“It’s Just a Matter of Adjustment”: Residents’ Perceptions and the Potential for Low-impact Home Practices

In addition to material, spatial and thermal standards and norms that influence the resource intensity of home environments, a key indicator of the environmental impact related to housing is found in residents’ ways of life. Of interest to the study presented in this paper is how residents’ perceptions of home and living standards relate to opinions on environmental issues and the reduction of resource use, exploring the potential and willingness to engage in low-impact ways of living. Empirical material from a questionnaire (n = 156) and interview study (n = 22) with residents in a tenant-owned housing association in Sweden provides insights into conventions and perceptions surrounding practices primarily linked to voluntary simplicity, living smaller as well as sharing spaces and resources. The study emphasizes the need for understanding residents’ perspectives and the implications this might have for targeting the resource intensity of homes in future development and policy.     

Creativity and Its Discontents: Professional Ideology and Creativity in Architect Work

Architects are a professional group that is commonly associated with creative and aesthetic work and with strong professional norms, values and identities. While such shared norms and beliefs are positive overall in terms of being constitutive of professional subject‐positions, an overemphasis on specific skills and qualities may also be regarded as a burden on members of the professional community. A study of a major Scandinavian architect office suggests that the perceived lack of creative and innovative thinking and accompanying dialogues and discussions among practising architects tends to produce cynicism and, to some extent, disappointment. As a consequence, professional ideologies may in some cases be out of joint with everyday work realities, and thereby to some extent produce expectations that are complicated to fulfil. Professional ideologies are thus both what integrates and consolidates a profession while at the same time prescribing ideal future scenarios for the professional community.     

Collaborative Information Seeking

An examination of the roles and dimensions of collaborative search reveals new opportunities for information-seeking support tools.     

Kinematics of the heart: strain-rate imaging from time-resolved three-dimensional phase contrast MRI

A four-dimensional mapping (three spatial dimensions + time) of myocardial strain-rate would help to describe the mechanical properties of the myocardium, which affect important physiological factors such as the pumping performance of the ventricles. Strain-rate represents the local instantaneous deformation of the myocardium and can be calculated from the spatial gradients of the velocity field. Strain-rate has previously been calculated using one-dimensional (ultrasound) or two-dimensional (2-D) magnetic resonance imaging) techniques. However, this assumes that myocardial motion only occurs in one direction or in one plane, respectively. This paper presents a method for calculation of the time-resolved three-dimensional (3-D) strain-rate tensor using velocity vector information in a 3-D spatial grid during the whole cardiac cycle. The strain-rate tensor provides full information of both magnitude and direction of the instantaneous deformation of the myocardium. A method for visualization of the full 3-D tensor is also suggested. The tensors are visualized using ellipsoids, which display the principal directions of strain-rate and the ratio between strain-rate magnitude in each direction. The presented method reveals the principal strain-rate directions without a priori knowledge of myocardial motion directions.     

Evaluations of the stability of sheathless electrospray ionization mass spectrometry emitters using electrochemical techniques

The processes that cause the failure of sheathless electrospray ionization (ESI) emitters, based on different kinds of gold coatings on fused-silica capillaries, are described and explained. The methods chosen for this study include electrochemical methods, ICPMS analysis of the electrolytes used, SEM studies, and electrospray experiments. Generally, the failure occurs by loss of the conductive coating. It is shown that emitters with sputter-coated gold lose their coatings because of mechanical stress caused by the gas evolution accompanying water oxidation or reduction. Emitters with gold coatings on top of adhesion layers of chromium and nickel alloy withstand this mechanical stress and have excellent durability when operating as cathodes. When operating as anodes, the adhesion layer is electrochemically dissolved through the gold film, and the gold film then flakes off. It is shown that the conductive coating behaves as a cathode even in the positive electrospray mode when the magnitude of a superimposed reductive electrophoretic current exceeds that of the oxidative electrospray current. Fairy-dust coatings developed in our laboratory (see Barnidge, D. R.; etal.Anal. Chem. 1999, 71, 4115-4118,) bygluing gold dust onto the emitter, are unaffected by the mechanical stress due to gas evolution. When oxidized, the fairy-dust coatings show an increased surface roughness and decreased conductivities due to the formation of gold oxide. The resistance of this oxide layer is however negligible in comparison with that of the gas phase in ESI. Furthermore, since no flaking and only negligible electrochemical etching of gold was found, practically unlimited emitter lifetimes may be achieved with fairy-dust coatings.     

Critical conditions for onset of mould growth under varying climate conditions

A performance-based service life design format based on climatic exposure on one hand and “resistance” of materials against mould growth on the other hand, is presented in this paper. A limit state for onset of mould growth is defined as the occurrence of traces of mould observed by microscopy. A dose–response model is proposed by which onset of mould growth can be predicted for an arbitrary climate history of combined relative humidity ? and temperature T. The model is calibrated and verified against a comprehensive set of experimental data published by Viitanen et al. [Viitanen H, Ritschkoff A-C. Mould growth in pine and spruce sapwood in relation to air humidity and temperature. Uppsala: Swedish University of Agricultural Sciences, Department of Forest Products; 1991. Report No. 221, 49 p.; Viitanen H. Modelling the time factor in the development of mould fungi – effect of critical humidity and temperature conditions in pine and spruce sapwood. Holzforschung 1997;51(1):6–14; Viitanen H. Modelling the time factor in the development of brown rot decay in pine and spruce sapwood – the effect of critical humidity and temperature conditions. Holzforschung 1997;51(2):99–106; Viitanen H, Bjurman J. Mould growth on wood under fluctuating humidity conditions. Material und Organismen 1995;29(1):27–46] describing mould development on spruce and pine sapwood as a function of climatic exposure. The model is applied to predict time to onset of mould growth under natural outdoor climate (under shelter) as well as mould development in building attics and in crawl space foundations. The predicted response shows reasonable agreement with experimental observations and proven experience, although biological processes of this type display great variability. The results show that a generally applicable, quantitative model can be used as a powerful tool for moisture safe design in practice. The model is designed to facilitate continuous improvement of prediction capability by further laboratory testing of various materials under specified climate conditions. In combination with currently available building physics software the model is suitable for moisture safe design of wood-based components in the building envelope.     

Exergy analysis of chemical-looping combustion systems

A power plant based on chemical-looping combustion offers both a possibility of high net power efficiency and separation of the greenhouse gas CO₂. This is due to the way the oxidation of the fuel takes place. Instead of oxidizing the fuel with oxygen from the combustion air, the fuel is oxidized by an oxygen carrier, i.e., an oxygen-containing compound. The oxygen carriers that have been suggested in previous studies are metal oxides like NiO, Fe₂O₃ and Mn₃O₄. The reduced oxygen carrier is in the next step reoxidized by air in a second reactor and then recirculated to the first reactor. In this way, fuel and air are never mixed and the fuel oxidation products CO₂ and water leave the system undiluted by air. All that is needed to get an almost pure CO₂ product is to condense the water vapour and remove the liquid water.Chemical-looping combustion (CLC) is also claimed to reduce the fuel exergy destruction in the overall reaction of combustion of the fuel. This gives a possibility to increase the net power efficiency.This paper gives an introduction to chemical-looping combustion. Results from simulations and a detailed exergy analysis of two different CLC gas turbine (GT) systems are also presented. The first system utilizes methane as a fuel and NiO as oxygen carrier. The second system utilizes a fuel gas mixture consisting mainly of CO and H₂, simulating a fuel gas from for instance coal gasification. Results for this system are given for simulations with both NiO and Fe₂O₃ as oxygen carrier. The two systems are compared to comparable simulated systems with conventional combustion of the same fuel. The exergy analysis shows that the irreversibilities generated upon combustion of the fuel are reduced. The net power efficiency of the CLC–GT systems is similar or higher than for the corresponding GT systems with conventional combustion. The net power efficiency of CLC systems could be even further increased if the exergy remaining in the exhaust could be utilized in an efficient way.     

Hydrogen permeability through rhenium and an Mo-Re alloy with and without chemically vapor-deposited tungsten coatings

The rate of silicon regrowth via transport of silicon through an overlying aluminum or aluminum alloy metallization at 500°C was studied as a function of doping level and grain size of the silicon and metal alloy composition, It is shown that the regrowth rate was significantly reduced or eliminated by (1) heavy phosphorus or nitrogen doping, (2) increasing the silicon grain size by laser annealing or (3) the use of an Al-Cu alloy for metallization. Conversely, the rate was found to be greater for Al-Si in comparison with Al-Cu or aluminum. These results are consistent with a model involving a nucleation step at the silicon-metal film interface and silicon transport through the grain boundaries of both films.     

Constitutive expression of the Wilms'' tumor gene (WT1) in the leukemic cell line U937 blocks parts of the differentiation program

OBJECTIVE: To characterize relationships among blood pressure, pulse rate, vitamin C status and other protective and risk factors for older British people, from a national survey. DESIGN: A cross-sectional analysis of survey data. SETTING: A population study, representative of mainland Britain. SUBJECTS: Among 914 people of both sexes living in the community, 373 were taking blood-pressure-lowering drugs and were therefore excluded from the analyses. INTERVENTIONS: Completion of an interview on health, lifestyle and dietary habits, recording of a 4-day dietary record, anthropometry and taking of a blood sample to determine haematological and biochemical status. MAIN OUTCOME MEASURES: Systolic and diastolic blood pressures, pulse rate, indices of micronutrient status including plasma ascorbate concentration, nutrient intake and haematology. RESULTS: Plasma ascorbate concentration was inversely correlated to systolic and diastolic blood pressures and pulse rate. Other covariates of blood pressure included age, sex, domicile, plasma retinol, fibrinogen and gamma-tocopherol concentrations, erythrocyte count, prothrombin time and urine sodium: creatinine ratio. Covariates of pulse rate included sex, domicile, plasma fibrinogen and platelet count. Blood pressure was also correlated to intake of vitamin C. CONCLUSIONS: Plasma ascorbate concentration and intake of vitamin C are covariates of blood pressure in older people living in Britain. New intervention studies are now needed, to test for possible causalities.     

Preparation of thermoset composites from natural fibres and acrylate modified soybean oil resins

Structural composites with a high content of renewable material were produced from natural fibres and an acrylated epoxidized soybean oil resin. Composites were prepared by spray impregnation followed by compression moulding at elevated temperature. The resulting composites had good mechanical properties in terms of tensile strength and flexural strength. Tensile testing as well as dynamical mechanical thermal analysis showed that increasing the fibre content, increased the mechanical properties. The resin can be reinforced with up to 70 wt % fibre without sacrifice in processability. The tensile modulus ranged between 5.8 and 9.7 GPa depending on the type of fibre mat. The study of the adhesion by low vacuum scanning electron microscopy shows that the fibres are well impregnated in the matrix. The aging properties were finally evaluated. This study shows that composites with a very high content of renewable constituents can be produced from soy bean oil resins and natural fibres. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009