Measurement system for long-term recording of wood moisture content with internal conductively glued electrodes

Moisture as an important influence factor on fungal growth needs to be considered for service life prediction of wood and wood-based products. Therefore, a long-term moisture measuring and data logging method for wood in weathered conditions was developed. The method is based on measuring the electrical resistance with glued electrodes for sustainable connection. The measuring point at the tip of the electrodes was glued conductively into the wood, the remaining outer part of the electrodes was glued with an isolating glue. For this purpose, special conductive and isolating glues and electrodes were developed and comparatively evaluated in laboratory tests. The most suitable system consisted of a 2k-epoxy resin, serving for the isolating glue and also as conductive glue (when mixed with graphite powder and ethanol) in combination with a partly isolated stainless steel cable, acting as both, electrode and cable. This system was further tested in combination with mobile mini data logger at 29 different exposure sites in Europe and the United States. After 4–6 years of natural weathering with many extreme climatic and moisture changes, no loosening or other detectable abnormality in 541 pairs of electrodes was observed. The data logging systems were working without any problems for 5 years with the first and only battery, and without any additional maintenance. For the calibration of the measuring system, resistance characteristics were determined for different provenances of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies Karst.), and Douglas fir (Pseudotsuga menziesii Franco).     

The cumulative power of incremental innovation and the role of project sequence management

In innovation and project management studies incremental development projects are perceived as theoreticlly and organisationally uninteresting. By means of a longitudinal study of product improvement projects at an automobile firm, this paper challenges such views and shows how the cumulative impact of the studied sequence resulted in a competitive repositioning of the company's product portfolio during a financially difficult period. Project managers achieved this by transcending the separation between exploration and exploitation projects; they not only adhered to time, cost and quality goals but also tried out new ways of testing and experimenting with controversial technical ideas. The paper analyzes the intensive inter project learning that generated these ambidextrous capabilities and emphasizes that practices at the project-level need to be buttressed by expanded management learning and capability development also at the sequence level.     

Long-run urban dynamics: understanding local housing market change in London

Abstract

Recently, a literature has emerged using empirical techniques to study the evolution of international cities over many centuries; however, few studies examine long-run change within cities. Conventional models and concepts are not always appropriate and data issues make long-run neighbourhood analysis particularly problematic. This paper addresses some of these points. First, it discusses why the analysis of long-run urban change is important for modern urban policy and considers the most important concepts. Second, it constructs a novel data set at the micro level, which allows consistent comparisons of London neighbourhoods in 1881 and 2001. Third, the paper models some of the key factors that affected long-run change, including the role of housing. There is evidence that the relative social positions of local urban areas persist over time but, nevertheless, at fine spatial scales, local areas still exhibit change, arising from aggregate population dynamics, from advances in technology, and also from the effects of shocks, such as wars. In general, where small areas are considered, long-run changes are likely to be greater, because individuals are more mobile over short than long distances. Finally, the paper considers the implications for policy.     

In Search of Public Sector–Private Sector Partnerships for Local Economic Development in South Africa

Partnerships between the public sector and private sector are considered to be important foundations for successful local economic development (LED) planning. This article analyses the multiple challenges that need to be addressed in forging viable LED partnerships between the public sector and private sector in South Africa. The findings are examined from a national survey conducted in 2009 with 30 business chamber associations across South Africa. The results point to markedly differing perceptions of the private sector and local government towards LED, questions of trust and mistrust between private sector and the public sector, and highlight the imperative for greater dialogue in order to provide the foundations for local partnerships for promoting LED.     

Geothermal use of an Alpine aquifer—Davos pilot study

Grundwasser - Topographically induced Alpine regional groundwater flow systems below the unconsolidated valley fillings constitute a substantial unused geothermal resource. Within the...     

Hydrodynamic damping of a magnetically oscillated cantilever close to a surface

We studied the frequency response of a magnetically driven atomic force microscope (AFM) cantilever close to a sample surface in liquids. Amplitude–frequency (tuning) curves showed pronounced differences in dependence on the tip–sample separation (from 1 to 50 μm), with significant shifts of the resonance peak. A model was developed in which the cantilever was described in a full shape manner and the hydrodynamic forces acting on the cantilever were approximately calculated. The slight inclination of the cantilever to the surface (15°) leads to a force profile along the cantilever. Therefore, the mathematical problem can be strictly solved only numerically. For an approximate analytical solution, the hydrodynamic force profile was approximated by a constant force along the cantilever for large separations and by a point force acting on the tip of the cantilever for small separations. The theoretical results calculated within this model agreed well with the experimental data and allowed to determine the cantilever mass in liquid M^*, the joint mass at the tip end m_t^*, and the coefficient of viscous interaction of the cantilever with free liquid, γ_∞.     

Comportement des acides amines dissous du milieu marin apres injection de chlore

Evidence that dissolved organic matter is one of the most significant sources of chlorine demand of seawaters (Fig. 1) used in cooling circuits is now well recognized. Nevertheless the specific role of the different kinds of compounds which form this organic material has seldom been studied and even less quantified; this is not surprising as less than 20% of the organic substances are identified. In this paper our objective was to define more quantitatively the effect of the dissolved free and combined amino-acids in the oxidant decay. Two main criteria justified the choice of these solutes:

1. (i)|the reactivity of chlorine and/or bromine towards amino groups;

2. (ii)|the role of these nitrogenous compounds in some biological mechanisms.

What happens to the halogen added and to the organic species during the first 20 min was investigated. The experimental conditions selected (concentrations, salinity, temperature and acidity) are those encountered in practice.The reactivity of the amino-acids towards chlorine is of course influenced by physicochemical properties such as the pH, but is particularly dependent upon the nature of the amino group. Whereas β and γ free amino-acids (Fig. 3) as also combined species (proteins) (Table 2) yield stable halogenocompounds like those produced with aliphatic amines (Fig. 2), α free amino-acids (COOH---CH---NH₂)|R on the other hand yield unstable haloamines which decompose rapidly (Fig. 4). Regarding these results, only the reactivity of the α compounds was afterwards studied as they are the largest fraction of the free amino-acids encountered in natural waters.After investigating the role of the side groups R in the kinetics and the efficiency of the consumption of the oxidant we examined, by liquid chromatography, the depletion of the nitrogenous species (Table 3). In each case the HPLC data relative to changes in the level of the organic compounds agree with those reported for the residual oxidant decay.A few experiments carried out on samples of seawater (Table 4) treated with 1 ppm of chlorine showed that around 5% of chlorine which dissipated during the first 3 min are consumed by the dissolved free amino-acids, the depletion of which is about 50%.     

Groundwater interaction in the coastal environment: hydrochemical,electrical and seismic approaches

The heterogeneous Plio-Quaternary coastal aquifer of the Mamora Basin is the most significant reservoir of Morocco. It is composed of sandstones, conglomerates, limestones and more or less argillaceous sands. The increase in the requirements for water in this area requires further information on the relations between the geometry of the aquifer and the salinity of the water. A hydrochemical analysis was undertaken and highlighted three zones of high mineralization. A geophysical approach allowed the determination of the principal aquifer levels, the localization of the various types of water (fresh, brackish and salt) and the geometry of the aquifer base. The results obtained by these two approaches provide a better image of the phenomena governing the groundwater flows and their interactions      

Studying sulfur functional groups in Norway spruce year rings using S L-edge total electron yield spectroscopy

Profiles of the major sulfur functional groups in mature Norway spruce wood tissue have been established for the first time. The big challenge was the development of a method suitable for sulfur speciation in samples with very low sulfur content (<100 ppm). This became possible by synchrotron X-ray absorption spectroscopy at the sulfur L-edge in total electron yield (TEY) detection mode with thin gold-coated wood slices. Functional groups were identified using sulfur compound spectra as fingerprints. Latewood of single year rings revealed metabolic plausible sulfur forms, particularly inorganic sulfide, organic disulfide, methylthiol, and highly oxidized sulfur. Form-specific profiles with Norway spruces from three different Swiss forest sites revealed high, but hitherto little-noticed, sulfur intensities attributable to natural heartwood formation and a common, but physiologically unexpected maximum around year ring 1986 with trees from the industrialized Swiss Plateau. It is hypothesized whether it may have resulted from the huge reduction in sulfur emissions after 1980 due to Swiss policy. Comparison with total S content profiles from optical emission spectroscopy underlined the more accurate and temporally better resolved TEY data with single wood year rings and it opened novel insights into the wood cell chemistry.     

AGORA剧院

Agora剧院是由Adriaan Geuze负责的莱利斯塔德中心城总体规划项目的一部分,旨在复兴这座冷清的城市,赋予其新的精神面貌。Agora剧院的设计通过关注剧院的根本功能——用各种技巧创造一个魔幻世界,来回应建筑本身承担的使命:战后荷兰城市的再生和复兴。建筑内外墙面层叠的多刻面表层由于打孔形成了一种万花筒般的世界舞台之效