323 research outputs found
Analysis of Inlet Air Cooling for IGCC Power Augmentation
Abstract Integrated Gasification Combined Cycles are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as an oxidant, an air separation unit is also part of the plant. Moreover, a producer gas cleaner unit is always present between the gasifier and the gas turbine. With respect to Natural Gas Combined Cycles, IGCCs are characterized by a consistent loss in the overall plant efficiency due to the conversion of the raw fuel in the gasifier and the electrical power parasitized for fuel production which considerably reduce the plant net electric power. Moreover, since these plants are based on gas-steam combined cycle power plants they suffer from a reduction in performance (a further net power decrease) when ambient temperature increases. Regarding this latter topic, different systems are currently used in gas turbine and combined cycle power plants in order to reduce gas turbine inlet air temperature, and, therefore, the impact of ambient conditions on performances. In this paper, a review of these systems is presented. Both systems based on water evaporative cooling and on refrigeration by means of absorption or mechanical/electrical chillers are described. Thermodynamic models of the systems are built within the framework of a commercial code for the simulation of energy conversion systems. A sensitivity analysis on the main parameters is presented. Finally, the models are applied to study the capabilities of the different systems by imposing the real temperature profiles of different sites for a whole year
Brand Hacking: collaborazione, innovazione e scambio di valore simbolico tra marche
Viviamo una nuova era che richiede ai brand fluidità , capacità di reinventarsi e adattarsi alle mutevoli esigenze e aspettative dei consumatori. In questo clima, nascono strategie di branding innovative, tra cui spicca il “Brand Hacking”, una strategia che non si limita a piccole modifiche o aggiustamenti all’immagine di un brand, ma che ambisce a trasfigurare, per un breve lasso di tempo, gli elementi fondanti della sua identità . Letteralmente significa “violazione del brand”, e consiste in un tipo di collaborazione tra Imprese in cui l’immaginario e gli stilemi formali di ciascuno dei brand “entra” nella comunicazione dell’altro con l’obiettivo di modificare, arricchire – e spesso
sovvertire, la narrativa e l’immagine della marca “violata” in modo dirompente quanto inaspettato. L’obiettivo è creare qualcosa di completamente nuovo e rivoluzionario, che catturi l’attenzione in modo “disruptive” e che, allo stesso tempo, dimostri la capacità del brand di adattarsi senza ingessature al contesto mediatico attuale
physiological weight loss in newborn puppies of boxer breed
In the first days after birth is common to see weight loss in puppies that should not exceed 10% of body weight at birth. The main causes of weight loss are urine and meconium issued followed by non-recovery of fluids expelled. The aims of the study were to check and outline growth curves in boxer breed during the first two week of life. In our study between 3th and 5th day after birth puppies retrieved the weight and got back a gain that leads to double in two weeks. We observed a mean weight loss of 11.26 g (2.27%) between the first two days of life, subsequently they recovered the birth weight on day four. In our study puppies that regained the birth weight earlier were the puppies with higher weight at birth and were the heaviest at day 13
Asymptomatic congenital cystic adenomatoid malformation of the lung: Is it time to operate?
ObjectiveThe optimal management of congenital adenomatoid malformation of the lung remains controversial. Prenatal ultrasonographic analysis has increasingly discovered asymptomatic lesions, raising questions about the need for and timing of surgical treatment for asymptomatic congenital adenomatoid malformation. The aim of our study was to analyze the short-term postoperative outcome of symptomatic congenital adenomatoid malformations compared with asymptomatic malformations.MethodsAll the data of patients presenting with congenital adenomatoid malformations histologically diagnosed and operated on between 1998 and 2005 at our institution were retrospectively reviewed. Patients were divided into 2 groups: group A comprised asymptomatic infants, and group B comprised symptomatic infants. Major outcomes considered were the length of ventilation, pleural drainage, and hospital stay. Postoperative morbidity and mortality were also evaluated. Asymptomatic patients were further stratified for age at the time of the operation to evaluate whether age at surgical intervention affects the outcome. The Fisher's exact and Mann–Whitney tests were used as appropriate.ResultsFifty-seven patients were consecutively treated. Thirty-five patients were given diagnoses of asymptomatic lesions and were enrolled into group A, whereas 22 patients presenting with symptoms were entered into group B. The lengths of ventilation, pleural drainage, and hospital stay were significantly longer in patients with symptomatic congenital adenomatoid malformations. Moreover, symptomatic patients presented with a higher postoperative complication rate. The age-based stratification of asymptomatic children did not show any difference on either postoperative mortality or major outcome considered.ConclusionChildren with congenital adenomatoid malformations operated on when asymptomatic present a better short-term outcome than symptomatic children. In addition, age at the time of the operation does not negatively affect the outcome. Our findings support early surgical treatment for asymptomatic congenital adenomatoid malformation
Diagnostic Workup of Neonates With Esophageal Atresia : Results From the EUPSA Esophageal Atresia Registry
Aim:Controversies exist on the optimal diagnostic workup for neonates with esophageal atresia (EA) with/without tracheoesophageal fistula (TEF). Aim of this study was to describe the current diagnostic policies in EA/TEF patients enrolled in an International multicenter registry. Methods:All patients consecutively registered from July 2014 to December 2017 in the EUPSA Esophageal Atresia Registry (EUPSA-EAR) were included in the study. Data related to diagnostic investigations among Centers forming the EUPSA-EAR were analyzed. Main Results:During the study period, 374 consecutive patients were recorded by 23 Centers. The majority of patients underwent chest X-rays, echocardiography, abdominal ultrasound, and abdominal X-rays. Preoperative bronchoscopy and esophageal gap measurement were performed in one third of the patients. Conclusions:Present data from a large cohort of patients from the EUPSA-EAR show both inter-institutional and intra-institutional variability in diagnostic workup of patients with EA/TEF. Efforts should be made to develop guidelines on the diagnostic workup for EA/TEF patients.Peer reviewe
Severe Milk-Alkali Syndrome in a Patient with Hypoparathyroidism Associated with 1,25(OH)2D, Hydrochlorothiazide and Anthranoid Laxative Consumption
Background: Milk-alkali syndrome is a life-threatening condition defined by the triad of hypercalcaemia, metabolic alkalosis and acute renal failure, and is associated with consumption of calcium and absorbable alkali.
Methods: We report the case of a patient admitted to a step-down unit of a large hospital in Italy.
Results: The patient was a 59-year-old woman with hypoparathyroidism and mild chronic kidney insufficiency, treated for a preceding episode of hypocalcaemia with high doses of calcitriol and calcium carbonate, who was also taking hydrochlorothiazide and unreported herbal anthranoid laxatives. The patient was admitted to hospital with severe hypercalcaemia, severe metabolic alkalosis and acute renal insufficiency. The patient was successfully treated with urgent dialysis, loop diuretics and calcitonin administration.
Conclusions: This case underlines the need for caution when treating patients with impaired calcium metabolism regulation, and suggests that herbal anthranoid laxatives might act as triggers for milk-alkali syndrome.
Phenotypical heterogeneity linked to adipose tissue dysfunction in patients with type 2 diabetes
Adipose tissue (AT) inflammation leads to increased free fatty acid (FFA) efflux and ectopic fat deposition, but whether AT dysfunction drives selective fat accumulation in specific sites remains unknown. The aim of the present study was to investigate the correlation between AT dysfunction, hepatic/pancreatic fat fraction (HFF, PFF) and the associated metabolic phenotype in patients with Type 2 diabetes (T2D). Sixty-five consecutive T2D patients were recruited at the Diabetes Centre of Sapienza University, Rome, Italy. The study population underwent clinical examination and blood sampling for routine biochemistry and calculation of insulin secretion [homoeostasis model assessment of insulin secretion (HOMA-β%)] and insulin-resistance [homoeostasis model assessment of insulin resistance (HOMA-IR) and adipose tissue insulin resistance (ADIPO-IR)] indexes. Subcutaneous (SAT) and visceral (VAT) AT area, HFF and PFF were determined by magnetic resonance. Some 55.4% of T2D patients had non-alcoholic fatty liver disease (NAFLD); they were significantly younger and more insulin-resistant than non-NAFLD subjects. ADIPO-IR was the main determinant of HFF independently of age, sex, HOMA-IR, VAT, SAT and predicted severe NAFLD with the area under the receiver operating characteristic curve (AUROC)=0.796 (95% confidence interval: 0.65-0.94, P=0.001). PFF was independently associated with increased total adiposity but did not correlate with AT dysfunction, insulin resistance and secretion or NAFLD. The ADIPO-IR index was capable of predicting NAFLD independently of all confounders, whereas it did not seem to be related to intrapancreatic fat deposition; unlike HFF, higher PFF was not associated with relevant alterations in the metabolic profile. In conclusion, the presence and severity of AT dysfunction may drive ectopic fat accumulation towards specific targets, such as VAT and liver, therefore evaluation of AT dysfunction may contribute to the identification of different risk profiles among T2D patients
Strong association between non alcoholic fatty liver disease (NAFLD) and low 25(OH) vitamin D levels in an adult population with normal serum liver enzymes
<p>Abstract</p> <p>Background</p> <p>Hypovitaminosis D has been recently recognized as a worldwide epidemic. Since vitamin D exerts significant metabolic activities, comprising free fatty acids (FFA) flux regulation from the periphery to the liver, its deficiency may promote fat deposition into the hepatocytes. Aim of our study was to test the hypothesis of a direct association between hypovitaminosis D and the presence of NAFLD in subjects with various degree of insulin-resistance and related metabolic disorders.</p> <p>Methods</p> <p>We studied 262 consecutive subjects referred to the Diabetes and Metabolic Diseases clinics for metabolic evaluation. NAFLD (non-alcoholic fatty liver disease) was diagnosed by upper abdomen ultrasonography, metabolic syndrome was identified according to the Third Report of National Cholesterol Education Program/Adult Treatment Panel (NCEP/ATPIII) modified criteria. Insulin-resistance was evaluated by means of HOMA-IR. Fatty-Liver-Index, a recently identified correlate of NAFLD, was also estimated. Serum 25(OH)vitamin D was measured by colorimetric method.</p> <p>Results</p> <p>Patients with NAFLD (n = 162,61.8%) had reduced serum 25(OH) vitamin D levels compared to subjects without NAFLD (14.8 ± 9.2 vs 20.5 ± 9.7 ng/ml, p < 0.001, OR 0.95, IC 95% 0.92-0.98). The relationship between NAFLD and reduced 25(OH)vitamin D levels was independent from age, sex, triglycerides, high density lipoproteins (HDL) and glycaemia (p < 0.005) and Fatty Liver Index inversely correlated with low 25(OH) vitamin D regardless sex, age and HOMA-IR (p < 0.007).</p> <p>Conclusions</p> <p>Low 25(OH)vitamin D levels are associated with the presence of NAFLD independently from metabolic syndrome, diabetes and insulin-resistance profile.</p
Phenotypic and genotypic Helicobacter pylori clarithromycin resistance and therapeutic outcome: benefits and limits
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