Approaches to establishing reference levels in interventional radiology

Reference levels in radiodiagnostics are a requirement stated by the Council Directive 97/43/EURATOM. Reference levels are also relevant for interventional procedures, in accordance with this Directive, which claims special attention to quality assurance programmes, including quality control and patient dose evaluations for special practices such as interventional radiology, to assess the convenience of corrective action depending on the measured doses. The present paper addresses a method of establishing reference levels in interventional radiology, in the framework of optimisation, discussing the ways of putting forward values with a degree of tolerance, to allow for procedure complexity, depending on patient pathology. The need for several estimators used together, namely fluoroscopy time, total number of images per procedure and dose-area product, is also emphasised, proposing a further skin dose estimate in case of risk of deterministic effects. Finally, a brief summary of principles is given for the correct management of reference levels in interventional radiology.     

Contrast Restoration by Adaptive Countershading

The ABSTRACT is to be in fully-justified italicized text, between two horizontal lines, in one-column format, below the author and affiliation information. Use the word “Abstract” as the title, in 9-point Times, boldface type, left-aligned to the text, initially capitalized. The abstract is to be in 9-point, single-spaced type. The abstract may be up to 3 inches (7.62 cm) long. Leave one blank line after the abstract, then add the subject categories according to the ACM Classification Index (see http://www.acm.org/class/1998/ ).     

Optimizing Disparity for Motion in Depth

Beyond the careful design of stereo acquisition equipment and rendering algorithms, disparity post‐processing has recently received much attention, where one of the key tasks is to compress the originally large disparity range to avoid viewing discomfort. The perception of dynamic stereo content however, relies on reproducing the full disparity‐time volume that a scene point undergoes in motion. This volume can be strongly distorted in manipulation, which is only concerned with changing disparity at one instant in time, even if the temporal coherence of that change is maintained. We propose an optimization to preserve stereo motion of content that was subject to an arbitrary disparity manipulation, based on a perceptual model of temporal disparity changes. Furthermore, we introduce a novel 3D warping technique to create stereo image pairs that conform to this optimized disparity map. The paper concludes with perceptual studies of motion reproduction quality and task performance in a simple game, showing how our optimization can achieve both viewing comfort and faithful stereo motion.     

Predictors of solvent effectiveness for dissolution of coal preasphaltenes

The dissolvabilities of coal preasphaltenes in several solvents with various solvent parameters were correlated. Generally dissolvability increased with increasing net hydrogen-bonding index, increasing donor number (DN) and increasing value of donor number minus acceptor number (AN) of the solvent. However, these trends show significant scatter and are not satisfactory as predictors of individual solvent behaviour. Plots of preasphaltene dissolvability against Hildebrand solubility parameter produce curves with broad maxima and several off-line points. Best results are obtained with DN/AN ratios, which yield smooth curves with narrow maxima and little scatter. These ratios are also shown to be useful predictors of the effectiveness of solvents for the extraction and swelling of coal.     

Hydrogen permeation in Fe-40 at.% Al alloy at different temperatures

The electrochemical permeation technique for studying transport and trapping of hydrogen in Fe-40 at.% Al alloy at temperatures of 5, 25, 45 and 65 °C was used in the paper. The influence of temperature on the effective hydrogen diffusion coefficient, hydrogen permeation rate and hydrogen solubility was determined. The activation energy of hydrogen diffusion in iron aluminide in the studied temperature range was also determined.     

Hydrolysis of pumpkin oil cake protein isolate and free radical scavenging activity of hydrolysates: Influence of temperature,enzyme/substrate ratio and time

The effect of hydrolysis parameters (temperature, initial enzyme/substrate ratio and time) on the hydrolysis of pumpkin oil cake protein isolate (PuOC PI) with acid protease from Aspergillus niger and the antioxidant potency of the obtained hydrolysates were studied by response surface methodology (RSM). The hydrolysis progress, measured by the degree of hydrolysis (DH), was described by a second-order polynomial model (R² = 0.77) and the conditions for optimum DH (42.94%) were found at temperature of 40 °C, enzyme/substrate ratio (E/S) 4.38 HUT/mg of substrate proteins and 85 min. The antiradical activity (AA) of the PuOC PI hydrolysates was examined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay; all hydrolysates showed a concentration dependent scavenging activity against DPPH radicals. The AA of hydrolysates was influenced by process parameters and was presented also by a second-order polynomial model (R² = 0.7). The conditions to achieve the highest DH did not result hydrolysates with the optimum AA; the highest AA ranged from 34% to 40% and were found in hydrolysates obtained at 50 °C.     

Improved Thermal Cycling Durability of Thermal Barrier Coatings Manufactured by PS-PVD

The plasma spray-physical vapor deposition (PS-PVD) process is a promising method to manufacture thermal barrier coatings (TBCs). It fills the gap between traditional thermal spray processes and electron beam physical vapor deposition (EB-PVD). The durability of PS-PVD manufactured columnar TBCs is strongly influenced by the compatibility of the metallic bondcoat (BC) and the ceramic TBC. Earlier investigations have shown that a smooth BC surface is beneficial for the durability during thermal cycling. Further improvements of the bonding between BC and TBC could be achieved by optimizing the formation of the thermally grown oxide (TGO) layer. In the present study, the parameters of pre-heating and deposition of the first coating layer were investigated in order to adjust the growth of the TGO. Finally, the durability of the PS-PVD coatings was improved while the main advantage of PS-PVD, i.e., much higher deposition rate in comparison to EB-PVD, could be maintained. For such coatings, improved thermal cycling lifetimes more than two times higher than conventionally sprayed TBCs, were measured in burner rigs at ~1250 °C/1050 °C surface/substrate exposure temperatures.     

The Implementation of Fluorescence‐Based Detection in LTCC (Low‐Temperature‐Co‐Fired‐Ceramics) Microfluidic Modules

The possibility of the application of fluorescence‐based detection method in a microfluidic system is discussed. It consists of a microfluidic module and complementary housing. Both parts are made from LTCC technology. Three microfluidic module designs are analysed. They vary by way of their constructions of a transparent window, which is used for the transmission of a fluorescence signal from the module to the photodetector integrated onto the housing. The influence of the type of materials used for optical windows on performance of the system is discussed. According to the performed measurements, a concentration as low as 0.03 ng/mL was detected.