Using immersive virtual reality (VR), this study examined the D/H ratio principle (where “D” means the depth or width of a public space and “H” means the height of its surrounding buildings.) that urban design theorists have suggested as an important design principle for public spaces. The authors built VR models of eight enclosed urban public squares with different D/H ratios ranging from 1/3 to 6/1. They then carried out an experiment in the form of a visual assessment survey using the VR models with 69 university students majoring in urban planning and compared the optimal D/H ratios from the experimental results with those proposed by urban design theorists. The statistical analysis of the experimental results revealed that the optimal D/H ratios for most qualities of public squares are larger than the optimal ratios claimed by theorists.

Corrosion of devices and pipes in refinery and petrochemical plants cause problems like deterioration of process efficiency and equipment reliability etc. Hence, a suitable technology is required to prevent accident caused by corrosion and raise process efficiency by forecasting the degree of corrosion. The corrosion problems on the top of the distillation column are more serious due to corrosive substances like hydrogen sulfide and chlorine etc. Therefore, in this study, corrosion rate was forecasted and applied through analysis of the corrosion mechanism on the top of refinery distillation column and the validity of the model was checked using the actual data.: considering interference effect caused by competitive reactions between caustic substances. The four components that affect corrosion the most, H2S, CO2, H+, and Cl–, were selected through analysis of the mechanism of corrosion on the top of refinery distillation tower. The model for the analysis of corrosion mechanism was analyzed in the viewpoint of transport phenomenon and reaction engineering, and parameters were estimated with the use of least-squares method.

Lactide synthesis is an energy-intensive process used to produce polylactic acid (PLA). In this study, we propose a continuous lactide synthesis process developed on the basis of a recently developed one-step reaction using a SnO 2 −SiO 2 nanocomposite catalyst. This process enables a rapid reaction time of 40 ms for the catalyst, which achieves 94% lactide yield.To design an efficient chemical process, reaction kinetics were developed and a heterogeneous reactor model was applied to the reactor. The proposed process has advantages over commercial processes, having both a rapid reaction rate and high yield. Moreover, its rapid reaction rate significantly increases the productivity. In addition, this process operates under atmospheric pressure, which makes it more energy efficient than commercial processes that operate under a high vacuum pressure of 20 mmHg. Therefore, the overall process is an effective alternative for lactide production.

This study focuses on the techniques of improving refinery reliability, profitability, and availability. In this study, a corrosion control document (CCD) knowledge base system in crude oil distillation unit process is developed. CCD consists of numerous parts namely damage mechanisms (DM), design data, critical reliability variables (CRV), guidelines, etc. To develop CCD, first off, a material selection diagrams (MSD) is drawn. The DM of each process effecting equipments that are based on American Petroleum Institute 571 should be chosen. Operating variables affecting severity of DM are selected in the beginning stage of CRV. Finally, guidelines are provided for the reliability of equipments.

With an increased emphasis on reduced carbon emissions, many research efforts focused on various carbon capture techniques have concurrently expanded in application. Pressure swing adsorption (PSA) is one of the key processes for carbon capture and storage (CCS). During the natural gas sweetening operation of PSA processes, a high volume of carbon dioxide is included in the waste flow (heavy product). To improve the CO2 purity of the waste flow, this work first performs the dynamic optimization of a general four-step dual PSA process. The objective of the rectifying unit is to maximize methane recovery while the objective of the stripping unit is to maximize carbon dioxide purity for CCS. In brief, decision variables for the rectifying unit are the step times, P/F ratios, and feeding velocities of each unit; the length of the bed is added as a decision variable for the stripping unit. Optimization results indicate that carbon dioxide purity increases from 41.4% to 76.3% and methane recovery increases from 78.5% to 95.4%.