Mathematical modelling of internal heat recovery in flash tank heat exchanger cascades

Flash tank evaporation combined with a condensing heat exchanger can be used when heat exchange is required between two streams and where at least one of these streams is difficult to handle (tends severely to scale, foul, causing blockages). To increase the efficiency of heat exchange, a cascade of these units in series can be used. Heat transfer relationships in such a cascade are very complex due to their interconnectivity, thus the impact of any changes proposed is difficult to predict. Moreover, the distribution of loads and driving forces in different stages and the number of designed stages faces tradeoffs which require fundamental understanding and balances. Addressing these problems this paper offers a mathematical model of a single unit flash tank evaporator combined with a condensing heat exchanger unit. This model is then developed for a chain of units. The purpose of this model is to allow an accurate study of the factors influencing efficiency of the system (maximum heat recovery) and evaluation of the impact of any alteration of the system, thus allowing for guided design or new or redesign of existing system

Acute heart failure admissions in New South Wales and the Australian Capital Territory: the NSW HF Snapshot Study

Objective: The primary aim of the NSW Heart Failure (HF) Snapshot was to obtain a representative cross-sectional view of patients with acute HF and their management in New South Wales and Australian Capital Territory hospitals. Design and setting: A prospective audit of consecutive patients admitted to 24 participating hospitals in NSW and the ACT with a diagnosis of acute HF was conducted from 8 July 2013 to 8 August 2013. Results: A total of 811 participants were recruited (mean age, 77 ± 13 years; 58% were men; 42% had a left ventricular ejection fraction ≥ 50%). The median Charlson Comorbidity Index score was 3, with ischaemic heart disease (56%), renal disease (55%), diabetes (38%) and chronic lung disease (32%) the most frequent comorbidities; 71% of patients were assessed as frail. Intercurrent infection (22%), non-adherence to prescribed medication (5%) or to dietary or fluid restrictions (16%), and atrial fibrillation/flutter (15%) were the most commonly identified precipitants of HF. Initial treatment included intravenous diuretics (81%), oxygen therapy (87%), and bimodal positive airways pressure or continuous positive airways pressure ventilation (17%). During the index admission, 6% of patients died. The median length of stay in hospital was 6 days, but ranged between 3 and 12 days at different hospitals. Just over half the patients (59%) were referred to a multidisciplinary HF service. Discharge medications included angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (59%), β-blockers (66%) and loop diuretics (88%).Conclusions: Patients admitted to hospital with acute HF in NSW and the ACT were generally elderly and frail, with multiple comorbidities. Evidence-based therapies were underused, and there was substantial interhospital variation in the length of stay. We anticipate that the results of the HF Snapshot will inform the development of strategies for improving the uptake of evidence-based therapies, and hence outcomes, for HF patients

Evaluation of the effects of L-Theanine on neurobehavior in an adult male Sprague-Dawley Rat Model of PTSD

Post-traumatic stress disorder (PTSD) continues to be one of the most common mental health disorders in the United States and may occur in response to traumatic experiences. Currently, there are no interventions that prevent the development of PTSD. L-Theanine (L-Th), a major compound in green tea has been found to decrease anxiety and prevent memory impairment and may have potential effects in the prevention of PTSD. Sixty rats were divided into six experimental groups: control vehicle, control L-Th, control naïve, PTSD vehicle, PTSD Pre-L-Th (prophylactic), PTSD Post-L-Th (non-prophylactic). PTSD was induced by a 3-day restraint/tail shock stress model. The effects of L-Th on neurobehavior were evaluated by Elevated Plus-Maze (EPM), Morris Water Maze (MWM), and Forced Swim Test (FST). Our study found that the total food intake weight of PTSD Pre-L-Th (prophylactic) rats were significantly increased compared to that of PTSD vehicle rats (p = .04). Administration of L-Th 24 hours before the initial PTSD event or for 10 days following the last PTSD stress event did not statistically improve mean open arm exploration on the EPM, spatial memory, and learning in the MWM or behavioral despair measured by the FST (p > 0.05). Although the 3-day restraint/tail shock stress model caused stress in the rodents, it did not produce reported PTSD-like anxiety and depression or spatial memory loss. The effect of Pre-L-Th or Post-L-Th treatment, on the neurobehavioral functions could not be effectively evaluated. However, this study provides a foundation for future studies to try different rodent PTSD models to induce PTSD-like neurobehavioral impairments to explore dosage, frequency, as well as the duration of L-Th administration before and/or after the post-traumatic event. The 3-day restraint/tail shock stress model caused stress in the rodents, Pre-L-Theanine treatment preconditioned the PTSD rats to endure stress

Developing Performance Indicators to Evaluate the Management Effectiveness of the Massachusetts Ocean Management Plan

In June 2009, the Massachusetts Executive Office of Energy and Environmental Affairs (EEA) released its draft Massachusetts Ocean Management Plan (draft plan) for public comment. The plan is required by the Oceans Act of 2008 to, among other things, be adaptive to evolving knowledge and understanding of the ocean environment. The plan’s Science Framework establishes a blueprint for future research and data acquisition and ensuring that the plan evolves and its management measures adapt to this new and enhanced information. As stated in Chapter 5 of the draft plan, an important part of the science framework is the development and implementation of a performance evaluation system with a series of indicators to help EEA and stakeholders evaluate the implementation of the Massachusetts Ocean Management Plan, identify the environmental and socio-economic impacts of plan management decisions, and identify new or emerging issues. Volume 2 of the draft plan contains a section entitled Development of Evaluation Measures for the Massachusetts Ocean Management Plan. This section outlines a proposed process “to identify measures of success or indicators that can be used to measure performance of management strategies in achieving desired outcomes.” As the development of indicators is a high priority of the draft plan, the Massachusetts Ocean Partnership (MOP) in consultation with EEA contracted with the Urban Harbors Institute (UHI) of the University of Massachusetts Boston (UMass Boston). The project team1 and other professionals from organizations and agencies experienced with the selection and use of indicators conducted the process outlined in Volume 2 of the draft plan to identify and select a set of environmental, socio-economic, and governmental indicators to evaluate the effectiveness of the Massachusetts Ocean Management Plan. The work described in this report also contributes to a broader interest and goal of the Massachusetts Ocean Partnership which is to coordinate indicator initiatives to inform ocean management and to advance the development and use of indicators of the ocean’s ability to provide ecosystem services. Currently, there are a number of initiatives, focusing on the coastal and ocean areas of the Northwest Atlantic/Gulf of Maine region, to develop indicators for various purposes and audiences. The process and products of this work in support of the Massachusetts Ocean Management Plan (e.g., the list of indicators and associated data) will be useful in collaborative efforts to integrate and coordinate these regional efforts

The GAMCIT gamma ray burst detector

The GAMCIT payload is a Get-Away-Special payload designed to search for high-energy gamma-ray bursts and any associated optical transients. This paper presents details on the design of the GAMCIT payload, in the areas of battery selection, power processing, electronics design, gamma-ray detection systems, and the optical imaging of the transients. The paper discusses the progress of the construction, testing, and specific design details of the payload. In addition, this paper discusses the unique challenges involved in bringing this payload to completion, as the project has been designed, constructed, and managed entirely by undergraduate students. Our experience will certainly be valuable to other student groups interested in taking on a challenging project such as a Get-Away-Special payload

Droits de l'homme et libertés fondamentales - Droit de propriété

Multiple myeloma (MM) is a B cell bone marrow neoplasia characterized by inflammation with an intense secretion of growth factors that promote tumor growth, cell survival, migration and invasion. The aim of this study was to evaluate the effects of pravastatin, a drug used to reduce cholesterol, in a MM cell line.Cell cycle and viability were determinate by Trypan Blue and Propidium Iodide. IL6, VEGF, bFGF and TGFβ were quantified by ELISA and qRT-PCR including here de HMG CoA reductase. It was observed reduction of cell viability, increase of cells in G0/G1 phase of the cell cycle and reducing the factors VEGF and bFGF without influence on 3-Methyl-Glutaryl Coenzyme A reductase expression.The results demonstrated that pravastatin induces cell cycle arrest in G0/G1 and decreased production of growth factors in Multiple Myeloma cell line

Patient preferences and willingness-to-pay for a home or clinic based program of chronic heart failure management: findings from the which? trial

BACKGROUND Beyond examining their overall cost-effectiveness and mechanisms of effect, it is important to understand patient preferences for the delivery of different modes of chronic heart failure management programs (CHF-MPs). We elicited patient preferences around the characteristics and willingness-to-pay (WTP) for a clinic or home-based CHF-MP. METHODOLOGY/PRINCIPAL FINDINGS A Discrete Choice Experiment was completed by a sub-set of patients (n = 91) enrolled in the WHICH? trial comparing home versus clinic-based CHF-MP. Participants provided 5 choices between hypothetical clinic and home-based programs varying by frequency of nurse consultations, nurse continuity, patient costs, and availability of telephone or education support. Participants (aged 71±13 yrs, 72.5% male, 25.3% NYHA class III/IV) displayed two distinct preference classes. A latent class model of the choice data indicated 56% of participants preferred clinic delivery, access to group CHF education classes, and lower cost programs (p<0.05). The remainder preferred home-based CHF-MPs, monthly rather than weekly visits, and access to a phone advice service (p<0.05). Continuity of nurse contact was consistently important. No significant association was observed between program preference and participant allocation in the parent trial. WTP was estimated from the model and a dichotomous bidding technique. For those preferring clinic, estimated WTP was ≈AU$9-20 per visit; however for those preferring home-based programs, WTP varied widely (AU$15-105). CONCLUSIONS/SIGNIFICANCE Patient preferences for CHF-MPs were dichotomised between a home-based model which is more likely to suit older patients, those who live alone, and those with a lower household income; and a clinic-based model which is more likely to suit those who are more socially active and wealthier. To optimise the delivery of CHF-MPs, health care services should consider their patients’ preferences when designing CHF-MPs.Jennifer A. Whitty, Simon Stewart, Melinda J. Carrington, Alicia Calderone, Thomas Marwick, John D. Horowitz, Henry Krum, Patricia M. Davidson, Peter S. Macdonald, Christopher Reid, Paul A. Scuffha