Control of volume resistivity in inorganic organic separators

Control of resistivity in NASA inorganic-organic separators is achieved by incorporating small percentages of high surface area, fine particle silica with other ingredients in the separator coating. The volume resistivity is predictable from the surface area of filler particles in the coating. The approach is applied to two polymer- plasticizer -filler coating systems, where the filler content of each is below the generally acknowledged critical pigment volume concentration of the coating. Application of these coating systems to 0.0254 cm thick (10-mil) fuel cell grade asbestos sheet produces inexpensive, flexible, microporous separators that perform as well as the original inorganic-organic concept, the Astropower separator

Separator development and testing of nickel-hydrogen cells

The components, design, and operating characteristics of Ni-H2 cells batteries were improved. A separator development program was designed to develop a separator that is resistant to penetration by oxygen and loose active material from then nickel electrode, while retraining the required chemical and thermal stability, reservoir capability, and high ionic conductivity. The performance of the separators in terms of cell operating voltage was to at least match that of state-of-the-art separators while eliminating the separator problems. The separators were submitted to initial screening tests and those which successfully completed the tests were built into Ni-H2 cells for short term testing. The separators with the best performance are tested for long term performance and life

A Foreword To: A Panel Discussion on Obviousness in Patent Litigation: KSR International v. Teleflex, 6 J. Marshall Rev. Intell. Prop. L. 590 (2007)

In KSR International Co. v. Teleflex Inc., the Supreme Court adhered to its prior views that a constitutional standard applied in determining whether an invention is “obvious.” Further, the Federal Circuit’s teaching-suggestion-motivation (“TSM”) test, which stipulated that an invention is not obvious unless some teaching, suggestion, or motivation to combine the elements of the invention exists, cannot replace or limit the constitutional standard. KSR eliminated the Federal Circuit’s requirement, holding that the TSM test is only one way to find an invention obvious and that a common sense approach should be used. KSR also noted that all persons skilled in an art have ordinary inventiveness, and more than ordinary inventiveness is needed to support a patent

Cross-linked polyvinyl alcohol films as alkaline battery separators

Cross-linking methods were investigated to determine their effect on the performance of polyvinyl alcohol (PVA) films as alkaline battery separators. The following types of cross-linked PVA films are discussed: (1) PVA-dialdehyde blends post-treated with an acid or acid periodate solution (two-step method) and (2) PVA-dialdehyde blends cross-linked during film formation (drying) by using a reagent with both aldehyde and acid functionality (one-step method). Laboratory samples of each cross-linked type of film were prepared and evaluated in standard separator screening tests. The pilot-plant batches of films were prepared and compared to measure differences due to the cross-linking method. The pilot-plant materials were then tested in nickel oxide - zinc cells to compare the two methods with respect to performance characteristics and cycle life. Cell test results are compared with those from tests with Celgard

A Rash Decision in Sunnyslope: Confusion Lingers Over Collateral Valuation

(Excerpt) This Comment argues that the Ninth Circuit’s Sunnyslope decision misconstrued the Rash Court’s holding and is divorced from the text and structure of the Code. Rash does not provide a brightline rule that answers valuation questions in cramdowns; it offers a flexible standard that is compatible with the Code’s protections for both debtors and secured creditors. Further, this Comment also argues that Sunnyslope could have been answered not as a valuation issue, but as a lien priority issue. In any event, the Ninth Circuit completely missed the mark in interpreting the Supreme Court’s holding in Rash and in understanding the text and structure of the Code

Polyvinyl alcohol membranes as alkaline battery separators

Polyvinly alcohol (PVA) cross-linked with aldehyde reagents yields membranes that demonstrate properties that make them suitable for use as alkaline battery separators. Film properties can be controlled by the choice of cross-linker, cross-link density and the method of cross-linking. Three methods of cross-linking and their effects on film properties are discussed. Film properties can also be modified by using a copolymer of vinyl alcohol and acrylic acid as the base for the separator and cross-linking it similarly to the PVA. Fillers can be incorporated into the films to further modify film properties. Results of separator screening tests and cell tests for several variations of PBA films are discussed

Polyvinyl alcohol cross-linked with two aldehydes

A film forming polyvinyl alcohol resin is admixed, in aqueous solution, with a dialdehyde crosslinking agent which is capable of crosslinking the polyvinyl alcohol resin and a water soluble acid aldehyde containing a reactive aldehyde group capable of reacting with hydroxyl groups in the polyvinyl alcohol resin and an ionizable acid hydrogen atom. The dialdehyde is present in an amount sufficient to react with from 1 to 20% by weight of the theoretical amount required to react with all of the hydroxyl groups of the polyvinyl alcohol. The amount of acid aldehyde is from 1 to 50% by weight, same basis, and is sufficient to reduce the pH of the aqueous admixture to 5 or less. The admixture is then formed into a desired physical shape, such as by casting a sheet or film, and the shaped material is then heated to simultaneously dry and crosslink the article

Design principles for nickel-hydrogen cells and batteries

Nickel-hydrogen cells and, more recently, bipolar batteries have been built by a variety of organizations. The design principles that have been used by the technology group at the NASA Lewis Research Center draw upon their extensive background in separator technology, alkaline fuel cell technology, and several alkaline cell technology areas. These design principles have been incorporated into both the more contemporary individual pressure vessel (IPV) designs that were pioneered by other groups, as well as the more recent bipolar battery designs using active cooling that are being developed at NASA Lewis Research Center and under contract. These principles are rather straightforward applications of capillary force formalisms, coupled with the slowly developing data base resulting from careful post test analyses. The objective of this overall effort is directed towards the low-Earth-orbit (LEO) application where the cycle life requirements are much more severe than the geosynchronous-orbit (GEO) application. A summary of the design principles employed is presented along with a discussion of the recommendations for component pore sizes and pore size distributions, as well as suggested materials of construction. These will be made based on our experience in these areas to show how these design principles have been translated into operating hardware

Initial performance of advanced designs for IPV nickel-hydrogen cells

Advanced designs for individual pressure vessel nickel hydrogen cells were conceived which should improve the life cycle at deep depths of discharge and improve thermal management. Features of the designs which are new and not incorporated in either of the contemporary cells (Air Force/Hughes, Comsat) are: (1) the use of alternate methods of oxygen recombination, (2) use of serrated edge separators to facilitate movement of gas within the cell while still maintaining required physical contact with the wall wick, and (3) use of an expandable stack to accommodate some of the nickel electrode expansion. The designs also consider electrolyte volume requirements over the life of the cells, and are fully compatible with the Air Force/Hughes design

A nearly zero-energy microgrid testbed laboratory: Centralized control strategy based on SCADA system

Currently, despite the use of renewable energy sources (RESs), distribution networks are facing problems, such as complexity and low productivity. Emerging microgrids (MGs) with RESs based on supervisory control and data acquisition (SCADA) are an effective solution to control, manage, and finally deal with these challenges. The development and success of MGs is highly dependent on the use of power electronic interfaces. The use of these interfaces is directly related to the progress of SCADA systems and communication infrastructures. The use of SCADA systems for the control and operation of MGs and active distribution networks promotes productivity and efficiency. This paper presents a real MG case study called the LAMBDA MG testbed laboratory, which has been implemented in the electrical department of the Sapienza University of Rome with a centralized energy management system (CEMS). The real-time results of the SCADA system show that a CEMS can create proper energy balance in a LAMBDA MG testbed and, consequently, minimize the exchange power of the LAMBDA MG and main grid