Design optimization of a compressor stage with counter-rotating rotors

The paper deals with the design optimization of the compressor stage with counter-rotating rotors, especially in order to create a model which, due to its parameters in real operation, would achieve the maximum possible values of efficiency. The primary goal of this work is to create a design of a compressor stage with counter-rotating rotors from a theoretical point of view. The compressor stage model is created using Inventor modelling software and the subsequent design evaluation and optimization is based on airflow analysis of the compressor stage using Ansys Discovery Live software. The secondary goal is to point out the existence and application of innovative and progressive technology of rapid prototyping in the world of aircraft component production and at the same time to emphasize its benefits in comparison with conventional production techniques applied in the initial stages of aircraft component production.

Application of BIM Based Information Management Technology in Prefabricated Buildings

Under the background of industrial transformation and green development of construction industry, prefabricated building has become an important means to promote the development of construction industrialization and environmental protection. In the period of new and old construction mode change, the construction links of in-depth design, component production, component transportation and assembly construction are added to the prefabricated building, which has higher requirements for the unity of the whole process of the construction project. BIM platform can unify the information of the whole process and coordinate the management of the whole process of the project. This paper expounds the application of information management technology based on BIM in the three processes of in-depth design, component production and transportation management of prefabricated building. Through the analysis and comparison of actual cases, it is concluded that the prefabricated building combined with BIM Technology has more advantages than traditional construction in design, management, capital, environmental protection, etc.

Automated Optimization for the Production Scheduling of Prefabricated Elements Based on the Genetic Algorithm and IFC Object Segmentation

Background: With the ever-increasing availability of data and a higher level of automation and simulation, production scheduling in the factory for prefabrication can no longer be seen as an autonomous solution. Concepts such as building information modelling (BIM), graphic techniques, databases, and interface development as well as heightened emphasis on overall-process optimization topics increase the pressure to connect to and interact with interrelated tasks and procedures. Methods: The automated optimization framework detailed in this study intended to generate optimal schedule of prefabricated component production based on the manufacturing process model and genetic algorithm method. An extraction and segmentation approach based on industry foundation classes (IFC) for prefabricated component production is discussed. During this process, the position and geometric information of the prefabricated components are adjusted and output in the extracted IFC file. Then, the production process and the completion time of each process have been examined and simulated with the genetic algorithm. Lastly, the automated optimization solution can be formed by the linking production scheduling database and the computational environment. Results: This shows that the implementation of the automated optimization framework for the production scheduling of the prefabricated elements improves the operability and accuracy of the production process. Conclusions: Based on the integration technique discussed above, the data transmission and integration in the mating application program is achieved by linking the Python-based application, the Structured Query Language (SQL) database and the computational environment. The implementation of the automated optimization framework model enables BIM models to play a better foundational role in patching up the technical gaps between prefabricated building designers and element producers.

Research on Lean Planning and Optimization for Precast Component Production Based on Discrete Event Simulation

Component factories are experiencing the problems associated with lean production, especially the accuracy of production time prediction and the unnecessary waste in terms of time and resource utilization. In order to solve these problems, a discrete event simulation- (DES-) based lean planning and optimization method for precast component production is proposed by integrating the complexity assessment (CS), discrete event simulation (DES), and lean management (LM). The method includes three submodels: improved production planning, DES, and lean analysis and optimization. In the submodel of improved production planning, a complexity evaluation index system for precast components is established through investigating five component factories, consulting seven domain experts and analysing relevant literature. In the submodel of DES, the DES technique is adopted to simulate and analyse the production activities of precast components. The submodel of lean analysis and optimization provides multidimensional analysis, comparative analysis, and suggestions. Finally, a detailed production case is selected to simulate and test the proposed method. The important findings are as follows: (1) this method can minimize the difference between the processing time of each workstation to avoid bottleneck stations as much as possible; (2) this method can capture the uncertainty during precast component production, and the most likely production time calculated by the method is 12.05 hours instead of the 11.50 hours originally estimated by the component factory; (3) this method can identify some unnecessary waste in the production process of precast components, including less than 50% utilization of workstations and unnecessary equipment purchases; (4) this method also provides some suggestions regarding production optimization. Due to the particularity of precast component production, it further expands the boundary of lean production methodology from the perspective of the construction industry rather than the manufacturing industry. The proposed method assists component factories in planning and optimizing the precast component production when they make detailed production plans.

Properdin Modulates Complement Component Production in Stressed Human Primary Retinal Pigment Epithelium Cells

The retinal pigment epithelium (RPE) maintains visual function and preserves structural integrity of the retina. Chronic dysfunction of the RPE is associated with retinal degeneration, including age-related macular degeneration (AMD). The AMD pathogenesis includes both increased oxidative stress and complement dysregulation. Physiological sources of oxidative stress in the retina are well known, while complement sources and regulation are still under debate. Using human primary RPE (hpRPE) cells, we have established a model to investigate complement component expression on transcript and protein level in AMD-risk and non-risk hpRPE cells. We evaluated the effect of properdin, a complement stabilizer, on the hpRPE cell-dependent complement profile exposed to oxidative stress. hpRPE cells expressed complement components, receptors and regulators. Complement proteins were also stored and secreted by hpRPE cells. We associated AMD-risk single nucleotide polymorphisms with an increased secretion of complement factors D (CFD) and I (CFI). Furthermore, we detected hpRPE cell-associated complement activation products (C3a, C5a) independent of any extracellularly added complement system. Exogenous properdin increased the mRNA expression of CFI and CFD, but decreased levels of complement components (C1Q, C3), receptors (C3AR, C5AR1, CD11B) and inflammation-associated transcripts (NLRP3, IL1B) in hpRPE cells exposed to oxidative stress. This properdin effect was time-dependently counter regulated. In conclusion, our data unveiled a local, genotype-associated complement component production in hpRPE cells, regulated by exogenous properdin. The local complement production and activation via blood-independent mechanisms can be a new therapeutic target for AMD.