-optimal storage conditions is one of the major challenges smallholder soybean farmers face. Hence, this study aimed to determine the effect of on-farm storage conditions on the seed quality of soybeans from smallholder farmers within the Gauteng Province, South Africa. The objectives of this study were to i) evaluate and ...
Aufsatz
Cost and return analysis of organic and conventional farming systems in the Ganga River Basin, India
(2024-02-26)
Conventional farming (CF) has significantly increased the aggregate supply of food grains and ensured food security for the growing population in India. However, it proved environmentally unsustainable due to its higher reliance on chemical inputs. Organic farming (OF) becomes an alternative approach that ensures the sustainability of the agricultural system. But, the transition from CF to OF can be a lengthy process, and farmers may experience income loss during its course. Farmers will switch only when they are ...
Aufsatz
On the low-cycle fatigue behavior of thermo-mechanically processed high-strength aluminum alloys
(2021)
In the present work low-cycle fatigue experiments were carried out on thermo-mechanically processed AA6082 and AA7075 sheets to evaluate mechanical properties under cyclic loading. Different cooling rates imposed by use of tempered forming tools after solutionizing and subsequent aging treatment led to the formation of precipitates with differing sizes and morphologies. Specimens thermo-mechanically processed in tools with temperatures of 24 °C and 200 °C showed superior mechanical properties under both monotonic and ...
Aufsatz
Influence of season and phytochemicals on the elemental composition of kobs’ diets in Old Oyo National Park, Nigeria
(2024-02-20)
Phytochemicals or plant secondary metabolites (PSMs) are known to counteract mineral nutrients (MNs) utilisation in herbivorous wildlife, yet studies on the interactions between PSMs and MNs in relation to herbivory, particularly for kobs (Kobus kob) are scarce. Composite samples of each of five major forage plants of kobs’ (Grewia mollis, Afzelia africana, Gardenia aqualla, Maranthes polyandra and Andropogon gayanus) were randomly collected in and around feeding sites of kobs in both dry and wet season. Using standard ...
Aufsatz
Partial purification of tannase enzyme produced by Bacillus licheniformis isolated from local soils
(2023-12-28)
Tannase is an enzyme that causes hydrolysis of a group of tannins (gallo-tannins) to gallic acid and glucose. This enzyme is of importance due to its numerous applications in many fields, such as in the food industry by enhancing tea and coffee flavour and improving the quality of fruit juices rich in tannins. Gallic acid is applied in the drug industry, and production of antioxidants is used in the oil industry. In this study, Tannase was produced by locally isolated Bacillus licheniformis using spent tea as substrate ...