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Topic Review
Small-Diameter Vascular Graft Engineering
The increased demands of small-diameter vascular grafts (SDVGs) globally has forced the scientific society to explore alternative strategies utilizing the tissue engineering approaches. Cardiovascular disease (CVD) comprises one of the most lethal groups of non-communicable disorders worldwide. It has been estimated that in Europe, the healthcare cost for the administration of CVD is more than 169 billion €. Common manifestations involve the narrowing or occlusion of blood vessels. The replacement of damaged vessels with autologous grafts represents one of the applied therapeutic approaches in CVD. However, significant drawbacks are accompanying the above procedure; therefore, the exploration of alternative vessel sources must be performed. Engineered SDVGs can be produced through the utilization of non-degradable/degradable and naturally derived materials. Decellularized vessels represent also an alternative valuable source for the development of SDVGs. In this review, a great number of SDVG engineering approaches will be highlighted. Importantly, the state-of-the-art methodologies, which are currently employed, will be comprehensively presented. A discussion summarizing the key marks and the future perspectives of SDVG engineering will be included in this review. Taking into consideration the increased number of patients with CVD, SDVG engineering may assist significantly in cardiovascular reconstructive surgery and, therefore, the overall improvement of patients’ life.
  • 803
  • 22 Dec 2020
Topic Review
Bronze and Brass Ornamental Work
The use of bronze dates from remote antiquity. This important metal is an alloy composed of copper and tin, in proportion which vary slightly, but may be normally considered as nine parts of copper to one of tin. Other ingredients which are occasionally found are more or less accidental. The result is a metal of a rich golden brown colour, capable of being worked by casting — a process little applicable to its component parts, but peculiarly successful with bronze, the density and hardness of the metal allowing it to take any impression of a mould, however delicate. It is thus possible to create ornamental work of various kinds. The process of casting is known as cire perdue, and is the most primitive and most commonly employed through the centuries, having been described by the monk Theophilus, and also by Benvenuto Cellini. Briefly, it is as follows: a core, roughly representing the size and form of the object to be produced, is made of pounded brick, plaster or other similar substance and thoroughly dried. Upon this the artist overlays his wax, which he models to the degree required in his finished work. Passing from the core through the wax and projecting beyond are metal rods. The modelling being completed, called lost-wax casting, the outer covering which will form the mould has to be applied; this is a liquid formed of clay and plaster sufficiently thin to find its way into every detail of the wax model. Further coatings of liquid are applied, so that there is, when dry, a solid outer coating and a solid inner core held together by the metal rods, with the work of art modelled in wax between. Heat is applied and the wax melts and runs out, and the molten metal is poured in and occupies every detail which the wax had filled. When cool, the outer casing is carefully broken away, the core raked out as far as possible, the projecting rods are removed and the object modelled in wax appears in bronze. If further finish is required, it is obtained by tooling.
  • 802
  • 28 Nov 2022
Topic Review
Mixed Criticality Technology
Embedded systems used in critical systems, such as aeronautics, have undergone continuous evolution in recent years. In this evolution, many of the functionalities offered by these systems have been adapted through the introduction of network services that achieve high levels of interconnectivity. The high availability of access to communications networks has enabled the development of new applications that introduce control functions with higher levels of intelligence and adaptation. In these applications, it is necessary to manage different components of an application according to their levels of criticality. The concept of “Industry 4.0” has recently emerged to describe high levels of automation and flexibility in production. The digitization and extensive use of information technologies has become the key to industrial systems. Due to their growing importance and social impact, industrial systems have become part of the systems that are considered critical. This evolution of industrial systems forces the appearance of new technical requirements for software architectures that enable the consolidation of multiple applications in common hardware platforms—including those of different criticality levels. These enabling technologies, together with use of reference models and standardization facilitate the effective transition to this approach. 
  • 802
  • 01 Feb 2021
Topic Review
Charles Stark Draper Laboratory
Draper is an United States not-for-profit research and development organization, headquartered in Cambridge, Massachusetts; its official name is "The Charles Stark Draper Laboratory, Inc". The laboratory specializes in the design, development, and deployment of advanced technology solutions to problems in national security, space exploration, health care and energy. The laboratory was founded in 1932 by Charles Stark Draper at the Massachusetts Institute of Technology (MIT) to develop aeronautical instrumentation, and came to be called the "MIT Instrumentation Laboratory". It was renamed for its founder in 1970 and separated from MIT in 1973 to become an independent, non-profit organization. The expertise of the laboratory staff includes the areas of guidance, navigation, and control technologies and systems; fault-tolerant computing; advanced algorithms and software solutions; modeling and simulation; and microelectromechanical systems and multichip module technology.
  • 802
  • 14 Oct 2022
Topic Review
Optimal Interpolation for infrared satellite data
Thermal infrared remote sensing measurements are blinded to surface emissions under cloudiness because infrared sensors cannot penetrate thick cloud layers. Therefore, surface and atmospheric parameters can be retrieved only in clear sky conditions giving origin to spatial fields flagged with missing pieces of information. Motivated by this we present a methodology to retrieve missing values of some interesting geophysical variables retrieved from spatially scattered infrared satellite observations in order to yield level 3 (L3), regularly gridded, data. The technique is based on a 2-Dimensional (2D) Optimal Interpolation (OI) scheme. The goodness of the approach has been tested on 15-min temporal resolution Spinning Enhanced Visible and Infrared Imager (SEVIRI) emissivity and surface temperature (ST) products over South Italy (land and sea), on Infrared Atmospheric Sounding Interferometer (IASI) atmospheric ammonia (NH3) concentration over North Italy and carbon monoxide (CO), sulfur dioxide (SO2) and NH3 concentrations over China. Sea surface temperature (SST) retrievals have been compared with gridded data from MODIS (Moderate-resolution Imaging Spectroradiometer) observations. For gases concentration, we have considered data from 3 different emission inventories, that is, Emissions Database for Global Atmospheric Research v3.4.2 (EDGARv3.4.2), the Regional Emission inventory in ASiav3.1 (REASv3.1) and MarcoPolov0.1, plus an independent study.
  • 802
  • 30 Oct 2020
Topic Review
Accuracy Improvement in Double-Sided Incremental Forming Process
Low geometric accuracy is one of the main limitations in double-sided incremental forming (DSIF) with a rough surface finish, long forming time, and excessive sheet thinning. The lost contact between the support tool and the sheet is considered the main reason for the geometric error. Toolpath compensations strategies improve geometric precision without adding extra tooling to the setup. It relies on formulas, simulation, and algorithm-based studies to enhance the part accuracy. Toolpath adaptation improves the part accuracy by adding additional equipment such as pneumatically or spring-loaded support tools or changing the conventional toolpath sequence such as accumulative-DSIF (ADSIF) and its variants. It also includes forming multi-region parts with various arrangements. Toolpath adaptation mostly requires experimental trial-and-error experiments to adjust parameters to obtain the desired shape with precision. Material redistribution strategies are effective for high-wall-angle parts.
  • 802
  • 05 May 2022
Topic Review
ProFatigue Software
The program was developed by the IEMES (Structural Integrity: Materials and Structures) Research Group at the University of Oviedo, in collaboration with Prof. Castillo of the University of Cantabria and Empa-Dübendorf (Swiss Federal Laboratories for Materials Science and Technology). ProFatigue is based on the Weibull’s regression model proposed by Castillo-Canteli in order to satisfy the physical and statistical conditions required by any valid fatigue model.
  • 802
  • 27 Nov 2020
Topic Review
Optimal Sizing of Hybrid Renewable Energy Sources Systems
Renewable energy solutions are appropriate for on-grid and off-grid applications, acting as a supporter for the utility network or rural locations without the need to develop or extend costly and difficult grid infrastructure. As a result, hybrid renewable energy sources (HRES) have become a popular option for grid-connected or standalone systems. HRES are systems that are reliable, CO2-emission-free, and an effective solution for minimizing dependency on one renewable resource. In attaining a reliable, clean, and cost-effective system, sizing optimal HRES is a crucial challenge.
  • 802
  • 24 Feb 2023
Topic Review
Millennium Falcon
Template:Infobox fictional spacecraft The Millennium Falcon is a fictional starship in the Star Wars franchise. The modified YT-1300 Corellian light freighter is primarily commanded by Corellian smuggler Han Solo (Harrison Ford) and his Wookiee first mate, Chewbacca (Peter Mayhew). Designed by the Corellian Engineering Corporation (CEC), the highly modified YT-1300 is durable, modular, and is stated as being the second-fastest vessel in the Star Wars canon. The Millennium Falcon first appears in Star Wars (1977), and subsequently in The Empire Strikes Back (1980), Return of the Jedi (1983), Revenge of the Sith (2005), The Force Awakens (2015), The Last Jedi (2017), and Solo: A Star Wars Story (2018). Additionally, the Falcon appears in a variety of Star Wars expanded universe materials, including books, comics, and games; James Luceno's novel Millennium Falcon focuses on the titular ship. It also appears in the 2014 animated film The Lego Movie in Lego form, with Billy Dee Williams and Anthony Daniels reprising their roles of Lando Calrissian and C-3PO, and Keith Ferguson voicing Han Solo.
  • 802
  • 09 Oct 2022
Topic Review
Short-Reach Transmission Systems
Short-reach transmission systems are very sensitive to component cost because these systems are often used in a data center, enabling data exchange between many servers and racks.
  • 802
  • 30 Mar 2021
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