Optimal Designs for Evaluating a Series of Treatments

Several articles in this journal have studied optimal designs for testing a series of treatments to identify promising ones for further study. These designs formulate testing as an ongoing process until a promising treatment is identified. This formulation is considered to be more realistic but substantially increases the computational complexity. In this article, we show that these new designs, which control the error rates for a series of treatments, can be reformulated as conventional designs that control the error rates for each individual treatment. This reformulation leads to a more meaningful interpretation of the error rates and hence easier specification of the error rates in practice. The reformulation also allows us to use conventional designs from published tables or standard computer programs to design trials for a series of treatments. We illustrate these using a study in soft tissue sarcoma

Canola yield formation under different population and water use levels

Non-Peer ReviewedOptimum population is the foundation for high yields under rain-fed agriculture and the optimum population depends on the water availability. However, establishing a good canola stand in the Canadian semiarid Prairie, where low temperature, water stress and soil crusting result in poor seed bed conditions, is difficult. A field study was conducted during 2000, a year with moderate soil moisture and good canola growing conditions, and 2001, a year with severe water and heat stress, to understand the plasticity of canola yield parameters at different (80 to 5 plants per square meter) plant populations. The primary response of canola to lower plant population was increased branching, although it did not compensate completely for the decreasing population. Increased branching was accompanied by increased production and increased distribution of pods on the primary and secondary branches. Canola exhibited plasticity in yield adjustment over a wide range of plant populations. Environmental conditions played a significant role in expressing canola plasticity. For example, in a normal year like 2000 canola maintained similar yield levels over a wider range of populations (80 to 20 pl m-2), while in a dry year like 2001 seed yield started declining with populations below 40 pl m-2. Ability to produce more pods, especially at lower population densities, was responsible for the environmental influence on yield formation

Superconducting Pairing Symmetries in Anisotropic Triangular Quantum Antiferromagnets

Motivated by the recent discovery of a low temperature spin liquid phase in layered organic compound $\kappa$-(ET)$_2$Cu$_2$(CN)$_3$ which becomes a superconductor under pressure, we examine the phase transition of Mott insulating and superconducting (SC) states in a Hubbard-Heisenberg model on an anisotropic triangular lattice. We use a renormalized mean field theory to study the Gutzwiller projected BCS wavefucntions. The half filled electron system is a Mott insulator at large on-site repulsion $U$, and is a superconductor at a moderate $U$. The symmetry of the SC state depends on the anisotropy, and is gapful with $d_{x^2-y^2}+id_{xy}$ symmetry near the isotropic limit and is gapless with $d_{x^2-y^2}$ symmetry at small anisotropy ratio.Comment: 6 pages, 5 figure

The new radiation-hard optical links for the ATLAS pixel detector

The ATLAS detector is currently being upgraded with a new layer of pixel based charged particle tracking and a new arrangement of the services for the pixel detector. These upgrades require the replacement of the opto-boards previously used by the pixel detector. In this report we give details on the design and production of the new opto-boards.Comment: Presentation at the DPF 2013 Meeting of the American Physical Society Division of Particles and Fields, Santa Cruz, California, August 13-17, 201

Gossamer Superconductivity near Antiferromagnetic Mott Insulator in Layered Organic Conductors

Layered organic superconductors are on the verge of the Mott insulator. We use Gutzwiller variational method to study a Hubbard model including a spin exchange coupling term. The ground state is found to be a Gossamer superconductor at small on-site Coulomb repulsion U and an antiferromagnetic Mott insulator at large U, separated by a first order phase transition. Our theory is qualitatively consistent with major experiments reported in organic superconductors.Comment: 5 pages, 3 figure

Electro-spraying and catalytic combustion characteristics of ethanol in meso-scale combustors with steel and platinum meshes

© 2018 Elsevier Ltd An experimental study on electro-spraying and catalytic combustion of ethanol at meso-scale is carried out. The electro-spraying process of ethanol is visualized and four typical spraying modes are identified. Based on droplet size measurements by a Phase Doppler Anemometer, the spraying at the cone-jet or multi-jet mode is suitable for meso-scale combustion. Two meso-combustors without and with the platinum catalyst, denoted as combustor A and combustor B, respectively, are designed to conduct the comparative experiments. The flame temperature at the cone-jet mode is higher than those at other modes when equivalence ratio φ = 1.0, and for the combustor with catalyst, fuel-lean conditions are favorable for stable combustion. It is also found that the carbon monoxide mole fraction in the exhaust decreases by at least 25% due to the catalytic effect. At the cone-jet electro-spraying mode, the combustion efficiencies of ethanol reach the highest value for both combustor A and combustor B due to smaller droplet size and more uniform droplet size distribution. Under the same conditions, combustion efficiency of ethanol can be improved by 4.5% for combustor B, which proves that the platinum catalyst can accelerate the decomposition of ethanol