Relationships between estimated flame retardant emissions and levels in indoor air and house dust

A significant number of consumer goods and building materials can act as emission sources of flame retardants (FRs) in the indoor environment. We investigate the relationship between the emission source strength and the levels of 19 brominated flame retardants (BFRs) and seven organophosphate flame retardants (OPFRs) in air and dust collected in 38 indoor microenvironments in Norway. We use modeling methods to back‐calculate emission rates from indoor air and dust measurements and identify possible indications of an emission‐to‐dust pathway. Experimentally based emission estimates provide a satisfactory indication of the relative emission strength of indoor sources. Modeling results indicate an up to two orders of magnitude enhanced emission strength for OPFRs (median emission rates of 0.083 and 0.41 μg h^?1 for air‐based and dust‐based estimates) compared to BFRs (0.52 and 0.37 ng h^?1 median emission rates). A consistent emission‐to‐dust signal, defined as higher dust‐based than air‐based emission estimates, was identified for four of the seven OPFRs, but only for one of the 19 BFRs. It is concluded, however, that uncertainty in model input parameters could potentially lead to the false identification of an emission‐to‐dust signal.     

Topology optimization with geometric uncertainties by perturbation techniques

The aim of this paper was to present a topology optimization methodology for obtaining robust designs insensitive to small uncertainties in the geometry. The variations are modeled using a stochastic field. The model can represent spatially varying geometry imperfections in devices produced by etching techniques. Because of under‐etching or over‐etching parts of the structure may become thinner or thicker than a reference design supplied to the manufacturer. The uncertainties are assumed to be small and their influence on the system response is evaluated using perturbation techniques. Under the above assumptions, the proposed algorithm provides a computationally cheap alternative to previously introduced stochastic optimization methods based on Monte Carlo sampling. The method is demonstrated on the design of a minimum compliance cantilever beam and a compliant mechanism. Copyright © 2012 John Wiley & Sons, Ltd.     

Test chamber investigation of the volatilization from source materials of brominated flame retardants and their subsequent deposition to indoor dust

Numerous studies have reported elevated concentrations of brominated flame retardants (BFRs) in dust from indoor micro‐environments. Limited information is available, however, on the pathways via which BFRs in source materials transfer to indoor dust. The most likely hypothesized pathways are (a) volatilization from the source with subsequent partitioning to dust, (b) abrasion of the treated product, transferring microscopic fibers or particles to the dust (c) direct uptake to dust via contact between source and dust. This study reports the development and application of an in‐house test chamber for investigating BFR volatilization from source materials and subsequent partitioning to dust. The performance of the chamber was evaluated against that of a commercially available chamber, and inherent issues with such chambers were investigated, such as loss due to sorption of BFRs to chamber surfaces (so‐called sink effects). The partitioning of polybrominated diphenyl ethers to dust, post‐volatilization from an artificial source was demonstrated, while analysis in the test chamber of a fabric curtain treated with the hexabromocyclododecane formulation, resulted in dust concentrations exceeding substantially those detected in the dust pre‐experiment. These results provide the first experimental evidence of BFR volatilization followed by deposition to dust.     

Predissociation of the 7Li2 2(3)Sigma+g State

Kawasaki disease (KD) is an acute febrile vasculitic syndrome with thrombocytosis occurring in childhood. Transient thrombocytosis of KD is sometimes the cause of complications such as coronary aneurysmal thrombosis and myocardial infarction. We have analysed blood TPO levels in KD and found that 26/31 acute-phase KD patients had detectable blood TPO levels (mean 173 pg/ml; range 89-294 pg/ml), which decreased immediately with the elevation of platelet counts in 5/12 patients studied. Elevated serum level of TPO may have an important role for this ill-defined disease.     

Ultrastructural changes in the resorptive epithelial cells of the small intestine in rats during increased motor activity and immobilization

Investigated were the structural changes in the epithelial resorptive cells of the duodenum and the jejunum of rats in the conditions of continuous and varying locomotor activity--intense locomotion, control, and immobilization. It was established that the microvilli in the immobilized animals were of a lower size, were irregularly distributed and lower in number. The inward bending of the lateral cell boundary was more slightly manifested. Disaggregations of the polysomes were also expressed. In rats loaded with higher locomotion activity there was more frequently a close association of the mitochondria with the granular endoplasmatic reticulum and the nucleus. The changes observed spoke of lowering of the active cell surface and lowering of the biosynthesis rate in the epithelial resorptive cells at immobilization and enhanced metabolic activity in locomotor loading.     

Robust topology optimization accounting for misplacement of material

The use of topology optimization for structural design often leads to slender structures. Slender structures are sensitive to geometric imperfections such as the misplacement or misalignment of material. The present paper therefore proposes a robust approach to topology optimization taking into account this type of geometric imperfections. A density filter based approach is followed, and translations of material are obtained by adding a small perturbation to the center of the filter kernel. The spatial variation of the geometric imperfections is modeled by means of a vector valued random field. The random field is conditioned in order to incorporate supports in the design where no misplacement of material occurs. In the robust optimization problem, the objective function is defined as a weighted sum of the mean value and the standard deviation of the performance of the structure under uncertainty. A sampling method is used to estimate these statistics during the optimization process. The proposed method is successfully applied to three example problems: the minimum compliance design of a slender column-like structure and a cantilever beam and a compliant mechanism design. An extensive Monte Carlo simulation is used to show that the obtained topologies are more robust with respect to geometric imperfections.     

Diagnostic value of chromosome examination in effusions from cancer patients

The correlations between histological type and clinical picture are reported by a retrospective study of 228 cases in Slesvig-Holstein with malignant non-Hodgkin lymphomas who were scheduled by th "Kiel classification".     

A scalable distributed paradigm for multi-user interaction with tiled rear projection display walls

We present the first distributed paradigm for multiple users to interact simultaneously with large tiled rear projection display walls. Unlike earlier works, our paradigm allows easy scalability across different applications, interaction modalities, displays and users. The novelty of the design lies in its distributed nature allowing well-compartmented, application independent, and application specific modules. This enables adapting to different 2D applications and interaction modalities easily by changing a few application specific modules. We demonstrate four challenging 2D applications on a nine projector display to demonstrate the application scalability of our method: map visualization, virtual graffiti, virtual bulletin board and an emergency management system. We demonstrate the scalability of our method to multiple interaction modalities by showing both gesture-based and laser-based user interfaces. Finally, we improve earlier distributed methods to register multiple projectors. Previous works need multiple patterns to identify the neighbors, the configuration of the display and the registration across multiple projectors in logarithmic time with respect to the number of projectors in the display. We propose a new approach that achieves this using a single pattern based on specially augmented QR codes in constant time. Further, previous distributed registration algorithms are prone to large misregistrations. We propose a novel radially cascading geometric registration technique that yields significantly better accuracy. Thus, our improvements allow a significantly more efficient and accurate technique for distributed self-registration of multi-projector display walls.     

Least squares approach for initial data recovery in dynamic data-driven applications simulations

In this paper, we consider the initial data recovery and the solution update based on the local measured data that are acquired during simulations. Each time new data is obtained, the initial condition, which is a representation of the solution at a previous time step, is updated. The update is performed using the least squares approach. The objective function is set up based on both a measurement error as well as a penalization term that depends on the prior knowledge about the solution at previous time steps (or initial data). Various numerical examples are considered, where the penalization term is varied during the simulations. Numerical examples demonstrate that the predictions are more accurate if the initial data are updated during the simulations.     

Two-dimensional ISAR model and image reconstruction with stepped frequency-modulated signal

A two-dimensional (2-D) inverse synthetic aperture radar (ISAR) return signal model that employs stepped frequency (SF) modulation is developed. The geometry of the examined ISAR scenario is described by analytical geometrical equations. The target to be imaged is represented by a rectangular grid of point scatterers, moving along a rectilinear trajectory at constant speed, without any rotational motion. Thus, the inverse synthetic aperture results from the translational motion of the target for a short period of time. The process of ISAR signal modelling through coherent summation of the SF-modulated signals reflected from different point scatterers of the target is thoroughly described. Moreover, an efficient ISAR image reconstruction approach, including cross-correlation-based range compression and fast-Fourier-transform-based azimuth compression, is presented through analytical mathematical expressions. Numerical simulations are carried out for various SF ISAR scenarios and high-resolution ISAR images are obtained by applying the proposed ISAR image reconstruction approach. Simulation results (ISAR images and corresponding entropy values) indicate the validity of the proposed 2-D SF ISAR return signal model and the efficiency of the proposed imaging algorithms. Finally, a numerical simulation result is illustrated, which shows the comparison of the performance of the proposed ISAR image reconstruction algorithms based on SF and linear frequency modulation waveforms. It is shown that the two waveforms attain almost the same ISAR image resolution.