141 research outputs found

    Otimização Operacional de um Sistema de Trigeração para Atender Demandas Variáveis

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    Este trabalho visa apresentar e discutir os procedimentos e resultados da otimização das estratégias operacionais de um sistema de trigeração de um centro de pesquisa para atender a demanda horosazonal de eletricidade, vapor e água gelada de modo que, minimize o custo de operação da planta. Nos dias atuais cada vez mais os sistemas térmicos estão mais complexos. Com isso, busca-se o melhor aproveitamento, com o objetivo de ter uma melhor produção e minimização dos custos produtivos. O centro de pesquisa em questão é composto de um sistema de cogeração que produz eletricidade e também calor (na forma de vapor e água quente) para acionar dois chillers por absorção (um a vapor e outro a água quente). Este centro ainda conta com outros grupos geradores e chillers complementares. Além destes equipamentos também tem a opção de usar uma demanda elétrica adicional contratada com a concessionária. O principal objetivo da otimização é determinar como operar o sistema de trigeração do centro e quando ou como usar a demanda contratada. Para se chegar a este resultado, todos os dados dos equipamentos e custos da central, e também os dados da demanda do centro, foram levantados e o modelo matemático foi desenvolvido. Nessa visão de otimização existe muitos métodos que podem ser empregados. Neste trabalho é usada a otimização matemática através do método do gradiente reduzido generalizado (GRG), com o auxílio do Solver no Microssoft Excel. Os resultados mostram que o método de otimização é muito eficaz dando resultados favoráveis a sua utilização

    OMBRA: Observing Montello BRoad Activity. Una rete temporanea per lo studio dei processi di deformazione attraverso la faglia del Montello (Alpi orientali).

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    L’area veneta delle Alpi orientali è caratterizzata da una debole sismicità di background. In particolare, l’attività sismica registrata negli ultimi 30 anni [Castello et al., 2006; Bollettino Sismico INGV1] mostra eventi di bassa energia (ML<3) lungo l’arco alpino in corrispondenza dell’anticlinale del Montello (situato a NW di Treviso). Sono noti però alcuni eventi di magnitudo medio-alta che hanno storicamente interessato la regione: l’episodio più significativo è il terremoto di Asolo del 1695 (Imax 10 e MaW 6.61), affiancato da tre ulteriori eventi sismici di intensità Imax≥VIII (magnitudo equivalente 6.0) avvenuti nel 778, 1286 e 1836 [CPTI Working group 2004] (Figura 1). Il Montello è catalogato tra i segmenti sismogeneticamente attivi del fronte alpino [Valensise and Pantosti, 2001; Galadini et al., 2005; Poli et al., 2008], originato dall’uplift di una struttura di thrust S-vergente, con slip rate di deformazione stimato tra 1.5 mm/yr [Burrato et al., 2009] e 1.8-2.0 mm/yr [Benedetti et al., 2000]. Scopo del progetto OMBRA è quello di studiare alcune questioni ancora aperte e scientificamente controverse. Ci si chiede come questi eventi storici forti possano integrarsi nel contesto della debole sismicità di fondo osservata recentemente. Inoltre è interessante capire come una velocità di placca relativamente alta possa accomodarsi nel pattern regionale e inoltre quali strutture tra l’anticlinale e il fronte alpino possano essere potenzialmente attive

    Systemic and Local Administration of Antimicrobial and Cell Therapies to Prevent Methicillin-Resistant Staphylococcus epidermidis-Induced Femoral Nonunions in a Rat Model

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    S. epidermidis is responsible for biofilm-related nonunions. This study compares the response to S. epidermidis-infected fractures in rats systemically or locally injected with vancomycin or bone marrow mesenchymal stem cells (BMSCs) in preventing the nonunion establishment. The 50% of rats receiving BMSCs intravenously (s-rBMSCs) died after treatment. A higher cytokine trend was measured in BMSCs locally injected rats (l-rBMSCs) at day 3 and in vancomycin systemically injected rats (l-VANC) at day 7 compared to the other groups. At day 14, the highest cytokine values were measured in l-VANC and in l-rBMSCs for IL-10. \ub5CT showed a good bony bridging in s-VANC and excellent both in l-VANC and in l-rBMSCs. The bacterial growth was lower in s-VANC and l-VANC than in l-rBMSCs. Histology demonstrated the presence of new woven bone in s-VANC and a more mature bony bridging was found in l-VANC. The l-rBMSCs showed a poor bony bridging of fibrovascular tissue. Our results could suggest the synergic use of systemic and local injection of vancomycin as an effective treatment to prevent septic nonunions. This study cannot sustain the systemic injection of BMSCs due to high risks, while a deeper insight into local BMSCs immunomodulatory effects is mandatory before developing cell therapies in clinics

    Negative emotions in migraineurs dreams : the increased prevalence of oneiric fear and anguish, unrelated to mood disorders

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    BACKGROUND: Migraineurs brain has shown some functional peculiarities that reflect not only in phonophobia, and photophobia, but also in mood and sleep. Dreaming is a universal mental state characterized by hallucinatory features in which imagery, emotion, motor skills, and memory are created de novo. We evaluated dream contents and associated emotions in migraineurs. MATERIALS AND METHODS: 412 subjects: 219 controls; and 148 migraineurs (66 with aura, MA; 82 without aura, MO), and 45 tension type headache patients (TTH). A semistructured retrospective self-reported questionnaire was used to evaluate dreams. The Generalized Anxiety Disorder Questionnaire (GAD-7), and the Patient Health Questionnaire (PHQ-9) were administered to evaluate anxiety and depression. RESULTS: Migraineurs showed increased levels of anxiety (P = 0.0002 for MA versus controls, P = 0.004 for MO versus controls). Fear and anguish during dreaming were more frequently reported by migraine patients compared to controls, independently by anxiety and depression scores. DISCUSSION: The brain of migraineurs seems to dream with some peculiar features, all with a negative connotation, as fear and anguish. It may be due to the recorded negative sensations induced by recurrent migraine pain, but it may just reflect a peculiar attitude of the mesolimbic structures of migraineurs brain, activated in both dreaming and migraine attacks

    Validation of a self-reported instrument to assess work-related difficulties in patients with migraine: the HEADWORK questionnaire

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    Background: The degree to which work-related difficulties are recognized in headache research is poor and often carried out with inadequate information such as "reduced ability to work as usual", which do not capture at all the variety of difficulties and the factors that impact over them. The aim of this paper is to present the validation of the HEADWORK questionnaire, which addresses the amount and severity of difficulties in work-related tasks and the factors that impact over them.Methods: We developed a set of items based on a previous literature review and patients' focus groups and tested it on a wide set of patients with episodic and chronic migraine attending eight different Italian headache centers. HEADWORK factor structure was assessed with exploratory and confirmatory factor analysis; internal consistency and construct validity were addressed as well.Results: The validation sample (N= 373) was mostly composed of patients with episodic migraine without aura (64.3%) and of females (81%). Factor analysis retrieved two different scales: "Work-related difficulties", composed of eleven items which explain 67.1% of the total variance, and "Factors contributing to work difficulties", composed of six items which explain 52.1% of the total variance. Both HEADWORK subscales have good measurement properties, with higher scores being associated to higher disability, lower quality of life, lower productivity, higher headache frequency and pain intensity.Conclusions: HEADWORK is a 17-item, two-scale questionnaire addressing the impact of migraine on work-related difficulties in terms of difficulties in general or specific skills, and the factors contributing to these difficulties, defined as negative impact on work tasks. It can be used to address disability weights for the purpose of calculating the burden of migraine, and to assess the balance between therapeutic and side effects of medication on productivity

    Task 4 - Garda - Deliverable D13: Scenari di scuotimento al bedrock a vari livelli di complessità

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    Progetto INGV-DPC S3 “Scenari di scuotimento in aree di interesse prioritario e/o strategico”Published4.2. TTC - Scenari e mappe di pericolosità sismicaope
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