El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This article proposes a mechanical development of a dry cell in order to obtain HHO through water electrolysis. Calculations and technical specifications of the materials used for implementation are supported by mathematical, physical and chemical formulas and theories (Faraday´s Law, electrolysis process and mechanical design). The importance of mechanical design is focused on achieving efficient use of the energy provided to the cell that allows the H2 and O2 molecules to be separated without overheating the cell, evaporating the water, loss of current due to the geometry of the electrodes (Foucault Current). Moreover, choosing materials for proper implementation and physical robustness is mandatory. In addition, the mechanical design is not justified in different articles. Nevertheless, the mechanical design of the cell and the efficiency in the production of HHO are related. Therefore, the mechanical design and the calculations were performed, as well as the construction of the dry cell to obtain HHO. The results of the implementation and production were placed and compared with what theoretically the dry cell should produce from the law of Faraday. Finally, the volumetric flow of HHO obtained was 2.70 L per minute. It means a production efficiency of 98.68%. It is higher than the majority of the dry cells. / Revisión por pares

The National Ignition Facility (NIF) is home to the world’s most energetic laser. The facility is one of the leading centers in inertial confinement fusion (ICF) experiments to research and understand sustainable fusion energy. To fully document and understand the physics occurring during experiments, precise diagnostics are used for a wide range of purposes. One diagnostic, the crystal backlighter imager (CBI), allows for X-ray imaging of the target at late stages of its implosion. The aim of this project was to increase the current capabilities of the CBI diagnostic with the addition of a second crystal. This thesis focuses on the design development of the 5 degrees of freedom precision stages used to align each of the crystals. The motivations for the addition of a second crystal are covered in the introduction. A ray tracing model was generated to explore the required range of travel for both crystals, as well as explore potential effects of transitioning to a two-crystal system. The requirements of the precision stage are outlined based on the flaws of the current stage and areas with desired improvements. A dynamic analysis was performed on modified supporting hardware for CBI, to determine areas of interest in redesigning components for the two-crystal system. Further research is performed on commercial and literature methods used to design precision optomechanical stages. Finally, the design development is documented outlining the considered options, modifications to the existing system, and the proposed design solution. A design is proposed that meets the project requirements set at the beginning of design development.

The price of the tools for making prototypes and small series of products, as well as the cost of additional changes in the tool are quite high and increase the price of the final product. A flexible tool provides an advantageous solution to create a wide variety of molds. In this thesis the area of flexible tooling is introduced. An experimental mechanism has been manufactured and tested. With the help of a methodical approach several solutions for a flexible tool design have been proposed. Based on the evaluation of all given criteria, the most suited version has been designed and manufactured. The tool has been tested and evaluated for the thermoforming process. Improvements and potential applications have been suggested. The results show that the flexible tool has some limitations but has a broad potential use in several applications.

With energy demands at an all time high, mechanical power systems are under great scrutiny. Substantial efforts are being made throughout the world to reduce energy use in common mechanical systems such as the internal combustion engine and transmission system. Eliminating or reducing efficiency losses in the transmission is a potential source of improving the efficiency of the system. To do so, various alternative types of transmissions are being investigated. At Brigham Young University, development of a Positively Engaged Continuously Variable Transmission (PECVT) is progressing. In addition to the efficiency increases that would occur as a result of operating the engine at a more constant speed, a PECVT type transmission may reduce efficiency losses that occur in a standard transmission by eliminating the disengagement of involute gear sets to change gear ratios of the transmission. For a PECVT, this is done by maintaining engagement of the input and output members of the transmission, while changing the gear ratio. Both of these types of losses are major contributing factors to the overall efficiency of the transmission and engine system, thus a PECVT is of great interest. The investigation for developing a feasible PECVT began with the identification of a behavioral issue identified in all known PECVT embodiments. This behavioral issue, known as the Non-Integer-Tooth-Problem (NITP), is due to the geometry of an involute gear and prevents specific gear ratios from being achieved. The research effort presented in this thesis returns to the conceptual design of a PECVT to address involutometry along with the NITP. A design tool entitled the Line-of-Action Model is developed which assists in quantifying how a conceptual solution can address the NITP using involutometry principles. As a result of the Line-of-Action Model, the Hybrid Involute Profile was discovered. Due to the simplicity of The Hybrid Involute Profile, it has proven to be an elegant solution to the NITP. Validation of the Hybrid Involute Profile concept was conducted to ensure that this concept satisfies the objectives and requirements of a PECVT and solves the NITP. The validation was completed using two case studies and a theoretical analysis. As a result of the validation, the Hybrid Involute Profile is declared a conceptual principal solution to the NITP. Fulfillment of the PECVT objectives, requirements list and elimination of the NITP by the Hybrid Involute Profile is also demonstrated. With the Hybrid Involute Profile as the conceptual principle solution, the development of a commercially viable PECVT is believed to be attainable.

<p>This thesis proposes the design and documents analysis for a Modular River Current Energy Converter (MRCEC) to improve the efficiency of hydrokinetic turbine power systems. The MRCEC can produce electricity from low-velocity river flow with increased energy affordability and availability. The MRCEC, for the scope of this thesis, consists of the hydroturbine and maintenance systems. The turbine in the MRCEC system is a cross-flow cycloidal turbine that yields a high power coefficient (0.515) through a novel pitch variance mechanism involving a 3D cam that adapts to varying river flow conditions to maximize operational efficiencies. The cycloidal turbine is a four-section three-blade turbine that uses a unique hydrofoil profile designed for the MRCEC. The cycloidal turbine is housed in a frame supported by a flotation system to harness energy from near-surface currents. The flotation system, in turn, is connected to the service dock which houses the mooring, debris blockage, and maintenance systems. The mooring system allows the MRCEC to be fixed at the working site while allowing for self-adjustment with varying river depths. The debris blockage system prevents debris carried by the river from interfering with an operational hydroturbine. The maintenance system enables the installation, operation, and maintenance functions by integrating a flipping mechanism to invert the turbine for transportation and maintenance purposes. Mechanisms of these systems are designed to appropriate standards, then simulated to validate functionality at all stages of installation, operation, and maintenance.</p>

Teniendo presente que la actividad pecuaria y ganadera es una las actividades primarias de supervivencia de un gran número de la población de las zonas de menor de desarrollo de nuestra patria, y dentro de estas actividades, cabe destacar, donde la cadena láctea como principal actividad de las familias de la sierra y selva, en el año 2016 se tiene que casi el 65% de las unidades agropecuarias se forjan en la sierra, 19% en la selva y 17% en la costa, en actividades de cultivos de pastos, forrajes, producción de leche, crianza de animales y posteriormente transformación en quesos y derivados lácteos, considerada la última como la principal actividad económica rentable de la población rural. En ese orden de ideas, la presente investigación tiene el objetivo proncipal de diseñar un molino con ciertas características para la molienda del quesillo, ( producto de haber cortado la leche con cuajo, ya sea casero o producto industrializado que se usa como cortante), antes de ser prensado y convertirse en queso e incrementar volumenes de producción en el distrito y provincia de Santa Cruz, departamento de Cajamarca, y por ende mejorar el abastecimiento del mercado local y la economía de las productoras, siguiendo el procedimiento del diseño mecánico, permitiendo su desarrollo y crecimiento industrial. Este molino consta de ciertas partes como: el disco como pieza fundamental para moler, eje principal, poleas, fajas de transmisión y rodamientos por lo que se determinaron algunas cargas a las que se encuentran sometido. Una vez conocida el funcionamiento del molino tipo disco, para determinar la velocidad se utilizó la fórmula del movimiento parabólico para determinar el alcance máximo de una partícula de quesillo molido, asi mismo se calculó el torque y dar paso a la potencia para la selección de un motor adecuado. Para su diseño y su futura construcción se necesito de un software CAD/ CAE, para este caso Solidworks 2016. Finalmente se realizó una evaluación económica calculando el TIR y VAN para conocer la viabilidad del proyecto, teniendo una inversión de 2 987, 52 soles para su construcción. / The main activities in the mountain and jungle from Peru in 2016, 64% of the agricultural was developed in the mountains, 20% in the jungle and 16% on the coast , about pasture and forage cultivation , husbandry, milk production and then being cheeses and dairy products, it was the best economic activity of the rural population. Therefore, this research has the objetive of designing a quesillo’s shredder with some requirements, before being pressed. and become cheese to increase production volumes in the Santa cruz province, department of Cajamarca, then we need to improve the supply of the local market and the producer’s economy, we have followed the mechanical design procedure allowing its development and growth industry. Also the parts of the shredder are: the disc as a fundamental piece for milling, the mechanical shaft, pulleys, transmission belts and bearings, it was important to calculate some loads, power, angular velocity and choose the shredder structure correctly to make the cheese’s machine. We knew disk-type shredder how it works, so we used some formulas like a parabolic movement, it was used to calculate the speed and the maximum range of a cheese’s particle,also we calculated the torque and the power to select an electric motor. Finally, we needed a CAD / CAE software, for our case Solidworks 2016, then we made an economic evaluation (IRR and NPV) to know the project viability, having an investment of 2987, 52 soles for its construction.

Cuttlebone, the endoskeleton of cuttlefish, offers an intriguing biological structural model for designing low-density cellular ceramics with high stiffness and damage tolerance. Cuttlebone is highly porous (porosity ~93%) and lightweight (density less than 20% of seawater), constructed mainly by brittle aragonite (95 wt%), but capable of sustaining hydrostatic water pressures over 20 atmospheres and exhibits energy dissipation capability under compression comparable to many metallic foams (~4.4 kJ/kg). Here we computationally investigate how such a remarkable mechanical efficiency is enabled by the multiscale structure of cuttlebone. Using the common cuttlefish, Sepia Officinalis, as a model system, we first conducted high-resolution synchrotron micro-computed tomography (µ-CT) and quantified the cuttlebone's multiscale geometry, including the 3D asymmetric shape of individual walls, the wall assembly patterns, and the long-range structural gradient of walls across the entire cuttlebone (ca. 40 chambers). The acquired 3D structural information enables systematic finite-element simulations, which further reveal the multiscale mechanical design of cuttlebone: at the wall level, wall asymmetry provides optimized energy dissipation while maintaining high structural stiffness; at the chamber level, variation of walls (number, pattern, and waviness amplitude) contributes to progressive damage; at the entire skeletal level, the gradient of chamber heights tailors the local mechanical anisotropy of the cuttlebone for reduced stress concentration. Our results provide integrated insights into understanding the cuttlebone's multiscale mechanical design and provide useful knowledge for the designs of lightweight cellular ceramics. Upon the prior curvature analysis of the cuttlebone walls, we discovered that the walls were primarily "saddle-shaped". Thus, the characterization of different curvatures, varying between flat, domed, saddled, or cylindrical surfaces, were explored. A mathematical model was utilized to generate multiple walls with different curvature characteristics. We observed the mechanical performance of these walls via finite-element analysis and formulated different techniques for designing effective ceramic structures through incorporation of curvature. / Master of Science / The cuttlefish is a marine species that instead of having an inflatable swim bladder like fish, is a mollusk capable of swimming by utilizing their skeleton, called the cuttlebone. The cuttlefish can freely traverse the waters by controlling the flow of water in and out of their brittle skeletons, changing their buoyancy. For this reason, the cuttlebone must be very porous yet strong to withstand the deep-water pressures, enticing an interest for closer observation of the structure which may be useful in engineering applications involving ceramic structures. In this study, we examined an actual cuttlebone structure to better visualize its features with high-resolution synchrotron micro-computed tomography (µ-CT) and tabulated its mechanical performance through a variety of tests using computational software. The skeletal design of the cuttlebone consists of multiple layered chambers supported by wavy, pillar-like walls. It was revealed that the cuttlebone is remarkable due to its multiscale design: the asymmetric geometry of the walls are designed to tolerate considerable amounts of energy while a stiff construction; at the chamber level, variation of walls (number, pattern, and waviness amplitude) helps avoid complete destruction of the structure in the event of an excessive force; at the entire skeletal level, various of chamber heights reduces inflicted stress in concentrated regions of the cuttlebone. The wavy walls were also observed to retain a saddle-shaped curviness, versus simple flat, domed, or cylindrical shaped walls. This created an incentive to explore the effects of curvature on the structural integrity of brittle ceramic structures. We developed an effective way for generating walls with different curvatures and observed the mechanical performance of each wall by crushing them in computer simulations. It was identified that adding curvature to brittle walls prolonged the failure period significantly. While the cylindrical walls were found to be rather stiff, saddle-shaped walls, although not capable of withstanding as much force as flat or cylindrical walls, has a more progressive failure behavior meanwhile maintaining high energy absorption, hence the saddled walls of the cuttlebone to allow maintenance and self-repair in damaged regions.

As a valuable asset in human augmentation and medical rehabilitation, exoskeletons have become a major area for research and development. They have shown themselves to be effective tools for training and rehabilitation of individuals suffering from limited mobility. However, most exoskeletons are not capable of balancing without the assistance of crutches from the user. Leveraging technology and techniques developed for force controlled humanoid robots, a project was undertaken to develop a fully self-balancing, compliant lower-body robotic exoskeleton. Due to their many beneficial features, series elastic actuators were utilized to power the joints on the exoskeleton. This thesis details the development of four linear series elastic actuators (LSEA) as part of this project. All 12-degrees of freedom will be powered by one of these four LSEA's. Actuator requirements were developed by examining human gait data and three robot-walking simulations. These four walking scenarios were synthesized into one set of power requirements for actuator development. Using these requirements, analytical models were developed to perform component trade studies and predict the performance of the actuator. These actuators utilize high-efficacy components, parallel electric motors, and liquid cooling to attain high power-to-weight ratios, while maintaining a small lightweight design. These analyses and trade studies have resulted in the design of a dual-motor liquid-cooled actuator capable of producing a peak force 8500N with a maximum travel speed of 0.267m/s, and three different single-motor actuators capable of producing forces up to 2450N continuously, with a maximum travel speeds up to 0.767m/s. / Master of Science / Patients who suffer a severe back injury that results in paralysis from the waist down (paraplegia) commonly regain mobility in their daily lives by using a wheelchair. However, staying in a seated position for long periods can cause serious medical issues to arise. In order to address these issues, lower-body exoskeletons have been developed to help patients walk again. Exoskeletons are mechanical devices a person can wear to enhance their physical strength or endurance beyond their normal capability. These exoskeletons have shown themselves to be effective tools for training and rehabilitation of individuals suffering from limited mobility. However, most exoskeletons are not capable of balancing the user while they walk. In order to maintain balance, the user must hold themselves up with crutches. As with a wheelchair, heavy dependence on crutches can lead to new medical issues for the patient. To solve this problem, technology and techniques created for humanoid robots were used to develop a fully self-balancing exoskeleton. This exoskeleton is known as the Orthotic Lower-body Locomotion Exoskeleton. This thesis details the development of four actuators to power all twelve joints of the exoskeleton. These actuators utilize high-efficiency components, multiple electric motors, and liquid cooling to maintain a small lightweight design and while obtaining very high-power outputs.

This report is part of a bachelor thesis implemented at Saab training systems AB in Huskvarna. It treats the concept development of the driveline on Moving infantry target, MIT. Today Saab has a problem in the shape of that their customers uses the wrong moment when tightening the cog belt of the driveline. As a consequence the cog belt has a high risk of snapping if it is too tight or pluck off if it is too loose. Thereto the electrical motors used in the MIT has gone out of production. The task boiled down to produce a number of proposals that improves the chucking or driveline solution together with finding a new electrical motor to replace the outdated one. A concept study was made containing detailed examinations together with Saab. To answer the problems questions, several product development methods were used, like Quality function deployment and Pugh’s matrix, to reach a final concept. The last concepts were modeled in a 3D-program for an easier comparison between their feasibility. The chosen solution consisted of two motors that via a gearing actuates the respective axle. By replacing the belt drive and choosing more lubrication free gears the maintenance is expected to be improved. In addition the product price is lowered by careful choices of components. The production of a prototype could not be implemented due to lack of time.

Scenic construction requires a strong understanding of a range of principles related to construction including: materials strength properties, mechanical components, electrical motor systems, fluid power systems, and finishing techniques. A manager of scenic construction, or a Technical Director (TD), is required to take artistic designs and ideas and create magical elements on stage that are safe for performers, installers, operators, and audiences. In order to create these onstage spectacles, a great deal of planning, engineering, and careful fabrication must take place. There are several ways for a Technical Director to gain the knowledge required to effectively work at any level of entertainment production. This mixed-methods research study asks: what are the ethical standards that guide how a TD’s work is completed? The thesis begins with a review of the job of the Technical Director in Live Entertainment and data from a survey conducted of professionals in scenic technology. Results from the survey were analyzed to provide both quantitative data, in the form of statistics, and qualitative response data. Additional discussion addresses a sample of the resources for structural design support available currently to the field, as well as challenges that some professionals confront in their typical practice. The thesis concludes a review of literature around engineering ethics and liability in engineering practice and recommendations for the incorporation of new ethical standards in live entertainment scenic production. / text