Liquefied natural gas vaporization facilities

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MedDensity

.analisi della singola immagine \u2043 lettura da file digitali in formato immagine (.jpg, .jpeg, .tiff, .png, .bmp) di immagini biomedicali ricavate con tecniche radiografiche di qualsiasi natura (ecografia, tomografia, risonanza magnetica, mammografia, tomosintesi) \u2043 identificazione automatica e con soglia modificabile manualmente secondo le esigenze della porzione di immagine da analizzare \u2043 calcolo automatico quantitativo della densit\ue0 della regione analizzata, definita come rapporto tra la superficie considerata densa e la superficie totale presa in considerazione, mediante metodi di analisi dell'istogramma dell'immagine (metodo della minimizzazione dell'entropia di Shanno e metodo integrale di calcolo, modelli di assorbimento della radiazione incidente esponenziale e lineare) \u2043 calcolo manuale quantitativo della densit\ue0 dell'immagine mediante procedura interattiva guidata dall'utente 2. analisi automatica di serie di immagini \u2043 lettura di una serie di file contenuti in una cartella \u2043 procedura automatica di valutazione quantitativa di ogni singola immagine secono la procedura di cui al punto 1 (parte automatica) \u2043 salvataggio dei dati in un file di testo contenente tutte le informazioni necessarie 3. analisi automatica di serie di immagini tomografiche \u2043 lettura delle slices tomografiche contenute in una cartella \u2043 procedura automatica di valutazione quantitativa della densit\ue0 delle immagini mediante procedimento di calcolo che permette la valutazione tridimensionale della densit\ue0 \u2043 salvataggio dei dati in un file di testo contenente tutte le informazioni necessari

Fascicular ratio: a new parameter to evaluate peripheral nerve pathology on magnetic resonance imaging: a feasibility study on a 3T MRI system.

The objective of the study was to define and quantitatively evaluate the fascicular ratio (FR) on magnetic resonance imaging (MRI) in patients with peripheral neuropathies compared with healthy controls. Forty control subjects (20 women, 20 men; age, 44.6 ± 13.4 years) and 40 patients with peripheral neuropathy (22 women, 18 men; age, 50.3 ± 10.2 years) were examined with a standard 3T MRI protocol. With customized software (with semiautomatic and automatic interface), the hypointense and hyperintense areas of the peripheral nerves corresponding to fascicular and nonfascicular tissue were examined on T1-weighted sequences. The ratio of fascicular pixels to total pixels was called FR. Correlation with FR calculated on high-resolution ultrasound was performed. The statistical analysis included the Mann–Whitney U test of controls versus patients, the receiver operating characteristic (ROC) analysis, and the subgroup analysis of patients according to etiologies of neuropathy. Intraobserver and interobserver agreement was calculated based on the evaluation made by 3 readers. Finally, a complete automatic evaluation was performed. On MRI, FRs were significantly increased in patients compared with controls (FR, 76.7 ± 15.1 vs 56 ± 12.3; P < 0.0001 for the semiautomatic interface; and FR 66.3 ± 17.5 vs 47.8 ± 18.4; P < 0.0001 for the automatic interface). The increase in FR was caused mainly by an increase in the hypointense part of the nerve. This observation was valid for all causes of neuropathies. ROC analysis found an area under the curve of 0.75 (95% confidence interval, 0.44–0.81) for FR to discriminate neuropathy from control. The correlation coefficient between MRI and ultrasound was significant (r = 0.49; 95% confidence interval for r, 0.21–0.70; P = 0.012). With the semiautomated evaluation, the mean intraobserver agreement was good (K = 0.86). The interobserver agreements were also good (reader 1 vs reader 2, k = 0.71; reader 2 vs reader 3, k = 0.78; reader 3 vs reader 1, k = 0.71). There were no statistically significant differences between the results obtained using the 2 methods. FR calculation on MRI is feasible, and it may be used in adjunct to standard MRI evaluation in peripheral nerve disorders

Classification proposal for room temperature magnetic refrigerators

Magnetic refrigeration promises to be a breakthrough technology in the field of refrigeration at room temperature. Several magnetic refrigerator prototypes have been developed by research groups, with different embodiments and process thermodynamics. This short paper follows an idealized line connecting, from a conceptual rather than historical point of view, the different geometries, and proposes a classification based essentially on the type of magnetic source, the type of magnetocaloric material, and the relative motion of the active elements of the device. The proposed taxonomy is then applied to some prototype presented in literature, showing its potential to give a comprehensive description of magnetic refrigeration devices by means of a twelve digit string

Integrated Solar-Assisted Heat Pumps for water heating coupled to gas burners; control criteria for dynamic operation

A direct expansion integrated solar-assisted heat pump (ISAHP) is compared to a traditional flat plate solar panel for low temperature (45 C) water heating applications. The (simulated) comparison is accomplished assuming both the devices are energy supplemented with an auxiliary standard gas burner, to provide the typical heat duty of a four-member family. Literature dynamical models of the systems involved have been used to calculate the main performance figures in a context of actual climatic conditions and typical stochastic user demand. The paper highlights new heat pump control concepts, needed when maximum energy savings are the main goal of the apparatus for given user demand. Simulations confirm the high collector efficiency of the ISAHP when its panel/evaporator works at temperature close to the ambient one. The device, with respect to a flat plate solar water heater, shows a doubled performance, so that it can do the same task just using an unglazed panel with roughly half of the surface

A classification methodology applied to existing room temperature magnetic refrigerators up to the year 2014

Magnetic refrigeration at room temperature is a promising technology with the potential of competing with traditional vapor compression technology. It promises high energy conversion efficiency values, and is environmental friendly. In fact it can operate with zero ODP (Ozone Depletion Potential) and low GWP (Global Warming Potential) fluids. Furthermore the process and the plant configuration are very simple and the device promise to be very compact, with low noise and vibrations. The literature shows many prototypes developed and built both with proof of principle purposes and with performance oriented purposes. Very different embodiments and arrangements can be conceived, operating with similar or identical conceptual behavior. An existing classification methodology is discussed and applied to a wide set of prototypes and test sections known in the literature up to the year 2014. In this short review, most used configurations and trends are described according to the proposed classification criteria. The method is able to highlight common and uncommon solutions, and to show conceptual differences and similarities between different embodiments, irrespective of the engineering solutions chosen by the designer

Liquefied natural gas submerged combustion vaporization facilities: process integration with power conversion units

Liquefied natural gas (LNG) vaporization facilities offer an excellent opportunity of primary energy saving by means of integration with power conversion units that is still weakly exploited in actual installations. This work focuses on the evaluation of primary energy saving achievable by the integration of an LNG vaporization facility with a gas turbine and with a cogenerative combined gas-steam power plant. The fuel energy saving ratio is used as the main performance parameter to evaluate the primary energy saving derived by system integration, with respect to conventional submerged combustion vaporization. Twelve possible configurations are analyzed with steady-state calculations. Results show that a primary energy saving greater than 15% with peak values up to 27%, corresponding to 2.98TJ/year, is achievable. The paper shows that the fuel energy saving ratio can be used as a synthetic and effective parameter to estimate the energy-saving potential of different plant configurations. \ua9 2011 John Wiley & Sons, Ltd

A compact dynamic model for household vapor compression refrigerated systems

In this study, a very simplified dynamic lumped model for the simulation of small-scale singletemperature vapor compression refrigerators working between two thermal sources with finite thermal capacity is presented. The model is compact enough to be employed in actual regulation systems, but adequate to describe the basic underlying physical phenomena relevant to the transient response of the refrigerated cell. The dynamic behavior of the system is simulated taking into account the main heat capacities involved in the heat transfer processes between the system, the refrigerating fluid and the outside. The numerical model has been validated by comparing the calculated results with transient experimental data coming from an instrumented chest-freezer. After a steady state tuning phase, the model was able to predict the transient temperature response of the cell with good accuracy

A Dimensionless Description of Active Magnetic Regenerators to Compare their Performance and to Simplify their Optimization

The behavior of active magnetic regenerators (AMR) can be described by means of a one-dimensional set of equations. A lot of geometrical, thermo-physical and magnetic parameters influence the behavior and performance of an AMR, together with external controls and operating parameters. Literature data on AMR performances, both experimental and numerical, are given in different conditions and configurations, so that a consistent comparison among different results is not straightforward, and sometimes even not possible. In this paper the most relevant parameters are outlined, by means of a derivation of the dimensionless 1-D AMR equations. The resulting reduced number of key parameters simplifies the performance optimization procedure. Moreover, if the proposed dimensionless set of parameters is reported each time in corresponding scientific work, a comparison of experimental or/and numerical results would become much more feasible and easy to be performed