Magnetic Excitations and Continuum of a Field-Induced Quantum Spin Liquid in α\alpha-RuCl3_3

We report on terahertz spectroscopy of quantum spin dynamics in $\alpha$-RuCl$_3$, a system proximate to the Kitaev honeycomb model, as a function of temperature and magnetic field. An extended magnetic continuum develops below the structural phase transition at $T_{s2}=62$K. With the onset of a long-range magnetic order at $T_N=6.5$K, spectral weight is transferred to a well-defined magnetic excitation at $\hbar \omega_1 = 2.48$meV, which is accompanied by a higher-energy band at $\hbar \omega_2 = 6.48$meV. Both excitations soften in magnetic field, signaling a quantum phase transition at $B_c=7$T where we find a broad continuum dominating the dynamical response. Above $B_c$, the long-range order is suppressed, and on top of the continuum, various emergent magnetic excitations evolve. These excitations follow clear selection rules and exhibit distinct field dependencies, characterizing the dynamical properties of the field-induced quantum spin liquid

Measurement of the tt̄W and tt̄Z production cross sections in pp collisions at √s = 8 TeV with the ATLAS detector

The production cross sections of top-quark pairs in association with massive vector bosons have been measured using data from pp collisions at s√ = 8 TeV. The dataset corresponds to an integrated luminosity of 20.3 fb−¹ collected by the ATLAS detector in 2012 at the LHC. Final states with two, three or four leptons are considered. A fit to the data considering the tt̄W and tt̄Z processes simultaneously yields a significance of 5.0σ (4.2σ) over the background-only hypothesis for tt¯Wtt¯W (tt̄Z) production. The measured cross sections are σtt̄W = 369 + 100−91 fb and σtt̄Z = 176 + 58−52 fb. The background-only hypothesis with neither tt̄W nor tt̄Z production is excluded at 7.1σ. All measurements are consistent with next-to-leading-order calculations for the tt̄W and tt̄Z processes

Towards the development of sustainable control options for the African root and tuber scale on cassava in Central Africa understanding the ecology of the associated ant Anoplolepis tenella

Anoplolepis tenella Santschi is an afrotropical ant widely distributed in the forest zones of Central Africa. It is the most frequent species associated with the African root and tuber scale (ARTS) Stictococcus vayssierei (Hemiptera: Stictococcidae), an afrotropical insect that infests a wide range of root and tuber plants, particularly cassava. We investigated the biology and ecology of A. tenella which is one of the factors favoring the proliferation of the scale in the field. A. tenella was more abundant in the mixed-crop fields. It was rare or absent in the lowland where the scale was also absent. A. tenella is actively engaged in the transport and dispersal of scale crawlers. Boric acid-sucrose solution significantly killed A. tenella workers and queens under laboratory conditions. This result was later demonstrated in a farmer participatory trial and reduced scale infestation on cassava. These results demonstrate that control of S. vayssierei in cassava fields is contingent to the reduction of the density of the associated ant A. tenella

Network coding approach to improving tcp throughput in wireless networks

Compared to traditional routing protocols, network coding is bandwidth efficient and can achieve high throughput gains. By intelligently mixing (coding) packets together, fewer transmissions are required and bandwidth becomes available for new data. The goal of this chapter is to show that when XOR network coding is used in conjunction with an opportunistic scheduling and the Transmission Control Protocol (TCP) window state, higher throughput can be achieved. The necessary motivation and background are provided to 308 Emerging Wireless Networks: Concepts, Techniques, and Applications enable the reader to acquire the essence of the problem. Finally, a cross-layer approach is proposed followed by simulation results

Subcritical water technology for wheat straw hydrolysis to produce value added products

The cellulosic nature of agriculture wastes makes them suitable raw materials for conversion processing to produce end products with high value added. The present works described the using of subcritical water technology for the utilization of wheat straw through hydrolysis to produce reducing sugar. The experiments were carried out under different conditions and the optimum hydrolysis parameters were investigated. The results revealed that the optimum conditions for hydrolysis were 190 °C temperature, 30 min hydrolysis time, water to straw ratio of 6/1 and feedstock particle size of 180–355 μm. The maximum obtained yield the reducing sugars (RS) under the optimum hydrolysis condition amounted to 51.5% (as weight percent) of the raw wheat straw. HPLC analysis for the produced RS showed the presence of 3.2% of total RS as glucose and 7.6% as xylose, the balance being other reducing sugars, e.g. arabinose, galactose and probably other oligomers. Finally, the ethanol production from the produced glucose was tested through fermentation process. Based on the obtained results, it was possible to propose a design for a process combining both sugars and bioethanol production