Apollo experience report: Guidance and control systems: Automated control system for unmanned mission AS-201

The Apollo command module heat shield and Apollo command and service module/Saturn launch vehicle structural integrity were evaluated in an unmanned test flight. An automated control system was developed to provide the mission event sequencing, the real-time ground control interface, and the backup attitude reference system for the unmanned flight. The required mission events, the design logic, the redundancy concept, and the ground-support-equipment concept are described and some development problem areas are discussed. The mission event time line and the real-time ground command list are included to provide an outline of the control system capabilities and requirements. The mission was accomplished with the automated control system, which functioned without flight anomalies

Assembling networks of microbial genomes using linear programming

<p>Abstract</p> <p>Background</p> <p>Microbial genomes exhibit complex sets of genetic affinities due to lateral genetic transfer. Assessing the relative contributions of parent-to-offspring inheritance and gene sharing is a vital step in understanding the evolutionary origins and modern-day function of an organism, but recovering and showing these relationships is a challenging problem.</p> <p>Results</p> <p>We have developed a new approach that uses linear programming to find between-genome relationships, by treating tables of genetic affinities (here, represented by transformed BLAST e-values) as an optimization problem. Validation trials on simulated data demonstrate the effectiveness of the approach in recovering and representing vertical and lateral relationships among genomes. Application of the technique to a set comprising <it>Aquifex aeolicus </it>and 75 other thermophiles showed an important role for large genomes as 'hubs' in the gene sharing network, and suggested that genes are preferentially shared between organisms with similar optimal growth temperatures. We were also able to discover distinct and common genetic contributors to each sequenced representative of genus <it>Pseudomonas</it>.</p> <p>Conclusions</p> <p>The linear programming approach we have developed can serve as an effective inference tool in its own right, and can be an efficient first step in a more-intensive phylogenomic analysis.</p

Crayons and Yarn

This portfolio contains poems, creative nonfiction, and short stories, all original pieces of writing produced while completing the Creative Writing Minor at Cedarville University. The poems come from my own life, and while they are not intended to be a cohesive narrative, arranged in this order they tell a story of growing up, leaving home, and finding love. The nonfiction pieces come from a collection centered around my experiences in high school marching band, though a love story is present there as well. The short stories also draw heavily from my own experiences and passions, exploring themes that are important to me through characters and situations, which are technically fictional, but also very familiar

Apollo experience report: Guidance and control systems. Mission control programmer for unmanned missions AS-202, Apollo 4, and Apollo 6

An unmanned test flight program required to evaluate the command module heat shield and the structural integrity of the command and service module/Saturn launch vehicle is described. The mission control programer was developed to provide the unmanned interface between the guidance and navigation computer and the other spacecraft systems for mission event sequencing and real-time ground control during missions AS-202, Apollo 4, and Apollo 6. The development of this unmanned programer is traced from the initial concept through the flight test phase. Detailed discussions of hardware development problems are given with the resulting solutions. The mission control programer functioned correctly without any flight anomalies for all missions. The Apollo 4 mission control programer was reused for the Apollo 6 flight, thus being one of the first subsystems to be reflown on an Apollo space flight

Influence of internal fluid velocities and media fill ratio on submerged aerated filter hydrodynamics and process performance for municipal wastewater treatment

Submerged aerated filters (SAFs) treat wastewater to achieve stringent organic carbon and ammonium (NH4+) effluent consents. Currently SAF design follows a black box approach, where inlet and outlet contaminant concentrations are monitored, with little consideration for internal hydrodynamic conditions. Although tracer tests have been used on bioreactors, integrated monitoring of internal fluid velocities, mixing characteristics and process performance has not been established for SAFs. Tracer tests were performed on a 7.74 m3 SAF, with internal recirculation at 100, 75, 50, 25 and 0% media fill ratios with and without biofilm on the media surface. Results suggested that, SAF internal hydrodynamic conditions directly influenced process performance and media fill ratios could be manipulated to provide optimum conditions for removal of biochemical oxygen demand (BOD5) and NH4+. A 50% media fill ratio showed optimum hydrodynamic conditions for BOD5 removal, with a removal efficiency of 70% (mass removal of 1.59 kg m−3 d−1). A 100% media fill ratio showed optimum hydrodynamic conditions for NH4+ removal, with a removal efficiency of 60% (mass removal of 0.14 kg m−3 d−1). Therefore optimisation of internal hydrodynamic conditions is key for selective contaminant removal and achieving high effluent quality

The effect of technique and transfer board use on the performance of wheelchair transfers

Transferring to and from the wheelchair seat is a necessary skill for many wheelchair users who wish to be independent in their everyday life. The performance of wheelchair transfers has been associated with the risk of falling and developing upper limb injuries. Both present a risk to the independence of the individual. Previous studies on wheelchair transfers have focused mainly on the analysis of sitting transfers performed by individuals with Spinal Cord Injury, which only represent a small portion of the wider wheelchair users’ population. The purpose of this letter is to investigate the effect of different transferring techniques (sitting, standing) and transfer board use on the ground reaction forces under the hands during transfer performance and transfer quality measured using the Transfer Assessment Instrument (TAI). Sitting transfers displayed generally higher peak and mean reaction forces underneath both leading and trailing hands compared to the other techniques, but the difference was only significant between sitting and standing transfers. Standing transfers had significantly lower TAI scores compared to sitting transfer, potentially indicating a decreased level of safety associated with their performance. Transfer boards were only partially effective in reducing the weight born by the upper limbs and they caused only a minor reduction in the overall TAI score in comparison to sitting transfers