1,004,217 research outputs found

    Low cost propulsion systems for the developing world

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    Space has often been referred to as the final frontier. It is the curiosity of what lies beyond our planet that drives us to turn to the skies. This quest for knowledge and the chance of travelling to the heavens has compelled people to devote their lives to space science, innovation and analysis of our ever-expanding universe. Today the most significant impact of rocketry comes in the form of manned spaceflight. Vehicles like the Space Shuttle and Soyuz began the trend of greater commercialization of manned rocketry, enabling widespread access to space. Whilst the curiosity of what lies beyond may have propelled the development of the space tourism industry, its current operational cost is estimated as 20−20-28 million per passenger per flight. Although the vision of providing low cost space travel still exists, its application is hindered by the costs associated with current space vehicles and mission operations. Furthermore, if we are to better understand our universe and are keen on commercializing space, we would require the space tourism industry to operate in a similar fashion to the aviation industry. As most current launch vehicles rely on chemical propulsion, the level of uncertainty in the market drives their fuel costs. In order to reduce the cost per flight, we must effectively increase the load factor per flight and operate multiple flights, enabling a greater number of paying passengers. In order to provide widespread access to space there needs to be a greater emphasis on the research and development of low cost Reusable Launch Vehicles (RLV) which predominantly rely on alternative fuel technologies, thereby reducing the overall cost per flight. Although progress would be slow, we would still be able to witness a boom in space tourism. This paper proposes the use of magnetic levitation and propulsion (Maglev) within a vacuum chamber as a viable low-cost propulsion technology. It aims to prove that such a system is capable of providing adequate thrust to future space vehicles. As Maglev systems allow for horizontal take-off and landing, such a launch system could be used in conjunction with current airports worldwide. Although the inception and creation of such a system may seem expensive, the long-term fiscal costs are relatively lower than current day systems. This is primarily because such a system relies on electrical power, whose supply and generation costs are much lower than that of chemical propellants. Also, the maintenance costs associated with the Maglev track are minimal, as during take-off there is no physical contact between the track and the launch vehicle. Similar to the aviation industry, the success of future space exploration programs and space tourism relies on international cooperation and alliances. This not only ensures that no one country dominates access to space, but also nurtures healthy competition by providing a level playing field. By implementing the afore mentioned system in politically stable developing nations, we ensure employment, innovation and motivation, all achieved through an international alliance. This system would not only ensure a faster urban development within these countries, but would also bring the vision of space science and exploration to a larger global audience. This paper discusses the overall cost analysis for a vacuum operated Maglev system, the various options available for the generation of power required by such a system and how the system’s long term costs can be aligned with the aviation industry

    A low-cost, flexible and portable volumetric capturing system

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    Multi-view capture systems are complex systems to engineer. They require technical knowledge to install and intricate processes to setup related mainly to the sensors’ spatial alignment (i.e. external calibration). However, with the ongoing developments in new production methods, we are now at a position where the production of high quality realistic 3D assets is possible even with commodity sensors. Nonetheless, the capturing systems developed with these methods are heavily intertwined with the methods themselves, relying on custom solutions and seldom - if not at all - publicly available. In light of this, we design, develop and publicly offer a multi-view capture system based on the latest RGB-D sensor technology. For our system, we develop a portable and easy-to-use external calibration method that greatly reduces the effort and knowledge required, as well as simplify the overall process

    Low cost concentrator

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    The key to concentrator cost effectiveness is the proper design of the reflector surface panels. The low cost concentrator reflective surface design is based on use of a thin, backsilvered mirror glass reflector bonded to a molded structural plastic substrate. This combination of reflective panel material offers excellent optical performance at low cost. The design approach, rationale for the selected configuration, and the development status are described. Reflective panel development and demonstration results are also presented

    Low-cost greenhouses improve food security in the Andes

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    Although the high Andes are the place of origin of the potato, the growing conditions are harsh and prone to frost, drought and hailstorms. This, coupled with a general lack of support for remote communities, has resulted in high levels of malnutrition and childhood mortality amongst the area’s inhabitants. In response, the International Potato Center (CIP) launched a study that aimed at enhancing the resilience and knowhow of local students and women farmers. The project focused on the design of low-cost greenhouses built from local materials, and optimizing the use of space and time within cultivation. A selection of horticultural crops suited to local environmental conditions and culinary tastes was also chosen for cultivation

    Low-cost automated vectors and modular environmental sensors for plant phenotyping

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    © 2020 by the authors. Licensee MDPI, Basel, Switzerland. High-throughput plant phenotyping in controlled environments (growth chambers and glasshouses) is often delivered via large, expensive installations, leading to limited access and the increased relevance of “affordable phenotyping” solutions. We present two robot vectors for automated plant phenotyping under controlled conditions. Using 3D-printed components and readily-available hardware and electronic components, these designs are inexpensive, flexible and easily modified to multiple tasks. We present a design for a thermal imaging robot for high-precision time-lapse imaging of canopies and a Plate Imager for high-throughput phenotyping of roots and shoots of plants grown on media plates. Phenotyping in controlled conditions requires multi-position spatial and temporal monitoring of environmental conditions. We also present a low-cost sensor platform for environmental monitoring based on inexpensive sensors, microcontrollers and internet-of-things (IoT) protocols

    Low cost lobed bearing

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    Separate sectors for each lobed area of the bearing are assembled into the bearing housing individually and bolted tightly against the housing inside diameter. The center of a grinding wheel and the center of the housing are offset, resulting in the desired inner radius and tilt of the sector

    Low cost instrumentation amplifier

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    Amplifier can be used for many applications requiring high input impedance and common mode rejection, low drift, and gain accuracy on order of one percent. Performance of inexpensive amplifier approaches that of some commercial instrumentation amplifiers in many specifications

    Low-cost interference lithography

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    The authors report demonstration of a low-cost ( ∌ 1000 USD) interference lithography system based on a Lloyd’s mirror interferometer that is capable of ∌ 300 nm pitch patterning. The components include only a 405 nm GaN diode-laser module, a machinist’s block, a chrome-coated silicon mirror, substrate, and double-sided carbon scanning electron microscopy (SEM) tape. The laser and the machinist’s block were assembled in a linear configuration, and to complete the system, the mirror and substrate were taped to perpendicular surfaces of the machinist’s block. Approximately 50 silicon substrates were prepared, exposed, and developed, after which some were inspected in a SEM. The associated laser spectrum was also measured, enabling calculation of the laser’s fringe visibility as it varied along the substrate surface. To compare the exposed resist pattern to the fringe visibility, the authors measured the first order diffraction efficiency as a function of position along the grating surface. Their measurements indicated that artifacts seen in both the optical spectrum and resulting grating patterns arose from the laser diode source, thus improving the source characteristics will be the topic of future work.Singapore-MIT Alliance for Research and Technolog

    Low-cost reusable instrumentation for laparoendoscopic single-site nephrectomy: assessment in a porcine model

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    PURPOSE: To test different sets of prebent instruments and a new reusable access device for laparoendoscopic single-site (LESS) surgery. MATERIALS AND METHODS: Three surgeons with previous experience in LESS performed 12 nephrectomies in six pigs. In all procedures, a multichannel access device (X-CONE) and a 5-mm extra-long telescope were used. Four sets of prebent instruments with different profiles (S-portal) were tested: Standard (one straight scissors and one curved grasper), Cuschieri, Carus, and Leroy set (each of them consisting of two curved instruments with different configurations). Assessment was performed based on both objective (procedure time; time to manage the pedicle; time to free kidney) and subjective parameters (entry/exit of instruments; triangulation; dissection up/down; dissection lateral; retraction; interdependence). The subjective assessment tool used was a Likert type scale (1 = easy to 5 = prohibitive). The access device was assessed by using objective (time to complete insertion of device after skin incision) and subjective (significant air leakage, movement constraint) parameters. RESULTS: Time to insertion of the X-CONE was <1 minute in all the cases. Surgeons reported significant insufflant leakage in 58% of cases. The procedure was completed in 10/12 (83%) cases. Mean operative time was 8.3 ± 4.2 minutes, being lower for the Carus group (4.5 min) and higher for the standard group (13 min). Among the different sets, the standard one obtained the best mean scores for all subjective parameters. CONCLUSIONS: X-CONE allows easy abdominal access, and its reusable properties represent cost savings for LESS compared with disposable devices. Prebent instruments might also represent attractive low-cost tools for LESS
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