A computationally efficient algorithm for solving population balance equations (PBEs) for describing the evolution of crystal size distribution (CSD) in seeded batch crystallization processes is developed. The algorithm is particularly suitable for solving problems with size-dependent growth and dissolution kinetics where temperature cycling is applied to modify the CSD. It is much faster than the quadrature method of moments (QMOM) which has been widely applied to solve this type of problem and has the added benefit that it provides the complete crystal size distribution rather than only the moments. These features make it especially well suited for solving problems in optimization and determination of feasible regions, where many batch simulations are required. The algorithm is applied to determine attainable regions for seed-grown product crystals (characterized by the mean and variance of the seed-grown product CSD) and analyze the trade-off between the objectives of minimizing batch time and nucleated crystal volume in a batch crystallization process with temperature cycling. Two main conclusions are drawn from the results. First, the attainable region expands with an increasing number of growth-dissolution cycles as expected, but the extent of the increase or decrease in the attainable variance depends on the sensitivity of the growth and dissolution rates to the crystal size. Second, the trade-off between the abovementioned objectives subject to constraints on the seed-grown crystal mean size and variance is significant and an outcome representing a good compromise can be achieved by specifying proper supersaturation and undersaturation set points.

Present-day osmotic pumps not only produce a constant release, but also have the ability to produce adjustable release according to practical requirements. Hence, technology combined, targeted, chronotherapy-based, ascending and compound osmotic pumps are a positive development. These latest advances offer various advantages compared with the classic osmotic pump, and enable them to meet the new needs for clinical use with fewer side effects and improved safety. In addition, following the improvements in the versatility and complexity of the novel osmotic pump system, conventional assessing parameters may fail to meet the increasing demand for information. Hence, novel imaging and monitoring technologies have been employed to monitor osmotic pumps from the coating process, processing steps, and polymer hydration to the changes in polymeric internal structure, which are associated with the different performance offered by the in vivo action of similar products.

No abstract

No abstract

In this paper, we mainly explore how to design and implement the user interfaces of Electricity Operation Information System based on Android. The paper extends its process as the following four aspects---requirements analysis, UI design, interaction design and programmatic implementation. In response to user actions fluidly and friendly, we add modules to handle exceptions. In the end, we give a briefly test on the system UI to ensure it run smoothly and make less mistakes. There are limited studies focusing on the flow design of UI combined with programmatic implementation. The UI design and implementation methodology has good reference at the early stage of developing an application, especially on Android platforms.