Composite indicator development using utility function and fuzzy theory

Construction companies use composite indicators (CIs) to evaluate their overall project performance. However, the conventional methodology of CIs development causes indiscrimination, relative calibration, and redundancy. To address these problems, we propose a novel methodology that uses fuzzy theories. The proposed methodology includes a utility function for normalizing, a fuzzy measure for weighting, and a fuzzy integral for aggregating. We conducted a case study to assess the quality of the proposed methodology versus the alternative methodologies on 25 real projects of a construction company. The result showed that the measurement reliability of the proposed normalization method (1.96) is greater than that of the two different normalization methods (10.44 and 2.8, respectively). In addition, the measurement accuracy of the proposed aggregation method is greater than those of the four different aggregation methods. Therefore, our proposed methodology can more consistently and accurately help evaluate the overall project performance or success.     

Comparison of critical adsorption scaling functions obtained from neutron reflectometry and ellipsometry

Carpenter et al. [Phys. Rev. E 59, 5655 (1999); 61, 532 (2000)] managed to explain ellipsometric critical adsorption data collected from the liquid-vapor interface of four different critical binary liquid mixtures near their demixing critical temperature using a single model. This was the first time a single universal function had been found which could quantitatively describe the surface critical behavior of many different mixtures. There have also been various attempts to investigate this surface critical behavior using neutron and x-ray reflectometries. Results have been mixed and have often been at variance with Carpenter et al. In this paper, the authors show that neutron reflectometry data collected from a crystalline quartz-critical mixture interface, specifically deuterated water plus 3-methylpyridine, can be quantitatively explained using the model of Carpenter et al. derived from ellipsometric data.     

Cryogenic Chemistry and Quantitative Non-Thermal Desorption from Pure Methanol Ices: High-Energy Electron versus X-Ray Induced Processes

X-Ray irradiation of interstellar ice analogues has recently been proven to induce desorption of molecules, thus being a potential source for the still-unexplained presence of gaseous organics in the coldest regions of the interstellar medium, especially in protoplanetary disks. The proposed desorption mechanism involves the Auger decay of excited molecules following soft X-ray absorption, known as X-ray induced electron-stimulated desorption (XESD). Aiming to quantify electron induced desorption in XESD, we irradiated pure methanol (CH₃OH) ices at 23 K with 505 eV electrons, to simulate the Auger electrons originating from the O 1s core absorption. Desorption yields of neutral fragments and the effective methanol depletion cross-section were quantitatively determined by mass spectrometry. We derived desorption yields in molecules per incident electron for CO, CO₂, CH₃OH, CH₄/O, H₂O, H₂CO, C₂H₆ and other less abundant but more complex organic products. We obtained desorption yields remarkably similar to XESD values.     

UV photodesorption of interstellar CO ice analogues: from subsurface excitation to surface desorption

Carbon monoxide is after H(2) the most abundant molecule identified in the interstellar medium (ISM), and is used as a major tracer for the gas phase physical conditions. Accreted at the surface of water-rich icy grains, CO is considered to be the starting point of a complex organic--presumably prebiotic--chemistry. Non-thermal desorption processes, and especially photodesorption by UV photons, are seen as the main cause that drives the gas-to-ice CO balance in the colder parts of the ISM. The process is known to be efficient and wavelength-dependent, but, the underlying mechanism and the physical-chemical parameters governing the photodesorption are still largely unknown. Using monochromatized photons from a synchrotron beamline, we reveal that the molecular mechanism responsible for CO photoejection is an indirect, (sub)surface-located process. The local environment of the molecules plays a key role in the photodesorption efficiency, and is quenched by at least an order of magnitude for CO interacting with a water ice surface.     

Orbital and bonding anisotropy in a half-filled GaFeO3 magnetoelectric ferrimagnet

We investigated the orbital anisotropy of GaFeO3 using the Fe L2,3-edge x-ray magnetic circular dichroism and the polarization dependent O K-edge x-ray absorption spectroscopy. We found that the system shows a considerably large orbital momentum and anisotropic Fe-O bonding, which are unexpected in a half-filled d5 system such as GaFeO3. The orbital and bonding anisotropies, which turn out to be induced by the lattice distortions with exotic off-centering site movements, contribute the large magnetocrystalline energy and magnetoelasticity. These results provide critical clues on the microscopic understanding of the magnetoelectricity.     

Dynamics of composite haldane spin chains in IPA-CuCl3

Magnetic excitations in the quasi-one-dimensional antiferromagnet IPA-CuCl3 are studied by cold neutron inelastic scattering. Strongly dispersive gap excitations are observed. Contrary to previously proposed models, the system is best described as an asymmetric quantum spin ladder. The observed spectrum is interpreted in terms of composite Haldane spin chains. The key difference from actual S=1 chains is a sharp cutoff of the single-magnon spectrum at a certain critical wave vector.