Study of component technologies for fuel cell on-site integrated energy system. Volume 2: Appendices

This data base catalogue was compiled in order to facilitate the analysis of various on site integrated energy system with fuel cell power plants. The catalogue is divided into two sections. The first characterizes individual components in terms of their performance profiles as a function of design parameters. The second characterizes total heating and cooling systems in terms of energy output as a function of input and control variables. The integrated fuel cell systems diagrams and the computer analysis of systems are included as well as the cash flows series for baseline systems

Study of component technologies for fuel cell on-site integrated energy systems

Heating, ventilation and air conditioning equipment are integrated with three types of fuel cells. System design and computer simulations are developed to utilize the thermal energy discharge of the fuel in the most cost effective manner. The fuel provides all of the electric needs and a loss of load probability analysis is used to ensure adequate power plant reliability. Equipment cost is estimated for each of the systems analyzed. A levelized annual cost reflecting owning and operating costs including the cost of money was used to select the most promising integrated system configurations. Cash flows are presented for the most promising 16 systems. Several systems for the 96 unit apartment complex (a retail store was also studied) were cost competitive with both gas and electric based conventional systems. Thermal storage is shown to be beneficial and the optimum absorption chiller sizing (waste heat recovery) in connection with electric chillers are developed. Battery storage was analyzed since the system is not electric grid connected. Advanced absorption chillers were analyzed as well. Recommendations covering financing, technical development, and policy issues are given to accelerate the commercialization of the fuel cell for on-site power generation in buildings

Pressure buildup during CO2 injection in brine aquifers using the Forchheimer equation

If geo-sequestration of CO2 is to be employed as a key emissions reduction method in the global effort to mitigate climate change, simple yet robust screening of the risks of disposal in brine aquifers will be needed. There has been significant development of simple analytical and semi-analytical techniques to support screening analysis and performance assessment for potential carbon sequestration sites. These techniques have generally been used to estimate the size of CO2 plumes for the purpose of leakage rate estimation. A common assumption has been that both the fluids and the geological formation are incompressible. Consequently, calculation of pressure distribution requires the specification of an arbitrary radius of influence. In this talk, a new similarity solution is derived using the method of matched asymptotic expansions. By allowing for slight compressibility in the fluids and formation, the solution improves on previous work by not requiring the specification of an arbitrary radius of influence. A large-time approximation of the solution is then extended to account for non-Darcy inertial effects using the Forchheimer equation. Both solutions are verified by comparison with finite difference solutions. The results show that inertial losses will often be comparable, and sometimes greater than, the viscous Darcy-like losses associated with the brine displacement, although this is strongly dependent on formation porosity and permeability

Resonance Interaction Induced by Metal Surfaces Catalyses Atom Pair Breakage

We present the theory for retarded resonance interaction between two identical atoms at arbitrary positions near a metal surface. The dipole-dipole resonance interaction force that binds isotropically excited atom pairs together in free space may turn repulsive close to an ideal (totally reflecting) metal surface. On the other hand, close to an infinitely permeable surface it may turn more attractive. We illustrate numerically how the dipole-dipole resonance interaction between two oxygen atoms near a metal surface may provide a repulsive energy of the same order of magnitude as the ground-state binding energy of an oxygen molecule. As a complement we also present results from density-functional theory.Comment: 5 pages, 5 figure

Perceiving animacy from shape

Superordinate visual classification—for example, identifying an image as “animal,” “plant,” or “mineral”—is computationally challenging because radically different items (e.g., “octopus,” “dog”) must be grouped into a common class (“animal”). It is plausible that learning superordinate categories teaches us not only the membership of particular (familiar) items, but also general features that are shared across class members, aiding us in classifying novel (unfamiliar) items. Here, we investigated visual shape features associated with animate and inanimate classes. One group of participants viewed images of 75 unfamiliar and atypical items and provided separate ratings of how much each image looked like an animal, plant, and mineral. Results show systematic tradeoffs between the ratings, indicating a class-like organization of items. A second group rated each image in terms of 22 midlevel shape features (e.g., “symmetrical,” “curved”). The results confirm that superordinate classes are associated with particular shape features (e.g., “animals” generally have high “symmetry” ratings). Moreover, linear discriminant analysis based on the 22-D feature vectors predicts the perceived classes approximately as well as the ground truth classification. This suggests that a generic set of midlevel visual shape features forms the basis for superordinate classification of novel objects along the animacy continuum

Recent advances in minimally invasive colorectal cancer surgery

Laparoscopy has improved surgical treatment of various diseases due to its limited surgical trauma and has developed as an interesting therapeutic alternative for the resection of colorectal cancer. Despite numerous clinical advantages (faster recovery, less pain, fewer wound and systemic complications, faster return to work) the laparoscopic approach to colorectal cancer therapy has also resulted in unusual complications, i.e. ureteral and bladder injury which are rarely observed with open laparotomy. Moreover, pneumothorax, cardiac arrhythmia, impaired venous return, venous thrombosis as well as peripheral nerve injury have been associated with the increased intraabdominal pressure as well as patient's positioning during surgery. Furthermore, undetected small bowel injury caused by the grasping or cauterizing instruments may occur with laparoscopic surgery. In contrast to procedures performed for nonmalignant conditions, the benefits of laparoscopic resection of colorectal cancer must be weighed against the potential for poorer long-term outcomes of cancer patients that still has not been completely ruled out. In laparoscopic colorectal cancer surgery, several important cancer control issues still are being evaluated, i.e. the extent of lymph node dissection, tumor implantation at port sites, adequacy of intraperitoneal staging as well as the distance between tumor site and resection margins. For the time being it can be assumed that there is no significant difference in lymph node harvest between laparoscopic and open colorectal cancer surgery if oncological principles of resection are followed. As far as the issue of port site recurrence is concerned, it appears to be less prevalent than first thought (range 0-2.5%), and the incidence apparently corresponds with wound recurrence rates observed after open procedures. Short-term (3-5 years) survival rates have been published by a number of investigators, and survival rates after laparoscopic surgery appears to compare well with data collected after conventional surgery for colorectal cancer. However, long-term results of prospective randomized trials are not available. The data published so far indicate that the oncological results of laparoscopic surgery compare well with the results of the conventional open approach. Nonetheless, the limited information available from prospective studies leads us to propose that minimally invasive surgery for colorectal cancer surgery should only be performed within prospective trials

Radiative damping in wave guide based FMR measured via analysis of perpendicular standing spin waves in sputtered Permalloy films

The damping $\alpha$ of the spinwave resonances in 75 nm, 120 nm, and 200nm -thick Permalloy films is measured via vector-network-analyzer ferromagnetic-resonance (VNA-FMR) in the out-of-plane geometry. Inductive coupling between the sample and the waveguide leads to an additional radiative damping term. The radiative contribution to the over-all damping is determined by measuring perpendicular standing spin waves (PSSWs) in the Permalloy films, and the results are compared to a simple analytical model. The damping of the PSSWs can be fully explained by three contributions to the damping: The intrinsic damping, the eddy-current damping, and the radiative damping. No other contributions were observed. Furthermore, a method to determine the radiative damping in FMR measurements with a single resonance is suggested

Humoral response in a patient with cutaneous nocardiosis

The clinical appearance of infection due to Nocardia spp. varies widely. The law sensitivity of direct microscopy and the slow growth of the organism challenge the laboratory diagnosis. We present the case of a skin abscess in an immunocompetent man caused by Nocardia brasiliensis. Diagnosis was made by cultivation and 16S rRNA sequencing. Using indirect immunofluorescence and Western blot, a strong antibody response to the N. brasiliensis isolate could be demonstrated. Serological tests might therefore be useful for the diagnosis and management of nocardial infections, copyright (R) 2000 S. Karger AG, Basel