87,476 research outputs found
A novel thermomechanics-based lifetime prediction model for cycle fatigue failure mechanisms in power semiconductors
No full textIn this paper, we propose different procedures to extract the statistical distribution of the thermal cycles suffered by power devices submitted to arbitrary mission profiles and we discuss the different lifetimes predicted by them under the assumption of linear accumulation of the damage produced by low cycling fatigue. Furthermore, we introduce a novel prediction procedure, which is based on some fundamental equations, which take into consideration the creep experienced by compliant materials when they are submitted to thermal cycles
Lifetime prediction and design of reliability tests for high power devices in automotive applications
No full textCombining biological and hydrogeological approaches: The grass Molinia arundinacea as a possible bioindicator of temporary perched aquifers in ophiolitic systems
No full textMicro-climatic controls and warming effects on flowering time in alpine snowbeds
No full textAlpine snowbed communities are among the habitats most threatened by climate change. The warmer temperature predicted, coupled with advanced snowmelt time, will influence flowering phenology, which is a key process in species adaptation to changing environmental conditions and plant population dynamics. However, we know little about the effects of changing micro-climate on flowering time in snowbeds and the mechanisms underlying such phenological responses. The flowering phenology of species inhabiting alpine snowbeds was assessed with weekly observations over five growing seasons. We analysed flowering time in relation to micro-climatic variation in snowmelt date, soil and air temperature, and experimental warming during the snow-free period. This approach allowed us to test hypotheses concerning the processes driving flowering phenology. The plants were finely tuned with inter-annual and intra-seasonal variations of their micro-climate, but species did not track the same micro-climatic feature to flower. At the growing-season time-scale, the air surrounding the plants was the most common trigger of the blooming period. However, at the annual time-scale, the snowmelt date was the main controlling factor for flowering time, even in warmer climate. Moreover, spatial patterns of the snowmelt influenced the developmental rate of the species because in later snowmelt sites the plants needed a lower level of heat accumulation to enter anthesis. Phenological responses to experimental warming differed among species, were proportional to the pre-flowering time-span of plants, and did not show consistent trends of change over time. Finally, warmer temperature produced an overall increase of flowering synchrony both within and among plant specie
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Effects of Wood-Derived Biochar on Soil Respiration of a European Beech Forest Under Current Climate and Simulated Climate Change
No full textBiochar (BCH) amendments represent a valuable strategy for increasing forest carbon stock, but their effects on soil respiration of beech forests under climate change are largely unknown. We conducted a short-term mesocosm experiment investigating the impact of BCH applications (0%, 10%, 20%, and 50%, v/v) on respiration of a European beech forest soil in N-Italy. The experiment, carried out in Parma, was conducted under both ambient and modified climatic conditions, involving higher soil temperatures (c. +1 K) and reduced precipitation (−50%). The experiment was performed during autumn 2022 and repeated in spring 2023, periods representing late and early summer, respectively. Soil respiration significantly increased with BCH applications when compared to controls, irrespective of the percentage applied. The highest values were recorded in the 20% amendment, while values were significantly lower in BCH 50%, similar to those recorded in BCH 10%. Although soil respiration and soil temperature were positively correlated, no effect of simulated warming was observed. No effects of precipitation reduction were also found, despite respiration being significantly influenced by soil moisture. These results provide an initial insight into the potentially negligible impact of BCH applications on soil respiration in European beech forests under both current and future climate scenarios
Surgical outcome of combined pulmonary and atrial resection for lung cancer.
No full textOBJECTIVES: The study was carried out to assess the short and long-term outcome of patients with non-small cell lung cancer infiltrating the left atrium treated by surgery.
METHODS: We retrospectively collected the hospital files of twenty-three consecutive patients operated on between 1982 and 2001 in two units of Thoracic Surgery. Four patients received an induction regimen. Fourteen right pneumonectomies, 8 left pneumonectomies and 1 right inferior lobectomy were performed. No cardiopulmonary bypass was employed.
RESULTS: In all patients the diagnosis of T4 atrial invasion was confirmed by pathological examination. A complete resection was achieved in nineteen patients (83%). With respect to nodal staging, there were 13 N0, 5 N1 and 4 N2 cases, respectively. Two deaths occurred during the one month postoperative period (9%). Three patients had postoperative atrial fibrillation. Two other patients had postpneumonectomy empyema without bronchopleural fistula and recovered, one after thoracoscopic debridement and the second after open window thoracostomy. Follow-up was completed on September 2002; only one patient was lost to follow-up. Median survival, excluding the perioperative mortality, was 20 months (range 4 - 62 months). The survival rate, calculated with the Kaplan-Meier method, was estimated as 63% at 1 year, 2 % at 3 years and 10% at 5 years. Using a Cox model analysis, lymph node stage and completeness of resection were not independent prognostic factors.
CONCLUSIONS: In cases of NSCLC with left atrial invasion complete resection is technically feasible in most instances without cardiopulmonary bypass. The acceptable operative risk and the encouraging long-term survival observed in this series suggest that NSCLC invading the left atrium should not be systematically considered as a definitive contraindication to surgery
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
- …
