112 research outputs found
Investigating the antioxidant properties and rutin content of Sea buckthorn (Hippophae rhamnoides L.) leaves and branches
The present study focused on the antioxidant properties and rutin content of leaves and branches of Hippophae rhamnoides L. (Sea buckthorn) in Turkey. Dried leaves (leaf tea), processed (PB) and unprocessed branches (UB) of Sea buckthorn (SBT) were extracted with ethanol and prepared in forms of aqueous extract (AE). All samples were analyzed for their contents of rutin, total phenolics (TPC), total flavonoids (TFC) and total antioxidant capacity by using DPPH and CUPRAC methods. TPC of leaves from ethanolic extracts (EE) were significantly higher than UB and PB extracts. The DPPH scavenging activity of extracts ranged from 41.93 ± 3.57 and 132.43 ± 6.57 mg trolox equivalent (TE)/g, and the antioxidant capacity measured with CUPRAC method were in between 129.4 ± 18.1 and 538.5 ± 34.8 mg TE/g. Both EE and AE of leaf samples had significantly higher rutin content compared to the UB and PB samples. Taking the high antioxidant and rutin content of leaves into account and with respect to their positive health effects, consumption of SBT as a herbal tea should be investigated.Keywords: Sea buckthorn, Hippophae rhamnoides, leaves, antioxidant, phenolic profile, rutin conten
Multi-layered Ruthenium-modified Bond Coats for Thermal Barrier Coatings
Diffusional approaches for fabrication of multi-layered Ru-modified bond coats for thermal
barrier coatings have been developed via low activity chemical vapor deposition and high activity
pack aluminization. Both processes yield bond coats comprising two distinct B2 layers, based on
NiAl and RuAl, however, the position of these layers relative to the bond coat surface is reversed
when switching processes. The structural evolution of each coating at various stages of the
fabrication process has been and subsequent cyclic oxidation is presented, and the relevant
interdiffusion and phase equilibria issues in are discussed. Evaluation of the oxidation behavior of
these Ru-modified bond coat structures reveals that each B2 interlayer arrangement leads to the
formation of α-Al 2 O 3 TGO at 1100°C, but the durability of the TGO is somewhat different and in
need of further improvement in both cases
Fireside Corrosion in Oxy-Fuel Combustion of Coal
Oxy-fuel combustion is based on burning fossil fuels in a mixture of recirculated flue gas and oxygen, rather than in air. An optimized oxy-combustion power plant will have ultra-low emissions since the flue gas that results from oxy-fuel combustion consists almost entirely of CO2 and water vapor. Once the water vapor is condensed, it is relatively easy to sequester the CO2 so that it does not escape into the atmosphere. A variety of laboratory tests comparing air-firing to oxy-firing conditions, and tests examining specific simpler combinations of oxidants, were conducted at 650-700 C. Alloys studied included model Fe-Cr and Ni-Cr alloys, commercial ferritic steels, austenitic steels, and nickel base superalloys. The observed corrosion behavior shows accelerated corrosion even with sulfate additions that remain solid at the tested temperatures, encapsulation of ash components in outer iron oxide scales, and a differentiation between oxy-fuel combustion flue gas recirculation choices
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Materials and Component Development for Advanced Turbine Systems
In order to meet the 2010-2020 DOE Fossil Energy goals for Advanced Power Systems, future oxy-fuel and hydrogen-fired turbines will need to be operated at higher temperatures for extended periods of time, in environments that contain substantially higher moisture concentrations in comparison to current commercial natural gas-fired turbines. Development of modified or advanced material systems, combined with aerothermal concepts are currently being addressed in order to achieve successful operation of these land-based engines. To support the advanced turbine technology development, the National Energy Technology Laboratory (NETL) has initiated a research program effort in collaboration with the University of Pittsburgh (UPitt), and West Virginia University (WVU), working in conjunction with commercial material and coating suppliers as Howmet International and Coatings for Industry (CFI), and test facilities as Westinghouse Plasma Corporation (WPC) and Praxair, to develop advanced material and aerothermal technologies for use in future oxy-fuel and hydrogen-fired turbine applications. Our program efforts and recent results are presented
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Materials and Component Development for Advanced Turbine Systems
Hydrogen-fired and oxy-fueled land-based gas turbines currently target inlet operating temperatures of âŒ1425-1760°C (âŒ2600-3200°F). In view of natural gas or syngas-fired engines, advancements in both materials, as well as aerothermal cooling configurations are anticipated prior to commercial operation. This paper reviews recent technical accomplishments resulting from NETLâs collaborative research efforts with the University of Pittsburgh and West Virginia University for future land-based gas turbine applications
Research approvals iceberg: how a 'low-key' study in England needed 89 professionals to approve it and how we can do better.
BACKGROUND: The red tape and delays around research ethics and governance approvals frequently frustrate researchers yet, as the lesser of two evils, are largely accepted as unavoidable. Here we quantify aspects of the research ethics and governance approvals for one interview- and questionnaire-based study conducted in England which used the National Health Service (NHS) procedures and the electronic Integrated Research Application System (IRAS). We demonstrate the enormous impact of existing approvals processes on costs of studies, including opportunity costs to focus on the substantive research, and suggest directions for radical system change. MAIN TEXT: We have recorded 491 exchanges with 89 individuals involved in research ethics and governance approvals, generating 193 pages of email text excluding attachments. These are conservative estimates (e.g. only records of the research associate were used). The exchanges were conducted outside IRAS, expected to be the platform where all necessary documents are provided and questions addressed. Importantly, the figures exclude the actual work of preparing the ethics documentation (such as the ethics application, information sheets and consent forms). We propose six areas of work to enable system change: 1. Support the development of a broad range of customised research ethics and governance templates to complement generic, typically clinical trials orientated, ones; 2. Develop more sophisticated and flexible frameworks for study classification; 3. Link with associated processes for assessment, feedback, monitoring and reporting, such as ones involving funders and patient and public involvement groups; 4. Invest in a new generation IT infrastructure; 5. Enhance system capacity through increasing online reviewer participation and training; and 6. Encourage researchers to quantify the approvals processes for their studies. CONCLUSION: Ethics and governance approvals are burdensome for historical reasons and not because of the nature of the task. There are many opportunities to improve their efficiency and analytic depth in an age of innovation, increased connectivity and distributed working. If we continue to work under current systems, we are perpetuating, paradoxically, an unethical system of research approvals by virtue of its wastefulness and impoverished ethical debate
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