4,335 research outputs found
Conceptual Model for Serious Games Design: Case Study of Children with Attention Deficit Hyperactivity Disorder
The field of Serious Games (SGs) is relatively new; however, so far, these have focused more on assessing impacts on results rather than identifying the most appropriate implementation phases to obtain a successful SG. The present work proposes a conceptual model for the design of SGs, which is based on four stages: Analysis, Design, Development, and Evaluation, under the life cycle of the software. For the validation of the model, an SG called ATHYNOS was developed, which was applied in a case study comparing it with the traditional therapy. The results obtained allowed to demonstrate that the SGs is a complementary tool for the treatment of children diagnosed with Attention Deficit Hyperactivity Disorder (ADHD).
Keywords: ATHYNOS, conceptual model, serious games design, attention deficit disorde
Characterization of the Physical Properties of the Coconut Fiber Residue With a View to its Agroindustrial Use
Ecuador is a multi-climatic country with the capacity to host a large number of plant species; one example is the coconut (Cocos nucifera), an ancestral food of tropical areas and warm climates, which is considered as raw material for various industrial processes, such as obtaining fats, oils, candies, etc. However, the external part of the coconut constituted by the bast or mesocarp has not been properly exploited. Coconut bast, which has high fiber content (coir fiber), from which three main types can be distinguished: long and thin, coarse, and shorter type, can become an agroindustrial alternative due to its mechanical properties. These properties are as good or better than synthetic fibers or polyester. This research therefore aims to characterize the physical parameters that determine the functionality of coconut fiber, such as its length, softness, brightness, color, diameter, and its appearance or slenderness, which is the relationship between length and diameter. This research also contributes to solving the environmental problem of waste generated by coconut production, moving towards a sustainable economy from an environmental point of view. This work determines that coconut fiber is composed of cellulose and wood that has low heat conductivity and impact resistance, and that its resistance and durability make it an adequate raw material in several production sectors.
Keywords: coconut fiber, characterization, properties, agribusiness.
Resumen
El Ecuador es un país multi climático con la capacidad de alojar una gran cantidad de especies vegetales, un ejemplo de ello es el coco (Cocos nucifera) un alimento ancestral de zonas tropicales y climas cálidos, este es considerado como materia prima de diversos procesos industriales como obtención de grasas, aceites, confites, etc., sin embargo, la parte externa del coco constituida por la estopa o mesocarpio no ha sido correctamente explotada. La estopa del coco por su alto contenido de fibra (fibra bonote), de la cual se pueden distinguir tres tipos principales: una larga y fina, una tosca y una más corta, se convertir en una alternativa agroindustrial debido a sus propiedades físico - mecánicas que son tan buenas o mejores que fibras sintéticas o el poliéster. Esta investigación tuvo por objeto caracterizar los parámetros físicos que describan la funcionalidad de la fibra de coco como son su longitud, suavidad, brillo, color. Para lo cual se realizó un estadística descriptiva de medidas de tendencia central como la media, se analizaron un total de 10 muestras de fibra de coco tomadas al azar de los 15 Kg de fibra obtenida de 50 cocos, teniéndose como resultado que para la suavidad el 80% de los participantes la ubican en el octavo lugar y el restante 20% en el noveno, lo que permite inferir que se tara de una fibra gruesa, rígida y áspera, para el brillo y luminosidad el 90% de los observadores determinaron que la fibra no posee esta característica. El 70% de las panelistas delimitaron que el color característico de la fibra fue el café claro y el restante 30% la considera de color beige.
Palabras clave: fibra de coco, caracterización, propiedades, agroindustria
Basic Considerations and Conceptual Design of a VSTOL Vehicle for Urban Transportation
On-demand air transport is an air-taxi service concept that should ideally use small, autonomous, Vertical Short Takeoff and Landing (VSTOL), “green”, battery-powered electric aircraft (eVSTOL). In addition, these aircraft should be competitive with modern helicopters, which are exceptionally reliable machines capable of the same task. For certification and economic purposes, mobile tilting parts should be avoided. The concept introduced in this paper simplifies the aircraft and makes it economical to build, certify and maintain. Four contrarotating propellers with eight electric motors are installed. During cruise, only two of the eight rotors available are not feathered and active. In the first step, a commercial, certified, jet-fueled APU and an available back-up battery are used. A second solution uses a CNG APU and the same back-up battery. Finally, the third solution has a high-density dual battery that is currently not available. A conceptual design is shown in this paper
Design Issues of Heavy Fuel APUs Derived from Automotive Turbochargers Part III: Combustor Design Improvement
Heavy fuel combustion problems with startup and operation may significantly reduce the microturbine efficiency in small APUs (Auxiliary Power Units). The use of commercial automotive-derived turbochargers solves the design problems of compressors and turbines but introduces large issues with combustors. The radial combustor proved to be the best design. Unfortunately, high-pressure injection is not practical for small units. For this reason, primary air and low-pressure fuel spray are heated and mixed. In any case, a high air swirl must achieve a satisfactory combustion efficiency. This swirl should be almost eliminated at the turbine intake. CFD analysis of the combustor design was, therefore, performed with several different geometries and design solutions. In the end, a large offset of the fresh pipe from the compressor proved to be the best solution for a high swirl in the combustion region. The combustion tends to eliminate the swirl, but an undesired tumble motion at the turbine intake takes place. To eliminate the tumble, two small fins were added to straighten the flow to the turbine
Effect of Different Urine Cow Nitrogen Rates and Different Moisture Conditions on Nitrogen Mineralization in an Andisol from Southern Chile
Urea present in cattle urine contributes large amounts of nitrogen (N) to grazed pastures, which can be an equivalent to approximately 1000 kg N ha−1. However, there are no studies in volcanic soils of southern Chile on the effect of different concentrations of urinary N deposited in the soil, nor of different wetting and drying conditions mimicking the variation of weather conditions on the nitrification process, from urea to NH4+ and total oxidized nitrogen (TON), throughout time. In addition, the inhibition on nitrification driven by the accumulation of NH3 at high rates of N applied to an Andisol have not been evaluated. Fresh cattle urine was applied at three different rates of N equivalent to 247 kg N ha−1 (Low N), 461 kg N ha−1 (Medium N), 921 kg N ha−1 (High N), and de-ionized water as Control. Further, three moisture conditions were imposed: constant moisture (CM), drying-rewetting (DRW) cycles at 7 days interval, and soil drying (SD). Destructive soil cores samples were evaluated for top and bottom halves individually every 7 days over a 36-d period to measure changes on inorganic N and pH. There were no interaction effects for N rates and soil moisture. The main effect of the different rates of N on mineralization was significant throughout the incubation period, while the effect of the different moisture conditions was var-iable over time. The High N was associated with elevated NH3 concentrations and could explain that total N mineralization was partially inhibited. These results suggest that the presence of different nitrifying microorganisms in the soil under different chemical and physical conditions determines nitrification, thus, the oxidation of ammonia should be studied in more detail as the first step of nitrification, specifically in volcanic soils
Electric Bike Product Conception and Styling According to Design Trends
The following case study portrays the several steps required to conceive a product from
scratch. The first step involves an in-depth analysis of today’s electric bicycle market in order to
obtain data and information relating to the levels of innovation and comfort required by customers.
Then, we evaluate the implementation of a useful method to understand the level of innovation that
the product must have to be competitive on the market. The second part studies the architecture of
the product, considering the different components already sold on the market which will become
part of the project. The third part concerns a comparison between different stylistic trends that the
vehicle may have (in order to outline the best one). The fourth part concerns the CAD realization of
the virtual model complete with all its parts, including a structural verification study of the frame.
The last part studies the presentation of the product to the customer, exploring different effective
ways to communicate what the strengths of the new product will be (also allowing them to customize
it before its realization). The plan for the realization of the new product, starting from the concept to
arrive at the final presentation to the customer, follows the methods proposed by applying a series of
steps to develop a generic new product in an efficient, sensible, and methodical manner. Therefore,
we will refer to quality function deployment (QFD), benchmarking (BM), design for X, until reaching
the final prototyping and testing phases
Biogenic gas emissions from soils measured using a new automated laboratory incubation system
Linking nitrogen cycling transformations to microbial diversity in freshwater ecosystems
This is an editorial for a special issu
Does cattle and sheep grazing under best management significantly elevate sediment losses? Evidence from the North Wyke Farm Platform, UK
Purpose: Intensive livestock grazing has been associated with an increased risk of soil erosion and concomitant negative impacts on the ecological status of watercourses. Whilst various mitigation options are promoted for reducing livestock impacts, there is a paucity of data on the relationship between stocking rates and quantified sediment losses. This evidence gap means there is uncertainty regarding the cost–benefit of policy preferred best management.
Methods: Sediment yields from 15 hydrologically-isolated field scale catchments on a heavily instrumented ruminant livestock farm in the south west UK were investigated over ~26 months spread across six years. Sediment yields were compared to cattle and sheep stocking rates on long-term, winter (November–April) and monthly time scales. The impacts of livestock on soil vegetation cover and bulk density were also examined. Cattle were tracked using GPS collars to determine how grazing related to soil damage.
Results: No observable impact of livestock stocking rates of 0.15 – 1.00 UK livestock units (LU) ha-1 for sheep and 0 - 0.77 LU ha-1 for cattle on sediment yields was observed at any of the three timescales. Cattle preferentially spent time close to specific fences where soils were visually damaged. However, there was no indication that livestock have a significant effect on soil bulk density on a field-scale. Livestock were housed indoors during winters when most rainfall occurs and best management practices were used which when combined with low erodibility clayey soils likely limited sediment losses.
Conclusion: A combination of clayey soils and soil trampling in only a small proportion of the field areas lead to little impact from grazing livestock. Within similar landscapes with best practice livestock grazing management, additional targeted measures to reduce erosion are unlikely to yield a significant cost-benefit
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