The Occurrence of Cold Spells in the Alps Related to ClimateChange

Author to whom correspondence should be addressed; E-Mail: [email protected];Tel.: +39-011-670-7891; Fax: +39-011-658-444.Received: 23 June 2010; in revised form: 27 July 2010 / Accepted: 27 July 2010 /Published: 2 August 2010Abstract: Climate change is not only a likely prospect for the end of this century, butit is already occurring. Part of the changes will include global warming and increasingtemperature variability, both at global and regional scales. This increased variability wasinvestigated in this paper from the point of view of the occurrence of cold spells in theAlps in the future climate (2071–2100), compared with the present climate (1961–1990).For this purpose, a regionalisation of the climate change effects was performed within theAlps. To avoid possible errors in the estimate of the 2m air temperature, the analysis wasperformed on the soil surface temperature. To get realistic values for this variable, a landsurface scheme, UTOPIA, has been run on the selected domain, using the output of theRegional Climate Model (RegCM3) simulations as the driving force. The results show that,in general, the number of cold breaks is decreasing over the Alps, due to the temperatureincrement. However, there are certain zones where the behaviour is more complicated. Theanalysis of the model output also allowed a relationship to be found between the numberof cold breaks and their duration. The significance of these results over the whole area wasassessed.Keywords: cold spells; climate change; LSPM; UTOPIA; climate extreme

Analytical and Experimental Study of The Effects of Non-Condensable in a Passive Condenser System for The Advanced Boiling Water Reactor

The main goal of the project is to study analytically and experimentally condensation heat transfer for the passive condenser system relevant to the safety of next generation nuclear reactor such as Simplified Boiling Water Reactor (BWR). The objectives of this three-year research project are to: (1) obtain experimental data on the phenomenon of condensation of steam in a vertical tube in the presence of non-condensable for flow conditions of PCCS, (2) develop a analytic model for the condensation phenomena in the presence of non-condensable gas for the vertical tube, and (3) assess the RELAP5 computer code against the experimental data. The project involves experiment, theoretical modeling and a thermal-hydraulic code assessment. It involves graduate and undergraduate students' participation providing them with exposure and training in advanced reactor concepts and safety system

Airborne Measurements of High Pollutant Concentration Events in the Free Troposphere over the West Coast of South Korea between 1997 and 2011

Aircrafts enable the direct measurement of chemical components in the free troposphere (FT). This study employed airborne measurements to examine the occurrences of high concentrations of SO2 and NOx in the FT over the coastal region west of the Seoul metropolitan area, South Korea. The data from a long-term (1997-2011) airborne measurement campaign were used to determine the meteorological conditions favorable for carrying these pollutants into the Seoul area. The back trajectory analyses of 21 instances of high FT pollutant concentration events showed ascending patterns from the major pollutant sources, mainly the industrial complexes in eastern China, in 9 instances and passing patterns in 12 instances. In the ascending instances, developing low-pressure systems over the source regions provide favorable conditions to uplift air pollutants from the surface into the FT. In the passing instances, an anomalous low-pressure system near the surface prevented airflows from descending into the boundary layer and upper-level anticyclonic systems helped to keep the ascending airflows in the FT. This study proposes the basic mechanisms for predicting air quality in the Seoul area, considering that air pollutants in the FT often entrain into the boundary layer to increase local concentrationsopen0

Genetic diagnosis of inborn errors of immunity using clinical exome sequencing

Inborn errors of immunity (IEI) include a variety of heterogeneous genetic disorders in which defects in the immune system lead to an increased susceptibility to infections and other complications. Accurate, prompt diagnosis of IEI is crucial for treatment plan and prognostication. In this study, clinical utility of clinical exome sequencing (CES) for diagnosis of IEI was evaluated. For 37 Korean patients with suspected symptoms, signs, or laboratory abnormalities associated with IEI, CES that covers 4,894 genes including genes related to IEI was performed. Their clinical diagnosis, clinical characteristics, family history of infection, and laboratory results, as well as detected variants, were reviewed. With CES, genetic diagnosis of IEI was made in 15 out of 37 patients (40.5%). Seventeen pathogenic variants were detected from IEI-related genes, BTK, UNC13D, STAT3, IL2RG, IL10RA, NRAS, SH2D1A, GATA2, TET2, PRF1, and UBA1, of which four variants were previously unreported. Among them, somatic causative variants were identified from GATA2, TET2, and UBA1. In addition, we identified two patients incidentally diagnosed IEI by CES, which was performed to diagnose other diseases of patients with unrecognized IEI. Taken together, these results demonstrate the utility of CES for the diagnosis of IEI, which contributes to accurate diagnosis and proper treatments

Viral Bcl-2-Mediated Evasion of Autophagy Aids Chronic Infection of γHerpesvirus 68

γ-herpesviruses (γHVs) have developed an interaction with their hosts wherein they establish a life-long persistent infection and are associated with the onset of various malignancies. One critical virulence factor involved in the persistency of murine γ-herpesvirus 68 (γHV68) is the viral homolog of the Bcl-2 protein (vBcl-2), which has been implicated to counteract both host apoptotic responses and autophagy pathway. However, the relative significance of the two activities of vBcl-2 in viral persistent infection has yet to be elucidated. Here, by characterizing a series of loss-of-function mutants of vBcl-2, we have distinguished the vBcl-2-mediated antagonism of autophagy from the vBcl-2-mediated inhibition of apoptosis in vitro and in vivo. A mutant γHV68 virus lacking the anti-autophagic activity of vBcl-2 demonstrates an impaired ability to maintain chronic infections in mice, whereas a mutant virus lacking the anti-apoptotic activity of vBcl-2 establishes chronic infections as efficiently as the wild-type virus but displays a compromised ability for ex vivo reactivation. Thus, the vBcl-2-mediated antagonism of host autophagy constitutes a novel mechanism by which γHVs confer persistent infections, further underscoring the importance of autophagy as a critical host determinant in the in vivo latency of γ-herpesviruses

Development of design and simulation model and safety study of large-scale hydrogen production using nuclear power.

Before this LDRD research, no single tool could simulate a very high temperature reactor (VHTR) that is coupled to a secondary system and the sulfur iodine (SI) thermochemistry. Furthermore, the SI chemistry could only be modeled in steady state, typically via flow sheets. Additionally, the MELCOR nuclear reactor analysis code was suitable only for the modeling of light water reactors, not gas-cooled reactors. We extended MELCOR in order to address the above deficiencies. In particular, we developed three VHTR input models, added generalized, modular secondary system components, developed reactor point kinetics, included transient thermochemistry for the most important cycles [SI and the Westinghouse hybrid sulfur], and developed an interactive graphical user interface for full plant visualization. The new tool is called MELCOR-H2, and it allows users to maximize hydrogen and electrical production, as well as enhance overall plant safety. We conducted validation and verification studies on the key models, and showed that the MELCOR-H2 results typically compared to within less than 5% from experimental data, code-to-code comparisons, and/or analytical solutions

Structural studies of imidazolium and phosphonium cations with aprotic hetero cyclic anions (AHAs) and investigation of electrochemical CO₂ reduction

Increasing carbon dioxide (CO₂) concentration in the atmosphere has become a crucial problem because it has greatly contributed to global warming. Previously, Aprotic Heterocyclic Anions (AHAs) based Ionic liquids (ILs) have been developed for post combustion CO₂ capture applications. In order to design the proper combination of ILs which balance the chemical and physical properties, the understanding of fundamental interactions between cations and anions is essential. Particularly, the hydrogen bonding between cations and anions has been identified as a crucial interaction that affects the determination of properties. In this study, we have selected imidazolium and phosphonium cations with good fluidity and thermal stability, pairing them with AHAs with varying basicity and geometry. We investigated the effect of hydrogen bonding in the selected ILs on chemical and physical properties by measuring and correlating the strength of hydrogen bonding with those chemical and physical properties. We found that the role of hydrogen bonding on the determination of physical properties in the selected IL is somewhat different depending on the choice of cation and different geometries of the anions. Furthermore, the structural and chemical knowledge that we gained was applied to the study of electrochemical CO₂ reduction. To focus on the utilization of ILs as additives to effectively catalyze CO₂ reduction on the surface, we have investigated the CO₂ chemistries of the different basic AHAs in diluted organic solvent, acetonitrile (MeCN) with a supporting electrolytes, and eventually compared with the CO₂ chemistries which were observed in the corresponding systems of neat ILs. Then, we have investigated the role of different CO₂ complexes on electrochemical CO₂ reduction. We found that cation-CO₂ complexes with imidazolium ILs did not improve electrochemical CO₂ reduction in non-aqueous systems. Also, unfortunately, anion-CO₂ complexes were not observed in non-aqueous systems due to the solvent effect. Finally, upon addition of water, the formation of bicarbonate with the reprotonated anions led to a slight improvement in electrochemical CO₂ reductionChemical Engineerin

Experimental and analytical study of the effects of noncondensable gas in a passive condenser system

Passive Containment Cooling System (PCCS) of the Simplified Boiling Water Reactor (SBWR) is a passive condenser system which is designed to remove energy from the reactor containment during a postulated reactor accident. The presence of noncondensable gas in the vapor can greatly reduce the performance of condensers. Hence a detailed knowledge of the heat removal performance of the PCCS in the presence of noncondensable gas is crucial for the safety and design optimization of the SBWR. The purpose of the present study is the experimental and theoretical investigation of the effects of noncondensable gas in a passive condenser system. Condensation experiments were performed for a vertical tube submerged in water pool. The present experimental data provide a new database for complete condensation, cyclic venting and through flow modes of the passive condenser. Cyclic venting mode was simulated by a control volume analysis. Analysis results showed that venting period decreases with noncondensable gas fraction. It was found that inception of venting can occur before the condenser is fully filled with noncondensable gas. A boundary layer model was developed for the prediction of the film condensation with noncondensable gas in a vertical tube. Full set of the governing equations for the liquid film and vapor-gas mixture regions were solved. A heat and mass analogy model was also developed with a specific purpose for use in the thermal hydraulic system analysis code. In the vapor-gas mixture region, general momentum, heat and mass transport relations derived by analytic method were used with the consideration of surface suction effect. The predictions from the models were compared with the experimental data and the agreement was satisfactory. A mechanistic condensation correlation was developed based on the experimental data and the analysis results. It contains all the heat transfer components in its functional relationships. New correlation can provide accurate estimation of local condensation heat transfer coefficient for wide range of operating parameters. The assessment of wall condensation models in RELAP5 code was performed. Experimental conditions were simulated with RELAP5. Code simulation showed quite different results compared with data. Therefore, the condensation model in RELAP5 needs to be improved