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Search Results: 1 - 10 of 593165 matches for " A. L. Gaspari "
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Horizontal Slug Flow in a Large-Size Pipeline: Experimentation and Modeling
Marruaz Keyla S.,Gon?alves Marcelo A. L.,Gaspari,Ribeiro Geraldo S.
Journal of the Brazilian Society of Mechanical Sciences , 2001,
Abstract: The knowledge of the slug flow characteristics is very important when designing pipelines and process equipment. When the intermittences typical in slug flow occurs, the fluctuations of the flow variables bring additional concern to the designer. Focusing on this subject the present work discloses the experimental data on slug flow characteristics occurring in a large-size, large-scale facility. The results were compared with data provided by mechanistic slug flow models in order to verify their reliability when modelling actual flow conditions. Experiments were done with natural gas and oil or water as the liquid phase. To compute the frequency and velocity of the slug cell and to calculate the length of the elongated bubble and liquid slug one used two pressure transducers measuring the pressure drop across the pipe diameter at different axial locations. A third pressure transducer measured the pressure drop between two axial location 200 m apart. The experimental data were compared with results of Camargo's1 algorithm (1991, 1993), which uses the basics of Dukler & Hubbard's (1975) slug flow model, and those calculated by the transient two-phase flow simulator OLGA.
Chronic NaHS Treatment Is Vasoprotective in High-Fat-Fed ApoE?/? Mice
Asha Ford,Mohammad Al-Magableh,Tracey A. Gaspari,Joanne L. Hart
International Journal of Vascular Medicine , 2013, DOI: 10.1155/2013/915983
Abstract: Hydrogen sulfide is emerging as an important mediator of vascular function that has antioxidant and cytoprotective effects. The aim of this study was to investigate the role of endogenous H2S and the effect of chronic exogenous H2S treatment on vascular function during the progression of atherosclerotic disease. ApoE?/? mice were fed a high-fat diet for 16 weeks and treated with the H2S donor NaHS or the cystathionine-γ-lyase (CSE) inhibitor D,L-propargylglycine (PPG), to inhibit endogenous H2S production for the final 4 weeks. Fat-fed ApoE?/? mice displayed significant aortic atherosclerotic lesions and significantly impaired endothelial function compared to wild-type mice. Importantly, 4 weeks of NaHS treatment significantly reduced vascular dysfunction and inhibited vascular superoxide generation. NaHS treatment significantly reduced the area of aortic atherosclerotic lesions and attenuated systolic blood pressure. Interestingly, inhibiting endogenous, CSE-dependent H2S production with PPG did not exacerbate the deleterious vascular changes seen in the untreated fat-fed ApoE?/? mice. The results indicate NaHS can improve vascular function by reducing vascular superoxide generation and impairing atherosclerotic lesion development. Endogenous H2S production via CSE is insufficient to counter the atherogenic effects seen in this model; however exogenous H2S treatment has a significant vasoprotective effect. 1. Introduction Hydrogen sulfide is a recently identified gasotransmitter reported to have numerous physiological effects in diverse processes including metabolism, inflammation, the nervous system, and the cardiovascular system [1]. The cardiovascular effects of this molecule are currently of major interest and include vascular relaxation, cardioprotection, and vasculoprotective effects [2, 3]. In mammalian cells, H2S is produced primarily by 2 pyridoxyl-5′-phosphate-dependent enzymes, cystathionine-β-synthase (CBS), and cystathionine-γ-lyase (CSE). Additionally, a role for 3-mercaptopyruvate sulfurtransferase in concert with cysteine aminotransferase has been identified in the vasculature [4]. With respect to vasoregulation, CSE is of particular interest as it is reported to be present in a range of vascular beds and its expression has been clearly identified in vascular smooth muscle cells. CSE has also been located in endothelial cells and additionally it is reported to contribute to endothelium-dependent vasorelaxation [5, 6]. Inhibition of CSE with the irreversible inhibitor D,L-propargylglycine (PPG) leads to an elevation of blood pressure in
Bariatric Surgery in Moderately Obese Patients: A Prospective Study
M. Cerci,M. I. Bellini,F. Russo,D. Benavoli,M. Capperucci,A. L. Gaspari,P. Gentileschi
Gastroenterology Research and Practice , 2013, DOI: 10.1155/2013/276183
Abstract: Introduction. Moderate obesity (BMI 30–35?kg/m2) affects 25% of the western population. The role of bariatric surgery in this context is currently debated, reserved for patients with comorbidity, as an alternative to conservative medical treatment. We describe our experience in moderately obese patients treated with bariatric surgery. Materials and Methods. Between September 2011 and September 2012, 25 patients with grade I obesity and comorbidities underwent bariatric surgery: preoperative mean BMI 33.2?kg/m2, 10 males, mean age 42 years. In presence of type 2 diabetes mellitus (T2DM) (56%), gastric bypass was performed; in cases with hypertension (64%) and obstructive sleep apnea (OSA) (12%), sleeve gastrectomy was performed. All operations were performed laparoscopically. Results. Mean follow-up was 12.4 months. A postoperative complication occurred: bleeding from the trocar site was resolved with surgery in local anesthesia. Reduction in average BMI was 6 points, with a value of 27.2?kg/m2. Of the 14 patients with T2DM, 12 (86%) discontinued medical therapy because of a normalization of glycemia. Of the 16 patients with arterial hypertension, 14 (87%) showed remission and 2 (13%) improvement. Complete remission was observed in patients with OSAS. Conclusions. The results of our study support the validity of bariatric surgery in patients with BMI 30–35?kg/m2. Our opinion is that, in the future, bariatric surgery could be successful in selected cases of moderately obese patients. 1. Introduction Obesity is a world epidemic with remarkable sanitary, social, and economic consequences. Clinically, severe or morbid obesity is defined as values of BMI in the Class III (BMI ≥ 40?kg/m2) and Class II (35 ≤ BMI ≥ 39.9?kg/m2 in the presence of comorbidities). Obesity is associated with an increased hazard ratio for all-cause mortality [1], as well as significant comorbidity [2]. According to different studies, 25% of the western population is affected by some degree of obesity that can be defined as moderate or Class I obesity (BMI between 30–35?kg/m2). According to the literature, also patients with Class I obesity have a definite risk of significant comorbidity, such as diabetes mellitus, hypertension, dyslipidemia, obstructive sleep apnea syndrome, and mortality [3]. Other studies suggest that the clinical picture of patients affected by Class I obesity can be improved as well as in patients with severe obesity by bariatric surgery, with weight loss and resolution of comorbidities. The present prospective study aimed to investigate the improvements or
Horizontal Slug Flow in a Large-Size Pipeline: Experimentation and Modeling
Marruaz, Keyla S.;Gon?alves, Marcelo A. L.;Gaspari,;Ribeiro, Geraldo S.;Fran?a, Fernando A.;Rosa, Eugênio S.;
Journal of the Brazilian Society of Mechanical Sciences , 2001, DOI: 10.1590/S0100-73862001000400009
Abstract: the knowledge of the slug flow characteristics is very important when designing pipelines and process equipment. when the intermittences typical in slug flow occurs, the fluctuations of the flow variables bring additional concern to the designer. focusing on this subject the present work discloses the experimental data on slug flow characteristics occurring in a large-size, large-scale facility. the results were compared with data provided by mechanistic slug flow models in order to verify their reliability when modelling actual flow conditions. experiments were done with natural gas and oil or water as the liquid phase. to compute the frequency and velocity of the slug cell and to calculate the length of the elongated bubble and liquid slug one used two pressure transducers measuring the pressure drop across the pipe diameter at different axial locations. a third pressure transducer measured the pressure drop between two axial location 200 m apart. the experimental data were compared with results of camargo's1 algorithm (1991, 1993), which uses the basics of dukler & hubbard's (1975) slug flow model, and those calculated by the transient two-phase flow simulator olga.
Cold fronts and metal anisotropies in the X-ray cool core of the galaxy cluster Zw1742+3306
S. Ettori,F. Gastaldello,M. Gitti,E. O'Sullivan,M. Gaspari,F. Brighenti,L. David,A. C. Edge
Physics , 2013, DOI: 10.1051/0004-6361/201321107
Abstract: (Context) In recent years, our understanding of the cool cores of galaxy clusters has changed. Once thought to be relatively simple places where gas cools and flows toward the centre, now they are believed to be very dynamic places where heating from the central Active Galactic Nucleus (AGN) and cooling, as inferred from active star formation, molecular gas, and Halpha nebulosity, find an uneasy energetic balance. (Aims) We want to characterize the X-ray properties of the nearby cool-core cluster Zw1742+3306, selected because it is bright at X-ray (with a flux greater than 1e-11 erg/s/cm2 in the 0.1-2.4 keV band) and Halpha wavelengths (Halpha luminosity > 1e40 erg/s). (Methods) We used Chandra data to analyze the spatial and spectral properties of the cool core of Zw1742+3306, a galaxy cluster at z=0.0757 that emits in Halpha and presents the brightest central galaxy located in a diffuse X-ray emission with multiple peaks in surface brightness. (Results) We show that the X-ray cool core of the galaxy cluster Zw1742+3306 is thermodynamically very active with evidence of cold fronts and a weak shock in the surface brightness map and of an apparently coherent, elongated structure with metallicity greater than the value measured in the surrounding ambient gas by about 50 per cent. This anisotropic structure is 280 x 90 kpc2 and is aligned with the cold fronts and with the X-ray emission on larger scales. We suggest that all these peculiarities in the X-ray emission of Zw1742+3306 are either a very fine-tuned output of a sloshing gas in the cluster core or the product of a metal-rich outflow from the central AGN.
Book review: Bray, M. (2009). Confronting the Shadow Education System: What Government Policies for What Private Tutoring? Paris: International Institute for Educational Planning. 134 p., ISBN 978-92-803-1333-8.
Katarina A?kerc,Romina Ple?ec Gaspari
CEPS Journal : Center for Educational Policy Studies Journal , 2012,
Abstract:
Modification in body weight associated with antiepileptic drugs
Gaspari, Camilla N. De;Guerreiro, Carlos A.M.;
Arquivos de Neuro-Psiquiatria , 2010, DOI: 10.1590/S0004-282X2010000200024
Abstract: antiepileptic drugs (aed) may cause body weight changes. objective: to evaluate the dietary habits and body weight associated with aed in epileptic patients. method: sixty-six patients were subjected to two interviews, and had their weight and body mass index calculated and compared at both times, interval between six to eight months. results: it was observed that 59.1% showed weight gain. the patients who had no weight gain had a greater proportion of individuals who engaged in some form of physical activity. however, of the 45 patients who maintained their initial dietary and medication pattern, 75.6% recorded a weight gain. weight gain was seen in 66.7% of patients on carbamazepine (n=18), 60% on valproate (n=5), 50% on carbamazepine+clobazam treatment (n=14), and 58.3% of patients on other(s) polytherapy (n=12). conclusion: the patient should be alerted to possible weight gain, and should be advised about dieting and participating in regular physical activity.
Substance abuse in first-episode schizophrenic patients: a retrospective study
Mauri MC,Volonteri LS,De Gaspari IF,Colasanti A
Clinical Practice and Epidemiology in Mental Health , 2006, DOI: 10.1186/1745-0179-2-4
Abstract: Several studies suggest a high comorbidity of substance abuse and schizophrenia, associated with higher frequency of relapse, more positive symptoms and depression, cognitive impairment, poorer outcome and treatment response. A high incidence of substance abuse is also observed in first-episode patients. Among patients with substance abuse, the onset precedes the onset of psychosis of several years in most cases. All the patients with a first episode of schizophrenia, at first admission to the Psychiatric Service of Diagnosis and Treatment of Ospedale Maggiore of Milan during the years 1990 to 2004, have been included in our study. The clinical evaluation has been obtained considering the following items of Brief Psychiatric Rating Scale (BPRS): conceptual disorganization, depressed mood, hostility, hallucinations, unusual content of thought. The results showed that 34.7% of first-episode schizophrenic patients had a lifetime history of substance abuse. The age of onset of schizophrenia is significantly lower for drug abusers than for patients without any type of abuse and for alcohol abusers (p < 0.005). In multi drug abusers, cannabis resulted the most frequently used (49%), followed by alcohol (13%), and cocaine (4%). Substance abusers have obtained a significant higher score in "thought disturbance" item (p < 0.005) and in "hostility" item (p < 0.005) compared to non substance abusers. Non drug abusers showed lower mean scores of "hostility" item compared to cocaine abusers and multi drug abusers (p < 0.005). Our findings seem to indicate that substance abuse in the early course of illness determines an earlier onset of schizophrenia and increases severity of some psychotic symptoms like "hallucination" and "unusual content of thought". Therefore persons incurring a risk of schizophrenia may be warned of the possible relation between substances and psychosis and have to be counselled against the use of them.
Temperature dependent vibrational spectra in non-crystalline materials: application to hydrogenated amorphous silicon
I. M. Kupchak,F. Gaspari,A. I. Shkrebtii,J. Perz
Physics , 2007, DOI: 10.1063/1.2946454
Abstract: We present a novel approach for parameter-free modeling of the structural, dynamical and electronic properties of non-crystalline materials based on ab-initio Molecular Dynamics, improved signal processing technique and computer visualization. The method have been extensively tested by investigating hydrogen and silicon dynamics in hydrogenated amorphous silicon (a-Si:H). By comparing the theoretical and experimental vibrational spectra we demonstrate how to relate vibrational properties to the structural stability, bonding and hydrogen diffusion. We extracted microscopic characteristics that cannot be obtained by other techniques, namely hydrogen migration and related bond switching, dangling bond passivation, low hydrogen activation energy, and a-Si:H stability in general, and we show, via the analysis of a test case, that our method provides a rigorous and realistic description of non-crystalline materials. We also demonstrate that this method offers the possibility of accessing other important macroscopic characteristics of amorphous silicon and can be used to model all the aspects of a-Si:H dynamics, including the detrimental Staebler-Wronski effect.
The Dance of Heating and Cooling in Galaxy Clusters: 3D Simulations of Self-Regulated AGN Outflows
M. Gaspari,C. Melioli,F. Brighenti,A. D'Ercole
Physics , 2010, DOI: 10.1111/j.1365-2966.2010.17688.x
Abstract: It is now widely accepted that heating processes play a fundamental role in galaxy clusters, struggling in an intricate but fascinating `dance' with its antagonist, radiative cooling. Last generation observations, especially X-ray, are giving us tiny hints about the notes of this endless ballet. Cavities, shocks, turbulence and wide absorption-lines indicate the central active nucleus is injecting huge amount of energy in the intracluster medium. However, which is the real dominant engine of self-regulated heating? One of the model we propose are massive subrelativistic outflows, probably generated by a wind disc or just the result of the entrainment on kpc scale by the fast radio jet. Using a modified version of AMR code FLASH 3.2, we explored several feedback mechanisms which self-regulate the mechanical power. Two are the best schemes that answer our primary question, id est quenching cooling flow and at the same time preserving a cool core appearance for a long term evolution (7 Gyr): one more explosive (with efficiencies 0.005 - 0.01), triggered by central cooled gas, and the other gentler, ignited by hot gas Bondi accretion (with efficiency 0.1). These three-dimensional simulations show that the total energy injected is not the key aspect, but the results strongly depend on how energy is given to the ICM. We follow the dynamics of best model (temperature, density, SB maps and profiles) and produce many observable predictions: buoyant bubbles, ripples, turbulence, iron abundance maps and hydrostatic equilibrium deviation. We present a deep discussion of merits and flaws of all our models, with a critical eye towards observational concordance.
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