146 research outputs found
Heterogeneous Information and Appraisal Smoothing
This study examines the heterogeneous appraiser behavior and its implication on the traditional appraisal smoothing theory. We show that the partial adjustment model is consistent with the traditional appraisal smoothing argument only when all the appraisers choose the same smoothing technique. However, if appraiser behavior is heterogeneous and exhibits cross-sectional variation due to the difference in their access to, and interpretation of information, the model actually leads to a mixed outcome: The variance of the appraisal-based returns can be higher or lower than the variance of transaction-based return depending on the degree of such heterogeneity. Using data from the residential market, we find that, contrary to what the traditional appraisal smoothing theory would predict, appraisal-based indices may not suffer any “smoothing” bias. These findings suggest that the traditional appraisal smoothing theory, which fails to consider the heterogeneity of appraiser behaviors, exaggerates the effect of appraisal smoothing.
Containment through mobility: migrants’ spatial disobediences and the reshaping of control through the hotspot system
This article deals with the modes of (contested) control that are at play at the Mediterranean frontier for containing, dividing and discipling unruly mobility. Building on ethnographic research conducted on the island of Lesvos and of Lampedusa, it focuses on the implementation and the functioning of the Hotspot System in Greece and in Italy, analysing beyond the fences of detention centres and by looking at the broader logistics of channels, infrastructures and governmental measures deployed for regaining control over migration movements. The article argues that more than control in terms of surveillance and tracking, the Hotspot System contributes to enforce forms of containment through mobility that consists in controlling migration by obstructing, decelerating and troubling migrants’ geographies – more than in fully blocking them. The article takes into account migrants’ refusals of being fingerprinted, showing how migrants radically unsettle the association between seeking refuge and lack of choice, enacting their right to choose where to go and claim asylum
Redetermination of di-μ-hydrido-hexahydridotetrakis(tetrahydrofuran)dialuminium(III)magnesium(II)
The structure of the title compound, [Mg(AlH4)2(C4H8O)4], has been redetermined at 150 K. The MgII ion is hexacoordinated to four tetrahydrofuran (THF) ligands, and two AlH4
− anions through bridging H atoms. The Al—H distances are more precise compared to those previously determined [Nöth et al. (1995 ▶). Chem. Ber. 128, 999–1006; Fichtner & Fuhr (2002 ▶). J. Alloys Compd, 345, 386–396]. The molecule has twofold rotation symmetry
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Quasi-Optical Terahertz Microfluidic Devices for Chemical Sensing and Imaging
We first review the development of a frequency domain quasi-optical terahertz (THz) chemical sensing and imaging platform consisting of a quartz-based microfluidic subsystem in our previous work. We then report the application of this platform to sensing and characterizing of several selected liquid chemical samples from 570–630 GHz. THz sensing of chemical mixtures including isopropylalcohol-water (IPA-H₂O) mixtures and acetonitrile-water (ACN-H₂O) mixtures have been successfully demonstrated and the results have shown completely different hydrogen bond dynamics detected in different mixture systems. In addition, the developed platform has been applied to study molecule diffusion at the interface between adjacent liquids in the multi-stream laminar flow inside the microfluidic subsystem. The reported THz microfluidic platform promises real-time and label-free chemical/biological sensing and imaging with extremely broad bandwidth, high spectral resolution, and high spatial resolution.Keywords: laminar flow,
terahertz,
chemical sensing and imaging,
molecule diffusion,
frequency domain,
microfluidic,
quasi-optical,
label fre
Enhanced reversible lithium storage in germanium nano-island coated 3D hexagonal bottle-like Si nanorod arrays
MOST of China [2009CB930704]; National Natural Science Foundation of China [61106118]; Science and Technology Project of Fujian Province of China [2013H0046]; Natural Science Foundation of Fujian Province of China [2011J01362]; Fundamental Research Funds for the Central Universities [2011121026]The rapid development of numerous microscale electronic devices, such as smart dust, micro or nano bio-sensors, medical implants and so on, has induced an urgent demand for integratable micro or nano battery supplies with high energy and power densities. In this work, 3D hexagonal bottle-like Si/Ge composite nanorod (NR) array electrodes with good uniformity and mechanical stability potentially used in micro or nano rechargeable Li-ion batteries (LIBs) were fabricated on Si substrates by a cost-effective, wafer scale and Si-compatible process. The optimized Ge nano-islands coated Si NR composite arrays as anode materials exhibit superior areal capacities and cycling performances by virtue of their favourable structural and improved conductivity features. The unique Si-based composite electrode in nanostructures can be technically and fundamentally employed to configurate all-solid-state Li-ion micro-batteries as on-chip power systems integrated into micro-electronic devices such as M/NEMS devices or autonomous wireless microsystems
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