MEMS UNDERWATER DIRECTION FINDING ACOUSTIC SENSOR

Acoustic sensors operating in underwater environments were designed and fabricated based on the ear structure of the parasitic fly, Ormia ochracea. The design was executed using COMSOL Multiphysics, including mass loading and viscous damping. The optimized sensors were fabricated using MEMSCAP commercial foundry service. The testing was performed using NPS water tanks and TRANSDEC’s San Diego underwater testing facility. For underwater characterization, a custom housing was made to immerse the sensors in a non-conducting fluid with acoustic impedance close to water. Measurements showed that the sensors could detect underwater sound with a narrow-band spectral response. Directional response of the sensors showed the expected cosine dependence, indicating their ability to detect the bearing of underwater sound sources. The sensor enclosure affected the measurements due to its non-uniform response to the incident sound. A reference hydrophone was similarly enclosed and COMSOL simulations performed to reduce and understand this effect. The results show that the enclosure produces unwanted resonance frequencies. For uniquely determining sound-source bearing, it is necessary to use two sensors at a canted angle. The circuit boards affected directional responses. COMSOL simulations were performed with actual-sized circuit boards. Several approaches to determine the optimal angle based on these observations are presented in this thesis.Lieutenant Commander, Argentina NavyApproved for public release; distribution is unlimited

A avaliação do comprometimento organizacional na implementação de um centro de serviços partilhados

Em Portugal, a competição que se verifica no mercado privado da saúde e a crescente necessidade de se tornarem cada vez mais eficientes e atingir níveis de serviço de excelência a um custo operacional mais reduzido, faz com que as organizações apostem na melhoria interna dos processos tornando-os cada vez mais ágeis. Cada organização tem de ser capaz de se reorganizar em termos operacionais e estratégicos de forma a otimizar os recursos, tendo como objetivo a criação de valor interno. Em prol da otimização de processos, o grupo GEPCS, Grupo Empresarial de Prestação de Cuidados de Saúde, optou pela criação de um centro de serviços partilhados na área de suporte das suas unidades de esterilização. A criação de um centro de serviços partilhados, enquanto sistema que é continuamente melhorado e reinventado através de benchmark, melhores práticas e redesenho de processos (Van der Linde et al., 2006), ambiciona proporcionar maior eficiência, criação de valor, redução de custos e um melhor atendimento aos clientes internos da organização. (Bergeron, 2002). Porém, qualquer mudança, enquanto chave para a implementação com sucesso das melhores estratégias de desenvolvimento (Nascimento, 2008), gera resistência por parte dos agentes envolvidos enquanto parte integrante da organização. Nesse sentido, o objetivo deste trabalho é demostrar que uma organização necessita da participação e comprometimento organizacional na implementação da mudança e na criação de um centro de serviços partilhados pois tal como defende Meyer (2009) “(…) o comprometimento é essencial para o sucesso da implementação da mudança”.The competition verified in the private healthcare market in Portugal and the growing need for process improvement in favour of greater processes efficiency and effectiveness, creates the need for each organization to make the internal processes more and more agile. Each organization must be able to reorganize itself in operational and strategic terms in order to optimize resources, with the objective of creating internal added value. In order to optimize processes, the GEPCS group, the Business Group of Providing HealthCare, chose for the creation of a shared services center in the support area of its sterilization units. The creation of a shared services center, as a system that is continuously improving and reinvented through benchmarks, best practices and process continuous redesign (Van der Linde et al., 2006), aims to provide greater efficiency, value creation, cost reduction and better service to the organization's internal customers. (Bergeron, 2002). However, any change, as key to the successful implementation of the best development strategies (Nascimento, 2008), generates resistance on the part of the agents involved as an integral part of the organization. The objective of this thesis is to demonstrate that an organization needs the participation and the organizational commitment in the implementation of the change during the creation of a shared services centres, as supported by Meyer (2009) “(…) commitment is essential for the success of the implementation of the change ”

Fabrication of MEMS Directional Acoustic Sensors for Underwater Operation

The article of record as published may be found at https://doi.org/10.3390/s20051245In this work, microelectromechanical systems (MEMS)-based directional acoustic sensors operating in an underwater environment are explored. The studied sensors consist of a free-standing single wing or two wings pivoted to a substrate. The sensors operate in a narrow frequency band determined by the resonant frequency of the mechanical structure. The electronic readout of the mechanical response is obtained using interdigitated comb finger capacitors attached to the wings. The characteristics of MEMS sensors immersed in silicone oil are simulated using finite element modeling. The performance of the sensors is evaluated both in air and underwater. For underwater testing and operation, the sensors are packaged in a housing containing silicone oil, which was specially developed to present near unity acoustic transmission. The measurements show that the resonant frequency of the sensors obtained in air shifts to a lower frequency when immersed in silicone oil, which is primarily due to the mass loading of the liquid. The peak sensitivity of the MEMS sensors is approximately 6 mV/Pa or −165 dB re 1 V/μPa, and the directional response shows a dipole pattern. The signal-to-noise ratio was found to be about 200 or 23 dB at 1 Pa incident sound pressure. The results show the potential of MEMS sensors to be used in underwater applications for sound source localization

Life cycle assessment of pig production a case study in Mexican Farm

Evaluación de cargas ambientales de modelos ganaderos, sistema producto porcino.The porcine mexican sector has an important participation worldwide, dynamics of growth has positioned it inside the principal producing countries, in such a way that, not only competes in satisfying the needs of the market, also in the creation of social value. The answer to environmental problems is for companies an indicator of competitiveness. The aim of this study was to evaluate the environmental burdens associated with pig production in a full-cycle farm, using life cycle assessment methodology. All activities carried out in the pig farm were evaluated (breeding, lactating, weaning, rearing-start, growth, development and finishing pig). The inventory integrates data on livestock feed, water and electricity consumption, as well as manure emission factors. The inventories were processed in the OpenLCA software version 1.7. The characterization factors of the ReCiPe Midpoint method were used. The results present impacts in the categories Agricultural land occupation, Climate change, Freshwater eutrophication, Marine eutrophication, Particulate matter formation, Photochemical oxidant formation, Terrestrial acidification and Water depletion.CONACyT. Beca de Doctorado de María del Rosario Villavicencio Gutiérrez. Proyecto de Investigación: Análisis de los inventarios y las asimetrías productivas ambientales y económicas de los sistemas ganaderos. clave: 4219/2016S

Intensification of cattle ranching production systems: Socioeconomic and environmental synergies and risks in Brazil

Intensification of Brazilian cattle ranching systems has attracted both national and international attention due to its direct relation with Amazon deforestation on the one hand and increasing demand of the global population for meat on the other. Since Brazilian cattle ranching is predominantly pasture-based, we particularly focus on pasture management. We summarize the most recurrent opportunities and risks associated with pasture intensification that are brought up within scientific and political dialogues, and discuss them within the Brazilian context. We argue that sustainable intensification of pasturelands in Brazil is a viable way to increase agricultural output while simultaneously sparing land for nature. Since environmental degradation is often associated with low-yield extensive systems in Brazil, it is possible to obtain higher yields, while reversing degradation, by adopting practices like rotational grazing, incorporation of legumes and integrated crop-livestock-forestry systems. Technical assistance is however essential, particularly for small- and medium-scale farmers. Sound complementary policies and good governance must accompany these measures so that a ‘rebound effect’ does not lead to increased deforestation and other adverse social and environmental impacts. It is also important that animal welfare is not compromised. Although the discussion is presented with respect to Brazil, some aspects are relevant to other developing countries

Alternativa de modelo linear para estimação da biomassa verde de Bambusa vulgaris Schrad. ex J.C. Wendl na existência de multicolinearidade.

The objective of this work was to use a multivariate statistical method as an alternative to estimate the green biomass of the main bamboo rod, Bambusa vulgaris Schrad. i.e.: J.C. Wendl., in the presence of multicollinearity. The data came from an experiment carried out for the Agroindustrial Excelsior S. A. (Agrimex) company located in the city of Goiana – PE. Quantified by their green biomass weight, 450 bamboo rods were used and 4 independent variables measured in the rod. Initially, the presence of the multicollinearity could be verified through the correlation matrix of the independent variables and the varience inflation factors, the alternative used was the regression of the principal components based on the covariate matrix. The result indicates that, when there is an interpretation to the main components, the model shows a satisfactory data adjust, and it could be used to estimate the green biomass of the main bamboo rod.O objetivo deste trabalho foi utilizar um método estatístico multivariado como opção para estimar a biomassa verde da haste principal do bambu, Bambusa vulgaris Schrad. ex J. C. Wendl., na existência de multicolinearidade. Os dados foram provenientes de um experimento conduzido pela empresa Agroindustrial Excelsior S. A. (Agrimex) localizada no Engenho Itapirema, município de Goiana, PE. Foram utilizadas 450 hastes de bambu, que tiveram sua biomassa verde quantificada por meio do peso e mensuração de quatro variáveis independentes. Inicialmente, comprovou-se a existência da multicolinearidade por meio da matriz de correlação das variáveis independentes e pelo fator de inflação da variância e a opção utilizada foi à regressão linear com os componentes principais que tem como base a matriz de covariância. O resultado indicou que ao existir uma interpretação para os componentes principais o modelo apresenta um ajuste satisfatório aos dados, podendo ser utilizado para estimar a biomassa verde da haste principal do bambu