Swedish Defence Research Agency

About: Swedish Defence Research Agency is a government organization based out in Stockholm, Sweden. It is known for research contribution in the topics: Radar & Synthetic aperture radar. The organization has 1413 authors who have published 2731 publications receiving 56083 citations. The organization is also known as: Totalförsvarets forskningsinstitut.

Methodologies for assessment of limit of detection and limit of identification using surface-enhanced Raman spectroscopy

Abstract: Here we rationally evaluate surface-enhanced Raman spectroscopy (SERS) substrates in terms of limit of detection (LOD), limit of identification (LOI) and dynamic range for ten common narcotic drug analytes. The drugs were amphetamine, cocaine, methadone, diazepam, methylphenidate, oxazepam, tramadol, morphine, buprenorphine and 6-monoacetylmorphine. A Raman microscope system was complemented with portable instrumentation, both in conjunction with commercial SERS substrates, and, by vibrational peak assignments, the functionality of substrates and pureness of samples was ensured. The dynamic range is explored qualitatively by concentration series measurements, where the Langmuir adsorption isotherm provided good fits. Moreover, an output fit parameter, the inverse of Langmuir constant, was found to roughly scale with LOD and can therefore be helpful in SERS substrate evaluations. Four different statistical methodologies were tested to estimate LOD: (i) a general formula to calculate a one-sided prediction interval for the mean value of blanks (LOD B ), (ii–iii) calculated from a one-sided prediction interval (at significance level 0.05) of a linear regression line, where the obtained limit of detection in the signal domain was sometimes outside the linear concentration range, which is why the corresponding concentration was calculated from (ii) a linear calibration curve (LOD LR ) and (iii) a non-linear calibration curve (LOD NR ), and (iv) using receiver operating characteristic (ROC) curves to estimate LOD ROC . Here, a new optimization approach was introduced for LOD ROC estimation, based on interpolation and thus better suited to handle a few data points spanning a large concentration range. LOI was assessed by discriminant analysis of partial least squares (PLS-DA) classification for seven of the drug compounds using PLS-DA, and the extracted LOIs were found to be higher than the LODs and were varying with respect to accuracy of the model which is strongly correlated to the probability of false positive detection that can be accepted.

Design of Vortex Generator Flow Control in Inlets

Abstract: This article summarizes the results of an optimization study of a microvortex generator flow control in an inlet. Five parameters optimization was carried out using the classical design of experiment method. Two main objectives were in focus: first, to develop the methodology and skills necessary to conduct a design of experiment optimization study in area of the flow control; and second, to develop the procedures which would be used during design of vortex generator flow control in inlets. New information about the dependency of the vortex generator flow control in inlet on its geometrical parameters were obtained. Several interesting configurations were located. The parameters of optimal settings were then used to set up the vortex generator installation in a generic inlet.

A Framework for Vulnerability Assessment of Electric Power Systems

Abstract: The infrastructure of a society consists of facilities such as communications, power supplies, transportation, water supplies, and the stock of buildings. In a broad definition of infrastructure, it is also possible to include basic societal functions like education, national defense, and financial and judicial systems. Here, the notion critical infrastructure will refer to the collection of large technical systems, for example electric power grids, which form the basis for most activities in a modern society, and are of great importance for the economic prosperity. Today, critical infrastructure protection is also considered to be a matter of national security.1

Reacting flow in an industrial gas turbine combustor: LES and experimental analysis

Abstract: In this investigation the physics of the reacting swirling flow of a commercial industrial gas turbine burner (SGT-100) was researched using combustion Large Eddy Simulation (LES) and experiments. In the experimental studies the flow field, temperature and major species concentrations were measured using Particle Image Velocimetry (PIV), OH Planar Laser-Induced Fluorescence (OH-PLIF), one-dimensional laser Raman scattering and OH chemiluminescence imaging. For the finite-rate chemistry LES, two global and two skeletal reaction mechanisms were utilized to evaluate the accuracy and tradeoffs of global and skeletal reaction mechanisms. This type of assessments has previously been carried out for simple flames but not for industrial flames at laboratory conditions with detailed measurement data. The LES predictions generally show very good agreement with the experimental data for the flow field, temperature and major species. Different reaction mechanisms do not affect the flow field as much as the temperature and species profiles, which show clear imprints of the selected reaction mechanism. The results further indicate that the industrial flame is best captured with the skeletal reaction mechanisms, whilst the global mechanisms predict too compact flames. The results from the skeletal reaction mechanisms are then used in conjunction with the experimental data to assess the flame characteristics which best can be described as interacting flamelets embedded in an environment of distributed reaction zones.

Pulling the Same Way? A Multi‐Perspectivist Study of Crisis Cooperation in Government

Abstract: After crises have occurred, limitations in crisis management capacity often cause surprise and frustration. An explanation that frequently recurs in evaluations is a lack of efficient cooperation between organizations. Even though crisis cooperation is anticipated and planned for, it seems to create several problems. How is cooperation possible between organizations with different mandates, cultures and professions? This paper aims to identify factors that strengthen or hamper cooperation in crisis management between Swedish government agencies. A rationalist organizational and a social psychological perspective are applied, respectively, to demonstrate the interdependence of organizational context and human behaviour. One conclusion is that long-term organizing and exercises could help authorities to identify strengths and weaknesses such as differences in regulations and culture. If carefully addressed and considered, such insights could improve the effectiveness of cooperation during crises.