Combustion Characteristics of Hydrogen/Air Mixtures in a Plasma-Assisted Micro Combustor

This work performs an analysis of plasma-assisted non-premixed H2-air flames in Y-shaped micro combustors in the presence of field emission dielectric barrier discharge (FE-DBD) plasma actuators. The combustion, flow, and heat transfer characteristics are numerically investigated, and the effect of sinusoidal plasma discharges on combustion performance is examined at various equivalence ratios (φ). A coupled plasma and chemical kinetic model is implemented, using a zero-dimensional model based on the solution of the Boltzmann equation and the ZDPlasKin toolbox to compute net charges and radical generation rates. The estimated body forces, radical production rates, and power densities in the plasma regions are then coupled with hydrogen combustion in the microchannel. Plasma-assisted combustion reveals improvements in flame length and maximum gas temperature. The results demonstrate that FE-DBDs can enhance mixing and complete the combustion of unreacted fuel, preventing flame extinction. It is shown that even in cases of radical and thermal quenching, these plasma actuators are essential for stabilizing the flame

Computer-assisted pre-operative automatic segmentation and registration tool for malunited radius osteotomy: A proof-of-concept study

Corrective osteotomy is a standard treatment for distal radius fractures in malunited radius cases. In order to increase the efficiency of the osteotomy pre-operative plan, in this study, a proof-of-concept framework of automatic computer-assisted segmentation and registration tool was developed for the purpose of malunited radius osteotomy pre-operative planning. The program consisted of the functions of segmentation, virtual cutting, automatic alignment and registration. One computed tomography (CT) scanning dataset of a patient's bilateral forearm was employed as an illustration example in this study. Three templates of 3D models including the healthy radius, and the pre- and post-correction injured radius were output as STL geometries for pre-operative plan purposes

MRI-based mechanical analysis of carotid atherosclerotic plaque using a material-property-mapping approach: A material-property-mapping method for plaque stress analysis

Background and objective Atherosclerosis is a major underlying cause of cardiovascular conditions. In order to understand the biomechanics involved in the generation and rupture of atherosclerotic plaques, numerical analysis methods have been widely used. However, several factors limit the practical use of this information in a clinical setting. One of the key challenges in finite element analysis (FEA) is the reconstruction of the structure and the generation of a mesh. The complexity of the shapes associated with carotid plaques, including multiple components, makes the generation of meshes for biomechanical computation a difficult and in some cases, an impossible task. To address these challenges, in this study, we propose a novel material-property-mapping method for carotid atherosclerotic plaque stress analysis that aims to simplify the process. Methods The different carotid plaque components were identified and segmented using magnetic resonance imaging (MRI). For the mapping method, this information was used in conjunction with an in-house code, which provided the coordinates for each pixel/voxel and tissue type within a predetermined region of interest. These coordinates were utilized to assign specific material properties to each element in the volume mesh which provides a region of transition. The proposed method was subsequently compared to the traditional method, which involves creating a composed mesh for the arterial wall and plaque components, based on its location and size. Results The comparison between the proposed material-property-mapping method and the traditional method was performed in 2D, 3D structural-only, and fluid-structure interaction (FSI) simulations in terms of stress, wall shear stress (WSS), time-averaged WSS (TAWSS), and oscillatory shear index (OSI). The stress contours from both methods were found to be similar, although the proposed method tended to produce lower local maximum stress values. The WSS contours were also in agreement between the two methods. The velocity contours generated by the proposed method were verified against phase-contrast magnetic resonance imaging (MRI) measurements, for a higher level of confidence. Conclusion This study shows that a material-property-mapping method can effectively be used for analyzing the biomechanics of carotid plaques in a patient-specific manner. This approach has the potential to streamline the process of creating volume meshes for complex biological structures, such as carotid plaques, and to provide a more efficient and less labor-intensive method

Optical Diagnostics for Solid Rocket Plumes Characterization: A Review

In recent decades, solid fuel combustion propulsion of spacecraft has become one of the most popular choices for rocket propulsion systems. The reasons for this success are a wide range of applications, lower production costs, simplicity, and safety. The rocket’s plumes leave the nozzle at high temperatures; hence, the knowledge of produced infrared (IR) emissions is a crucial aspect during the design and tests of the rocket motors. Furthermore, rocket plume composition is given by N2, H2, H2O, CO and CO2, while solid rocket motors (SRM) additionally inject some solid particles, given by metal fuel additives in the propellant grain, i.e., aluminum oxide (Al2O3) particles. The main issue is the detection of the particles remaining in the atmosphere due to the exhaust gas of the solid rocket propulsion system that could have effects on ozone depletion. The experimental characterization of SRM plumes in the presence of alumina particles can be conducted using different optical techniques. The present study aims to review the most promising ones with a description of the optics system and their potential applications for SRM plume measurements. The most common measurement techniques are infrared spectroscopy imaging, IR imaging. UV–VIS measurements, shadowgraph, and Schlieren optical methods. The choice of these techniques among many others is due to the ability to study the plume without influencing the physical conditions existing in and around the study object. This paper presents technical results concerning the study of rocket engines plumes with the above-mentioned methods and reveals the feasibility of the measurement techniques applied

PD-0283: 4D dose accumulation for dose painting by numbers for lung cancer

In conventional radiotherapy of locally advanced lung cancer (LALC) doses levels are homogeneously delivered to the entire PTV, whereat dose escalation is restricted by normal tissue toxicity. Several studies have shown the geometrical correlation between high FDG uptake in a PET scan and tumour recurrence. This is the rationale for FDG-based local dose escalation, e.g. by dose prescription on the voxel values of a PET scan – dose painting by numbers (DPBN). The aim of this study is to investigate the robustness of the DPBN plans against tumour motio

Divergent behavior of hydrogen sulfide pools and of the sulfur metabolite lanthionine, a novel uremic toxin, in dialysis patients.

Dialysis patients display a high cardiovascular mortality, the causes of which are still not completely explained, but are related to uremic toxicity. Among uremic toxins, homocysteine and cysteine are both substrates of cystathionine β-synthase and cystathionine γ-lyase in hydrogen sulfide biosynthesis, leading to the formation of two sulfur metabolites, lanthionine and homolanthionine, considered stable indirect biomarkers of its production. Hydrogen sulfide is involved in the modulation of multiple pathophysiological responses. In uremia, we have demonstrated low plasma total hydrogen sulfide levels, due to reduced cystathionine γ-lyase expression. Plasma hydrogen sulfide levels were measured in hemodialysis patients and healthy controls with three different techniques in comparison, allowing to discern the different pools of this gas. The protein-bound (the one thought to be the most active) and acid-labile forms are significantly decreased, while homolanthionine, but especially lanthionine, accumulate in the blood of uremic patients. The hemodialysis regimen plays a role in determining sulfur compounds levels, and lanthionine is partially removed by a single dialysis session. Lanthionine inhibits hydrogen sulfide production in cell cultures under conditions comparable to in vivo ones. We therefore propose that lanthionine is a novel uremic toxin. The possible role of high lanthionine as a contributor to the genesis of hyperhomocysteinemia in uremia is discusse

Editors, Publishers, Impact Factors, and Reprint Income

Harvey Marcovitch discusses new research findings from Andreas Lundh and colleagues that examined the effect of publishing industry-funded clinical trials on journal citations and reprint income at six major medical journals

Gestione sostenibile delle foreste Mediterranee e uso energetico delle biomasse forestali residuali

he book describes the reasons that led the Regional Department of Rural and Territorial Development to take part in the PROFORBIOMED Project. They can be summarized by the need to dispose of a tool for the sustainable management of all the state-owned forests of the Region. As a matter of fact, the Project aims at developing a model of sustainable forest management, through the recovery and reuse of wood scraps from ordinary silvicultural operations, to be used for the production of power and heat inside of a process adopting natural renewable energy sources. The main actions taken and the methodologies adopted are described, as well as the principles and instruments required for the setting up and execution of the work. Some of the most relevant are: the drafting of “Forest Management Plans”, the “Short Supply Chain” and the “Biomass Traceability Protocol”, together with the application of “Best Practices” of Management and the “Monitoring of impacts” caused by the woody biomass extraction procedures. The “forest – wood – energy” chain developed and proposed is exclusively related to the territory pertaining to one municipality, and with CHP plants fed with biomass exclusively produced within the territory of each municipality, in strict compliance with the “sustainable forest management” principles, as well as with the fundamental principle of “short supply chain”. For these reasons the CHP plans proposed shall be sized according to the biomass available in each municipality, with the possibility of integrating residual forest biomass with other waste wood resources potentially available in the territory and coming from prunings in agricultural activities. Therefore, the replicable model prepared and proposed by PROFORBIOMED aims at appraising from the economic point of view a waste product, such is currently considered the residual forest biomass from the forests of Sicily, and at the same time significantly improving the natural environment, thanks to the reduction in oil consumption

Attitudes towards complementary and alternative medicine in chronic pain syndromes: a questionnaire-based comparison between primary headache and low back pain

<p>Abstract</p> <p>Background</p> <p>Complementary and Alternative Medicine (CAM) is widely used and popular among patients with primary headache or low back pain (LBP). Aim of the study was to analyze attitudes of headache and LBP patients towards the use of CAM.</p> <p>Methods</p> <p>Two questionnaire-based surveys were applied comparing 432 primary headache and 194 LBP patients.</p> <p>Results</p> <p>In total, 84.75% of all patients reported use of CAM; with significantly more LBP patients. The most frequently-used CAM therapies in headache were acupuncture (71.4%), massages (56.4%), and thermotherapy (29.2%), in LBP thermotherapy (77.4%), massages (62.7%), and acupuncture (51.4%). The most frequent attitudes towards CAM use in headache vs. LBP: "leave nothing undone" (62.5% vs. 52.1%; p = 0.006), "take action against the disease" (56.8% vs. 43.2%; p = 0.006). Nearly all patients with previous experience with CAM currently use CAM in both conditions (93.6% in headache; 100% in LBP). However, the majority of the patients had no previous experience.</p> <p>Conclusion</p> <p>Understanding motivations for CAM treatment is important, because attitudes derive from wishes for non-pharmacological treatment, to be more involved in treatment and avoid side effects. Despite higher age and more permanent pain in LBP, both groups show high use of CAM with only little specific difference in preferred methods and attitudes towards CAM use. This may reflect deficits and unfulfilled goals in conventional treatment. Maybe CAM can decrease the gap between patients' expectations about pain therapy and treatment reality, considering that both conditions are often chronic diseases, causing high burdens for daily life.</p