Prediction of Battery Life and Behavior from Analysis of Voltage Data

A method for simulating charge and discharge characteristics of secondary batteries is discussed. The analysis utilizes a nonlinear regression technique where empirical data is computer fitted with a five coefficient nonlinear equation. The equations for charge and discharge voltage are identical except for a change of sign before the second and third terms

Cadmium migration in aerospace nickel cadmium cells

The effects of temperature, the nature of separator material, charge and discharge, carbonate contamination, and the mode of storage are studied with respect to the migration of active material from the negative toward the positive plate. A theoretical model is proposed which takes into account the solubility of cadmium in various concentrations of hydroxide and carbonate at different temperatures, the generation of the cadmiate ion, Cd(OH)3(-), during discharge, the migration of the cadmiate ion and particulate Cd(OH)2 due to electrophoretic effects and the movement of electrolyte in and out of the negative plate and, finally, the recrystallization of cadmiate ion in the separator as Cd(OH)2. Application of the theoretical model to observations of cadmium migration in cycled cells is also discussed

Modeling taper charge with a non-linear equation

Work aimed at modeling the charge voltage and current characteristics of nickel-cadmium cells subject to taper charge is presented. Work reported at previous NASA Battery Workshops has shown that the voltage of cells subject to constant current charge and discharge can be modeled very accurately with the equation: voltage = A + (B/(C-X)) + De to the -Ex where A, B, D, and E are fit parameters and x is amp-hr of charge removed during discharge or returned during charge. In a constant current regime, x is also equivalent to time on charge or discharge

Accelerated test design

The design of an accelerated life test program for electric batteries is discussed. A number of observations and suggestions on the procedures and objectives for conducting an accelerated life test program are presented. Equations based on nonlinear regression analysis for predicting the accelerated life test parameters are discussed

Engineering Bacillus megaterium for production of functional intracellular materials

Background: Over the last 10-15 years, a technology has been developed to engineer bacterial polyhydroxybutyrate (PHB) inclusions as functionalized beads, for applications such as vaccines, diagnostics and enzyme immobilization. This has been achieved by translational fusion of foreign proteins to the PHB synthase (PhaC). The respective fusion protein mediates self-assembly of PHB inclusions displaying the desired protein function. So far, beads have mainly been produced in recombinant Escherichia coli which is problematic for some applications as the lipopolysaccharides (LPS) co-purified with such inclusions are toxic to humans and animals. Results: In this study, we have engineered the formation of functional PHB inclusions in the Gram-positive bacterium Bacillus megaterium, an LPS-free and established industrial production host. As B. megaterium is a natural PHB producer, the PHB-negative strain PHA05 was used to avoid any background PHB production. Plasmid-mediated T7 promoter-driven expression of the genes encoding β-ketothiolase (phaA), acetoacetyl-CoA-reductase (phaB) and PHB synthase (phaC) enabled/effected PHB production by B. megaterium PHA05. To produce functionalized PHB inclusions, the N- and C-terminus of PhaC was fused to four and two IgG binding Z-domains from Staphylococcus aureus, respectively. The ZZ-domain PhaC fusion protein was strongly overproduced at the surface of the PHB inclusions and the corresponding isolated ZZ-domain displaying PHB beads were found to purify IgG with a binding capacity of 40-50 mg IgG/g beads. As B. megaterium has the ability to sporulate and respective endospores could co-purify with cellular inclusions, a sporulation negative production strain was generated by disrupting the spoIIE gene in PHA05. This strain did not produce spores when tested under sporulation inducing conditions and it was still able to synthesize ZZ-domain displaying PHB beads. Conclusions: This study provides proof of concept for the successful genetic engineering of B. megaterium as a host for the production of functionalized PHB beads. Disruption of the spoIIE gene rendered B. megaterium incapable of sporulation but particularly suitable for production of functionalized PHB beads. This sporulation-negative mutant represents an improved industrial production strain for biotechnological processes otherwise impaired by the possibility of endospore formation.fals

Secondary aerospace batteries and battery materials: A bibliography, 1969 - 1974

This annotated bibliography on the subject of secondary aerospace battery materials and related physical and electrochemical processes was compiled from references to journal articles published between 1969 and 1974. A total of 332 citations are arranged in chronological order under journal titles. Indices by system and component, techniques and processes, and author are included

Annual fecundity, batch fecundity, and oocyte atresia of Atka mackerel (Pleurogrammus monopterygius) in Alaskan waters

Annual potential fecundity, batch fecundity, and oocyte atresia were estimated for Atka mackerel (Pleurogrammus monopterygius) collected in Alaskan waters during 1993−94. Atka mackerel were assumed to be determinate spawners on the basis of decreasing fecundity after batch spawning events. Histological examination of the ovaries indicated that oocytes in the vitellogenic stage and higher had been spawned in the current spawning season. For an average female of 40 cm, potential annual fecundity was estimated to be 41,994 eggs, average batch size (i.e., batch fecundity) was estimated to be 6689 eggs, and there were 6.13 batches per spawning season. Atresia was estimated by examining postspawning specimens and was found to be substantial. The average amount of atresia for a 40-cm fish was estimated to be 11,329 eggs, resulting in an estimated realized fecundity of only 30,664 eggs and 4.64 batches of eggs per spawning season

Barriers to women in the UK construction industry

Purpose – This paper aims to identify the main barriers that lead to the under-representation of women in the UK construction industry. The study, funded by ConstructionSkills, seeks to explore the issues that women face and investigate the potential positive impact that continuous professional development (CPD) may have upon improving the retention and career progression of women. Design/methodology/approach – The study uses an open-ended grounded theory (GT) approach, including 231 semi-structured questionnaires and nine focus groups with women from a range of professional occupations. All the findings were analysed using keyword analysis to identify the top two barriers that women face, alongside a series of cross-cutting key themes and issues. Findings – The findings reveal that male-dominated organisational cultures and inflexible working practices are the main barriers to women in the UK construction industry, irrespective of job role or profession. This paper concludes by arguing for a sea-change in the expansion of CPD opportunities for women in managerial, confidence and communication based skills, with accompanying networking and support systems to facilitate the retention and advancement of women in the industry sector. Research limitations/implications – Due to the research approach, the data are not generalisable. Therefore, researchers are advised to research and test the findings with a larger group. Researchers are also recommended to investigate the impact of expanded CPD opportunities for both men and women. Originality/value – The paper puts forward a business case for the advancement of specific CPD training for women, to facilitate the expansion of equality and diversity in the workforce in the UK construction industry

Ulnar Collateral Ligament Reconstruction with Traditional Docking Compared to Novel Surgical Techniques

Background: Ulnar Collateral Ligament Reconstruction (UCLR) is a surgical procedure on one of the main ligaments that provides normal stability for the elbow joint against excessive valgus stress. Damage to this ligament is common in athletes performing overhead throwing activities, primarily baseball players, due to excessive valgus stress during the throwing motion. The most common form of treatment for this type of injury is reconstructive surgery of the ligament, especially if athletes wish to return to sport participation. This type of surgery is extremely invasive and requires extensive post-operative rehabilitation in order to facilitate return to play. To date, many surgical techniques have been proposed and evaluated, but there are no conclusive comparison studies on patient outcomes following UCLR. Purpose: The purpose of this paper is to analyze previous studies on UCLR techniques and determine if there is a single superior surgical method leading to improved biomechanical outcomes and decreased failure measures. Our focused clinical question was identifying if the traditional docking technique compared to novel docking techniques during UCLR superior in relation to biomechanical outcomes and failure measures in cadaveric tissue. Methodology: The study design in this paper is a critically appraised topic. Various scholarly databases such as PubMed, MEDLINE and SportDiscus were utilized to search for studies related to UCLR surgical techniques. After an initial search, a list of fifteen relevant studies were identified. Each study was then scrutinized and evaluated to meet predetermined inclusion criteria and a minimum score of 6/9 on the PEDro scale. All studies not meeting these requirements were excluded. This left a total of five articles which were then used to answer the clinical question for this paper. The inclusion criteria involved meeting a cadaveric age of 16-60 y, objective measures of valgus testing, angular displacement, stiffness and modes of failure as post-operative outcomes. Further, we included studies that had a minimum of seven cadaver pairs tested, and studies were required to compare traditional docking to at least one novel technique. Results: All five studies involved compared at least one novel surgical technique to the docking technique. Four studies found no significant overall difference between the native and reconstructed states of any surgical technique. One study found no overall significant difference, but did identify slight differences in biomechanical properties. Discussion: All conclusions from individual studies demonstrate comparable findings between all UCLR techniques. Biomechanics, kinematics and failure modes in the acute stages following surgery in cadavers are similar between UCLR techniques. Despite all that has been done, additional research is still necessary to determine a superior surgical technique