High-Power Shape Memory Alloy Catapult Actuator for High-Speed and High-Force Applications

Nickel-Titanium (NiTi) based shape memory alloy (SMA) wires are already often used in industrial actuator applications. Their high energy density allows the building of light-weight actuator systems with high forces using small installation spaces. Combined with the biocompatibility of NiTi, a huge field of applications can be covered by SMA actuated systems. In systems like emergency brakes or switch disconnectors, which require high forces as well as high actuation speed, the high-power capability of NiTi actuators is exploited. The presented work details the development and characterization of a giant power catapult demonstrator, that combines the high-speed and high-force capability of SMA wires. To illustrate the vast force, speed, and power potential of SMA wires, a bowling ball is launched from its resting position vertically into the air using SMA wires. For demonstration purposes, a target altitude for the bowling ball of 500 mm is chosen. With the height and the overall accelerated mass given, an actuation force F≅ 920 N is needed. The instantaneous energy release from the designed power source results in the targeted flight height and an overall peak power of P≅ 0.5 MW

Ein logisch-topologischer Kalkül zur Konstruktion von integrierten Schaltkreisen

Es wird ein CAD-System ICAD-IC vorgestellt, das den Entwurf integrierter Schaltungen unterstützen soll. Der Kern des Systems besteht in einem Netzkalkül, der es erlaubt, neben der logischen Information auch geometrische Informationen zu handhaben. Dieser Kalkül besitzt verschiedene Ausprägungen, die den Entwurf auf verschiedenen Entwurfsebenen unterstützen. Das System ist um den Kalkül herum entwickelt, wie etwa ALGOL um die Numerik. Soweit das System bis jetzt entwickelt ist, betrifft es die logisch-topologische Entwurfsebene und den Übergang zur topographischen Entwurfsebene. Wir stellen hier das Konzept des Kalküls vor und erläutern an Beispielen einige Grundlagenuntersuchungen zu diesem Thema.We present a CAD-system \u27CAD-IC\u27, supporting the automatic design of integrated circuits. The kernel of the system is based on a "calculus of nets", which allows both, the handling of logical and geometrical information. Depending on the design-level different versions of this calculus may be adopted. The system itself is built around this calculus, as f.e. ALGOL around numerics. As far as the system is developed at the moment, it mainly deals with the logical-topological design level and the transition to the topographical level. We give the main ideas of the calculus and illustrate some basic investigations with help of examples

Physician behavior and technology diffusion in health care

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 127-132).Chapter 1 examines geographic variations in physician practice styles by exploring the role of physician-specific factors such as preferences and learned behavior versus environment-level factors such as hospital capacity. I exploit cardiologist migration across geographic regions and find that physicians who start off in the same region and subsequently move to dissimilar regions practice similarly before the move but very differently after the move. Based on this change in behavior, baseline estimates imply that the role of the environment on physician behavior is twice as important as physician-specific factors. Specifically, a one percentage point change in practice environment results in an immediate 2/3 percentage point change in physician behavior, with no further changes over time. Chapter 2 (co-authored with Leila Agha) explores the diffusion of new cancer drugs by testing the influence of physician investigators who lead clinical trials. The basic idea is to exploit variation across drugs in the location of clinical trials to test whether geographic proximity to a principal investigator influences the speed of technology adoption. Using original data on clinical trial study authors and sites for 21 new cancer drugs along with Medicare claims data from 1998-2008, we estimate that patients are 30% more likely to receive treatment with a new drug if they seek care in the hospital referral region where the drug's principal investigator practices. This effect, which is estimated in the first two years following initial FDA approval, fades over time until there is no apparent difference in utilization after four years. Chapter 3 (co-authored with Leila Agha) explores the prescribing of new cancer drugs for off-label (non-FDA approved) indications, yielding three key results. First, over 20% of new cancer drug use within the Medicare population over 1998-2008 was applied to off-label cancers. Second, geographic proximity to the principal investigator of a drug's pivotal clinical trial-a factor which appears to significantly boost on-label usage-has no discernible impact on off-label prescribing. Third, we find that prescribing increases following FDA approval expansions, suggesting that approval status influences patient treatment and thus may provide a useful policy instrument for directing medical technology adoption.by David Paul Molitor.Ph.D

Measuring the weak mixing angle with the P2 experiment at MESA

The P2 experiment in Mainz aims to measure the weak mixing angle in electron- proton scattering to a precision of 0.13 %. In order to suppress uncertainties due to proton structure and contributions from box graphs, both a low average momentum transfer $Q^2$ of $4.5\cdot 10^{-3}$ GeV$^2/c^2$ and a low beam energy of 155 MeV are chosen. In order to collect the enormous statistics required for this measurement, the new Mainz Energy Recovery Superconducting Accelerator (MESA) is being constructed. These proceedings describe the motivation for the measurement, the experimental and accelerator challenges and how we plan to tackle them.Comment: Proceedings of the PhiPsi15, Sep. 23-26, 2015, Hefei, Chin

Genome-Wide Association Mapping in <i>Arabidopsis</i> Identifies Previously Known Flowering Time and Pathogen Resistance Genes

There is currently tremendous interest in the possibility of using genome-wide association mapping to identify genes responsible for natural variation, particularly for human disease susceptibility. The model plant Arabidopsis thaliana is in many ways an ideal candidate for such studies, because it is a highly selfing hermaphrodite. As a result, the species largely exists as a collection of naturally occurring inbred lines, or accessions, which can be genotyped once and phenotyped repeatedly. Furthermore, linkage disequilibrium in such a species will be much more extensive than in a comparable outcrossing species. We tested the feasibility of genome-wide association mapping in A. thaliana by searching for associations with flowering time and pathogen resistance in a sample of 95 accessions for which genome-wide polymorphism data were available. In spite of an extremely high rate of false positives due to population structure, we were able to identify known major genes for all phenotypes tested, thus demonstrating the potential of genome-wide association mapping in A. thaliana and other species with similar patterns of variation. The rate of false positives differed strongly between traits, with more clinal traits showing the highest rate. However, the false positive rates were always substantial regardless of the trait, highlighting the necessity of an appropriate genomic control in association studies.</p

Genome-Wide Association Mapping in Arabidopsis Identifies Previously Known Flowering Time and Pathogen Resistance Genes

There is currently tremendous interest in the possibility of using genome-wide association mapping to identify genes responsible for natural variation, particularly for human disease susceptibility. The model plant Arabidopsis thaliana is in many ways an ideal candidate for such studies, because it is a highly selfing hermaphrodite. As a result, the species largely exists as a collection of naturally occurring inbred lines, or accessions, which can be genotyped once and phenotyped repeatedly. Furthermore, linkage disequilibrium in such a species will be much more extensive than in a comparable outcrossing species. We tested the feasibility of genome-wide association mapping in A. thaliana by searching for associations with flowering time and pathogen resistance in a sample of 95 accessions for which genome-wide polymorphism data were available. In spite of an extremely high rate of false positives due to population structure, we were able to identify known major genes for all phenotypes tested, thus demonstrating the potential of genome-wide association mapping in A. thaliana and other species with similar patterns of variation. The rate of false positives differed strongly between traits, with more clinal traits showing the highest rate. However, the false positive rates were always substantial regardless of the trait, highlighting the necessity of an appropriate genomic control in association studies

Immunochip analysis identifies multiple susceptibility loci for systemic sclerosis

In this study, 1,833 systemic sclerosis (SSc) cases and 3,466 controls were genotyped with the Immunochip array. Classical alleles, amino acid residues, and SNPs across the human leukocyte antigen (HLA) region were imputed and tested. These analyses resulted in a model composed of six polymorphic amino acid positions and seven SNPs that explained the observed significant associations in the region. In addition, a replication step comprising 4,017 SSc cases and 5,935 controls was carried out for several selected non-HLA variants, reaching a total of 5,850 cases and 9,401 controls of European ancestry. Following this strategy, we identified and validated three SSc risk loci, including DNASE1L3 at 3p14, the SCHIP1-IL12A locus at 3q25, and ATG5 at 6q21, as well as a suggested association of the TREH-DDX6 locus at 11q23. The associations of several previously reported SSc risk loci were validated and further refined, and the observed peak of association in PXK was related to DNASE1L3. Our study has increased the number of known genetic associations with SSc, provided further insight into the pleiotropic effects of shared autoimmune risk factors, and highlighted the power of dense mapping for detecting previously overlooked susceptibility loci

Alternate wetting and drying in Bangladesh : Water saving farming practice and the socioeconomic barriers to its adoption

The compilation of this review was funded by a grant given to the authors by the University of Aberdeen.Peer reviewedPublisher PD