Mobility,education and labor market outcomes for U.S. graduates: Is selectivity important?

The literature on human capital, and its positive effects on individuals and regional economies, is now vast. The linkages between human capital and migration have also found a fertile ground in recent years especially in Europe where many studies have focused on interregional migration of graduates and highly skilled individuals. However, the literature on this phenomenon in the USA is less developed. Using the SESTAT database from NSF, this paper aims at contributing to the understanding of inter-state migration behavior of graduates in the USA and its effects on their career outcomes. It builds on the existing literature not only by focusing specifically on the US context, but also incorporating into the empirical model a correction for the possible selection bias that arises from the dual relationship between migration propensity and human capital endowment. Our estimated Mincerian earning equations, corrected for migrant self-selectivity, show that indeed repeat migration is associated with higher average salaries, while late migration is associated with a salary penalty. As for the other control variables, our results are consistent with what has been found in the labor economics literature. Female workers suffer from a salary penalty, while experience, level of education and employer size are all associated with higher average salaries. The labor market also rewards different fields of study differently.     

First‐mover advantages of the European Union's climate change mitigation strategy

This paper assesses the costs and benefits for the European Union (EU) as a first mover in climate change mitigation. Scenarios of EU and global climate action to 2050 are quantified using the GEME3‐RD model, a global multi‐sectoral computable general equilibrium model with endogenous technology progress and detailed representation of the clean energy technologies. The model includes two‐factor learning curves (stock and research and development funding) for clean energy technologies, such as electric vehicles, carbon capture and storage, and renewable and efficient appliances. Funding of research and development is endogenously derived as a production factor enabling productivity improvement. The scenarios compare stylised climate strategies, which are asymmetric by world region and have different emission reduction profiles over time. Assuming that strong climate mitigation action will be undertaken only after 2030, the scenarios compare two main strategies for the EU: pursuing strong emission reduction unilaterally until 2030 versus deferring action for the period after 2030. Asymmetric climate action by region enables asymmetric innovation and manufacturing of clean energy technologies. The macroeconomic assessment of the climate action strategies does not only depend on costs of clean technologies but also on induced technology progress implying asymmetric effects on manufacturing and trade by region, taking into account spillovers. The model‐based projections show clear advantages for the EU as a first mover in climate change mitigation compared with a delaying of climate action until 2030. Delayed climate action until 2030 implies higher gross domestic product losses for the EU compared with unilateral action until 2030. The model finds benefits of early action by the EU driven by activity and progress related to clean energy technologies as the EU can achieve competitive advantages over other world regions pursuing climate action later. Copyright © 2016 John Wiley & Sons, Ltd.     

Wavelength tuning analysis and spectral characteristics ofthree-section DBR lasers

A theoretical model for the design of three-section distributed Bragg reflector (DBR) lasers using the transfer matrix method is presented. The oscillation parameters, the tuning behavior, and the linewidth are derived. The effect of a discontinuity of the waveguide at the active-passive interface is accounted for by using scattering matrix parameters, easily combined with the transfer matrix method. The influence of such an interface is studied and the importance of optical losses at this point is discussed     

The effect of sterols on the oxidation of edible oils

The effect of sterols on the oxidation of a triglyceride mixture, similar in composition to olive oil, has been studied at 180°C. Δ⁵-Avenasterol and fucosterol are effective as antioxidants, whilst other sterols, including cholesterol and stigmasterol, are ineffective. The antioxidant effect of Δ⁵-avenasterol increases with concentration in the range 0·01% to 0·1%.An hypothesis is presented to explain the effectiveness of the sterols as antioxidants. It is concluded that lipid free radicals react rapidly with sterols at unhindered allylic carbon atoms. Isomerisation leads to a relatively stable allylic tertiary free radical, which is slow to react further, and this interrupts the autoxidation chain.     

Development of Deep Learning Models for Predicting the Effects of Exposure to Engineered Nanomaterials on Daphnia magna

This study presents the results of applying deep learning methodologies within the ecotoxicology field, with the objective of training predictive models that can support hazard assessment and eventually the design of safer engineered nanomaterials (ENMs). A workflow applying two different deep learning architectures on microscopic images of Daphnia magna is proposed that can automatically detect possible malformations, such as effects on the length of the tail, and the overall size, and uncommon lipid concentrations and lipid deposit shapes, which are due to direct or parental exposure to ENMs. Next, classification models assign specific objects (heart, abdomen/claw) to classes that depend on lipid densities and compare the results with controls. The models are statistically validated in terms of their prediction accuracy on external D. magna images and illustrate that deep learning technologies can be useful in the nanoinformatics field, because they can automate time‐consuming manual procedures, accelerate the investigation of adverse effects of ENMs, and facilitate the process of designing safer nanostructures. It may even be possible in the future to predict impacts on subsequent generations from images of parental exposure, reducing the time and cost involved in long‐term reproductive toxicity assays over multiple generations.     

Measurements for assessing the exposure from 3G femtocells

Femtocells are low-power access points, which combine mobile and broadband technologies. The main operation of a femtocell is to function as a miniature base station unit in an indoor environment and to connect to the operator's network through a broadband phone line or a coaxial cable line. This study provides the first experimental measurements and results in Greece for the assessment of exposure to a femtocell access point (FAP) indoors. Using a mobile handset with the appropriate software, power level measurements of the transmitted (Tx) and the received by the mobile handset signal were performed in two different and typical (home and office) environments. Moreover, radiofrequency electric field strength and frequency selective measurements with a radiation meter (SRM-3000) were carried out in the proximity of the FAP installation point. The cumulative distribution functions of the Tx power at most cases (except one) show that in 90% of all points the power of the mobile phone was lower by at least 7 dB during FAP operation. At a distance of ～1 m from the FAP (in its main beam), power flux density measurements show that there is very little difference between the two situations (FAP ON and OFF). As a conclusion, the use of femtocells indoors improves reception quality, reduces the Tx power of the user's mobile terminal and results in an indiscernible increase of the electromagnetic field in front of the unit, at values that are extremely low compared with reference levels of exposure guidelines.     

Excimer Laser Micromachining of CMSX2 and TA6V Alloys

Excimer laser may be used in the micromachining of various materials, especially in cases where surface finishing by a conventional machining method is difficult. In this study, the process was applied onto two high performance alloys: CMSX2 and TA6V, widely used in the aircraft industry. An attempt was made to determine the relationship between the laser parameters (fluence, frequency, pulse number) and the shape of the formed craters, the proportion of the ablated material and the laser hardening effects. Energy density of 2.5 kJ.cm^-2 was found to be the critical value above which the amount of material ablated and resolidified tend to a constant rate, while the depth attained was influenced only by the other laser parameters (frequency and number of pulses). For the highest energy density applied (10.2 kJ.cm^-2) the formed craters were cone-shaped, in the case of CMSX2, and rectangular, in the case of rolled TA6V. In fact, a prior rolling procedure of TA6V had a great influence on the ablation mechanism. Shock waves occurred hardening affect only the region of CMSX2 sub-surface.     

Hydrogen effect on a low carbon ferritic-bainitic pipeline steel

Hydrogen effect on an API 5L X65 low carbon ferritic-bainitic steel is investigated, by evaluating the fracture toughness parameters in air and in hydrogen environment. The hydrogen environment is manifested by in situ hydrogen charging of the X65 steel, using the electrolytic solution NS4, which simulates the electrolyte trapped between the pipeline steel and the coating in a buried pipeline. The fracture toughness results of the X65 are compared to two other pipeline steels with different microstructures, namely an X52 and an X70, possessing a banded ferritic-pearlitic and banded ferritic-mixed bainitic-pearlitic microstructure, respectively. The X65 steel exhibits significant reduction of fracture toughness parameter J₀ integral due to hydrogen charging and insignificant variation of fracture toughness parameter K_Q. Comparing the three steels, the lowest reduction of J₀ integral due to hydrogen charging, is met on the X52 and the highest in the X65.