476 research outputs found

    Harvesting systems for steep terrain in the Italian Alps: state of the art and future prospects

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    Steep slope forest operations in Central Europe and in particular in the Alps are strongly related to the adoption of the cable-based harvesting system, even if innovative ground-based harvesting system, even if innovative ground-based harvesting systems have been proposed in the last years. In this context, the present works aim to acquire a thorough knowledge of yarding technologies used by the logging companies of the central Italian Alps, to evaluate their professionality in steep slope forest operations, and to predict the potential diffusion of innovative steep slope harvesting systems in the area. The results show a large number of logging companies (106) working with cable-based systems and in particular with four different standing skyline yarding technologies. The analysis of professionality in using cable cranes shows big differences between the companies. In particular, it identifies a consistent group of companies with a highly mechanized machinery fleet and high skills and experience in steep slope forest operations. These enterprises evidence a still limited potential diffusion of the innovative ground-based harvesting systems in the area, even if it is theoretically possible according to the GIS analysis of morphology and forest road networ

    Cable tensile force monitoring in steep slope forest operations

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    The interest in active sustainable management of mountain forests is increasing around the world. Great effort, in particular, is focusing on the identification of efficient, safe, and sustainable steep slope harvesting solutions adapted to different environmental conditions. The main attention is moving toward winch-assist harvesting systems on trafficable terrain and European designed standing skyline mobile tower yarders on non-trafficable terrain. These cable-supported harvesting solutions have similar safety issues related to the use of tensioned wire ropes and the use of natural anchors. This research focused on the analysis of cable tensile force while operating with these harvesting solutions in ordinary harvesting sites and operational conditions. First, a state-of-the-art about the steep slope cable-supported harvesting solutions and their main safety issues was completed. A particular focus was dedicated to the significant works on cable tensile force monitoring. Following, field studies were successfully carried out to monitor the cable tensile forces on ordinary logging operations. The survey interested eleven mobile tower yarders, observed on twelve different cable lines in the Italian Alps, and three large integrated-winch forwarders, observed on eight trails in the interior of British Columbia (Canada). A similar approach, based on the integration of tensile force monitoring, video recording of the operations, ground profile analysis, and load measurement/estimation, was applied to both the cable-supported systems. The case studies, the methodological approach used for the data collection and analysis, and the results of the monitoring are presented and reported in detail

    Complete Simulation of an IEEE 802.11 Wireless Network using a Full Wave Electromagnetic Tool Dynamically Coupled to a RF System Simulator

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    The purpose of this study is to fully evaluate a short range IEEE 802.11g channel at 2.4 GHz frequency by dynamic linking Ansys HFSS, a full wave electromagnet tool, and Ansys Designer, a system level design simulator. The study presented in paper shows the integration of a 3D field solver and a circuit solver that enables the calculation of radiation patterns, electric field plots, bit error rate, constellation plots while incorporates the actual transmitter and receiver antennas and devices as well as TX/RX system with numerous modulation schemes. Multipath effects are also considered because the entire physical environment is modeled. Frequency and time domain responses are seamlessly combined in order to yield a complete response of the entire system. The scenario of the WiFi network is a room comprised of a router, a notebook and a phone. The concepts shown in this paper can be applied to Zigbee, Bluetooth, WiMax and many other wireless network types

    Modelling noise propagation generated by forest operations: a case study in Southern Italy

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    Noise is defined as an undesired sound that constitutes an unwarranted disturbance potentiality modifying animal behaviour or normal functioning. Forest operations commonly involve the use of equipment and machines that can produce noise and be a potential permanent or temporary disturbance for the wildlife. This study simulates noise propagation in a natural area generated during coppice stand harvesting by direct field noise measurements and the application of a specific GIS model. Two working phases were investigated: felling and yarding operations. Two potential systems were analyzed for the yarding operations: a) yarding by mobile cable yarder and b) skidding by tractor with a three point log grapple. The results are reported in terms of excess noise area for the third-octave bandwidths with the centre in 500 Hz, 1000 Hz and 2000 Hz. Felling by chainsaws presented the largest area where noise exceeds the ambient natural noise, while in the case of yarding, mobile cable yarding operations presented a smaller area of excess noise than skidding by tractor

    Contributions to the three-dimensional virtual treatment planning of orthognathic surgery

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    Orientadores: José Mario De Martino, Luis Augusto PasseriTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: A tecnologia mais recente à disposição da Cirurgia Ortognática possibilita que o diagnóstico e o planejamento do tratamento das deformidades dentofaciais sejam realizados sob uma representação virtual tridimensional (3D) da cabeça do paciente. Com o propósito de contribuir para o aperfeiçoamento desta tecnologia, o trabalho apresentado nesta tese identificou e tratou quatro problemas. A primeira contribuição consistiu na verificação da validade da hipótese de que a mudança de definição do plano horizontal de Frankfort não produz diferenças de medição clinicamente relevantes quando sob indivíduos cujos crânios são consideravelmente simétricos. Os resultados da análise realizada no contexto deste tese indicam que, ao contrário do que se presumia, a hipótese é falsa. A segunda contribuição consistiu na extensão do método de análise cefalométrica de McNamara para que ele pudesse produzir valores 3D. Ao contrário de outros métodos de análise cefalométrica 3D, a extensão criada produz valores verdadeiramente 3D, não perde as informações do método original e preserva as definições geométricas originais das linhas e planos cefalométricos. A terceira contribuição consistiu a) no estabelecimento de normas cefalométricas para brasileiros adultos de ascendência europeia, a partir de imagens de tomografia computadorizada de feixe cônico, que produz uma imagem craniofacial mais precisa e confiável do que a telerradiografia; e b) na avaliação de dimorfismo sexual, para a identificação de características anatômicas diferenciadas entre homens e mulheres desta população. A quarta e última contribuição consistiu na automatização da principal etapa da tecnologia em questão, na qual o cirurgião executa o reposicionamento dos segmentos ósseos maxilares no crânio. O método criado é capaz de corrigir automaticamente os problemas dentofaciais mais comuns tratados pela Cirurgia Ortognática, que envolvem maloclusão esquelética, assimetria facial e discrepância de maxilares. Todas as contribuições deste trabalho foram publicadas em periódicos internacionais do campo da Odontologia e afinsAbstract: The latest technology available for orthognathic surgery allows the diagnosis and treatment planning of dentofacial deformities based on a three-dimensional (3D) virtual representation of the patient's head. In order to contribute to the improvement of this technology, the work presented in this thesis identified and treated four problems. The first contribution consisted in testing the validity of the hypothesis that changing the definition of the Frankfort horizontal plane does not produce clinically relevant measurement differences for subjects whose skulls are considerably symmetrical. The results of the analysis performed in this thesis indicate that, contrary to what was presumed, the hypothesis is false. The second contribution is an extension of the McNamara's method of cephalometric analysis to produce 3D values. Unlike other methods of 3D cephalometric analysis, the extension produces true 3D values, does not lose information captured by the original method, and preserves the original geometric definitions of the cephalometric lines and planes. The third contribution consisted in a) establishing cephalometric norms for Brazilian adults of European descent, based on images from cone-beam computed tomography, which produce a more accurate and reliable craniofacial image than cephalometric radiography; and b) evaluating sexual dimorphism, for the identification of distinct anatomic features between males and females of this population. The fourth contribution consisted in automating the main stage of the technology in question, in which the surgeon performs the positioning of jaw bone segments in the skull. The created method is able to automatically correct the most common dentofacial problems treated by orthognathic surgery, which involves skeletal malocclusion, facial asymmetry, and jaw discrepancy. The contributions of this work were published in international journals of the field of Dentistry and relatedDoutoradoEngenharia de ComputaçãoDoutor em Engenharia ElétricaCAPE

    Tensile force monitoring on large winch-assist forwarders operating in British Columbia

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    The forest industry around the world is facing common challenges in accessing wood fiber on steep terrain. Fully mechanized harvesting systems based on specialized machines, such as winch-assist forwarders, have been specifically developed for improving the harvesting perfor- mances in steep grounds. While the mechanization process is recognized as a safety benefit, the use of cables for supporting the machine traction needs a proper investigation. Only a few studies have analyzed the cable tensile forces of winch-assist forwarders during real operations, and none of them focused on large machines normally used in North America. Consequently, a preliminary study focused on tensile force analysis of large winch-assist forwarders was conducted in three sites in the interior of British Columbia during the fall of 2017. The results report that in 86% of the cycles, the maximum working load of the cable was less than one-third of the minimum breaking load. The tensile force analysis showed an expected pattern of minimum tensile forces while the forwarders were traveling or unloading on the road site and high tensile forces when operating on steep trails, loading or traveling. Further analysis found that the maximum cycle tensile forces occurred most frequently when the machines were moving uphill, independently of whether they were empty or loaded. While the forwarders were operating on the trails, slope, travel direction, and distance of the machines from the anchor resulted statistically significant and able to account for 49% of tensile force variability. However, in the same conditions, the operator settings accounted for 77% of the tensile force variability, suggesting the human factor as the main variable in cable tensile force behavior during winch-assist operations

    GIS applications in forest operations and road network planning: An overview over the last two decades

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    A systematic literature review was settled to investigate the application of GIS in terms of methods, complexity and accuracy to support decision on forestry operations and forest road network planning. A comprehensive search for relevant studies was performed to retrieve as many relevant international scientific publications dealing with forestry operations and forest road network planning in the period 1996\u20132015. The analysis was based on the development of a systematic literature review comprising three steps: \uf0de implementation of the database searches by well-defined search terms \uf0de identification of all the publications meeting the requirements of the search terms by abstract \uf0de choice of the most relevant publications analysis of the contents. In this review, \ubbGIS and forest operations\uab includes all the descriptors dealing with GIS ap- plied to support forest operations decision and analysis, while \ubbGIS and forest roads\uab includes all the papers dealing with the analysis, management and planning of forest road or forest road networks. A total of 372 references and 82 publications were selected for the analysis as they were clearly in conformity with the review topics (GIS applications in forest operations and road network planning). The analysis showed that GIS has also been applied successfully and unambiguously to har- vesting and transportation engineering in forest operations management. Further to the pre- vailing use concerning applications to support tactical planning, a significant number of recent publications have turned successfully to GIS applied at operational level. Again, despite the prevailing use concerning applications to support tactical planning, a significant number of recent publications have also turned successfully to GIS applied at operational level with the topics of Forest Operations Management in terms of optimization, productivity and safety analysis. By considering the recent evolution and improvement of GIS technology and the increasing availability of spatial data, as well their improvement in quality and resolution, the application of GIS in forest harvesting and transportation engineering as well as in forest operations management will expand in the near future

    Tractor cabin ergonomics analyses by means of Kinect motion capture technology

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    Kinect is the de facto standard for real-time depth sensing and motion capture cameras. The sensor is here proposed for exploiting body tracking during driving operations. The motion capture system was developed taking advantage of the Microsoft software development kit (SDK), and implemented for real-time monitoring of body movements of a beginner and an expert tractor drivers, on different tracks (straight and with curves) and with different driving conditions (manual and assisted steering). Tests show how analyses can be done not only in terms of absolute movements, but also in terms of relative shifts, allowing for quantification of angular displacements or rotations

    The Myopathic Protein Myotilin in Developing Mouse and in Muscle Function

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    Skeletal muscle cells are highly specialised in order to accomplish their function. During development, the fusion of hundreds of immature myoblasts creates large syncytial myofibres with a highly ordered cytoplasm filled with packed myofibrils. The assembly and organisation of contractile myofibrils must be tightly controlled. Indeed, the number of proteins involved in sarcomere building is impressive, and the role of many of them has only recently begun to be elucidated. Myotilin was originally identified as a high affinity a-actinin binding protein in yeast twohybrid screen. It was then found to interact also with filamin C, actin, ZASP and FATZ-1. Human myotilin is mainly expressed in striated muscle and induces efficient actin bundling in vitro and in cells. Moreover, mutations in myotilin cause different forms of muscle disease, now collectively known as myotilinopathies. In this thesis, consisting of three publications, the work on the mouse orthologue is presented. First, the cloning and molecular characterisation of the mouse myotilin gene showed that human and mouse myotilin share high sequence homology and a similar expression pattern and gene regulation. Functional analysis of the mouse promoter revealed the myogenic factor-binding elements that are required for myotilin gene transcription. Secondly, expression of myotilin was studied during mouse embryogenesis. Surprisingly, myotilin was expressed in a wide array of tissues at some stages of development; its expression pattern became more restricted at perinatal stages and in adult life. Immunostaining of human embryos confirmed broader myotilin expression compared to the sarcomeric marker titin. Finally, in the third article, targeted deletion of myotilin gene in mice revealed that it is not essential for muscle development and function. These data altogether indicate that the mouse can be used as a model for human myotilinopathy and that loss of myotilin does not alter significantly muscle structure and function. Therefore, disease-associated mutant myotilin may act as a dominant myopathic factor.Myotiliini on lihaksen niin kutsutuissa Z-linjassa sijaitseva proteiini, joka toimii omalta osaltaan lihaksen sarkomeerien rakenteen säilyttäjänä ja organisoijana. Myotiliinimutaatiot aiheuttavat erilaisia lihassairauksia, esimerkiksi Limb-Girdle Muscular Dystrophy ja Myofibrillar Myopathy. Myotiliini sitoutuu itsensä ja erilaisia sarkomeerin proteiinia: alfa-aktiniini, aktiini, filamiini C, FATZ ja ZASP. Väitöskirjassa on kolme töitä. Ensimmäisessä selvitettiin hiiren myotiliini geeni ja promoottori. Toisessa osatyössä kartoitettiin myotiliinin ilmentyminen hiiren ja osaksi myös ihmisen sikiönkehityksen eri vaiheissa. Kolmannessa osatyössä tuotettiin myotiliinin suhteen poistogeeninen hiirimalli ja selvitettiin poiston seuraukset. Työ osoitti ettei myotiliinin suhteen poistogeenisellä hiirellä ole normaali-olosuhteissa poikkeavaa fenotyyppiä, myotiliini ei ole välttämätön/on korvattavissa lihasten sikiönkehityksessä ja toiminnassa

    Estudo e implementação de um processo de fabricação de microponteiras de Si utilizando plasma de hexafluoreto de enxofre e oxigenio

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    Orientador: Edmundo da Silva BragaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de ComputaçãoResumo: Desenvolvemos e caracterizamos um processo de fabricação de microponteiras de silício utilizando plasma de radiofreqüência (RF). Foram estabelecidos processos de corrosão iônica reativa (RIE) do silício e dióxido de silício em um reator de placas paralelas utilizando SF6 e a mistura gasosa SF6/O2. Foram caracterizadas as grandezas exigidas ao processo de fabricação, tais como taxa de corrosão, seletividade, anisotropia e qualidade da superfície, e foram comparadas a outros processos. Foram analisados e caracterizados os mecanismos de corrosão do processo desenvolvido. Microponteiras de silício com diferentes razões de aspectos foram caracterizadas e fabricadas utilizando a mistura gasosa em diferentes proporções. Os melhores resultados foram obtidos utilizando-se um plasma com uma concentração de 25% de oxigênio e 75% de hexafluoreto de enxofreAbstract: We have developed and characterized a silicon microtip fabrication process using radiofrequency (RF) plasma. Reactive Ion Etching processes of silicon and silicon dioxide in a parallel plate reactor were established using SF6 and SF6/O2 gas mixture. The parameters of the fabrication process, such as the etch rate, selectivity, anisotropy and surface quality were characterized and compared with other processes. The etching mechanisms of the developed process were analyzed and characterized. Silicon microtips with different aspect ratios were fabricated and characterized using the gaseous mixture at different concentrations. The best results were obtained using plasma comprised of 25% of oxygen and 75% of sulfur hexafluorideMestradoEletrônica, Microeletrônica e OptoeletrônicaMestre em Engenharia Elétric
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