46,772 research outputs found

    Evaluación del desempeño sísmico de un edificio aislado con irregularidad torsional

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    Perú es un país ubicado en una región de alto peligro sísmico, y es una tarea de la ingeniería diseñar y construir edificaciones de baja vulnerabilidad ante los efectos destructivos del movimiento del terreno. Los sistemas modernos de protección sísmica como aisladores de base permiten este propósito; sin embargo, el uso de estos dispositivos en edificios de tipologías especiales, como el caso de edificios con demandas de torsión resulta necesario estudiar para comprobar su efectividad en la protección de los edificios. La norma técnica de aislamiento sísmico E.031, permite el uso de aisladores de base en edificios con irregularidad torsional; no obstante, en la actualidad no existe estudios que evidencien, si el uso de aisladores de base en edificios con demandas de torsión, dentro de los límites que acepta la norma técnica E.031 permite un adecuado desempeño sísmico de la superestructura. El objetivo principal de este trabajo es demostrar si los sistemas de aislamiento sísmico protegen adecuadamente los edificios con problemas de torsión, mediante el estudio de un caso. Se diseñó un edificio aislado de 5 pisos ubicado en la zona costera del Perú, con irregularidad torsional, el diseño se realizó de acuerdo a los requerimientos de las normas peruanas. Luego se realizó el análisis dinámico incremental (IDA) para 7 pares de registros sísmicos representativos de terremotos de subducción de la costa peruana. Se obtuvieron relaciones entre la máxima aceleración del suelo (PGA) y las rotaciones inelásticas en columnas del primer nivel, también se relacionó a las derivas de entrepiso. Para el modelo no lineal del edificio se utilizó los lineamientos del ASCE/SEI-41-13, 2014. Para valores de PGA de 0.25g todos los elementos están en el rango elástico y para el valor de 0.675g (sismo con periodo de retorno de 2475 años) los valores de los giros inelásticos en los elementos estructurales alcanzan el 26% del umbral de daño correspondiente a ocupación inmediata. Al emplear la relación daño-deriva sugerida por HAZUS para edificios convencionales los resultados indican que el edifico habría superado el umbral de daño moderado sin superar el umbral de daño extensivo. Esta aparente contradicción con los resultados de las rotaciones inelásticas en los elementos se debe a que la relación dañoderiva sugerida por HAZUS corresponde a edificios de base fija diseñados con factores de reducción de fuerzas sísmica

    Does international patent collaboration have an effect on entrepreneurship?

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    .Entrepreneurship is one of the main pillars of growth in any economy. Achieving a high rate of entrepreneurship in a region has become the priority objective of governments and firms. However, in many cases, new firm creation is conditioned by relations or collaboration in innovation with agents from other countries. Previous literature has analyzed the mechanisms that foster entrepreneurship. This paper attempts to shed light on the influence of international patent collaboration (IPC) on entrepreneurial activity at country level taking into account the timing of this relationship. An empirical study is proposed to verify whether IPC leads to greater entrepreneurship and to analyze the gestation period between international patenting actions and firm creation. Using the Generalized Method of Moments, the two hypotheses proposed were tested in a data panel of 30 countries for the period 2005–2017. Results show the influence of IPC in promoting entrepreneurship in the same year, but especially in the following year. The study offers implications for entrepreneurs and public agents. IPC affects the integration and interaction of international agents in a country, favors the production of new knowledge, and increases positive externalities in a territory. All this facilitates the creation of new companies with a high innovative component.S

    Layout optimization of structures with distributed self-weight, lumped masses and frictional supports

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    The well-known ‘ground structure’-based truss layout optimization method has recently been extended to allow accurate modelling of distributed self-weight. By incorporating equally stressed catenaries in the ground structure, non-conservative errors caused by neglecting bending effects within members carrying their own weight are eliminated. However, in cases where the self-weight of a structure has a favourable role in supporting the applied loads, solutions that include convoluted arrangements of overlapping elements may often be generated. To address this, an enhanced layout optimization formulation is proposed that explicitly allows inclusion of favourable unstressed masses, such as counterweights. Frictional supports are also modelled and the cost of abutments and anchorages taken account of in the formulation. The efficacy of the proposed methodology is demonstrated through application to benchmark examples and to the conceptual design of a simplified long-span bridge structure, considering both ground anchored and self-anchored alternatives

    Coloniality and the Courtroom: Understanding Pre-trial Judicial Decision Making in Brazil

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    This thesis focuses on judicial decision making during custody hearings in Rio de Janeiro, Brazil. The impetus for the study is that while national and international protocols mandate the use of pre-trial detention only as a last resort, judges continue to detain people pre-trial in large numbers. Custody hearings were introduced in 2015, but the initiative has not produced the reduction in pre-trial detention that was hoped. This study aims to understand what informs judicial decision making at this stage. The research is approached through a decolonial lens to foreground legacies of colonialism, overlooked in mainstream criminological scholarship. This is an interview-based study, where key court actors (judges, prosecutors, and public defenders) and subject matter specialists were asked about influences on judicial decision making. Interview data is complemented by non-participatory observation of custody hearings. The research responds directly to Aliverti et al.'s (2021) call to ‘decolonize the criminal question’ by exposing and explaining how colonialism informs criminal justice practices. Answering the call in relation to judicial decision making, findings provide evidence that colonial-era assumptions, dynamics, and hierarchies were evident in the practice of custody hearings and continue to inform judges’ decisions, thus demonstrating the coloniality of justice. This study is significant for the new empirical data presented and theoretical innovation is also offered via the introduction of the ‘anticitizen’. The concept builds on Souza’s (2007) ‘subcitizen’ to account for the active pursuit of dangerous Others by judges casting themselves as crime fighters in a modern moral crusade. The findings point to the limited utility of human rights discourse – the normative approach to influencing judicial decision making around pre-trial detention – as a plurality of conceptualisations compete for dominance. This study has important implications for all actors aiming to reduce pre-trial detention in Brazil because unless underpinning colonial logics are addressed, every innovation risks becoming the next lei para inglês ver (law [just] for the English to see)

    Exploring the effects of spinal cord stimulation for freezing of gait in parkinsonian patients

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    Dopaminergic replacement therapies (e.g. levodopa) provide limited to no response for axial motor symptoms including gait dysfunction and freezing of gait (FOG) in Parkinson’s disease (PD) and Richardson’s syndrome progressive supranuclear palsy (PSP-RS) patients. Dopaminergic-resistant FOG may be a sensorimotor processing issue that does not involve basal ganglia (nigrostriatal) impairment. Recent studies suggest that spinal cord stimulation (SCS) has positive yet variable effects for dopaminergic-resistant gait and FOG in parkinsonian patients. Further studies investigating the mechanism of SCS, optimal stimulation parameters, and longevity of effects for alleviating FOG are warranted. The hypothesis of the research described in this thesis is that mid-thoracic, dorsal SCS effectively reduces FOG by modulating the sensory processing system in gait and may have a dopaminergic effect in individuals with FOG. The primary objective was to understand the relationship between FOG reduction, improvements in upper limb visual-motor performance, modulation of cortical activity and striatal dopaminergic innervation in 7 PD participants. FOG reduction was associated with changes in upper limb reaction time, speed and accuracy measured using robotic target reaching choice tasks. Modulation of resting-state, sensorimotor cortical activity, recorded using electroencephalography, was significantly associated with FOG reduction while participants were OFF-levodopa. Thus, SCS may alleviate FOG by modulating cortical activity associated with motor planning and sensory perception. Changes to striatal dopaminergic innervation, measured using a dopamine transporter marker, were associated with visual-motor performance improvements. Axial and appendicular motor features may be mediated by non-dopaminergic and dopaminergic pathways, respectively. The secondary objective was to demonstrate the short- and long-term effects of SCS for alleviating dopaminergic-resistant FOG and gait dysfunction in 5 PD and 3 PSP-RS participants without back/leg pain. SCS programming was individualized based on which setting best improved gait and/or FOG responses per participant using objective gait analysis. Significant improvements in stride velocity, step length and reduced FOG frequency were observed in all PD participants with up to 3-years of SCS. Similar gait and FOG improvements were observed in all PSP-RS participants up to 6-months. SCS is a promising therapeutic option for parkinsonian patients with FOG by possibly influencing cortical and subcortical structures involved in locomotion physiology

    Advantages of Ion Mobility Coupled with HPLC/UPLC

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    Ion mobility is a new separation technique that can be coupled with high performance liquid chromatography (HPLC) or ultra-performance liquid chromatography (UPLC). Variances in cross-sectional ionic areas of different molecules create differential speeds through a gas allowing for millisecond separations. Combining ion mobility with both liquid chromatography and mass spectrometry with fragmentation, separations can be achieved on the second (HPLC), millisecond (ion mobility), and microsecond (mass spectrometry) timescales. This orthogonal separation greatly cleans up mass spectral data of co-eluting peaks from the liquid chromatography and adds to the descriptive data of each ion. With descriptive data such as retention time, cross-sectional area, m/z ratio, and mass spectral fragmentation, many options become available for analytical analysis. Options ranging from descriptive data collation into instrument libraries to sensitivity enhancement for trace analysis will be explored in this chapter along with the description of different forms of ion mobility

    Development of an Electrodialysis (ED) Desalination System Using Cement Mortar-Structured Zeolite Membranes from Corn Stover (Zea Mays) Ash

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    Zeolite A was synthesized from corn (Zea Mays) stover ash using a hydrothermal method. The corn stover ash and synthesized zeolite A were characterized by X-ray fluorescence (XRF), thermogravimetry (TG-DTA), Brunauer-Emmert-Teller (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The effects of calcination time, fusion ratios, and curing time were examined. The yield and cation exchange capacity (CEC) of the synthesized zeolite A were investigated using statistical test via the Response Surface Methodology employing a Central Composite Design through the multiple objective optimizations with desirability function. The obtained optimum parameters for the maximum % yield (75.08%) and CEC (2.282 meq/g) were as follows: calcination temperature (534.5oC), fusion ratios (1:1.708), and curing time (10.50 hours). The maximum overall desirability of 0.5970 was attained. Response surface methodology by a two-level full factorial central composite design optimized the binder ratios, applied voltage and cell pair for cement mortar-structured zeolite membrane employing synthesized zeolite A in hydrogen form (zeolite HA) in an electrodialysis (ED) desalination system. All of the variables examined, specifically the binder ratio (15.00%), the applied voltage (15.00V), and the number of stacked cell pairs (3 pairs) were found to have an influence on sodium ion removal (80.68%). The developed model enables prediction of the separation percentage of an ED cell under various operating conditions. In summary, an ED desalination system built on corn stover-based cement mortar-structured zeolite membranes was proven to be an efficient alternative method for treating saltwater or brackish water and ultimately producing fresh water. The study successfully demonstrated its aim to develop a technology application that is novel and is a potent alternative for an ED desalination system that is simple, economical, and readily available for rural communities to gain access to clean and freshwater

    Walking with the Earth: Intercultural Perspectives on Ethics of Ecological Caring

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    It is commonly believed that considering nature different from us, human beings (qua rational, cultural, religious and social actors), is detrimental to our engagement for the preservation of nature. An obvious example is animal rights, a deep concern for all living beings, including non-human living creatures, which is understandable only if we approach nature, without fearing it, as something which should remain outside of our true home. “Walking with the earth” aims at questioning any similar preconceptions in the wide sense, including allegoric-poetic contributions. We invited 14 authors from 4 continents to express all sorts of ways of saying why caring is so important, why togetherness, being-with each others, as a spiritual but also embodied ethics is important in a divided world

    How to Be a God

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    When it comes to questions concerning the nature of Reality, Philosophers and Theologians have the answers. Philosophers have the answers that can’t be proven right. Theologians have the answers that can’t be proven wrong. Today’s designers of Massively-Multiplayer Online Role-Playing Games create realities for a living. They can’t spend centuries mulling over the issues: they have to face them head-on. Their practical experiences can indicate which theoretical proposals actually work in practice. That’s today’s designers. Tomorrow’s will have a whole new set of questions to answer. The designers of virtual worlds are the literal gods of those realities. Suppose Artificial Intelligence comes through and allows us to create non-player characters as smart as us. What are our responsibilities as gods? How should we, as gods, conduct ourselves? How should we be gods
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