Extraction and quantification of left ventricular deformation modes

We have developed a method that decomposes the deformation of the left ventricle (LV) between end diastole (ED) and end systole (ES) into separate deformation modes such as longitudinal shortening, wall thickening, and twisting. The deformation was initially found from the motion of an LV finite-element mesh that was fitted to clinically obtained magnetic resonance (MR) tagged images. A mode coefficient was calculated for each deformation mode to quantify the different modes and, thus allowing for discrimination of normal and abnormal deformation patterns. We applied the method to 13 normal subjects and 13 diabetes patients. By using the ED mesh as reference and adding the extracted deformation modes multiplied by their mode coefficients, an approximate ES mesh was calculated and compared with the "true" ES mesh found from the MR images. For the 26 subjects the average Euclidean distance was less than 1.7+/-0.9 mm between the nodes of the approximated and true ES meshes. The coefficient values for the patient group showed significantly less longitudinal shortening, less wall thickening, more longitudinal twisting and also more bulging of the septum into the LV when compared with the normal subjects. We conclude that the developed method successfully quantifies the deformation into several modes of deformation and is capable of distinguishing the deformation of a group of patients from a group of normal subjects.     

Navigation in desktop virtual environments: an evaluation and recommendations for supporting usability

Virtual reality (VR) can provide useful tools for a variety of applications. However, for these tools to be effective, they must be easy to use. In virtual environments (VEs), usability is impaired by poorly designed navigation systems. Insufficient realism and missing physiological orientation and motion cues impair spatial learning in desktop VEs. Capabilities for navigation in a VE are far more varied than in reality; so much greater flexibility can be offered, but designing VEs with too many options can overwhelm users. To assist designers in building effective, usable navigation systems for VEs, navigation techniques must be evaluated to identify which features actually support users in accomplishing their tasks and which features create unnecessary problems.This study evaluates navigation in two different VEs to develop recommendations for the design of navigation systems in desktop VEs. The study consists of an objective assessment of navigation control dynamics, a guideline-based evaluation and a review of data collected during two experimental studies. The findings indicate that real-world constraints, specialised navigation techniques and feedback regarding location and direction of travel are needed to support navigation in desktop VEs.     

Nordic Safety Climate Questionnaire (NOSACQ-50): A new tool for diagnosing occupational safety climate

Although there is a plethora of questionnaire instruments for measuring safety climate or culture, very few have proven able to present a factor structure that is consistent in different contexts, and many have a vague theoretical grounding. The Nordic Safety Climate Questionnaire (NOSACQ-50) was developed by a team of Nordic occupational safety researchers based on organizational and safety climate theory, psychological theory, previous empirical research, empirical results acquired through international studies, and a continuous development process. Safety climate is defined as workgroup members’ shared perceptions of management and workgroup safety related policies, procedures and practices. NOSACQ-50 consists of 50 items across seven dimensions, i.e. shared perceptions of: 1) management safety priority, commitment and competence; 2) management safety empowerment; and 3) management safety justice; as well as shared perceptions of 4) workers’ safety commitment; 5) workers’ safety priority and risk non-acceptance; 6) safety communication, learning, and trust in co-workers’ safety competence; and 7) workers’ trust in the efficacy of safety systems. Initial versions of the instrument were tested for validity and reliability in four separate Nordic studies using native language versions in each respective Nordic country. NOSACQ-50 was found to be a reliable instrument for measuring safety climate, and valid for predicting safety motivation, perceived safety level, and self-rated safety behavior. The validity of NOSACQ-50 was further confirmed by its ability to distinguish between organizational units through detecting significant differences in safety climate.

Relevance to industry

NOSACQ-50 will enable comparative studies of safety climate between and within companies, industries and countries. It is suitable for research purposes as well as for practical use in evaluating safety climate status, as a diagnostic tool, and in evaluating the effect of safety climate interventions.     

K5公寓

这座公寓大楼位于GrünerlФkka,是最丰富多彩和引人注目的区域,被称之为奥斯陆城中的纽约。这块地是至今尚存的19世纪住房与小规模工业亲密交融的罕见典型,遍布着规则排列的窗户和阁楼。为此,新建筑也模仿了这一做法,只是在墙面上加以变化,从而与周围环境既形成了对比,又十分融洽。     

Bubble Evolution on Different Carbon Anode Designs in Cryolite Melt

Metallurgical and Materials Transactions B - The anode potential has been shown to be highly dependent on anode geometry and orientation in the Hall–Héroult process. This work is an...     

Enabling openness of valuable information resources: Curbing data subtractability and exclusion

In this paper we investigate how data openness can be made possible in communal settings. We adopt a utility perspective that foregrounds the use value of data, conceptualizing them as “goods.” On the basis of this conceptualization we explore 2 key goods' attributes: subtractability and exclusion. Our theoretical basis is built upon concepts from the theory of the commons, power theorizing, and notions related to data and information. Empirically, we investigate openness in the genetics domain through a longitudinal study of the evolving communal infrastructure for data related to 2 genes influencing women's susceptibility to breast and ovarian cancer (BRCA1 and BRCA2). We follow the continuously shifting “topology” of the BRCA information infrastructure and trace the multiple repositories that are put in place and the different arrangements for data collection, curation/quality assurance, access, and control that are tried out. In our analysis, we illustrate the actors' strategies for curbing the subtractability and exclusion attributes of data. We then propose a theoretically informed and empirically grounded framework that can guide understanding and action taking to enable data openness.     

Three-Layer Electrorefining of Silicon

To make electrical energy from photovoltaic (PV) silicon (Si) solar cells competitive, the cost in each of the PV manufacturing process steps has to be diminished. Today, high-purity Si is produced by an energy-intensive process exhibiting high irreversible thermodynamic losses. The purity of the product from this process (99,9999999 pct [9 N]) far exceeds what generally is accepted to be the requirements for PV purposes (4 to 6 N). Here we show a novel method for the purification of Si based on the principle of electrochemical refining in a molten high-melting-point fluoride electrolyte at temperatures above the melting point of silicon 1685 K (1412 °C). The method comprised a vertical stack of three molten layers with a metal alloy at the bottom, an intermediate electrolyte layer, and purified metal at the top. The integrity of the layers being secured was through the immiscibility of the liquids and the careful tailoring of the individual densities. Boron (B), exhibiting similar thermodynamic properties to Si, effectively was not removed. A suitable low-B feedstock may be identified in kerf from the sawing of mono- or multicrystalline Si blocks into wafers. To produce purified metal in the 6 N range, practice from electrorefining of aluminum shows that long-term, stable operation in large-scale industrial reactors is needed. The trends and mechanisms observed in the laboratory scale indicate that high purity also can be achieved for Si provided that these criteria can be met.     

Sintering and annealing effects on ZnO microstructure and thermoelectric properties

The influence of different thermal treatments on zinc oxide has been investigated regarding the thermal diffusivity and structural properties of doped and undoped samples. ZnO powders having various grain sizes and morphologies, with or without aluminum doping, have been prepared under different temperatures by spark plasma sintering (SPS). The microstructural properties and thermal diffusivities of the prepared samples have been measured before and after annealing treatments in air at 800 °C. In undoped samples, the crystallite sizes increased after the annealing treatments, while it was retained in the Al-doped samples. The thermal diffusivities, microstrain and degree of preferred orientation were affected by the SPS temperature and the annealing; however, the general trends were retained after the annealing treatments. Lower maximum temperature yielded a lower degree of preferred orientation, less microstrain, higher density of grain boundaries, lower thermal diffusivities and, for Al-doped samples, lower electrical conductivity and a difference in zT-values from 0.2 to 0.3 at 800 °C. Calculations of the wavelengths and mean free paths of the phonons that contribute to the main part of the thermal conductivity have been conducted and reveal that nanostructures <12 nm are required to lower the thermal conductivity by quantum confinement.