HC-290 (Propane) Vaporisation Inside a Brazed Plate Heat Exchanger

This paper presents the heat transfer coefficients measured during HC-290 (Propane) vaporisation inside a brazed plate heat exchanger: the effects of heat flux, saturation temperature (pressure) and outlet conditions are investigated. The heat transfer coefficients show weak sensitivity to saturation temperature (pressure) and great sensitivity to heat flux and outlet conditions. The saturated boiling experimental heat transfer coefficients are compared with two well-known equations for nucleate boiling (Cooper (1984) and Gorenflo (1993)). The mean absolute percentage deviation between experimental and calculated heat transfer coefficients is 26.9% and 16.6% for Cooper (1984) and Gorenflo (1993) equation respectively. The heat transfer measurement has been complemented with IR thermography in order to quantify the portion of the heat transfer surface affected by vapour super-heating

Extended stellar kinematics of elliptical galaxies in the Fornax cluster

We present extended stellar kinematics for a sample of 13 elliptical galaxies in the Fornax cluster. Major-axis velocity dispersion profiles (VDPs) and rotation curves (RCs) are given for 12 of the galaxies. A major feature of this data is the spatial extension: for 8 galaxies the data extends beyond 1 R_e, and for 5 it extends beyond 2 R_e. Compared to the previously available data, this corresponds to an increase in spatial coverage by a factor from 1 to 5. Five of the ellipticals in the sample turn out to be rotationally-supported systems, having positive rotation parameter log (V/sigma)*. One of these five, and another 3 galaxies from the remaining sample, display evidence for bar-like kinematics. The data indicate that the true number of `dynamically hot' stellar systems, is much lower than previously thought: of the Es in the present sample only 1/4 are confirmed as `pressure-supported' systems. The data reveal a host of individual peculiarities, like: wiggles, strong gradients, and asymmetries in the rotation curve and/or in the velocity dispersion profile, thus showing that the presence of kinematically distinct components and/or triaxiality is a common characteristic of this class of object.Comment: 27 pages, includes 15 eps figures. Accepted for publication in A&A Sup

design and simulation of two robotic systems for automatic artichoke harvesting

The target of this research project was a feasibility study for the development of a robot for automatic or semi-automatic artichoke harvesting. During this project, different solutions for the mechanical parts of the machine, its control system and the harvesting tools were investigated. Moreover, in cooperation with the department DISPA of University of Catania, different field structures with different kinds of artichoke cultivars were studied and tested. The results of this research could improve artichoke production for preserves industries. As a first step, an investigation on existing machines has been done. From this research, it has been shown that very few machines exist for this purpose. Based also on previous experiences, some proposals for different robotic systems have been done, while the mobile platform itself was developed within another research project. At the current stage, several different configurations of machines and harvesting end-effectors have been designed and simulated using a 3D CAD environment interfaced with Matlab®. Moreover, as support for one of the proposed machines, an artificial vision algorithm has been developed in order to locate the artichokes on the plant, with respect to the robot, using images taken with a standard webcam

Fibroepithelioma of Pinkus: Solitary tumor or sign of a complex gastrointestinal syndrome

Fibroepithelioma of Pinkus (FEP), which is considered to be an uncommon variant of basal cell carcinoma, has been described in association with other systemic diseases. However, no specific studies are currently available on this subject. The aim of our study was to evaluate the clinical and morphological characteristics of FEP and investigate whether this rare tumor is a single entity or seen in the context of a more complex syndrome. We retrospectively analyzed 49 cases of FEP diagnosed and excised in a single academic institution from 1995 to 2011. The tumors were mainly located on the trunk (77.55%), followed by the lower extremities (12.20%) and the head and neck (10.20%). In 9 of the 49 cases (18%), FEP was associated with gastrointestinal tumors. The abovementioned cases are presented in an attempt to make clinicians more aware of a possible association between FEP and gastrointestinal cancer. Although a possible underlying common genetic background between FEP and gastrointestinal tumors was not provided, our study suggests that patients with FEP should be screened for the occurrence of gastrointestinal tumors

Cisplatin induced toxicity in rat tissues: The protective effect of Lisosan G

The protective effect of a powder of grain (Lisosan G) against cisplatin-induced toxicity in rats was studied. Male rats were fed with Lisosan G before injection of cisplatin and four days later they were killed and blood was collected along with hepatic, renal and testicular tissues. The results showed that cisplatin treatment increased plasma blood urea nitrogen, creatinine and hydrogen peroxide and decreased cytochrome P450 content in renal and hepatic tissues. It also reduced the plasmatic testosterone level and caused a depletion of testicular 17a-progesterone hydroxylase activity. In the group fed with Lisosan G and treated with cisplatin blood urea nitrogen and creatinine returned to the control level indicating a protective effect of Lisosan G. It was also observed that the ones fed with Lisosan G were able to attenuate the decrease in the P450-dependent activities and the activities of antioxidant enzymes as well. Lisosan G protected the testicular 17a-progesterone hydroxylase activity and increased the plasma testosterone level compared to animals treated only with cisplatin. Our results showed a protective effect of Lisosan G against the cisplatin induced toxicity. The protective effect of Lisosan G could be associated mainly with the attenuation of the oxidative stress and the preservation in antioxidant enzymes

Energy and Economic Performance Analysis of Heat Recovery Devices Under Different Climate Conditions

High performance buildings typically relies on extreme envelope performances in terms of insulation level, solar gains valorization and airtightness. The energy needs are limited and the system sizing is reduced to increase the recourse to renewable energy sources. The only exception to this trend is related to the ventilation, which is even more crucial because of the infiltration control. Mechanical ventilation is a common option to ensure an appropriate ventilation rate and a suitable indoor air quality. Heat recovery devices are widely used to save energy in buildings mechanical ventilation systems. Their contribution in the design or operating phases is typically assessed in terms of effectiveness, which expresses the ratio between the amount of energy – sensible and/or total – actually recovered and the maximum recoverable under ideal configuration. However the effectiveness of recovery devices is not a constant value and depends on the operating – outdoor and indoor –conditions and control strategy. In order to evaluate the energy and cost savings allowed by heat recovery systems, these aspects have to be considered, and their relative impact on different heat recovery technologies accounted for. In this work, some of them are analyzed in detail and their contribution to the device effectiveness is discussed. The objective is to understand the influence of the air conditions (fresh and exhaust) on the energy savings considering different sensible and total heat recovery devices and operative constraints which could affect the control strategy. The analysis starts from hourly weather data, representative of different climate types, to quantify the actual effectiveness of different heat recovery systems. The impact of indoor conditions on the sensible and latent recovery is analyzed, defining appropriate control strategies to prevent excessive moisture recovery and discomfort issues when the indoor humidity is considered. Moreover, the effect of condensation and frosting on the hourly and annual performance of each kind of devices is analyzed. Three different climatic conditions have been considered. Sensible fixed-plate cross flow heat recovery system have been compared with enthalpy wheels By means of a parameterization of the operating constraints and the expression of the main quantities in specific terms, depending only on the building use, it has been possible to generalize the main results, making them independent of a specific case study, and to compare different technologies and climatic contexts. Seasonal and annual energy and economic performances have been quantified, as well as their sensitivity to specific calculation assumptions, such as the building type, the investment and energy costs, providing a synthetic overview of the technical and economic viability of the considered technologies and a geographic mapping of their competitiveness

Comparison Between The Performance Of Sensible And Total Heat Recovery Devices And A Liquid Desiccant Twin-Tower System

A significant share of the energy demand in high performance buildings is related to mechanical ventilation. Aside traditional heat recovery devices, liquid desiccant system can play a role. The performance of liquid desiccant devices and consequently their potential in energy savings is complex to estimate due to the influence of process parameters as well as the physical parameters of the fluids. A simple twin-tower configuration has been proposed as a reference system for assessing the control strategy and the potential of this technology to reduce the ventilation load. It consists of one absorption tower that treats the outside air and one that uses the exhaust air to regenerate the liquid desiccant. This configuration acts as a heat exchanger between the outlet and exhaust air streams with the liquid desiccant as heat and mass transfer medium. The heat and mass transfer between the fluid flows in the two towers has been modelled, and the energy saving potential in heating and cooling mode has been calculated based on annual hourly weather data. In order to assess the results, a comparison with the savings potential by sensible and total heat recovery have been performed considering 66 locations across Europe. Limitation and control strategies have been considered to prevent excessive indoor humidity considering different indoor latent load and airchange rates