Classification of zero-energy resonances by dissociation of Feshbach molecules

We study the dissociation of Feshbach molecules by a magnetic field sweep across a zero-energy resonance. In the limit of an instantaneous magnetic field change, the distribution of atomic kinetic energy can have a peak indicating dominance of the molecular closed-channel spin configuration over the entrance channel. The extent of this dominance influences physical properties such as stability with respect to collisions, and so the readily measurable presence or absence of the corresponding peak provides a practical method of classifying zero-energy resonances. Currently achievable ramp speeds, e.g. those demonstrated by Duerr et al. [Phys. Rev. A 70, 031601 (2005)], are fast enough to provide magnetic field changes that may be interpreted as instantaneous. We study the transition from sudden magnetic field changes to asymptotically wide, linear ramps. In the latter limit, the predicted form of the atomic kinetic energy distribution is independent of the specific implementation of the two-body physics, provided that the near-resonant scattering properties are properly accounted for.Comment: 10 pages, 5 eps figure

Evolution of the bilayer nu = 1 quantum Hall state under charge imbalance

We use high-mobility bilayer hole systems with negligible tunneling to examine how the bilayer nu = 1 quantum Hall state evolves as charge is transferred from one layer to the other at constant total density. We map bilayer nu = 1 state stability versus imbalance for five total densities spanning the range from strongly interlayer coherent to incoherent. We observe competition between single-layer correlations and interlayer coherence. Most significantly, we find that bilayer systems that are incoherent at balance can develop spontaneous interlayer coherence with imbalance, in agreement with recent theoretical predictions.Comment: 4 pages, 4 figure

Tracking Nonlinear Correlation for Complex Dynamic Systems Using a Windowed Error Reduction Ratio Method

Studying complex dynamic systems is usually very challenging due to limited prior knowledge and high complexity of relationships between interconnected components. Current methods either are like a “black box” that is difficult to understand and relate back to the underlying system or have limited universality and applicability due to too many assumptions. This paper proposes a time-varying Nonlinear Finite Impulse Response model to estimate the multiple features of correlation among measurements including direction, strength, significance, latency, correlation type, and nonlinearity. The dynamic behaviours of correlation are tracked through a sliding window approach based on the Blackman window rather than the simple truncation by a Rectangular window. This method is particularly useful for a system that has very little prior knowledge and the interaction between measurements is nonlinear, time-varying, rapidly changing, or of short duration. Simulation results suggest that the proposed tracking approach significantly reduces the sensitivity of correlation estimation against the window size. Such a method will improve the applicability and robustness of correlation analysis for complex systems. A real application to environmental changing data demonstrates the potential of the proposed method by revealing and characterising hidden information contained within measurements, which is usually “invisible” for conventional methods

Kinetics, Activation Parameters, and Mechanism of the Acid Hydrolysis of tert-Butyl Acetate in Aqueous DMSO

The rate of the acid-catalysed hydrolysis of tert-butyl acetate was found to decrease pronouncly in the presence of increasing amounts of DMSO. The observed activation energy decreased progressively with increasing DMSO content of the medium and the change was attributed to a gradual interconversion of the two concurrent and competing reaction mechanisms AALl and AAc2. The overall reaction rate was analysed theoretically as two individual rate constants corresponding to the respective mechanisms. The percentage contribution of each mechanism was then estimated and found to be concordant with the values determined experimentally by others using 180 tracer technique. The proportion of the AALl mechanism was found to increase both with increasing temperature and decreasing DMSO content. The relative abundance of the transition state belonging to each of the involved mechanisms was discussed in the light of the solvating power of the binary DMSO-H20 solvent system. The effect of the molar concentration of water as well as the dielectric constant of the medium on the reaction kinetics was studied. The thermodynamic parameters of activation showed strong dependence on solvent composition and their values were determined by the relative contributions of the two mechanistic routes of the reaction

A Decade of Research on Staked Cucumber Production (Bulletin #844)

Fresh-market cucumber has been an important vegetable crop in Southern states for many years. The objectives of these studies were: 1) to determine the influence of staking on yield, fruit quality and related traits of cucumbers; 2) to develop improved cultural techniques to enhance the yield of staked cucumbers; and 3) to minimize the expense of training the plants vertically.https://digitalcommons.lsu.edu/agcenter_bulletins/1051/thumbnail.jp

Analisis Biodiversitas Serangga Di Hutan Kota Malabar Sebagai Urban Ecosystem Services Kota Malang Pada Musim Pancaroba

Serangga merupakan kelompok organisme dominan. Keberadaan serangga pada suatu tempat dapat menjadi indikator biodiversitas, kesehatan ekosistem, dan degradasi landscape. Peranan serangga dalam ekosistem diantaranya adalah sebagai polinator, dekomposer, predator dan parasitoid. Tujuan penelitian adalah untuk mengetahui kemampuan hutan kota Malabar dalam menyediakan habitat untuk biodiversitas serangga kota. Penelitian dilaksanakan di hutan kota Malabar, Malang, pada bulan Mei sampai Juni 2014. Metode penelitian yang digunakan ini adalah metode kuadran yang terdiri dari 4 kuadran. Dalam 1 kuadran terdapat 16 pitfall, 1 light trap dan 4 yellow-pan trap serta dengan penangkapan menggunakan sweepnet. Penentuan pemasangan perangkap dilakukan dengan metode diagonal. Dari hasil pengambilan sampel dan identifikasi serangga yang dilakukan pada Hutan Kota Malabar diperoleh 10 ordo dan 26 famili. Terdapat dominasi pada masing-masing kuadran yang didominasi oleh ordo Hymenoptera dan Collembola. Dengan suhu dalam hutan yang lebih rendah dari pada suhu di luar lokasi yang lebih tinggi, rata-rata 24,75°C dan kelembaban 79,14% membuat serangga cukup nyaman di dalam lingkungan hutan kota, hal ini ditunjukkan dari hasil perhitungan indeks keanekaragaman dari masing-masing kuadran yang mempunyai indeks keanekaragaman yang sedang/kondisi lingkungan sedang

Bacterial Anti-Adhesion of Coated and Uncoated Thin-Film-Composite (TFC) Polyamide (PA) Membranes

This study investigates the bacterial anti-adhesion performance of uncoated and coated reverse osmosis (RO) membranes. All the membranes were commercially available fully-aromatic thin-film-composite (TFC) polyamide (PA) membranes. Two of the TFC PA membranes (SW30 and BW30) were coated using polyvinyl alcohol (PVA) coating, while the other three membranes (LE, XLE and NF90) were uncoated. Among the characterised TFC PA membranes, the PVA coated were more hydrophilic and their surface energy was higher in comparison to uncoated. In addition, the PVA coated membranes had lower surface roughness. AFM interaction force measurement demonstrated higher repellence performance for the more polar surface. Bacteria attachment test showed differences between the coated and the uncoated membranes. Indeed, the increase in hydrophilicity and surface polarity showed decrease in the attachment of Pseudomonas aeruginosa cells. Moreover, the results demonstrated that the surface polarity showed better correlation with the attachment of the bacteria. In addition, the type of the surface roughness may somehow contribute to the bacteria repellence