Enhancement of the availability of desalination plants by means of in-service inspections

Design and manufacture of graphite components for 21st century small modular reactors

The paper considers the process of creating a permanent connection from the EP693 heat-resistant alloy of the Ni-Cr-W-Co-Mo system used in the manufacture of components and parts of gas turbine engines by welding on the TruLaser Cell 7020 CO2 complex with pulse-periodic radiation. EP367 filler wire of the Ni—Mo—Cr—Mn system was used to obtain the weld. The influence of heat treatment on the structure and properties of the heat-affected zone and the weld was studied. Based on the research results, the weld structure and kinks obtained by laser welding was studied, weld physical and mechanical properties were identified, the maximum endurance limit for welded joints was determined at 2•106 cycles. The expediency of laser welding of the heat-resistant dispersion-hardening nickel alloy in the manufacture of shells for the turbine support and stator of gas turbine engines was determined. It was found that combined heat treatment (quenching and aging) provides optimal values of strength limits at room and elevated temperatures, as well as short-term strength of welded joints. Based on the strength calculation of the turbine support and stator of gas turbine engines and the obtained experimental data on the strength of welded joints made using laser welding with pulse-periodic radiation, the safety factor was 1.35 to 3.0. This technology is proposed to be introduced into production in the manufacture of parts and assemblies such as shells for the turbine support and stator of gas turbine engines in order to improve the quality of welds by reducing the time of high-temperature heating due to lower heat input.

Three-dimensional printing of cementitious materials for construction has been extensively investigated in recent years, with several demonstration projects successfully carried out. These efforts aim to leverage the printing process to achieve more efficient production of components compared to conventional concrete technologies. This includes both the process itself (eliminating the formwork stage) and the flexibility in producing complexly shaped elements. To maximize the potential of 3D printing in the construction industry, additional steps must be taken, grounded in a holistic view of the entire process. This involves integration of the production chain, including design, materials, and manufacturing of components, to create elements with optimal performance, encompassing structural, environmental, and architectural aspects. Such multi-functionality requires the viewing of 3D printing not just as a production technology but as a platform enabling the integration of all these components. To advance this approach, quantitative tools are developed to optimize the following three key components: material composition; manufacturing parameters to ensure buildability; and design tools to optimize multiple performance criteria, particularly structural and architectural shape. A demonstration component, namely a post-tensioned beam, featuring two multi-functional characteristics—structural and architectural—is designed, produced, and evaluated. The scientific concepts and research tools used to develop these quantitative design tools are multidisciplinary, including rheological characterization, control of the internal structure and composition of granular materials, simulation of the mechanical behavior of green material during printing, and the hardened properties of the components, all utilizing structural optimization to enhance performance.

This work presents a methodology of 3D modeling suitable for the design and manufacture of components with complex forms of organic inspiration. It is applied to a real case of development of a sculptural element related to the corporate image of a company. In the introduction, the boundary conditions of the project and the product to be modeled with the starting specifications are presented. Next, the stages followed for the execution of the project that give justification to the methodology developed are described. The document shows the general flow of activities presenting in each one the particularities and resolved contingencies. The tangible results of the project that includes the variations of the model generated for 3D animation equipped with articulated bones are also exposed. It has been experimentally verified that the proposed modeling methodology allows the integration of components designed by CAD, generates topologies coherent with innovative criteria that they facilitate production through additive manufacturing with related surfaces free of errors. It is, therefore, a hybrid method based on the manipulation of mesh polygons with accessible tools that is suitable for the design and manufacture of bio-inspired products, paleontological reconstructions, prostheses or bio-engineering components. The UV coordinate maps and the designed textures make it possible for the same geometry or simplified versions of the manufactured model to be modified by means of 3D animation techniques with skeletons, to be used in virtual representations and in augmented reality environments, increasingly demanded in the field of Graphic Engineering.

Population density and plant availability interplay to shape browsing intensity by roe deer in a deciduous forest

The manufacture of parts by metal forming is a widespread technique in sectors such as oil and gas and automotives. It is therefore important to make a research effort to know the correct set of parameters that allow the manufacture of correct parts. This paper presents a process analysis by means of the finite element model. The use case presented in this paper is that of a 3-m diameter pipe component with a thickness of 22 mm. In this type of application, poor selection of process conditions can result in parts that are out of tolerance, both in dimensions and shape. A 3D finite element model is made, and the symmetry of the tube section generated in 2D is analysed. As a novelty, an analysis of the process correction as a function of the symmetrical deformation of the material in this case in the form of a pipe is carried out. The results show a correct fitting of the model and give guidelines for manufacturing.

Silicon carbide may well be the best known material for the manufacture of high performance optical components. A combination of extremely high specific stiffness (r/E), high thermal conductivity and outstanding dimensional stability make silicon carbide superior overall to beryllium and low-expansion glass ceramics. A major impediment to wide use of a ceramic material such as silicon carbide is the ability to create a design that fully utilizes these properties while addressing limitations such as brittleness. This paper discusses an approach for design that will optimize the use of properties while considering the manufacturability of the component. POCO has developed a manufacturing process that lends itself to efficient design of complex optical components. The manufacturing process described here-in begins by machining the component from a special type of graphite. This graphite is easily machined with multi-axis CNC machine tools to any level of complexity and lightweighting required. The graphite is then converted completely to silicon carbide with very small and very predictable dimensional change. After conversion to silicon carbide the optical surface is coated with very fine grain silicon carbide which is easily polished to extreme smoothness using conventional optical polishing techniques. The design approach presented requires an iterative process between the 'system' designer and the materials and component designer. Both he fabrication process and the design approach are described in this paper.

To drive emissions reduction and performance improvement of the gas turbines, Siemens Energy is working continuously with the development and implementation of new advanced technologies. This paper describes the integration of groundbreaking additive manufacturing (AM) technology into the design and manufacturing of gas turbine components. Siemens Energy is already implemented AM technology in the design and manufacturing of combustor components to run gas turbines on green fuels. As an example, the implementation of AM burners in medium-size gas turbines (MTG) with Dry Low Emission (DLE) combustors expands their fuel flexibility and ability to run on hydrogen-rich gases. Today, the SGT-600, -700 and -800 can be offered to run on fuel with up to 75 vol% H2 in the fuel. Integrating AM technology into the design and manufacturing of turbine’s components, such as vanes and blades, leads to substantial improvements in gas turbine efficiency and, as a result, gas turbine fuel consumption and emissions reduction. This paper describes the infusion of AM technology into the design and manufacturing of hot gas path components, in the turbine vanes of Siemens Energy gas turbines. Improving the efficiency of turbine and turbine components is driven by utilizing new advanced cooling systems and better aerodynamics enabled by the practically unlimited capability of AM design and manufacturing. Successful design, manufacturing and field validation of AM vanes in Siemens Energy SGT-700 gas turbine are presented and discussed in this paper. The reliable operation of AM components under real field operation conditions has been confirmed by the total accumulated field experience, which already exceeds 1,700,000 operating hours.

Experimental limitation of oviposition sites affects the mating system of an arachnid with resource defence polygyny

Mega-prostheses required for reconstructing large gaps in bone after limb-saving surgeries for osteo-sarcoma patients have a long development cycle. This includes design of prosthesis components and surgical armamentarium, followed by pilot batch production, lab testing, human clinical trials and regulatory approvals. Most manufacturers stay away due to small market size coupled with the difficulties and high costs involved. Prostheses developed in the West are often unsuitable and unaffordable for the majority of Indian patients. There is a need for high-quality yet low-cost prostheses that are compatible with the anatomy and functionality of local population. An inter-disciplinary group comprising orthopedic oncologists, mechanical engineers and materials scientists from three different organizations in India took up the above challenge. They developed a novel modular tumour knee prosthesis with rotating hinge, as well as surgical armamentarium with femoral and tibial cutting jigs and other instruments. Knee simulator and testing machines were developed to test the prosthesis. A dedicated pilot production facility along with inspection and quality management system was set up. The new prosthesis provides flexion-extension up to 120 degrees and axial rotation of ±5 degrees. It successfully completed ten million cycles of fatigue and wear testing. The regulatory body of the government and institutional ethical committees of hospitals approved the human clinical trials, which are currently in progress. The design, manufacturing and testing of the prosthesis components and armamentarium took more than a decade and presented many challenges. These were overcome by several technological innovations by the engineering team and continuous feedback from the surgeons. The experience is expected to be useful to all others interested in this field.

The influence of thickness/grain size ratio in microforming through crystal plasticity

To understand the effect of plant availability/structure on the population size and dynamics of insects, a specialist herbivore in the presence of two of its parasitoids was studied in four replicated time-series experiments with high and low plant availabilities; under the latter condition, the herbivore suffered from some periods of resource limitation (starvation) and little plant-related structural refuges. Population dynamics of the parasitoid Cotesia vestalis was governed mainly by the delayed density-dependent process under both plant setups. The parasitoid, Diadegma semiclausum, under different plant availabilities and different coexistence situations (either +competitor or -competitor) showed dynamics patterns that were governed mainly by the delayed density process (significant lags at weeks 2-4). Both the competing parasitoids did not experience beneficial or costly interferences from each other in terms of their own population size when the plant resource was limited. Variation in the Plutella xylostella population under limited plant availability is higher than that under the other plant setup. For both parasitoids, under limited plant setup, the extinction risk was lower when parasitoids were engaged in competition, while under the unlimited plant setup, the mentioned risk was higher when parasitoids competed. In this situation, parasitoids suffered from two forces, competition and higher escaped hosts.

Effects of a nitrification inhibitor on nitrogen species in the soil and the yield and phosphorus uptake of maize.

Phosphorus rich sewage sludge ash is a promising source to produce phosphorus recycling fertilizer. However, the low plant availability of phosphorus in these ashes makes a treatment necessary. A thermochemical treatment (800–1000 °C) with alkali additives transforms poorly plant available phosphorus phases to highly plant available calcium alkali phosphates (Ca,Mg)(Na,K)PO4. In this study, we investigate the use of K2SO4 as additive to produce a phosphorus potassium fertilizer in laboratory-scale experiments (crucible). Pure K2SO4 is not suitable as high reaction temperatures are required due to the high melting point of K2SO4. To overcome this barrier, we carried out series of experiments with mixtures of K2SO4 and Na2SO4 resulting in a lower economically feasible reaction temperature (900–1000 °C). In this way, the produced phosphorus potassium fertilizers (8.4 wt.% K, 7.6 wt.% P) was highly plant available for phosphorus indicated by complete extractable phosphorus in neutral ammonium citrate solution. The added potassium is, in contrast to sodium, preferably incorporated into silicates instead of phosphorus phases. Thus, the highly extractable phase (Ca,Mg)(Na,K)PO4 in the thermochemical products contain less potassium than expected. This preferred incorporation is confirmed by a pilot-scale trial (rotary kiln) and thermodynamic calculation.

Maintenance duration estimate for a DEMO fusion power plant, based on the EFDA WP12 pre-conceptual studies