Peter V. Nielsen

Knowledge management and innovation performance

Purpose - The purpose of this paper is to show why the establishment of “learning organisations” must be a central element of knowledge management – especially in firms operating on markets where product innovation is an important parameter of competition. Design/methodology/approach - The argument straddles and combines insights related to management and organisation theory with an evolutionary economic analysis of the relationship between innovation, learning and knowledge. It is supported by an empirical analysis of survey data on Danish private sector firms. The survey was addressed to all firms in the private urban sector with 25 or more employees, supplemented with a stratified proportional sample of firms with 20-25 employees. Findings - The analysis shows that firms that introduce several organisational practices, assumed to characterise the learning organisation, are more innovative than the average firm. Research limitations/implications - The empirical findings are limited to the private sector and do not cover public sector organisations. Practical implications - The learning organisation characteristics have a positive impact on dynamic performance and there are obviously lessons to be learned from the successful firms operating in turbulent environments that introduce specific organisational characteristics such as job rotation, inter-divisional teams, delegation of responsibility and reducing the number of levels in the organisational hierarchy. Originality/value - The paper puts “knowledge management” into the wider concept of “learning economy” and shows how a key element of knowledge management is to enhance the learning capacity of the firm.

Thermoanaerobacter mathranii sp. nov., an ethanol-producing, extremely thermophilic anaerobic bacterium from a hot spring in Iceland

Abstract The extremely thermophilic ethanol-producing strain A3 was isolated from a hot spring in Iceland. The cells were rod-shaped, motile, and had terminal spores; cells from the mid-to-late exponential growth phase stained gram-variable but had a gram-positive cell wall structure when viewed by transmission electron microscopy. Strain A3 used a number of carbohydrates as carbon sources, including xylan, but did not utilize microcrystalline cellulose. Fermentation end products were ethanol, acetate, lactate, CO2, and H2. The temperature optimum for growth was between 70 and 75° C, and growth occurred in the range of 50–75° C. The pH range for growth was 4.7–8.8, with an optimum at pH 7.0. Strain A3 was sensitive to tetracycline, chloramphenicol, penicillin G, neomycin, and vancomycin at 100 mg/l but was not sensitive to chloramphenicol and neomycin at 10 mg/l, which indicates that strain A3 belongs to the eubacteria. Addition of 50.66 kPa H2 or 2% NaCl did not affect growth. The isolate grew in the presence of exogenously added 4% (w/v) ethanol. The G+C ratio was 37 mol%. 16S rDNA studies revealed that strain A3 belongs to the genus Thermoanaerobacter. Genotypic and phenotypic differences between strain A3 and other related species indicate that strain A3 can be assigned to a new species, and the name Thermoanaerobacter mathranii is proposed.

Characteristics of Airflow from Open Windows

Abstract In natural ventilation systems fresh air is often provided through opening of windows. However, the knowledge of the performance of windows is rather limited, especially with regard to their impact on thermal comfort and draught risk in the occupied zone. This paper describes and summarizes the results of a series of laboratory measurements that is performed on two different window types to determine the characteristics of the air flow in rooms. It is shown that the air flow can be described by traditional theory for jets and stratified flow and semi-empirical flow element models are developed for estimation of thermal comfort parameters in the occupied zone.

BUOYANCY-AFFECTED FLOWS IN VENTILATED ROOMS

Calculations of velocity and temperature distributions in rooms with ventilation arrangements are reported. The method involves the solution, in finite-difference form, of two-dimensional equations for the conservation of mass, momentum, energy, turbulence energy, and dissipation rate, with algebraic expressions for the turbulent viscosity and heat diffusivity. The results are shown to be in reasonable agreement with available experimental data and the method is then applied to provide additional information useful for design purposes.

CFD and Ventilation Research

UNLABELLED There has been a rapid growth of scientific literature on the application of computational fluid dynamics (CFD) in the research of ventilation and indoor air science. With a 1000-10,000 times increase in computer hardware capability in the past 20 years, CFD has become an integral part of scientific research and engineering development of complex air distribution and ventilation systems in buildings. This review discusses the major and specific challenges of CFD in terms of turbulence modelling, numerical approximation, and boundary conditions relevant to building ventilation. We emphasize the growing need for CFD verification and validation, suggest ongoing needs for analytical and experimental methods to support the numerical solutions, and discuss the growing capacity of CFD in opening up new research areas. We suggest that CFD has not become a replacement for experiment and theoretical analysis in ventilation research, rather it has become an increasingly important partner. PRACTICAL IMPLICATIONS We believe that an effective scientific approach for ventilation studies is still to combine experiments, theory, and CFD. We argue that CFD verification and validation are becoming more crucial than ever as more complex ventilation problems are solved. It is anticipated that ventilation problems at the city scale will be tackled by CFD in the next 10 years.

The Flow Properties of Rooms With Small Ventilation Openings

Measured and calculated properties relevant to the flow in ventilated rooms are reported. The measurements were obtained by laser-Doppler anemometry in a small-scale model room with a single square inlet. The calculations made use of a numerical procedure which solves, in finite-difference form, the elliptic partial-differential equations for three components of velocity, the pressure, the turbulence energy and its dissipation rate. Calculated results are shown to be in close agreement with the present measurements and with other available experimental data. With this justification, the procedure is used to quantify the dependence of the velocity characteristics of different geometric arrangements. The results provide guide lines for the design of ventilation systems.

Control of airborne infectious diseases in ventilated spaces.

We protect ourselves from airborne cross-infection in the indoor environment by supplying fresh air to a room by natural or mechanical ventilation. The air is distributed in the room according to different principles: mixing ventilation, displacement ventilation, etc. A large amount of air is supplied to the room to ensure a dilution of airborne infection. Analyses of the flow in the room show that there are a number of parameters that play an important role in minimizing airborne cross-infection. The air flow rate to the room must be high, and the air distribution pattern can be designed to have high ventilation effectiveness. Furthermore, personalized ventilation may reduce the risk of cross-infection, and in some cases, it can also reduce the source of infection. Personalized ventilation can especially be used in hospital wards, aircraft cabins and, in general, where people are in fixed positions.

Observing and quantifying airflows in the infection control of aerosol- and airborne-transmitted diseases: an overview of approaches.

Summary With concerns about the potential for the aerosol and airborne transmission of infectious agents, particularly influenza, more attention is being focused on the effectiveness of infection control procedures to prevent hospital-acquired infections by this route. More recently a number of different techniques have been applied to examine the temporal–spatial information about the airflow patterns and the movement of related, suspended material within this air in a hospital setting. Closer collaboration with engineers has allowed clinical microbiologists, virologists and infection control teams to assess the effectiveness of hospital isolation and ventilation facilities. The characteristics of human respiratory activities have also been investigated using some familiar engineering techniques. Such studies aim to enhance the effectiveness of such preventive measures and have included experiments with human-like mannequins using various tracer gas/particle techniques, real human volunteers with real-time non-invasive Schlieren imaging, numerical modelling using computational fluid dynamics, and small scale physical analogues with water. This article outlines each of these techniques in a non-technical manner, suitable for a clinical readership without specialist airflow or engineering knowledge.

Distribution of exhaled contaminants and personal exposure in a room using three different air distribution strategies

UNLABELLED The level of exposure to human exhaled contaminants in a room depends not only on the air distribution system but also on peoples different positions, the distance between them, peoples activity level and height, direction of exhalation, and the surrounding temperature and temperature gradient. Human exhalation is studied in detail for different distribution systems: displacement and mixing ventilation as well as a system without mechanical ventilation. Two thermal manikins breathing through the mouth are used to simulate the exposure to human exhaled contaminants. The position and distance between the manikins are changed to study the influence on the level of exposure. The results show that the air exhaled by a manikin flows a longer distance with a higher concentration in case of displacement ventilation than in the other two cases, indicating a significant exposure to the contaminants for one person positioned in front of another. However, in all three cases, the exhalation flow of the source penetrates the thermal plume, causing an increase in the concentration of contaminants in front of the target person. The results are significantly dependent on the distance and position between the two manikins in all three cases. PRACTICAL IMPLICATIONS Indoor environments are susceptible to contaminant exposure, as contaminants can easily spread in the air. Human breathing is one of the most important biological contaminant sources, as the exhaled air can contain different pathogens such as viruses and bacteria. This paper addresses the human exhalation flow and its behavior in connection with different ventilation strategies, as well as the interaction between two people in a room. This is a key factor for studying the airborne infection risk when the room is occupied by several persons. The paper only takes into account the airborne part of the infection risk.

Impact of organisational change on mental health: a systematic review

Although limited evidence is available, organisational change is often cited as the cause of mental health problems. This paper provides an overview of the current literature regarding the impact of organisational change on mental health. A systematic search in PUBMED, PsychInfo and Web of Knowledge combining MeSH search terms for exposure and outcome. The criterion for inclusion was original data on exposure to organisational change with mental health problems as outcome. Both cross-sectional and longitudinal studies were included. We found in 11 out of 17 studies, an association between organisational change and elevated risk of mental health problems was observed, with a less provident association in the longitudinal studies. Based on the current research, this review cannot provide sufficient evidence of an association between organisational change and elevated risk of mental health problems. More studies of long-term effects are required including relevant analyses of confounders.