A low-cost radiation detection system to monitor radioactive environments by unmanned vehicles

AbstractUnconventional scenarios with hazardous radioactive levels are expected as consequences of accidents in the industrial sector of the nuclear energy production or following intentional releases of radioactive materials for terrorist purposes (dirty bombs, indoor contaminations, etc.). Nowadays, the need to balance the high standards of safety and security through an effective detection network is a matter of paramount importance. In this work, the authors' challenge has been to design, realize and test a low-cost gamma detection and spectroscopy system which may be used in unmanned vehicles in general and/or drones with low payload capabilities. The designed platform may be used to carry out mapping or localization operations in order to reduce the risk factor for first responders or for the population affected by radiological and nuclear events. In this paper, the design process of a gamma ray detection and spectroscopy system based on affordable and commercially available technologies is presented along with the results of our ongoing characterization of the prototype

Feshbach resonances in ultracold K(39)

We discover several magnetic Feshbach resonances in collisions of ultracold K(39) atoms, by studying atom losses and molecule formation. Accurate determination of the magnetic-field resonance locations allows us to optimize a quantum collision model for potassium isotopes. We employ the model to predict the magnetic-field dependence of scattering lengths and of near-threshold molecular levels. Our findings will be useful to plan future experiments on ultracold potassium atoms and molecules.Comment: 7 pages, 6 figure

Sudden death in lambda light chain AL cardiac amyloidosis: a review of literature and update for clinicians and pathologists

Light chain (AL) amyloidosis is the most common type of systemic amyloidosis, affecting around 10 people per million per year. In Europe, approximately 5000 new diagnosis per year are reported. Deposition of amyloid fibrils derived from antibody light chains are key pathogenic agents in AL amyloidosis. They can be deposited in multiple organs but cardiac involvement carries a major risk of mortality. The prognosis is poor in cases associated with multiple myeloma. The average survival is around 1 year. Up to half of all patients with cardiac amyloidosis die suddenly; 75% ofthose deaths are due to heart failure. Ventricular arrhythmia is also associated with cardiac amyloidosis and unexpected death. It is crucial to make a diagnosis and start treatment at an early stage. Recent data suggest that cardiac amyloidosis has become a treatable and curable condition with a combination of agents targeting multiple steps of the amyloid cascade. ICD implantation may not be as effective for the therapy of light chain (AL) cardiac amyloidosis as supposed earlier. In cases of unexpected and sudden death, autopsy may show unknown conditions and is valuable to assess existing risks for family members. Even after careful autopsy, a proportion of sudden deaths, ranging from 2 to 54%, remain unexplained and this broad range of values is likely due to the heterogeneity of autopsy protocols. Post mortem diagnosis of cardiac amyloidosis still represents a challenge for forensic pathologists. Detailed morphologic study of the heart and a complete histopathologic study are mandatory. Immunohistochemistry is essential for amyloid subclassification. A review of existing literature is performed by the authors and a methodological approach in post mortem diagnosis of light chain AL cardiac amyloidosis is proposed. Both macroscopic and microscopic findings are discussed

Numerical investigation on the use of Dimethyl Ether (DME) as an alternative fuel for compression-ignition engines

Dimethyl Ether (DME) is an oxygenated fuel that could favour the transition of the heavy-duty transportation sector to carbon neutrality thanks to its similarities in terms of thermophysical properties with diesel fuel, which will facilitate the retrofitting of existing architectures, and the possibility to achieve good trade-offs between NOx emissions, soot formation and overall combustion efficiency. The possibility of producing it from a multitude of carbon-neutral sources and the low hydrogen-to-carbon ratio would allow for an overall lower CO2 output, making an attractive option in limiting the global warming impact of the heavy-duty transportation sector. In the present work, a numerical analysis of the combustion process of DME is carried out. First, the numerical setup is validated against experimental data available for a constant volume vessel with an initial density of 14.8 kg/m3, discussing the capabilities of a chemistry-based combustion model using tabulated kinetics of homogeneous reactors: the Tabulated Well Mixed (TWM) model. Ignition delay times (IDT) are compared for a wide range of temperatures, from 750 K to 1100 K, and oxygen concentrations, from 15% to 21%. The same setup is then applied in the simulation of a heavy-duty internal combustion engine (ICE). A first validation was done to assess the performance of the numerical methodology in a traditional Mixing Controlled Compression Ignition (MCCI) scenario. Then, two other points were simulated: an MCCI condition with 35% of EGR and a Late-Premixed Charge Compression Ignition (L-PCCI) one, with 35% of EGR and an SOIe of 4 CAD aTDC. Local temperature distributions were compared, analyzing the effect of these technologies in NOx emission mitigation and their impact on gross indicated efficiency (& eta;g), showing the advantages that using DME can have on a real-world application

Diffuse calcifications protect carotid plaques regardless of the amount of neoangiogenesis and related histological complications

Background. Neoangiogenesis is crucial in plaque progression and instability. Previous data from our group showed that Nestin-positive intraplaque neovessels correlated with histological complications. The aim of the present work is to evaluate the relationship between neoangiogenesis, plaque morphology, and clinical instability of the plaque. Materials and Methods. Seventy-three patients (53 males and 20 females, mean age 71 years) were consecutively enrolled. Clinical data and 14 histological variables, including intraplaque hemorrhage and calcifications, were collected. Immunohistochemistry for CD34 and Nestin was performed. RT-PCR was performed to evaluate Nestin mRNA (including 5 healthy arteries as controls). Results. Diffusely calcified plaques (13/73) were found predominantly in females (P=0.017), with a significantly lower incidence of symptoms (TIA/stroke (P=0.019) than noncalcified plaques but with the same incidence of histological complications (P=0.156)). Accordingly, calcified and noncalcified plaques showed similar mean densities of positivity for CD34 and Nestin. Nestin density, but not CD34, correlated with the occurrence of intraplaque hemorrhage. Conclusions. Plaques with massive calcifications show the same incidence of histological complications but without influencing symptomatology, especially in female patients, and regardless of the amount of neoangiogenesis. These results can be applied in a future presurgical identification of patients at major risk of developing symptoms

Competitive equilibrium in the italian wholesale electricity market

The market power analysis in electricity market is relevant for understanding the competitive development of the industry’s restructuring and the liberalization process. The paper analyzes the market power exercised by power generators in the Italian wholesale electricity market. Following the approach of Wolak (2003, 2009), the extent of market power is measured using the Lerner index computed as the inverse of arc elasticity of the residual demand faced by each Cournot competitors. Then, the market supply curves have been adjusted to entail market power effects and the new market resolutions were derived. The new equilibrium prices are the competitive ones and represent the market clearing price that would have been if the electricity market was competitive and the effects of unilateral market power were removed

Competitive equilibrium in the italian wholesale electricity market

The market power analysis in electricity market is relevant for understanding the competitive development of the industry’s restructuring and the liberalization process. The paper analyzes the market power exercised by power generators in the Italian wholesale electricity market. Following the approach of Wolak (2003, 2009), the extent of market power is measured using the Lerner index computed as the inverse of arc elasticity of the residual demand faced by each Cournot competitors. Then, the market supply curves have been adjusted to entail market power effects and the new market resolutions were derived. The new equilibrium prices are the competitive ones and represent the market clearing price that would have been if the electricity market was competitive and the effects of unilateral market power were removed