Improving daylighting performance of mirrored light pipes

This paper assesses and compares the performances of two daylight collection strategies, one passive and one active, for large-scale mirrored light pipes (MLP) illuminating deep plan buildings. Both strategies use laser cut panels (LCP) as the main component of the collection system. The passive system comprises LCPs in pyramid form, whereas the active system uses a tiled LCP on a simple rotation mechanism that rotates 360° in 24 hours. Performance is assessed using scale model testing under sunny sky conditions and mathematical modelling. Results show average illuminance levels for the pyramid LCP ranging from 50 to 250 lux and 150 to 200 lux for the rotating LCPs. Both systems improve the performance of a MLP. The pyramid LCP increases the performance of a MLP by 2.5 times and the rotating LCP by 5 times, when compared to an open pipe particularly for low sun elevation angles.

Optimization of microcavity OLED by varying the thickness of multi-layered mirror

We optimized the emission efficiency from a microcavity OLEDs consisting of widely used organic materials, N,N'-di(naphthalene-1-yl)-N,N'-diphenylbenzidine (NPB) as a hole transport layer and tris (8-hydroxyquinoline) (Alq(3)) as emitting and electron transporting layer. LiF/Al was considered as a cathode, while metallic Ag anode was used. TiO2 and Al2O3 layers were stacked on top of the cathode to alter the properties of the top mirror. The electroluminescence emission spectra, electric field distribution inside the device, carrier density, recombination rate and exciton density were calculated as a function of the position of the emission layer. The results show that for certain TiO2 and Al2O3 layer thicknesses, light output is enhanced as a result of the increase in both the reflectance and transmittance of the top mirror. Once the optimum structure has been determined, the microcavity OLED devices can be fabricated and characterized, and comparisons between experiments and theory can be made.

Some reflections about P2M : the place of the mirror

The purpose of this paper is to provide some insights about P2M, and more specifically, to develop some thoughts about Project Management seen as a Mirror, a place for reflection…, between the Mission of organisation and its actual creation of Values (with s: a source of value for people, organisations and society). This place is the realm of complexity, of interactions between multiple variables, each of them having a specific time horizon and occupying a specific place, playing a specific role. Before developing this paper I would like to borrow to my colleague and friend, Professor Ohara, the following, part of a paper going to be presented at IPMA World Congress, in New Delhi later this year in November 2005. “P2M is the Japanese version of project & program management, which is the first standard guide for education and certification developed in 2001. A specific finding of P2M is characterized by “mission driven management of projects” or a program which harness complexity of problem solving observed in the interface between technical system and business model.” (Ohara, 2005, IPMA Conference, New Delhi) “The term of “mission” is a key word in the field of corporate strategy, where it expresses raison d’être or “value of business”. It is more specifically used for expressing “the client needs” in terms of a strategic business unit. The concept of mission is deemed to be a useful tool to share essential content of value and needs in message for complex project.” (Ohara, 2005, IPMA Conference, New Delhi) “Mission is considered as a significant “metamodel representation” by several reasons. First, it represents multiple values for aspiration. The central objective of mission initiative is profiling of ideality in the future from reality, which all stakeholders are glad to accept and share. Second, it shall be within a stretch of efforts, and not beyond or outside of the realization. Though it looks like unique, it has to depict a solid foundation. The pragmatic sense of equilibrium between innovation and adaptation is required for the mission. Third, it shall imply a rough sketch for solution to critical issues for problems in reality.” (Ohara, 2005, IPMA Conference, New Delhi) “Project modeling” idea has been introduced in P2M program management. A package of three project models of “scheme”, “system” and “service” are given as a reference type program. (Ohara, 2005, IPMA Conference, New Delhi) If these quotes apply to P2M, they are fully congruent with the results of the research undertaken and the resulting meta-model & meta-method developed by the CIMAP, ESC Lille Research Centre in Project & Program Management, since the 80’s. The paper starts by questioning the common Project Management (PM) paradigm. Then discussing the concept of Project, it argues that an alternative epistemological position should be taken to capture Page 2 / 11 the very nature of the PM field. Based on this, a development about “the need of modelling to understand” is proposed grounded on two theoretical roots. This leads to the conclusion that, in order to enables this modelling, a standard approach is necessary, but should be understood under the perspective of the Theory of Convention in order to facilitate a situational and contextual application.

Size evolution and optical properties of self-assembled InAs quantum dots on different matrix

InAs quantum dots have been grown by solid source molecular beam epitaxy on different matrix to investigate the effect on the structure and optical properties. High density of 1.02 x 10(11) cm(-2) of InAs islands on In0.15Ga0.85As and In0.15Al0.85As underlying layer has been achieved. Atomic force microscopy and photoluminescence spectra show the size evolution of InAs islands on In0.15Ga0.85As underlying layer. A strong 1.3 mum photoluminescence from InAs islands on In0.15Ga0.85As underlying layer and with InGaAs strain-reduced layer has been obtained. Single-mirror light emitting diode structures with InAs quantum dots capped by InGaAs grown on InGaAs layer as active layer were fabricated and the corresponding radiative efficiency was deduced to be as high as 20.5%. Our results provide important information for optimizing the epitaxial structures of 1.3 mum wavelength quantum dots devices. (C) 2003 Elsevier B.V. All rights reserved.

Entanglement detection in hybrid optomechanical systems

We study a device formed by a Bose-Einstein condensate (BEC) coupled to the field of a cavity with a moving end mirror and find a working point such that the mirror-light entanglement is reproduced by the BEC-light quantum correlations. This provides an experimentally viable tool for inferring mirror-light entanglement with only a limited set of assumptions. We prove the existence of tripartite entanglement in the hybrid device, persisting up to temperatures of a few milli-Kelvin, and discuss a scheme to detect it.

Electronic Business Contracts between Services

Electronic contracts mirror the paper versions exchanged between businesses today, and offer the possibility of dynamic, automatic creation and enforcement of restrictions and compulsions on service behaviour that are designed to ensure business objectives are met. Where there are many contracts within a particular application, it can be difficult to determine whether the system can reliably fulfil them all, yet computer-parsable electronic contracts may allow such verification to be automated. In this chapter, we describe a conceptual framework and architecture specification in which normative business contracts can be electronically represented, verified, established, renewed, and so on. In particular, we aim to allow systems containing multiple contracts to be checked for conflicts and violations of business objectives. We illustrate the framework and architecture with an aerospace aftermarket example.

Characterizing Physical Properties of Wetting Paper by Air Coupled Ultrasound and Light

This thesis reports investigations into the paper wetting process and its effects on the surface roughness and the out-of-plane (ZD) stiffness of machine-made paper. The aim of this work was to test the feasibility of employing air-borne ultrasound methods to determine surface roughness (by reflection) and ZD stiffness (by through transmission) of paper during penetration of distilled water, isopropanol and their mixtures. Air-borne ultrasound provides a non-contacting way to evaluate sample structure and mechanics during the liquid penetration event. Contrary to liquid immersion techniques, an air-borne measurement allows studying partial wetting of paper. In addition, two optical methods were developed to reveal the liquid location in paper during wetting. The laser light through transmission method was developed to monitor the liquid location in partially wetted paper. The white light reflection method was primarily used to monitor the penetration of the liquid front in the thickness direction. In the latter experiment the paper was fully wetted. The main results of the thesis were: 1) Liquid penetration induced surface roughening was quantified by monitoring the ultrasound reflection from the paper surface. 2) Liquid penetration induced stiffness alteration in the ZD of paper could be followed by measuring the change in the ultrasound ZD resonance in paper. 3) Through transmitted light revealed the liquid location in the partially wetted paper. 4) Liquid movement in the ZD of the paper could be observed by light reflection. The results imply that the presented ultrasonic means can without contact measure the alteration of paper roughness and stiffness during liquid transport. These methods can help avoiding over engineering the paper which reduces raw material and energy consumption in paper manufacturing. The presented optical means can estimate paper specific wetting properties, such as liquid penetration speed, transport mechanisms and liquid location within the paper structure. In process monitoring, these methods allow process tuning and manufacturing of paper with engineered liquid transport characteristics. With such knowledge the paper behaviour during printing can be predicted. These findings provide new methods for paper printing, surface sizing, and paper coating research.

Stray light analysis of SALEX instrument

Discrepancies between recent global earth albedo anomaly data obtained from the climate models, space and ground observations call for a new and better earth reflectance measurement technique. The SALEX (Space Ashen Light Explorer) instrument is a space-based visible and IR instrument for precise estimation of the global earth albedo by measuring the ashen light reflected off the shadowy side of the Moon from the low earth orbit. The instrument consists of a conventional 2-mirror telescope, a pair of a 3-mirror visible imager and an IR bolometer. The performance of this unique multi-channel optical system is sensitive to the stray light contamination due to the complex optical train incorporating several reflecting and refracting elements, associated mounts and the payload mechanical enclosure. This could be further aggravated by the very bright and extended observation target (i.e. the Moon). In this paper, we report the details of extensive stray light analysis including ghosts and cross-talks, leading to the optimum set of stray light precautions for the highest signal-to-noise ratio attainable.