Building performance assessment of user behaviour as a post occupancy evaluation indicator: Case study on youth housing in Egypt

Youth housing prototypes are widely spread all over Egypt as a cheap economic housing for youth which are designed in a number of different shapes. A post occupancy evaluation (POE) has been conducted to one of these prototypes to assess some modifications spontaneously done by users to the original design for the sake of enhancing building performance, e.g., creating new openings to improve lighting and natural ventilation thermal comfort, and making sunshades to control direct sunlight and thermal radiation. These assessments have been validated using simulation techniques i.e. CFD, thermal and daylight simulations, to compare natural ventilation, thermal comfort, and daylight energy efficiency in the original designs to that in the user modified. A wind tunnel test has been conducted to validate the standard k–epsilon turbulence CFD simulation in addition to daylighting in-situ measurements to validate natural lighting. The outcome of this research could be widely used as an important feedback tool in the future designs of the same prototype to evaluate user behaviour role in building performance efficiency. The research showed that some of these behaviours has improved thermal comfort by 60% to 87% from the original design while daylight efficiency has been improved by 31.8% to 41.4% while sensible cooling loads’ improvement ranges from 27.4% to 77.2% for the northern zone and 29.9% to 91.6% for the southern one, and thus, it could be used as a reliable POE feedback tool.     

Improving Design Coordination for Building Projects. I: Information Model

Detailed design of building projects is a complex multidisciplinary process highly dependent upon effective aggregation of individual designs to produce a coherent set of final design documents. Throughout the detailed design process, changes are frequently introduced and need to be properly managed among the various members of the design team. This paper presents an information model for storing design information, recording design rationale, and managing design changes. The proposed model is built around a central library of generalized building components that can be used to describe a complete building project hierarchy. Each component allows the designer to store desired performance criteria and related design rationale. Each component is also sensitive to its own changes and automatically communicates such changes to affected parties through preset communication paths. The model, as such, provides improved design coordination and control over changes, thus helping to increase the consistency and productivity of the overall design process. Conceptual details of the model are described in this paper, and model implementation into a collaborative design system is presented in a companion paper.     

French Abstract

The main contribution of this study to the understanding of agenda-setting and priming effects is its focus on the role of evaluative tone in all stages of the agenda setting/priming process. First, the public's evaluation of issue importance, which is the dependent variable in most agenda-setting studies, is influenced by the issue saliency in the news and by the evaluative tone of media coverage (positive, negative, or neutral). This evaluative tone or affective attribute attached to the issue is part of the second-level agenda setting. Second, these affective attributes that people attach to issues further play an important role in the process of priming, on which they have both indirect and direct impacts. Priming, therefore, carries with it an affective component: It is a combination of message strength and direction. Third, the political judgments of individuals are also directly influenced by media-affective attributes. All of the arguments are supported by the empirical analyses.     

Improved Algorithms for Some Competitive Location Centroid Problems on Paths, Trees and Graphs

We consider a common scenario in competitive location, where two competitors (providers) place their facilities (servers) on a network, and the users, which are modeled by the nodes of the network, can choose between the providers. We assume that each user has an inelastic demand, specified by a positive real weight. A user is fully served by a closest facility. The benefit (gain) of a competitor is his market share, i.e., the total weight (demand) of the users served at his facilities. In our scenario the two providers, called the leader and the follower, sequentially place p and r servers, respectively. After the leader selects the locations for his p servers, the follower will determine the optimal locations for his r servers, that maximize his benefit. An (r,p)-centroid is a set of locations for the p servers of the leader, that will minimize the maximum gain of the follower who can establish r servers. In this paper we focus mainly on the cases where either the leader or the follower can establish only one facility, i.e., either p=1, or r=1. We consider two versions of the model. In the discrete case the facilities can be established only at the nodes, while in the absolute case they can be established anywhere on the network. For the (r,1)-centroid problem, we show that it is strongly NP-hard for a general graph, but can be approximated within a factor e/(e?1). On the other hand, when the graph is a tree, we provide strongly polynomial algorithms for the (r,p)-centroid model, whenever p is fixed. For the (1,1)-centroid problem on a general graph, we improve upon known results, and give the first strongly polynomial algorithm. The discrete (1,p)-centroid problem has been known to be NP-hard even for a subclass of series-parallel graphs with pathwidth bounded by 6. In view of this result, we consider the discrete and absolute (1,p) centroid models on a tree, and present the first strongly polynomial algorithms. Further improvements are shown when the tree is a path.     

Influence of copper nanoparticles capped by cationic surfactant as modifier for steel anti-corrosion paints

The synthesized cationic surfactant N-(2-(2-mercaptoacetoxy) ethyl)-N,N-dimethyldodecan-1-aminium bromide (QSH) was used to prepare colloidal copper nanoparticles (CuNPs) in water through the chemical reduction method. The obtained copper nanoparticles were characterized by FTIR spectrum and transmission electron microscopy (TEM). The corrosion performance was evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements in addition to the salt spray test. The results obtained from these methods were in good agreement. Results showed that the modified coating provide a good coverage and an additional corrosion protection of the carbon steel.     

Genetically engineered pfabA pfabR bacteria: an electrochemical whole cell biosensor for detection of water toxicity

We describe here a bacterial sensor for electrochemical detection of toxic chemicals. The sensor constitutes recombinant bacteria harboring plasmids encoding the fabA and fabR genes and has high-resolution amperometric response to membrane-damaging chemicals. For example, it can detect phenol at concentrations ranging between 1.6 and 16 ppm within 20 min. The high sensitivity is achieved by using the fabA promoter fused to a reporter gene-encoded beta-galactosidase on a low copy number plasmid, under the control of the FabR repressor. The use of electrochemical whole cell sensors enables sensitive, fast, easy to operate, and cost-effective detection of water toxicity threats.     

Nanoparticle PEBBLE sensors for quantitative nanomolar imaging of intracellular free calcium ions

Ca(2+) is a universal second messenger and plays a major role in intracellular signaling, metabolism, and a wide range of cellular processes. To date, one of the most successful approaches for intracellular Ca(2+) measurement involves the introduction of optically sensitive Ca(2+) indicators into living cells, combined with digital imaging microscopy. However, the use of free Ca(2+) indicators for intracellular sensing and imaging has several limitations, such as nonratiometric measurement for the most-sensitive indicators, cytotoxicity of the indicators, interference from nonspecific binding caused by cellular biomacromolecules, challenging calibration, and unwanted sequestration of the indicator molecules. These problems are minimized when the Ca(2+) indicators are encapsulated inside porous and inert polyacrylamide nanoparticles. We present PEBBLE nanosensors encapsulated with rhodamine-based Ca(2+) fluorescence indicators. The rhod-2-containing PEBBLEs presented here show a stable sensing range at near-neutral pH (pH 6-9). Because of the protection of the PEBBLE matrix, the interference of protein-nonspecific binding to the indicator is minimal. The rhod-2 PEBBLEs give a nanomolar dynamic sensing range for both in-solution (K(d) = 478 nM) and intracellular (K(d) = 293 nM) measurements. These nanosensors are useful quantitative tools for the measurement and imaging of the cytosolic nanomolar free Ca(2+) levels.     

Fundamental absorption edge of semiconductor alloys with the direct-gap energy-band structure

A procedure convenient for practical application to the calculations of the fundamental absorption spectra of semiconductor alloys with the direct-gap energy-band structure is developed. The procedure is based on the knowledge of the fundamental absorption spectra of binary constituents of the alloy, takes into account the nonparabolic structure of the conduction band, and involves only one adjustable parameter that characterizes the inhomogeneous broadening of the spectra. The procedure is tested by the examples of the best-studied and practically most important Al _x Ga_{1 − x} As alloys, the (Al _x Ga_{1 − x} )_0.5In_0.5P alloys isostructural to GaAs, and the Ga _x In_{1 − x} As alloys isostructural to InP. The procedure can be used in the case of other III–V and II–VI compounds. The results make it possible to calculate the intrinsic luminescence spectra of the alloys.