| 1. |
|
|
| 2. |
|
|
| 3. |
- Nadeau, P., et al.
(author)
-
Prolonged energy harvesting for ingestible devices
- 2017
-
In: Nature Biomedical Engineering. - : Nature Publishing Group. - 2157-846X. ; 1:3
-
Journal article (peer-reviewed)abstract
- Ingestible electronics have revolutionized the standard of care for a variety of health conditions. Extending the capacity and safety of these devices, and reducing the costs of powering them, could enable broad deployment of prolonged-monitoring systems for patients. Although previous biocompatible power-harvesting systems for in vivo use have demonstrated short (minute-long) bursts of power from the stomach, little is known about the potential for powering electronics in the longer term and throughout the gastrointestinal tract. Here, we report the design and operation of an energy-harvesting galvanic cell for continuous in vivo temperature sensing and wireless communication. The device delivered an average power of 0.23 μW mm -2 of electrode area for an average of 6.1 days of temperature measurements in the gastrointestinal tract of pigs. This power-harvesting cell could provide power to the next generation of ingestible electronic devices for prolonged periods of time inside the gastrointestinal tract.
|
|
| 4. |
- Bassi, Claudio, et al.
(author)
-
The 2016 update of the International Study Group (ISGPS) definition and grading of postoperative pancreatic fistula : 11 Years After
- 2017
-
In: Surgery. - : Elsevier BV. - 0039-6060 .- 1532-7361. ; 161:3, s. 584-591
-
Journal article (peer-reviewed)abstract
- Background: In 2005, the International Study Group of Pancreatic Fistula developed a definition and grading of postoperative pancreatic fistula that has been accepted universally. Eleven years later, because postoperative pancreatic fistula remains one of the most relevant and harmful complications of pancreatic operation, the International Study Group of Pancreatic Fistula classification has become the gold standard in defining postoperative pancreatic fistula in clinical practice. The aim of the present report is to verify the value of the International Study Group of Pancreatic Fistula definition and grading of postoperative pancreatic fistula and to update the International Study Group of Pancreatic Fistula classification in light of recent evidence that has emerged, as well as to address the lingering controversies about the original definition and grading of postoperative pancreatic fistula. Methods: The International Study Group of Pancreatic Fistula reconvened as the International Study Group in Pancreatic Surgery in order to perform a review of the recent literature and consequently to update and revise the grading system of postoperative pancreatic fistula. Results: Based on the literature since 2005 investigating the validity and clinical use of the original International Study Group of Pancreatic Fistula classification, a clinically relevant postoperative pancreatic fistula is now redefined as a drain output of any measurable volume of fluid with an amylase level >3 times the upper limit of institutional normal serum amylase activity, associated with a clinically relevant development/condition related directly to the postoperative pancreatic fistula. Consequently, the former "grade A postoperative pancreatic fistula" is now redefined and called a "biochemical leak," because it has no clinical importance and is no longer referred to a true pancreatic fistula. Postoperative pancreatic fistula grades B and C are confirmed but defined more strictly. In particular, grade B requires a change in the postoperative management; drains are either left in place >3 weeks or repositioned through endoscopic or percutaneous procedures. Grade C postoperative pancreatic fistula refers to those postoperative pancreatic fistula that require reoperation or lead to single or multiple organ failure and/or mortality attributable to the pancreatic fistula. Conclusion: This new definition and grading system of postoperative pancreatic fistula should lead to a more universally consistent evaluation of operative outcomes after pancreatic operation and will allow for a better comparison of techniques used to mitigate the rate and clinical impact of a pancreatic fistula. Use of this updated classification will also allow for more precise comparisons of surgical quality between surgeons and units who perform pancreatic surgery.
|
|
| 5. |
- Knight, R, et al.
(author)
-
GTPOM: Thermo-economic optimization of whole gas turbine plant
- 2006
-
In: Journal of Engineering for Gas Turbines and Power. - : ASME International. - 1528-8919 .- 0742-4795. ; 128:3, s. 535-542
-
Journal article (peer-reviewed)abstract
- Trends towards distributed power generation and the deregulation of energy markets are increasing the requirement for software tools that optimize power generation plant design and operation. In this context, this paper describes the GTPOM (thermo-economic optimization of whole gas turbine plant) European project, funded in part through the European Commissions 5th Framework Programme, focusing on the development and demonstration of an original software tool for the thermo-economic analysis and optimization of conventional and advanced energy systems based on gas turbine plant. PSEconomy, the software tool developed during the GTPOM project, provides a thermo-economic optimization capability for advanced and more-conventional energy systems, enabling the complex trade-offs between system performance and installed costs to be determined for different operational duties and market scenarios. Furthermore, the code is capable of determining the potential benefits of innovative cycles or layout modifications to existing plants compared with current plant configurations. The economic assessment is performed through a complete through-life cycle cost analysis, which includes the total capital cost of the plant, the cost of fuel, O&M costs and the expected revenues from the sale of power and heat. The optimization process, carried out with a GA-based algorithm, is able to pursue different objective functions as specified by the User. These include system efficiency, through-life cost of electricity and through-life internal rate of return. Three case studies demonstrating the capabilities of the new tool are presented in this paper covering a conventional combined cycle system, a biomass plant and a CO2 sequestration gas turbine cycle. The software code is now commercially available and is expected to provide significant advantages in the near and long-term development of energy cycles.
|
|
| 6. |
- Nazarov, A, et al.
(author)
-
Vapour phase deposition of thin siloxane coatings on the iron surface. The impact of the layer structure and oxygen adsorption on corrosion stability
- 2021
-
In: Coatings. - : MDPI. - 2079-6412. ; 11:10
-
Journal article (peer-reviewed)abstract
- The mechanism of iron corrosion protection by thin siloxane films was clarified. Quartz crystal microbalance technique (QCM) was applied to control the vapour phase deposition of alkoxysilanes and the formation of thin siloxane films. It was shown that the addition of water vapour increased the thickness of the grafted siloxane films. Crystal-like films spontaneously grow to 10–16 monolayers at 100% RH of Ar flow due to the catalytic effect of the surface. X-ray photoelectron (XPS) and Auger spectroscopies analysed the thin siloxane films and Scanning Kelvin Probe (SKP) showed the formation of iron-siloxane bonds passivating the iron surface. The films showed high hydrophobicity and corrosion inhibition in humid air contaminated by sulphur dioxide. Thick films were less ordered, hydrophilic and accelerated the corrosion of iron. For corrosion protection, the presence of oxygen in the atmosphere is extremely important. In a wet Ar atmosphere, contaminated by sulphur dioxide, the surfaces are not stable and quickly corroded. Oxygen adsorption stabilizes the surface oxide film that correspondingly preserves the anchoring iron-siloxane bonds and enables corrosion protection by the coating. © 2021 by the authors.
|
|
| 7. |
|
|
| 8. |
- Renuke, Avinash, et al.
(author)
-
High-Efficient Bladeless Expander Concept
- 2023
-
In: E3S Web of Conferences. - : EDP Sciences.
-
Conference paper (peer-reviewed)abstract
- Tesla bladeless expanders are promising in energy harvesting and small-scale power generation applications due to their lower cost and simplicity in design. Although such expanders exhibit very high rotor efficiency (analytical total to static efficiency ~ 90%), it shows poor performance when coupled with a stator (experimental total to static efficiency ~30%) due to losses present in the stator and stator-rotor interaction. This paper presents the design and experiment of a novel, high-efficient Tesla bladeless expander concept. The concept arises from the loss phenomena in the stator-rotor interaction in conventional bladeless expanders, which are among the main causes of the low performance. This concept is believed to bring the bladeless expanders to the same performances as the traditional ones with vanes, compared to which however the bladeless machines boast greater simplicity, robustness, and the absence of performance decay as the size decreases, competing even in the contexts for traditional turbomachinery. The high-efficient bladeless expander prototype with water as a working fluid is designed and developed, representing the similitude case for a liquid butane heat pump. The available isentropic power across the throttling process in the butane case is 3.3 kW @10000 rpm. The turbine consists of 24 nozzles and 150 disks separated by 0.1 mm spacers. The turbine shaft is connected to the high-speed electric generator. The performance test on the expander is carried out at rotational speeds ranging from 3000 rpm to 6200 rpm and with differential pressure across the expander up to 14 bar. Experimental ventilation loss is characterised and its effect on the performance of the expander is discussed. The preliminary results of the expander under investigation showed satisfactory production of power with an acceptable efficiency range. It is also shown that the present concept is promising and able to address the major i.e., stator-rotor interaction which is the major source of loss in the traditional bladeless expander.
|
|
| 9. |
- Renuke, Avinash, et al.
(author)
-
Performance Investigation Of Stator-Less And Blade-Less Radial Expander
- 2023
-
In: Proc. ASME Turbo Expo. - : American Society of Mechanical Engineers (ASME). - 9780791887035
-
Conference paper (peer-reviewed)abstract
- Interests in small-scale turbomachinery are gaining momentum, particularly around waste heat recovery using Organic Rankine Cycle (ORC), energy harvesting, pico-hydro, refrigeration and heat pumps and small-scale power generation. These applications demand to have economical, simple construction, and reasonably efficient machines. The performance of bladed turbomachine at a small scale is poor mainly due to viscous losses and relatively large clearances. In some cases, like ORC, it requires a lubrication system, making it complex and costly. Bladeless or Tesla turbomachinery is seen as one of the solutions for these applications due to its simple construction and cost-effectiveness. However, the experimental efficiency of the bladeless turbines/compressors is found in the low region, < 40%. In this article, the performance of a bladeless turbine is investigated using a vaneless volute configuration, making the turbine stator-less (vaneless volute) and bladeless (vaneless rotor). This study presents numerical and experimental performance investigation with a volute as a stator of the bladeless rotor. 3D Numerical results show very promising performance of the turbine with total to static efficiencies calculated above 65%. In the second part of the article, turbine prototype components, assembly and test set-up are discussed. Experimental maximum efficiency of 41.5±0.88% at 3.5 kg/s@5000 rpm and power of 915 W is obtained. This is the highest recorded efficiency for the Tesla turbine in peer-reviewed research. The overall turbine performance from 3D numerical simulation with ventilation and mechanical losses is compared with experimental results. This work demonstrates that the proposed stator-less/volute configuration provides an efficient way for bladeless or Tesla turbines, particularly for low-head applications.
|
|
