189 research outputs found

    Iterated tubular algebras

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    Analysis by Finite Element Method to Redesign a Jointed-Telescopic Crane for Elevation of Personnel

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    This paper proposes a numerical assessment of a crane for elevation of personnel by finite element analysis, validated with experimental data from constituent components of the crane. The original design of the crane consists of a jointed section of coplanar arms and a telescopic section of collinear arms. As a reference, the standard ANSI/SIA 92.2 was used to determine maximum loads and the consequent effects on the constituent components of the crane. This standard is suitable for crane designs distributed and commercialized in Mexico. The proposed numerical analysis is carried out through a finite element analysis, which is based on the assembly method of kinematic pairs, taking into account dynamic loads and their resulting reaction at each element. The mechanical performance of each component is assessed with the minimal security factor parameter. However, in those components where the MSF was insufficiently in accordance with the standard, a variety of modifications to redesign a given component was proposed. Subsequently, a detailed structural analysis on the proposed redesign was carried out, in which higher security factors were obtained in comparison to the original design. Finally, the numerical results of the proposed redesign were validated through experimental measurements of strain, using strain gauges attached on a crane prototype, which was manufactured according to the proposed redesigned model.Наведено чисельний розрахунок підйомного крана для підняття персоналу на основі скінченноелементного аналізу, підтверджений експериментальними даними по складових його компонентах. Оригінальна модель підйомного крана включає зчленовані секції компланарних стріл і телескопічної секції колінеарних стріл. Максимальні навантаження та іх вплив на складові компоненти підйомного крана визначено згідно зі стандартом ANSI/SIA 92.9, що використовується для моделей підйомного крана, розповсюджених і комерціалізованих у Мексиці. Скінченноелементний аналіз базується на методі складання кінематичних пар з урахуванням динамічного навантаження та їх результуючої реакції на кожен елемент. Механічні характеристики кожного компонента оцінюються за параметром мінімального фактора безпеки. Однак у тих компонентах, де цей фактор не відповідає стандарту, пропонується безліч модифікацій для перепроектування даного компонента. Проведено детальний структурний аналіз запропонованої їх модернізації й отримано більш високі фактори безпеки порівняно з оригінальною моделлю. Чисельні результати запропонованої модернізації підтверджено експериментальними вимірюваннями деформацій при використанні тензодатчиків, установлених на прототипі підйомного крана, який виготовлено згідно із запропонованою перепроектованою моделлю.Представлен численный расчет подъемного крана для поднятия персонала на основе конечноэлементного анализа, подтвержденный экспериментальными данными по составным его компонентам. Оригинальная модель подъемного крана состоит из сочлененных секций компланарных стрел и телескопической секции коллинеарных стрел. Максимальные нагрузки и их влияние на составные компоненты подъемного крана определены согласно стандарту ANSI/SIA 92.2, применяемому для моделей подъемного крана, распространенных и коммерциализированных в Мексике. Конечноэлементный анализ основан на методе сборки кинематических пар с учетом динамических нагрузок и их результирующей реакции на каждый элемент. Механические характеристики каждого компонента оценены по параметру минимального фактора безопасности. Однако в тех компонентах, где этот фактор не соответствует стандарту, предложено множество модификаций для перепроектирования данного компонента. Выполнен также подробный структурный анализ предложенной их модернизации и получены более высокие факторы безопасности по сравнению с оригинальной моделью. Численные результаты предложенной модернизации подтверждены экспериментальными измерениями деформаций при использовании тензодатчиков, установленных на прототипе подъемного крана, который был изготовлен согласно предложенной перепроектированной модели

    SEOM clinical guidelines in early stage breast cancer (2018)

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    Breast cancer is the most common cancer in women in our country and it is usually diagnosed in the early and potentially curable stages. Nevertheless, around 20–30% of patients will relapse despite appropriate locoregional and systemic therapies. A better knowledge of this disease is improving our ability to select the most appropriate therapy for each patient with a recent diagnosis of an early stage breast cancer, minimizing unnecessary toxicities and improving long-term efficacy

    The first Hochschild cohomology group of a schurian cluster-tilted algebra

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    Given a cluster-tilted algebra B we study its first Hochschild cohomology group HH1(B) with coefficients in the B-B-bimodule B. We find several consequences when B is representation-finite, and also in the case where B is cluster-tilted of type Ã.Fil: Assem, Ibrahim. University of Sherbrooke; CanadáFil: Redondo, Maria Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Matemática Bahía Blanca. Universidad Nacional del Sur. Departamento de Matemática. Instituto de Matemática Bahía Blanca; Argentin

    Recommendations by the Spanish Society of Hospital Pharmacy, the Spanish Society of Oncology Nursing and the Spanish Society of Medical Oncology for the safe management of antineoplastic medication in cancer patients

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    Aim: To define recommendations that permit safe management of antineoplastic medication, minimise medication errors and improve the safety of cancer patients undergoing treatment. Methods: By reviewing the literature and consulting the websites of various health organisations and agencies, an expert committee from the Spanish Society of Hospital Pharmacy and the Spanish Society of Medical Oncology defined a set of safe practices covering all stages of providing cancer therapy to patients. The Spanish Society of Oncology Nursing revised and endorsed the final list. Results: In total, 68 recommendations arranged in five sections were defined. They include issues concerning the training of health professionals, the technological resources needed, treatment planning, informing the patient and his/her family, the processes of prescribing, preparing, dispensing and administering cancer therapy (orally, parenterally or intrathecally), assessing patient adherence and treatment toxicity. Conclusions: It is essential for healthcare establishments to implement specific measures designed to prevent medication errors, in order to ensure the safety of cancer patients treated with antineoplastic medication

    User-friendly tail bounds for sums of random matrices

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    This paper presents new probability inequalities for sums of independent, random, self-adjoint matrices. These results place simple and easily verifiable hypotheses on the summands, and they deliver strong conclusions about the large-deviation behavior of the maximum eigenvalue of the sum. Tail bounds for the norm of a sum of random rectangular matrices follow as an immediate corollary. The proof techniques also yield some information about matrix-valued martingales. In other words, this paper provides noncommutative generalizations of the classical bounds associated with the names Azuma, Bennett, Bernstein, Chernoff, Hoeffding, and McDiarmid. The matrix inequalities promise the same diversity of application, ease of use, and strength of conclusion that have made the scalar inequalities so valuable.Comment: Current paper is the version of record. The material on Freedman's inequality has been moved to a separate note; other martingale bounds are described in Caltech ACM Report 2011-0

    Estructura y evolución tectónica del sector oriental del margen continental cantábrico: resultados de los perfiles de sísmica multicanal MARCONI

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    El Golfo de Vizcaya se formó durante el Cretácico como consecuencia de la apertura del Océano Atlántico. La convergencia entre las placas Euroasiática e Ibérica durante el Cenozoico dio lugar al levantamiento de la cordillera pirenaico-cantábrica y al cierre parcial del Golfo de Vizcaya. La mayor parte de esta deformación tiene lugar en el margen Noribérico, haciendo de este área un lugar único para estudiar los estadios iniciales de la deformación de un margen pasivo. En el verano de 2003, el experimento sísmico MARCONI permitió adquirir 11 perfiles de sísmica de reflexión vertical profunda utilizando el buque Hespérides, lo que ha proporcionado una nueva imagen 3D de la estructura cortical del sector SE del Golfo de Vizcaya. Los datos muestran que la estructura de este margen se caracteriza por una espesa secuencia de sedimentos meso-cenozoicos (hasta 4 s TWT, hasta > 6 km) parcialmente deformada por cabalgamiento y pliegues asociados, vergentes al N. Se han diferenciado tres conjuntos sedimentarios separados por discordancias que se corresponden con las secuencias alpinas pre-, sin- y postectónicas. Los datos sísmicos muestran también la existencia de cuencas mesozoicas con evidencias de inversión tectónica y la existencia de fallas y estructuras laterales coincidiendo con los importantes cañones submarinos de dirección aproximada N-S. Teniendo tambien en cuenta otros datos geofísicos, la estructura general del sector SE del Golfo de Vizcaya se ha interpretado como una corteza continental adelgazada o transicional deslizada hacia el S por debajo del extremadamente abrupto y muy deformado talud continental Noribérico

    Determinants of the current and future distribution of the West Nile virus mosquito vector Culex pipiens in Spain

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    Changes in environmental conditions, whether related or not to human activities, are continuously modifying the geographic distribution of vectors, which in turn affects the dynamics and distribution of vector-borne infectious diseases. Determining the main ecological drivers of vector distribution and how predicted changes in these drivers may alter their future distributions is therefore of major importance. However, the drivers of vector populations are largely specific to each vector species and region. Here, we identify the most important human-activity-related and bioclimatic predictors affecting the current distribution and habitat suitability of the mosquito Culex pipiens and potential future changes in its distribution in Spain. We determined the niche of occurrence (NOO) of the species, which considers only those areas lying within the range of suitable environmental conditions using presence data. Although almost ubiquitous, the distribution of Cx. pipiens is mostly explained by elevation and the degree of urbanization but also, to a lesser extent, by mean temperatures during the wettest season and temperature seasonality. The combination of these predictors highlights the existence of a heterogeneous pattern of habitat suitability, with most suitable areas located in the southern and northeastern coastal areas of Spain, and unsuitable areas located at higher altitude and in colder regions. Future climatic predictions indicate a net decrease in distribution of up to 29.55%, probably due to warming and greater temperature oscillations. Despite these predicted changes in vector distribution, their effects on the incidence of infectious diseases are, however, difficult to forecast since different processes such as local adaptation to temperature, vector-pathogen interactions, and human-derived changes in landscape may play important roles in shaping the future dynamics of pathogen transmission.info:eu-repo/semantics/acceptedVersio

    Exploring Health Science Students’ Notions on Organ Donation and Transplantation: A Multicenter Study

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    The knowledge acquired during university education about organ donation and transplantation (ODT) decisively influences the information future health professionals transmit. This is important in ODT where the participation of the general public is essential to obtain organs. Objective: To determine notions of Spanish medicine and nursing students on ODT and its relationship with attitude toward ODT. Methods and Design: and design. We conducted a sociologic, multicenter, and observational study. The population for our study consisted of medical and nursing students in Spanish universities. Our database was the Collaborative International Donor Project, stratified by geographic area and academic course. A validated questionnaire (PCID-DTO-RIOS) was self-administered and completed anonymously. Our sample consisted of 9598 medical and 10, 566 nursing students (99% confidence interval; precision of ±1%), stratified by geographic area and year of study. Results: The completion rate for our study was 90%. Only 20% (n=3640) of students thought their notions on ODT were good; 41% (n=7531) thought their notions were normal; 36% (n=6550) thought their notions were scarce. Comparing groups, there were differences between those who believed that their notions on ODT were good (44% nursing vs 56% medical students; P < .000), and those who believed it scarce (54% nursing vs 46% medical students; P < .000). Notions on ODT were related with attitude toward the donation of one''s own organs: those who considered their notions were good were more in favor then those who considered it scarce (88% vs 72%; P < .000). Conclusion: Only 20% of Spanish medical and nursing students thought their notions on ODT were good. Having good knowledge is related to a favorable attitude towards ODT. Receiving specific information on the subject could improve their knowledge about ODT during their training
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