Shear Strength Parameters of Improved Peat by Chemical Stabilizer.

The present research aimed to discuss the applicability of cationic grouts in geotechnical engineering. The effects of several cationic stabilizers such as monovalent (sodium silicate), divalent (calcium oxide and calcium chloride), and trivalent (aluminum hydroxide) were investigated on shear strength improvement of tropical peat samples. The unconfined compressive strength (UCS) tests were performed after the time frame of 7, 21, and 30 days as curing time, respectively. Apart from the physicochemical characteristics of the stabilized peat, scanning electron microscopy and energy-dispersive X-ray spectroscopy tests were also carried out to study the ongoing microstructural changes. It is to be noted that the shear strength values for peat samples rose to 8, 6, 6, and 4 % of sodium silicate, calcium oxide, calcium chloride, and aluminum hydroxide, respectively. The highest observed UCS outcome is the one taken from the calcium oxide where the UCS of treated peat after 30-day curing time increased to 76 kPa. The strength changes resulted from the various cationic stabilizers can best be explained via the consideration within the mineralogical composition as well as those physicochemical changes happening in the peat

Populism, inequality and representation: Negotiating ‘the 99%’ with Occupy London

When Occupy London emerged with a global wave of protest movements in October 2011, it embodied and advanced discursive forms that have characterised the unsettling of political consensus following the financial crisis. The central claim that ‘We are the 99%’ staged a fundamental tension, between a populist appeal to the figure of ‘the people’, and a contrary orientation seeking to critique inequality while rejecting forms of representation and identity. This article – which draws on three years of ethnographic fieldwork with Occupy London (October 2011–October 2014) and a critical theorisation of the figure of ‘the people’ in radical movements – follows movement participants’ negotiation of the tension at the heart of the discourse of ‘the 99%’. It offers an account of the conflicting meanings and practices that emerged, arguing that the result was a creative contradiction that sustained the movement for a time, while setting the terms of its ultimate breakdown. Identifying the concept of ‘representation’ as the site of particular controversy, this is unpicked through a number of key figures (Pitkin, Marx, Spivak, Puchner, Deleuze and Guattari) as the basis for an empirical account of Occupy’s practice of assembly, which offered partial, imperfect ‘solutions’ to these tensions. The article concludes with some implications for the limits and possibilities of both a grassroots populism and a politics against representation, in the context of political developments since

Electron quasi-confined-optical-phonon interactions in wurtzite GaN/AlN quantum wells

The equation of motion for the p-polarization field in a wurtzite GaN/AlN multilayer heterostructure is solved for the quasi-confined-optical-phonon modes based on the dielectric-continuum model and Loudon’s uniaxial crystal model. The polarization eigenvector, the dispersion relation of the quasi-confined-optical-phonon modes and the electron-quasi-confined-phonon interaction Fröhlich-like Hamiltonian are derived. The analytical formulas can be directly applied to single/multiple quantum wells (QW’s) and superlattices. The electron-quasi-confined-phonon coupling functions are investigated for a given AlN/GaN/AlN single QW with full account of the strains of the QW structures and the anisotropy effect of wurtzite crystals. We find that there are two kinds of quasi-confined-optical-phonon modes in the GaN/AlN QW’s: the GaN-layer quasi-confined-optical-phonon modes and the AlN-layer quasi-confined-optical-phonon modes. There are infinite quasi-confined-optical-phonon branches, labelled by a quantum number n (n=1,2,...), with definite symmetry with respect to the center of the AlN/GaN/AlN single QW for a given phonon wave number q. The dispersions of the quasi-confined-optical-phonon modes with smaller n are more obvious than the ones with larger n. Moreover, the modes with smaller n are much more important for their electron-quasi-confined-phonon interactions than those with larger n. In most cases, it is enough to consider the modes with n≤ 8 for the electron-quasi-confined-phonon interactions in a single GaN/AlN QW. The higher frequency modes are more significant than the lower ones. The long-wavelength quasi-confined-optical-phonon modes are much more important for the electron-quasi-confined-phonon interactions. The GaN-layer quasi-confined-optical-phonon energies and their electron-quasi-confined-phonon interaction strength are markedly increased due to the strains of the QW structures. The influence of the strains on the the AlN-layer electron-quasi-confined-phonon interactions can be ignored. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2005

Advanced turbulence modeling for the computation of highly separated subsonic flows

Communication to : 16th international conference on numerical method for fluid dynamics, Arcachon (france), July 6-10, 1998SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1998 n.128 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Adult breast, lung, pancreatic, upper and lower gastrointestinal cancer patients with hospitalized venous thromboembolism in the national French hospital discharge database

Abstract Background Venous thromboembolism (VTE) and cancer are strongly associated. In France, evidence on patients with pancreatic, upper GI [gastrointestinal], lower GI, lung, or breast cancer-associated VTE and their hospital management is limited. The aims of this study were to provide data on the number of hospitalized VTE events among cancer patients, the patients’ characteristics, and their hospital management to estimate the burden of disease and the hospital burden of cancer-related VTE and to provide guidance on research. Methods This longitudinal, observational, and retrospective study was based on the comprehensive hospital discharge database (PMSI). Adult patients (≥ 18 years old) hospitalized with a cancer of interest in 2016 and hospitalized (within 2 years with VTE (captured a as a principal, related, or significant associated diagnosis) were included in the study. Results We identified 340,946 cancer patients, of which 7.2% (24,433 patients) were hospitalized with VTE. The proportions of hospitalized VTE were 14.6% (3,237) for patients with pancreatic cancer, 11.2% (8,339) for lung cancer, 9.9% (2,232) for upper GI cancer, 6.7% (7,011) for lower GI cancer, and 3.1% (3,614) for breast cancer. Around two thirds of cancer patients with a hospitalized VTE had active cancer (with metastases and/or receiving chemotherapy during the six months prior to the index date): from 62% of patients with pancreatic cancer to 72% with breast cancer. Around a third of patients were admitted to the hospital through the emergency room, up to 3% of patients stayed in an intensive care unit. The average length of stay ranged from 10 (breast cancer) to 15 days (upper GI cancer). Nine (lower GI cancer) to 18% (pancreatic cancer) of patients died during the VTE hospital stay. Conclusions The burden of cancer-associated VTE is substantial, both in terms of the number of patients affected and in the hospital use. These findings offer guidance on future research on VTE prophylaxis in a very high-risk population, particularly in patients with active cancer

Raman scattering in GaN pillar arrays

We present a detailed study of GaN pillar arrays by atomic force microscopy (AFM), Raman spectroscopy, and photoluminescence (PL) spectroscopy. AFM is used to characterize the shape of the GaN pillars and revealed a large roughness of etched pillar surfaces. Raman scattering spectra of the pillars are well described by angular dispersion of polar optical phonons induced by the three-dimensional shape of the pillar. Additional Raman scattering has been tentatively assigned to the activation of the high frequency B-1 silent mode by defects introduced during the ion etching. This result is well correlated with the appearance of donor and acceptor-related PL of the GaN pillars. N vacancy or/and Ga interstitials would be likely candidates for donors in the nonstoichiometric GaN near the surface of the etched pillars. (C) 2002 American Institute of Physics

Optical investigation of micrometer and nanometer-size individual GaN pillars fabricated by reactive ion etching

We present an optical investigation of GaN pillars using both micro-Raman (mu-Raman) and microphotoluminescence (mu-PL) spectroscopy. GaN pillars of diameter ranging from 100 nm to 5 mum were fabricated by electron beam lithography and reactive ion etching (RIE) with SiCl4 plasma. Optical measurements of both mu-Raman and mu-PL on individual pillars show consistent variations in the properties of the fabricated GaN structures as a function of GaN pillar size. mu-PL mapping gives strong evidence for defect-induced donors and/or acceptors near the facets of the RIE etched pillars. RIE for the nanostructuration of GaN could be used in the future to allow spectroscopic studies of a few or single quantum objects such as GaN quantum dots. (C) 2002 American Institute of Physics