Effects of low-grade gas composition on the energy/exergy performance of a polygeneration system (CH2HP) based on biomass gasification and ICE

Bio-hydrogen from sustainable biomass (i.e. agro-industrial residues) gasification can play a relevant role in the hydrogen economy, providing constant hydrogen from renewable sources. Nowadays, most hydrogen production systems integrate one or more water-gas shift (WGS) units to maximize the hydrogen yield that, however, needs additional syngas treatments, investment and operational costs. Besides, different electricity inputs are needed along the process to power the compression of raw syngas, shifted syngas, and pure hydrogen to the desired pressure. This common process integration with WGS generates a kind of off-gas from the hydrogen separation unit whose composition may or may not be suitable for power production, depending on the operating conditions of the gasification unit. In this regard, this work proposes a different approach in which no WGS reactors are involved and the off-gas is used to generate heat and power to provide the energy input needed by the system. In particular, the authors tested the bio-syngas and the corresponding off-gas in a 4-cylinders, spark ignition natural gas internal combustion engine operated in cogeneration mode with the aim to analyse the effect of removing the hydrogen from the original bio-syngas on mechanical/electric and thermal power, on fuel efficiency and CO2 specific emission

performance analysis of biofuel fed gas turbine

Abstract The present paper deals with the study of the performance of a heavy-duty gas turbine running on biofuels. In particular, synthesis gas from glycerol steam reforming was used to feed the combustion turbine. Engine performances were compared with methane fed ones. Therefore, a mathematical model of the gas turbine was implemented using GateCycle software. Model calibration was made using gas turbine on-design parameters, while performance test results were compared with experimental running data. The resulting analysis highlighted that the mathematical model is able to correctly simulate engine behaviour in different combustion turbine running conditions thus validating the mathematical model. The combustion turbine studied was integrated with a syngas generator plant and overall efficiency was evaluated. The analysis of the results confirms that using biofuels a reduction in engine performance occurs. On the contrary, integrating the gas turbine and syngas generator plant an overall efficiency increase was registered

A case report of thyroid carcinoma confined to ovary and concurrently occult in the thyroid. Is conservative treatment always advised?

Introduction: Struma ovarii is an ovarian teratoma, represented in more than 50% by thyroid tissue. Five percent of struma ovarii cases have been proven to be malignant and, as in the thyroid gland, papillary thyroid carcinoma is the most common histotype arising in struma ovarii. Because of the unusual occurrence of this tumor, its management and follow-up after pelvic surgery is still controversial. Usually, total thyroidectomy followed by radioiodine treatment is the choice treatment in metastatic malignant struma ovarii, while these procedures are still controversial in non-metastatic thyroid cancer arising in struma ovarii. Case Presentation: We report a female with follicular variant of papillary thyroid carcinoma arising in struma ovarii. After pelvic surgery, thyroid morphofunctional examinations were performed and a single nodular lesion in the left lobe was discovered. The patient underwent total thyroidectomy and histological examination showed a papillary carcinoma. Radioiodine-ablation of residual thyroid tissue was performed and levothyroxine mildly-suppressive treatment was started. Conclusions: A more aggressive treatment should not be denied for malignant struma ovarii without any evidence, even when apparently confined into the ovary. However, in selected cases, aggressive treatment may be advisable to decrease the risk of recurrence and to allow an accurate follow-up

Start up of biological sequencing batch reactor (SBR) and short-term biomass acclimation for polyhydroxyalkanoates production

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on the turbine induced damping in oscillating water column wave energy converter

Abstract The present paper deals with a study of the damping induced by a turbine in the power take off of an small scale Oscillating Water Column Wave Energy Converter. In order to study the turbine-induced damping, an experimental setup was built. The experimental setup consists of a wave flume 2000 mm long, 190 mm high and 96 mm wide with an impermeable beach as a dissipative system at the end to avoid wave reflections. The system is all built in Plexiglas to allow optical real-time observation. An Oscillating Water Column chamber model was placed in the measurement area between the wave-maker and the dissipative beach. The chamber was 37 mm long, 200 mm high and 96 mm wide also built in Plexiglas. In order to study the effect of turbine-induced damping on the system, a calibrated and variable hole was used to simulate the turbine presence, while outflow and inflow air velocity were measured by means of Particle Image Velocimetry (PIV) method. Pressures and velocities of air and water as well as the free water surfaces evolution were measured at different wave frequencies and heights

on the wind turbine wake mathematical modelling

Abstract The present paper deals with a study on the wind turbine wake mathematical modelling as well as experimental validation by means of wind tunnel experiments. In particular, different wind turbine wake's equations were implemented and results compared with experimental data. Therefore, an experimental setup was implemented in the wind tunnel test section with a small-scale wind turbine, while velocity deficit was measured. A design of experiment based on three parameters variation was defined: wind velocity, turbine rotational speed and distance from the wind turbine rotor. In the same experimental conditions simulations were carried out by means of three 1D equations. In particular, Jensen, Larsen and Frandsen equations were studied. Comparing theoretical and experimental results, it is evident that Larsen mathematical model is in good agreement with experimental data, while Jensen and Frandsen mathematical models are able to identify only mean and peak velocity deficit, respectively

Gestión económico-financiera y responsabilidad social de las fundaciones: un análisis para las fundaciones empresariales y financieras

El sector fundacional tiene un elevado peso en España y desempeña un papelfundamental en la cobertura de multitud de necesidades sociales de la población, enáreas de actuación donde otras organizaciones e instituciones no pueden llegar. Lacreación de las mismas tiene siempre una orientación no lucrativa, aunque puederesponder a orígenes diferentes, desde desarrollar las actividades de responsabilidadsocial de una gran empresa a canalizar la obra social de una entidad financiera.Partiendo de la hipótesis de que el origen de las fundaciones es importante para definirsu comportamiento, estructura y objetivos, en este trabajo se analiza la gestióneconómica y la responsabilidad social de distintos tipos de fundaciones, tratando decontrastar posibles diferencias entre ellas. En concreto, se analizan las fundacionescreadas por las empresas que cotizan en el mercado de valores y las creadas por lasentidades financieras, al objeto de detectar los patrones que guían su gestióneconómico-financiera y la divulgación de información relativa a buen gobierno yresponsabilidad social.Con el fin de analizar estas posibles diferencias, se lleva a cabo un análisiscomparativo por grupos de entidades. Por un lado, el grupo de las fundaciones creadaspor empresas cotizadas versus el grupo creado por empresas no cotizadas y, por otro,el de las fundaciones bancarias versus un grupo de fundaciones creadas por empresasno financieras.Los resultados obtenidos ponen de manifiesto que las fundaciones creadas porempresas cotizadas no presentan diferencias significativas con las fundaciones creadaspor empresas no cotizadas; mientras que las fundaciones bancarias sí presentandiferencias significativas respecto al resto de fundaciones empresariales, en gestión yresponsabilidad social corporativa.<br /

Ultrafiltration in the treatment of refractory congestive heart failure.

Artificial subtraction of fluids and solutes was evaluated in the course of acute and chronic heart failure when it became refractory to standard intensive medical treatment. A group of 19 patients (mean age 57 years), 9 with ischemic, 2 amyloidotic, 4 valvular, and 4 idiopathic cardiomyopathy, were treated. In 17 patients extracorporeal ultrafiltration (UF) by means of a polysulfonate ultrafilter was adopted along 125 sessions (105 assisted by a roller pump and 20 as a slow continuous ultrafiltrate). In two patients continuous peritoneal dialysis was adopted. In every case UF was well tolerated. Ultrafiltrate volumes ranged from 1680 to 3500 ml for every session with corresponding Na losses ranging from 194 to 434 mEq/session. Improved clinical and functional status with reduction of edema was observed in 17 of 19 patients. In 12 patients UF could be discontinued due to restored response to diuretics; 5 of these patients could subsequently undergo heart surgery (1 transplant, 3 valve replacement, 1 coronary bypass). The remaining 7 patients survived on medical therapy alone for an average of 228 days. In 7 of 19 cases, UF could not be discontinued, and these patients died after an average of 23 days of treatment. In conclusion, UF proved to be effective in eliminating salt-fluid overload and restoring response to medical treatment. Patients who are potential surgical candidates seem to be the most suitable for UF

A comparison between two different in vitro basophil activation tests for gluten- and cow's milk protein sensitivity in irritable bowel syndrome (IBS)-like patients.

Abstract Background: The diagnosis of food hypersensitivity (FH) in adult patients with gastrointestinal symptoms, beyond the immediate IgE-mediated clinical manifestations, is very often difficult. The aims of our study were to: 1) evaluate the frequency of FH in patients with irritable bowel syndrome (IBS)-like clinical presentation; and 2) compare the diagnostic accuracy of two different methods of in vitro basophil activation tests. Methods: Three hundred and five patients (235 females, age range 18–66 years) were included and underwent a diagnostic elimination diet and successive double-blind placebo-controlled (DBPC) challenges. Two different methods of in vitro basophil activation tests (BAT) (CD63 expression after in vitro wheat or cow’s milk proteins stimulation) were evaluated: one was performed on separated leukocytes, and the other on whole blood. Results: Ninety patients of the 305 studied (29.5%) were positive to the challenges and were diagnosed as suffering from FH. BAT on separate leukocytes showed a sensitivity of 86% and a specificity of 91% in FH diagnosis. BAT on whole blood showed a sensitivity of 15%–20% and a specificity of 73% in FH diagnosis (p&lt;0.0001 compared to the other method). Conclusions: About one third of the IBS patients included in the study were suffering from FH and were cured on the elimination diet. The BAT based on CD63 detection on whole blood samples did not work in FH diagnosis and showed a significantly lower sensitivity, specificity and diagnostic accuracy than the assay based on separated leukocytes.</jats:p