Studies of Oval Tube and Fin Heat Exchangers

Heating Ventilation and air-conditioning (HVAC) is a system which changes the temperature of the surroundings for the purposes of cooling or heating. This system requires energy to maintain a temperature difference from the outside temperature. Optimizing the flow over the evaporator coils is one way to increase the cooling efficiency. This will reduce the power required to have a sustainable system. Optimizing the flow to increase the energy transfer between the fins and the incoming air could result in a greater Coefficient of Performance (COP). This will be achieved by changing the geometry of the tubes for greater interaction with the flow. For reduced recirculation, an oval design for the tube geometry was chosen. These studies will be simulated using Computational Fluid Dynamics (CFD) as the main comparison between the different models. The different models will be a standard oval shaped tube geometry with 20 degrees angles of attack alternating through the rows. This method could, in theory, increase the overall heat transfer coefficient of the heat exchanger because of more mixing of the flow through the evaporator. In conclusion, this study will analyze the effects of changing the geometry and alternating the angle of attack of the evaporator tubes along rows, on the overall heat transfer and pressure drop across the model

Studies of Oval Tube and Fin Heat Exchangers

Heating Ventilation and air-conditioning (HVAC) is a system which changes the temperature of the surroundings for the purposes of cooling or heating. This system requires energy to maintain a temperature difference from the outside temperature. This is important since minimized power is one of the requirements for the system to achieve a better efficiency. Optimizing the flow over the evaporator coils is one way to increase the cooling efficiency. This will reduce the power required to have a sustainable system. Optimizing the flow to increase the energy transfer between the fins and the incoming air could result in a greater Coefficient of Performance (COP). This will be achieved by changing the geometry of the tubes for greater interaction with the flow. For reduced recirculation, an oval design for the tube geometry was chosen. These studies will be simulated using Computational Fluid Dynamics (CFD) as the main comparison between the different models. The different models will be a standard oval shaped tube geometry with different angles of attack alternating through the rows. This method could, in theory, increase the overall heat transfer coefficient of the evaporator because of more mixing of the flow through the evaporator. In conclusion, this study will analyze the effects of changing the geometry and alternating the angle of attack of the evaporator tubes along rows, on the overall heat transfer coefficient and pressure drop across the model. POSTER PRESENTATION IGNITE AWAR

E-ARK: Harmonising pan-European archival processes to ensure continuous access to e-government records and information

There has been a widespread shift to electronic ways of conducting business that has transformed existing relationships between governments, governments and citizens, and governments and business. This move to electronic interactions is supported by new busi- ness systems that streamline and automate transactions, enable integration of information and service delivery and enhance collaboration between participants. Such changes in the way government business is carried out have significant implications for how public ad- ministrations document their activities and make that information available to both gov- ernment and citizens to aid future decision making and accountability. Because digital rec- ords are particularly vulnerable to technological obsolescence and media decay, ensuring future access to the information created by government is a challenging issue for all juris- dictions. This paper focus on the E-ARK project, a European endeavour to standardise and create tools for consistently transferring digital records between business systems and digi- tal archives. The E-ARK approach has the potential to simplify and make consistent diverse approaches to solving the issue of how to transfer information between the ICT systems in use in government, and the archives charged with the responsibility for ongoing and man- agement of the information considered to be of long-term significance.This work was co-funded by KEEP SOLUTIONS, LDA

Perceived stress as a risk factor for peptic ulcers:a register-based cohort study

BACKGROUND: The association between stress and peptic ulcers has been questioned since the discovery of helicobacter pylori. This study examined whether high perceived everyday life stress was associated with an increased risk of either receiving a triple treatment or being diagnosed with a peptic ulcer. METHODS: Cohen’s perceived stress scale measured the level of stress in a general health survey in 2010 of 17,525 residents of northern Jutland, Denmark, and was linked with National Danish registers on prescription drugs and hospital diagnoses. Cox proportional hazard regression was used to estimate the risk of either receiving a triple treatment or being diagnosed in a hospital with a peptic ulcer, in relation to quintiles of stress levels. RESULTS: A total of 121 peptic ulcer incidents were recorded within 33 months of follow-up. The lowest stress group had a cumulative incidence proportion of either receiving triple treatment or being diagnosed with peptic ulcer of approximately 0.4%, whereas the highest stress group had a cumulative incidence proportion of approximately 1.2%. Compared with that of the lowest stress group, those in the highest stress group had a 2.2-fold increase in risk of either receiving triple treatment or being diagnosed with peptic ulcer (HR 2.24; CI 95% 1.16:4.35) after adjustment for age, gender, socioeconomic status, non-steroid anti-inflammatory drug use, former ulcer and health behaviours. There was no difference in risk between the four least stressed quintiles. Subgroup analysis of diagnosed peptic ulcer patients revealed the same pattern as the main analysis, although the results were not significant. CONCLUSION: The highest level of perceived everyday life stress raised the risk of either receiving triple treatment or being diagnosed with peptic ulcer during the following 33 months more than twice compared with that of the lowest level of perceived stress

ALTERNATE HIGH EFFICIENCY PARTICULATE AIR (HEPA) FILTRATION SYSTEM

In Phase IIA of this project, CeraMem has further developed and scaled up ceramic HEPA filters that are appropriate for use on filtration of vent gas from HLW tanks at DOE sites around the country. This work included procuring recrystallized SiC monoliths, developing membrane and cement materials, and defining a manufacturing process for the production of prototype full sizes HEPA filters. CeraMem has demonstrated that prototype full size filters can be manufactured by producing 9 full size filters that passed DOP aerosol testing at the Oak Ridge Filter Test Facility. One of these filters was supplied to the Savannah River Technical Center (SRTC) for process tests using simulated HLW tank waste. SRTC has reported that the filter was regenerable (with some increase in pressure drop) and that the filter retained its HEPA retention capability. CeraMem has also developed a Regenerable HEPA Filter System (RHFS) design and acceptance test plan that was reviewed by DOE personnel. The design and acceptance test plan form the basis of the system proposal for follow-on work in Phase IIB of this project

Alcohol consumption and mortality in patients undergoing coronary artery bypass graft (CABG):a register-based cohort study

BACKGROUND: Previous studies have shown that compared with abstinence and heavy drinking, moderate alcohol consumption is associated with a reduced risk of mortality among the general population and patients with heart failure and myocardial infarction. We examined the association between alcohol consumption and mortality in coronary artery bypass graft (CABG) patients. METHOD: We studied 1,919 first-time CABG patients using data on alcohol consumption and mortality obtained from Danish national registers from March 2006 to October 2011. Alcohol consumption was divided into the following groups: abstainers (0 units/week), moderate consumers (1–14 units/week), moderate-heavy drinkers (15–21 units/week) and heavy drinkers (>21 units/week). Hazard ratios (HR) of all-cause mortality were calculated using Cox proportional hazard regression analysis. RESULTS: The median follow-up was 2.2 years [IQR 2.0]. There were 112 deaths, of which 96 (86 %) were classified as cardiovascular. Adjustments for age and sex showed no increased risk of all-cause mortality for the abstainers (HR 1.61, 95 % CI, 1.00–2.58) and moderate-heavy drinkers (HR 1.40, 95 % CI, 0.73–2.67) compared with moderate consumers. However, heavy drinkers had a high risk of all-cause mortality compared with moderate consumers (HR 2.44, 95 % CI, 1.47–4.04). A full adjustment showed no increase in mortality for the abstainers (HR 1.59, 95 % CI, 0.98–2.57) and moderate-heavy drinkers (HR 1.68, 95 % CI, 0.86–3.29), while heavy drinkers were associated with an increased mortality rate (HR 1.88, 95 % CI, 1.10–3.21). There was no increased risk of 30-day mortality for the abstainers (HR 0.74, 95 % CI, 0.23–2.32), moderate-heavy drinkers (HR 0.36, 95 % CI, 0.07–1.93) and heavy drinkers (HR 2.20, 95 % CI, 0.65–7.36). CONCLUSION: There was no increased risk of mortality for abstainers (0 units/week) or moderate-heavy drinkers (15–21 units/week) following a CABG. Only heavy drinking (>21 units/week) were significantly associated with an increased mortality rate. These results suggest that only heavy drinking present a risk factor among CABG patients

SIP Creation on Relational Databases (Full Scale Pilot 1)

This report contains information gathered during the execution of E-ARK Pilot 1: SIP Creation on Relational Databases

E‐ARK Dissemination Information Package (DIP) Final Specification

The primary aim of this report is to present the final version of the E-ARK Dissemination Information Package (DIP) formats. The secondary aim is to describe the access scenarios in which these DIP formats will be rendered for use

Enhancement of nonclassical properties of two qubits via deformed operators

We explore the dynamics of two atoms interacting with a cavity field via deformed operators. Properties of the asymptotic regularization of entanglement measures proving, for example, purity cost, regularized fidelity and accuracy of information transfer are analyzed. We show that the robustness of a bipartite system having a finite number of quantum states vanishes at finite photon numbers, for arbitrary interactions between its constituents and with cavity field. Finally it is shown that the stability of the purity and the fidelity is improved in the absence of the deformation parameters

HD 91669b: A New Brown Dwarf Candidate from the McDonald Observatory Planet Search

We report the detection of a candidate brown dwarf orbiting the metal-rich K dwarf HD 91669, based on radial-velocity data from the McDonald Observatory Planet Search. HD 91669b is a substellar object in an eccentric orbit (e=0.45) at a separation of 1.2 AU. The minimum mass of 30.6 Jupiter masses places this object firmly within the brown dwarf desert for inclinations i>23 degrees. This is the second rare close-in brown dwarf candidate discovered by the McDonald planet search program.Comment: Accepted for publication in A