Synthesis of novel Ir complexes and their application in organic light emitting diodes

Three new substituted arylpyridine coordinated iridium complexes Ir(DPP)₂(acac), Ir(BPP)₂(acac) and Ir(FPP)₂(acac) have been synthesized and used as emitter in OLED. The EL devices based on these complexes emitted in the green to yellow spectral range. The results showed that these complexes have strong phosphorescent characters. For the device based on Ir(FPP)₂(acac), the maximum brightness reached 14180 cd m⁻² and the maximum external efficiency reached 17.0 cd A⁻¹.     

DAMAGE HEALING AND STRENGTHENING BEHAVIOUR IN INTELLIGENT MULLITE/SiC CERAMICS

Abstract Fifteen kinds of mullite/SiC samples with different microstructures were prepared in order to examine the effect of Sic volume% and Sic grain size on mullite morphology and mechanical properties. Special attention was paid to the effect of heat-treatment on fracture stress. It is shown that these materials have damage self-healing characteristics. The best mullite/SiC system, within the given test conditions, is 20% by volume of Sic, having a grain sue of 0.56 μm, and the best condition for damage healing is a 1 h heat treatment at 1300°C in an air atmosphere.     

Characteristics of the polyaniline films vacuum deposited at a high background pressure

Polyaniline films with different thickness were deposited on unheated glass substrates by vacuum evaporating HCl-doped polyaniline pellets at a high background pressure. Micromorphological, compositional, structural and electrical properties of the films were studied by using field emission scanning electron microscopy, energy dispersive of X-ray spectroscopy, Fourier transform infrared spectroscope and sub-femtoamp source meter. The polyaniline films consist of a large number of flakes. Some flakes are perpendicular to the substrate and they are more in the thick film compared with the thin film. No chlorine is detected in the films. The aromatic structure of polyaniline is retained in all the polyaniline films. However, the polar structure of polyaniline is destroyed in the films. The polyaniline film is in a higher oxidation state compared with the HCl-doped polyaniline pellet. The conductivity of the polyaniline films ranges from 10⁻⁸ to 10⁻⁹ S/cm and is lower than that of the HCl-doped polyaniline pellet as the starting material. Besides, the conductivity decreases with increasing film thickness.     

STUDIES OF THE THERMALPERFORMANCE OF BUILDINGSIN SUMMER IN SOUTHERN EUROPE

This paper describes the studies carried out in project PASCOOL to document and assess the thermal performance of selected buildings in Southern Europe and to identify possible improvements. Twenty-three buildings from nine European countries were surveyed and monitored for a short period during summertime. The measurements and survey data obtained formed the basis for sensitivity studies with thermal simulation. The selection encompassed buildings of typical construction, including both recent and traditional, residential and non-residential. The sensitivity studies addressed the effects of shading, thermal inertia, ventilation, window orientation and colour of external surfaces, envelope insulation, and occupancy patterns. The paper presents the methodology adopted for the measurements and sensitivity studies and discusses the main conclusions drawn from the studies- It identifies options for improving occupant thermal comfort with little or no mechanical cooling.     

Making Patterns on Graphene

Graphene‐based nanostructures are considered as promising alternatives to silicon‐based mesostructures in future electronic nanodevices. The lithographical patterning of graphene, which are essential steps in any form of microelectronic processing, present interesting challenges because of the atomic layer thickness of graphene. Mesoscopic devices based on graphene require high spatial resolution patterning that will induce as little damage as possible. This research news highlights and evaluates recent developments in the nanostructuring and patterning of graphene.     

Incentives for Combined Heat and Power plants: How to increase societal benefits?

Investments in new combined heat-and-power (CHP) facilities have fallen short of harnessing what is believed to be CHP's full achievable economic potential and attenuate societal benefits of reducing emissions and increasing resiliency of the power system. Various reasons have been found to explain this “CHP gap,” an example of the “energy-efficiency gap.” This paper examines the effects of understated capital costs and low and volatile CHP capacity factors, which historically are demonstrated by a large number of existing US units, on the economics of CHP facilities and thereby provide a possible explanation for the CHP gap. Given the probability distribution of profitability for a CHP plant, an incentive structure that is modeled similar to insurance against risk of unfavorable outcomes, might compare favorably to the present one-time upfront capital incentive model for attracting new investments. We recommend further research on assurance-based incentives for CHP projects.     

Expanding argon plasma interacting with lithium surface

In this thesis, the interaction between Ar Plasma and lithium is studied by Langmuir probe and Spectrometer. We have studied the effects of the applied discharge current, the gas flow rate, the magnetic field on emission spectrum, electron temperature and electron density. The experimental results show that spectrum intensity, electron temperature and electron density all increase with the increasing discharge current, gas flow rate or magnetic field when the other experimental conditions were fixed, and it is also found that the intensity of Li-670.78 nm increases slowly at first and then increases rapidly, at last, it tends to be stable figure at the beginning of experiment. What is more, spectrum of lithium (670.78 nm) is also detected at the first diagnostic window (viewing window).     

Distributed generation and demand response dispatch for a virtual power player energy and reserve provision

Recent changes in the operation and planning of power systems have been motivated by the introduction of Distributed Generation (DG) and Demand Response (DR) in the competitive electricity markets' environment, with deep concerns at the efficiency level. In this context, grid operators, market operators, utilities and consumers must adopt strategies and methods to take full advantage of demand response and distributed generation. This requires that all the involved players consider all the market opportunities, as the case of energy and reserve components of electricity markets.The present paper proposes a methodology which considers the joint dispatch of demand response and distributed generation in the context of a distribution network operated by a virtual power player. The resources' participation can be performed in both energy and reserve contexts. This methodology contemplates the probability of actually using the reserve and the distribution network constraints. Its application is illustrated in this paper using a 32-bus distribution network with 66 DG units and 218 consumers classified into 6 types of consumers.     

Experimental study on spiral flow passive solar water heater

This study presents the experimental analysis of spiral flow flat plate collector passive solar water heater. A solar water heater was fabricated with spiral shaped copper water tube fixed on the flat plate aluminium absorber plate. The experiments were conducted at Kovilpatti (9°10′ N, 77°52′ E), India, during summer. Variations in exit water temperature and efficiency of the system were studied for different mass flow rates. Around 2 pm, the system reached the maximum efficiency point. The maximum efficiency of the system was 65.98% at 0.015 kg/s mass flow with exit water temperature of 95°C when the ambient temperature was 36°C.     

Sustainability considerations of biodiesel based on supply chain analysis

Developing clean and renewable energy resources ranks as one of the greatest challenges facing mankind in the medium to long term. The issues associated with developing non-fossil energy are intimately connected with economic development and prosperity, quality of life and global stability, and require smart strategies for sustainable development. This study presents a relative sustainability assessment of biodiesel, taking into account its full life cycle with the main goal of comparing alternative feedstocks, either currently used or promising for future use such as microalgae. A set of sustainability metrics relevant for biodiesel is identified using only the data available in the literature and taking into account all the three dimensions of sustainability: environmental, societal, and economic. Although this study does not attempt to identify which feedstock or process is the best, its procedural suggestions may be valuable to practitioners and policy makers seeking to identify the best alternatives. The conclusions, however, are limited by the availability and the quality of the data used in the analyses.