Abstract The aim of this case study is to develop a process model including both heat integration and separation processes by means of ASPEN PLUS simulation software. Previous studies have attempted to develop kinetic models or to retrieve optimal policies for operating the process multitubular catalytic fixed-bed reactor. This time a rigorous model is developed in ASPEN CUSTOM MODELER and expo...

Detailed chemical process simulations are a useful tool in designing and optimizing complex systems and architectures for human life support. Dynamic and steady-state models of these systems help contrast the interactions of various operating parameters and hardware designs, which become extremely useful in trade-study analyses. NASA’s Exploration Life Support technology development project rec...

This paper describes the ASPEN system for automation of planning and scheduling for space mission operations. ASPEN contains a number of innovations including: an expressive but easy to use modeling language, multiple search (inference) engines, iterative repair suited for mixed-initiative human in loop operations, real-time replanning and response (in the CASPER system), and plan optimization....

Vegetative regeneration of aspen can be initiated through manipulations that provide hormonal stimulation, proper growth environment, and sucker protection—the three elements of the aspen regeneration triangle. The correct course of action depends upon a careful evaluation of the size, vigor, age, and successional status of the existing clone. Soils and site productivity, competition from other...

Algorithms to solve security games have seen successful real-world deployment by LAX police and the Federal Air Marshal Service. These algorithms provide randomized schedules to optimally allocate limited security resources for infrastructure protection. Unfortunately, these algorithms fail to scale-up or to provide a correct solution for massive security games with arbitrary scheduling constra...

This study aimed to determine whether Syrian (golden) hamsters, Mesocricetus auratus, prefer certain bedding materials and whether bedding material can affect paw condition, body weight gain and wheel-running activity. In a first experiment, 26 male hamsters had access to two connected cages, each cage containing a different bedding material (either pine shavings, aspen shavings, corn cob or wo...

Gray wolves (Canis lupus) were reintroduced into Yellowstone National Park in 1995–96, thus completing the park’s large predator guild. In the fall of 2010, approximately 15 years after wolf reintroduction, we sampled ten genera/species of berry-producing shrubs within 97 aspen (Populus tremuloides) stands in the park’s northern ungulate winter range. Regression analysis indicated shrub heights...

To study the impact of ozone (O3) and O3 plus CO2 on aspen growth, we planted two trembling aspen clones, differing in sensitivity to O3 in the ground in open-top chambers and exposed them to different concentrations of O3 and O3 plus CO, for 98 days. Ozone exposure (58 to 97 microl l(-1)-h. total exposure) decreased growth and modified crown architecture of both aspen clones. Ozone exposure de...