The timing of disability insurance application: a choice-based semiparametric hazard model

We use a choice-based subsample of Social Security Disability Insurance applicants from the 1978 Social Security Survey of Disability and Work to test the importance of policy variables on the timing of application for disability insurance benefits following the onset of a work limiting health condition. We correct for choice-based sampling by extending the Manski-Lerman (1977) correction to the likelihood function of our continuous time hazard model defined with semiparametric unmeasured heterogeneity and find that this correction significantly affects the results. We find that economic variables-the size of the disability benefit, expected wage earnings and accommodation-matter.Insurance ; Social security

The effects of local voids and imperfections of surrounding rock on the performance of existing tunnel lining

Local voids and imperfections may exist around the tunnel due to reasons such as inadequate back infill behind the lining, insufficient local lining thickness, ground water erosion, and other imperfect construction related activities. Such local voids and imperfections generally will lead to local contact loss and discontinuity in the ground-lining interaction. This paper evaluates the effect of local voids and imperfections developing around the tunnel vault area on the mechanical performance of tunnel lining. Based on field investigation results, a series of voids and imperfections with different geometries are defined to reflect cases resulting from different causes. Numerical parametric analyses were performed to investigate how those voids and imperfections influence the internal force and the safety factor of the lining, and the reinforced concrete lining were modelled with the smeared crack model to examine the development of cracking directions and patterns. Furthermore, the numerical approach was verified by comparing with field investigations and measurements. This study aims to investigate the most unsafe situation due to local voids and imperfections around the tunnel, and the modelled cracking feature shows a way to preliminary evaluate the possible local voids and imperfections behind tunnel lining based on field observation

Improved hole-injection contact for top-emitting polymeric diodes

In this letter, an efficient hole-injection contact was achieved for the top-emitting polymeric light-emitting diodes (PLEDs). The anode has a structure of metal/molybdenum oxide/poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS). It has been found that hole injection was significantly improved by inserting a thin layer of MoO3 between aluminum and PEDOT:PSS. An ultraviolet photoelectron spectroscopy (UPS) was used to investigate the change of work function, and photovoltaic measurement confirmed that the improved hole injection is due to the reduction of barrier height, resulted from the addition of transition metal oxide. PEDOT:PSS layer was found necessary in anode structure to further enhance the hole injection and electroluminance efficiency. A peak power efficiency of 11.42lm∕W was achieved at current density of 1.2mA/cm2 for the white emission top-emitting PLEDs

The Extended Coupled Cluster Treatment of Correlations in Quantum Magnets

The spin-half XXZ model on the linear chain and the square lattice are examined with the extended coupled cluster method (ECCM) of quantum many-body theory. We are able to describe both the Ising-Heisenberg phase and the XY-Heisenberg phase, starting from known wave functions in the Ising limit and at the phase transition point between the XY-Heisenberg and ferromagnetic phases, respectively, and by systematically incorporating correlations on top of them. The ECCM yields good numerical results via a diagrammatic approach, which makes the numerical implementation of higher-order truncation schemes feasible. In particular, the best non-extrapolated coupled cluster result for the sublattice magnetization is obtained, which indicates the employment of an improved wave function. Furthermore, the ECCM finds the expected qualitatively different behaviours of the linear chain and the square lattice cases.Comment: 22 pages, 3 tables, and 15 figure

The role of the Boudouard and water-gas shift reactions in the methanation of CO or CO2 over Ni/γ-Al2O3 catalyst

The Boudouard and the water-gas shift reactions were studied at different temperatures between 453 and 490 K over a Ni/γ-Al2O3 catalyst in a Carberry batch reactor using various mixtures of CO, H2 and CO2. The activity of the Boudouard reaction was found to be low, compared to the water-gas shift reaction, and diminished over time, suggesting that the temperature was too low for significant activity after an initiation period of CO adsorption. Furthermore, the rate of the Boudouard reaction has been reported to decrease in the presence of H2O and H2. The water-gas shift reaction was found to be the main reaction responsible for the production of CO2 in a mixture of CO, H2 and H2O in the batch reactor. The ratio of the total amount of CO consumed to the total amount of CO2 produced showed that the catalyst was also active towards hydrogenation, where the rate of the hydrogenation reaction was very much faster than the water-gas shift reaction. The resulting ratio of pH2 to pCO was found to be extremely low, probably leading to the production of long-chain hydrocarbons. The stoichiometry of the overall reaction was such that for every mole of mole of CO2 produced, 1.5 mol of CO was consumed in the batch reactor. Kinetic studies were performed in the batch reactor. An Eley-Rideal mechanism was found to provide a good agreement with the experimental results over a wide range of partial pressures of steam and CO

Meta-analysis of airway epithelium gene expression in asthma

Differential gene expression in the airway epithelium of patients with asthma versus controls has been reported in several studies. However, there is no consensus on which genes are reproducibly affected in asthma. We sought to identify a consensus list of differentially expressed genes (DEGs) using a meta-analysis approach. We identified eight studies with data that met defined inclusion criteria. These studies comprised 355 cases and 193 controls and involved sampling either bronchial or nasal epithelium. We conducted study-level analyses, followed by a meta-analysis. Likewise, we applied a meta-analysis framework to the results of study-level pathway enrichment. We identified 1273 DEGs, 431 of which had not been identified in previous studies. 450 DEGs exhibited large effect sizes and were robust to study population differences in age, sex, race/ethnicity, medication use, smoking status and exacerbations. The magnitude of differential expression of these 450 genes was highly similar in bronchial and nasal airway epithelia. Meta-analysis of pathway enrichment revealed a number of consistently dysregulated biological pathways, including putative transcriptional and post-transcriptional regulators. In total, we identified a set of genes that is consistently dysregulated in asthma, that links to known and novel biological pathways, and that will inform asthma subtype identification

The Effect of ePortfolio Satisfaction on Students’ Learning Motivation and Internet Self-efficacy

This study aims to investigate the effect of e-Portfolio satisfaction on students’ learn­ing motivation and Internet self-efficacy toward the use of e-Portfolio. The data collected for this study occurred over 3 months. Participants were 450 students taking the course of common at an university. The counting of 443 questionnaires was received. The findings revealed that there were positive correlations between learning motivation, Internet self-efficacy, and e-Portfolio satisfac­tion. For gender, the result showed that there were no significant Internet self-efficacy differences between gender. Besides, there were the significant differences in learning motivations and in Internet self-efficacy between the two groups. Furthermore, the multistep regression analysis in­dicated that the learning motivation was the significant predictor of Internet self-efficacy, and In­ternet self-efficacy was the significant predictor of e-Portfolio satisfaction. Based on the findings, educators and researchers needed to pay attention to these influences and take these factors into consideration in e-Portfolio. The study concludes by assessing the overall gains and shortcomings of the reform effort toward using the e-Portfolio to help student self-learning