Multiwavelength observations of blazars

The INTEGRAL mission has played a major role in blazar science, thanks to its sensitive coverage of a spectral region (3-100 keV) that is critical for this type of sources, to its flexibility of scheduling and to the large field of view of its cameras. A number of flat-spectrum radio quasars (up to z ~ 3) and BL Lac objects were observed by INTEGRAL together with facilities at all wavelengths. These results have advanced our knowledge of blazars from a physical and cosmological point of view. This paper reviews some of these outcomes, with particular reference to the INTEGRAL program for blazars in outburst as targets of opportunity, with a perspective into a future of multi-messenger astronomyComment: 7 pages, 1 figure, invited talk at the 11th INTEGRAL Conference "Gamma-Ray Astrophysics in Multi-Wavelength Perspective", Amsterdam, 10-14 October 2016. To be published in the Conf. Proceeding

Time-independent Anisotropic Plastic Behavior by Mechanical Subelement Models

The paper describes a procedure for modelling the anisotropic elastic-plastic behavior of metals in plane stress state by the mechanical sub-layer model. In this model the stress-strain curves along the longitudinal and transverse directions are represented by short smooth segments which are considered as piecewise linear for simplicity. The model is incorporated in a finite element analysis program which is based on the assumed stress hybrid element and the iscoplasticity-theory

Peer Effects, Social Networks, and Intergroup Competition in the Workplace

Using weekly data for defect rates (proportion of defective output) for all weavers in a Chinese textile firm during a 12 months (April 2003 - March 2004) period, we provide some of the first rigorous evidence on the presence and nature of peer effects in the manufacturing workplace. First, a worker is found to put in more effort and improve her performance when she is working with more able teammates. Second, by exploiting the well-documented fact that an exogenouslyformed strong divide between urban resident workers and rural migrant workers exists in firms in Chinese cities, we provide novel evidence on the interplay between social networks (urban resident group and rural migrant group) and peer effects. Specifically, we find that a worker puts in more effort when she is working with more able outgroup teammates but not when working with more able ingroup teammates, pointing to intergroup competition as a powerful source of the peer effects. Such peer effects across the social network, combined with the presence of incentive to outperform teammates at this firm, are largely consistent with recent experimental evidence on the important role that group identities play in facilitating altruistic behaviors.peer effects in the workplace; social networks; intergroup competition

On Hybrid and mixed finite element methods

Three versions of the assumed stress hybrid model in finite element methods and the corresponding variational principles for the formulation are presented. Examples of rank deficiency for stiffness matrices by the hybrid stress model are given and their corresponding kinematic deformation modes are identified. A discussion of the derivation of general semi-Loof elements for plates and shells by the hybrid stress method is given. It is shown that the equilibrium model by Fraeijs de Veubeke can be derived by the approach of the hybrid stress model as a special case of semi-Loof elements

Performance Spillovers and Social Network in the Workplace: Evidence from Rural and Urban Weavers in a Chinese Textile Firm

We provide some of the first rigorous evidence on performance spillovers and social network in the workplace. The data we use are rather extraordinary – weekly data for rejection rates (proportion of defective output) for all weavers in a firm during a 12 months (April 2003-March 2004) period, more than 10,000 observations. Our fixed effect estimates first point to significant spillovers of performance from high-ability weavers to low-ability weavers. On the other hand, we find no evidence for performance spillovers from low-ability to high-ability weavers. The findings are consistent with the knowledge sharing hypothesis that low-ability workers learn from high-ability workers but not vice versa. Second, by exploiting the well-documented fact that an exogenously-formed sharp divide between urban workers and rural migrant workers exists in firms in Chinese cities, we find that performance spillovers/knowledge sharing take place only within the confines of social network. Specifically rural low-ability weavers are found to improve their performance as their high-ability teammates (who are also rural migrants) improve their performance while they do not benefit from performance improvement of their high-ability teammates who are urban residents. Such heterogeneous performance interdependence of workers within the same team suggests that our evidence for performance spillovers is less likely to be a result of team specific demand shocks that generate spurious performance interdependence of all team members.knowledge sharing, performance spillovers, social network

Performance calculations for 1000 MWe MHD/steam power plants

The effects of MHD generator operating conditions and constraints on the performance of MHD/steam power plants are investigated. Power plants using high temperature combustion air preheat (2500 F) and plants using intermediate temperature preheat (1100 F) with oxygen enrichment are considered. Variations of these two types of power plants are compared on the basis of fixed total electrical output (1000 MWe). Results are presented to show the effects of generator plant length and level of oxygen enrichment on the plant thermodynamic efficiency and on the required generator mass flow rate. Factors affecting the optimum levels of oxygen enrichment are analyzed. It is shown that oxygen enrichment can reduce magnet stored energy requirement