Polychromatic femtosecond fluorescence studies of metal–polypyridine complexes in solution

Femtosecond-resolved broadband fluorescence studies are reported for[M(bpy)3]2+ (M = Fe, Ru), RuN3 and RuN719 complexes in solution. We investigated the pump wavelength dependence of the fluorescence of aqueous [Fe(bpy)3]2+ and the solvent and ligand dependence of the fluorescence of Ru-complexes excited at 400 nm. For all complexes, the 1MLCT fluorescence appears at zero time delay with a mirror-like image with respect to the absorption. It decays in 630–45 fs due to intersystem crossing to the 3MLCT states, but a longer lived component of 190 fs additionally shows up in RuN719 and RuN3. No solvent effects are detected. The very early dynamics are characterized by internal conversion (IC) and intramolecular vibrational redistribution (IVR) processes on a time scale which we estimate to 610 fs using the 1MLCT lifetime as an internal clock

Why Do States Develop Multi-tier Emigrant Policies? Evidence from Egypt

Why do states vary their policies towards their citizens abroad, and why are some emigrant groups treated preferentially to others? The literature on the politics of international migration has yet to explore this as a separate field of inquiry, assuming that states adopt a single policy that encourages, sustains or prevents emigration abroad. Yet, in the case of Egypt, the state developed a multi-tiered policy that distinctly favoured specific communities abroad over others. I hypothesise that policy differentiation is based upon the perceived utility of the emigrant group remaining abroad versus the utility of its return. This utility is determined by two factors: the sending state’s domestic political economy priorities and its foreign policy objectives

Interaction between Education and Household Wealth on the Risk of Obesity in Women in Egypt

Obesity is a growing problem in lower income countries particularly among women. There are few studies exploring individual socioeconomic status indicators in depth. This study examines the interaction of education and wealth in relation to obesity, hypothesising that education protects against the obesogenic effect of wealth

The violent youth of bright and massive cluster galaxies and their maturation over 7 billion years

In this study, we investigate the formation and evolution mechanisms of the brightest cluster galaxies (BCGs) over cosmic time. At high redshift (z ∼ 0.9), we selected BCGs and most massive cluster galaxies (MMCGs) from the Cl1604 supercluster and compared them to low-redshift (z ∼ 0.1) counterparts drawn from the MCXC meta-catalogue, supplemented by Sloan Digital Sky Survey imaging and spectroscopy. We observed striking differences in the morphological, colour, spectral, and stellar mass properties of the BCGs/MMCGs in the two samples. High-redshift BCGs/MMCGs were, in many cases, star-forming, late-type galaxies, with blue broad-band colours, properties largely absent amongst the low-redshift BCGs/MMCGs. The stellar mass of BCGs was found to increase by an average factor of 2.51 ± 0.71 from z ∼ 0.9 to z ∼ 0.1. Through this and other comparisons, we conclude that a combination of major merging (mainly wet or mixed) and in situ star formation are the main mechanisms which build stellar mass in BCGs/MMCGs. The stellar mass growth of the BCGs/MMCGs also appears to grow in lockstep with both the stellar baryonic and total mass of the cluster. Additionally, BCGs/MMCGs were found to grow in size, on average, a factor of ∼3, while their average Sérsic index increased by ∼0.45 from z ∼ 0.9 to z ∼ 0.1, also supporting a scenario involving major merging, though some adiabatic expansion is required. These observational results are compared to both models and simulations to further explore the implications on processes which shape and evolve BCGs/MMCGs over the past ∼7 Gyr

Improved morphology control using a modified two-step method for efficient perovskite solar cells

© 2014 American Chemical Society. A two-step wet chemical synthesis method for methylammonium lead(II) triiodide (CH3NH3PbI3) perovskite is further developed for the preparation of highly reproducible solar cells, with the following structure: fluorine-doped tin oxide (FTO)/TiO2 (compact)/TiO2 (mesoporous)/CH3NH3PbI3/spiro-OMeTAD/Ag. The morphology of the perovskite layer could be controlled by careful variation of the processing conditions. Specifically, by modifying the drying process and inclusion of a dichloromethane treatment, more uniform films could be prepared, with longer emission lifetime in the perovskite material and longer electron lifetime in solar cell devices, as well as faster electron transport and enhanced charge collection at the selective contacts. Solar cell efficiencies up to 13.5% were obtained

Human Hand Gesture Recognition

A Human Computer Interaction(HCI) between computers and human understands human language and improve a user friendly interface. Gestures a non-verbal form of communication supplies the HCI interface. The aim of gesture recognition is to make a system which can recognize specific-human gestures and employ them to convey information or for device control. Real-time visionbased hand gesture recognition is attempting to be more and more suitable for HCI with the assistance of the latest advances in the area of computer vision and pattern recognition. The gesture will able to reduce the use of most Prominent hardware devices which are used to control the activities of the computer. In this paper we introduces a mechanism for human computer interaction utilizing open source OpenCV. The proposed algorithm consists of preprocessing, segmentation and feature extraction.In segmentation we are used threshold BINARY-INV+threshold OTSU.Then make use of contours, convex hull and convexity defects to find the hand gesture.The hand gesture images are captured by a camera. That is used as the input to the algorithm. The proposed algorithm is able to recognize the number of fingers present in the hand gesture